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Structured AbstractObjective To evaluate the effect of organic gel solvents (70% acetone and 90% ethanol) and ultrasound in the removal of metallic brackets. Materials and Methods Metallic brackets were bonded with light-cured orthodontic composite (Transbond XT) in 120 human bicuspids and divided into 6 groups for the enamel etch-and-rinse adhesive system (XT) and 6 groups to self-etching system (SEPT) according to pretreatment to removal test: control, 70% acetone, 90% ethanol, ultrasound, 70% acetone+ultrasound, and 90% ethanol+ultrasound. The brackets were subjected to removal by shear testing and Adhesive Remnant Index (ARI) evaluation. Some specimens were prepared and its adhesive interface and etching ability observed by scanning electron microscopy (SEM). Results Only the factor ‘ultrasound’ and its interaction with ‘adhesive’ were detected as a source of variance, with the SEPT/ultrasound showing the lowest shear strength than the other groups. Regardless the factor ‘ultrasound’, XT showed a higher ARI than SEPT; however, when the solvents were used, no differences were detected between XT and SEPT. Conclusion The organic solvents were not effective in reducing shear bond strength. The etch-and-rinse adhesive system showed a higher and more favorable ARI score than the self-etching primer. The behavior of the organic solvents on ARI showed to be better when associated with the self-etching primer. The ultrasound was effective in reducing the shear bond strength of the self-etching adhesive system but not in affecting the ARI of the adhesive systems.

Objective: To analyze the clinical and laboratory properties of the recently introduced APC flash-free orthodontic adhesive. Material and Methods: After bonding of 80 brackets on human teeth (group A: APC flash-free adhesive n = 40, group B: APC Plus adhesive n = 40), the following measurements were recorded: time for bonding, stereomicroscopic evaluation of excess adhesive, color penetration (methylene blue, 0.5%/24 h), and Adhesive Remnant Index (ARI) score after debonding. Results: The time needed for bonding differed significantly between the two groups (A: 19.5 s/tooth vs B: 33.8 s/tooth). The adhesive excess, which was metrically measured from the bracket edge, ranged from 166.27 µm to 81.66 µm (group A) and 988.53 µm to 690.81 µm (group B). After methylene coloration in group A, 52 of 80 measurements showed discoloration on the bracket-adhesive and/or adhesive-enamel interface, while for group B, 78 of 80 were coloration positive. The ARI scores did not differ, with an average ARI score of 2.0 for group A and 2.8 for group B. Conclusion: The flash-free adhesive significantly reduced the time needed for the bonding process. The excess resin expanded 0.16 to 0.08 mm over the bracket margin. The new technology seems to facilitate a smooth and sufficient marginal surface of the adhesive, which clinically might improve reduction of plaque accumulation.

Objective: To evaluate adhesive performance in terms of debonding forces of precoated metal and ceramic brackets 4 years after expiration. Materials and Methods: Buccal and lingual surfaces of embedded extracted maxillary premolars were etched with 34% Tooth Conditioner Gel (Dentsply Caulk, Milford, Del), rinsed, and dried. Transbond MIP (3M Unitek, Monrovia, Calif) was applied prior to placing adhesive precoated brackets (APC II Victory stainless steel and APC Plus Clarity ceramic brackets, 3M Unitek). The preexpiration brackets had 29–35 months before, and the postexpiration brackets were 45–52 months past, their expiration dates. Sample size was 17–21 per group. Debonding forces were determined by subjecting the bonded brackets to a shear force in a universal testing machine. Debonding forces were compared using two-way ANOVA. Debonded surfaces were examined under a stereomicroscope to determine failure modes, which were compared using the chi-square test. Results: No statistically significant difference was found in debonding forces (P = .8581) or failure modes (P = .4538) between expired and unexpired brackets. Metal brackets required statistically significantly higher debonding forces than did ceramic brackets (P = .0001). For both expired and unexpired brackets, failure modes were mostly cohesive in the adhesive layer for ceramic brackets, and mixed between adhesive and cohesive failure in the adhesive layer for metal brackets. Conclusions: Adhesive precoated brackets did not have any reduction in enamel-adhesion properties up to 4 years after their expiration date. Extended shelf life testing for precoated dental brackets may be worth considering.

Introduction\ud \ud Professional regulatory bodies in the UK and Europe state that dental graduates should be able to manage orthodontic emergency patients. Therefore, the aim of this study was to explore dental student experiences of treating orthodontic emergencies within a teaching institution.\ud Materials and method\ud \ud This study was designed as a single-centre evaluation of teaching based in a UK university orthodontic department. The participants were fourth-year dental students who treated orthodontic emergency patients under clinical supervision as part of the undergraduate curriculum. Student logbook entries for one academic year detailing the types of emergencies treated and structured, reflective commentaries for each procedure were analysed using thematic analysis methods. The total numbers and types of orthodontic emergencies treated by students were presented. Overall, self-reported student confidence in managing orthodontic emergencies was calculated. Themes, which represented student reflections, were identified.\ud Results\ud \ud Seventy-two students participated in the study. Overall, 69% of students stated they were confident in managing orthodontic emergencies. Students treated a range of emergencies, of which the most frequent was debonded brackets (38%). Reflections from student commentaries were housed under a primary theme of building procedural confidence. Three subthemes were identified: (i) theory-practice integration; (ii) expanding clinical experience; and (iii) importance of a supportive clinical learning environment.\ud Conclusion\ud \ud The majority of dental students were confident in managing orthodontic emergencies. Theoretical knowledge supplemented by exposure to a range of clinical problems within a supported learning environment made students feel more confident.

Summary The purpose of this in vivo study was to compare the morphology of the enamel surfaces before bracket bonding and 6 and 12 months after debonding. Replicas of thirty-two maxillary second premolars of 16 volunteers were made before bracket bonding (T0), after debonding (T1), 6 months (T2), and 12 months (T3) later. Scanning electron microscope (SEM) images of the labial enamel surfaces were taken at T0, T1, T2, and T3 at increasing magnifications and analyzed according to the enamel damage index EDI. Data evaluation by using Friedman test followed by Wilcoxon signed ranks test with Bonferroni adjustment did not reveal statistically significant differences in the mean EDI at T0, T2, and T3, whereas the mean EDI at T1 was significantly higher than at T0, T2, and T3 (p

OBJECTIVE: To assess enamel surface under scanning electron microscopy (SEM) after resin removal and enamel polishing procedures following brackets debonding, as well as compare the time required for these procedures. METHODS: A total of 180 deciduous bovine incisors were used. The enamel surface of each tooth was prepared and brackets were bonded with light cured Transbond XT composite resin. Brackets were removed in a testing machine. The samples were randomized and equally distributed into nine groups according to the resin removal and polishing technique: Group 1, 30-blade tungsten carbide bur in high speed; Group 2, 30-blade tungsten carbide bur in high speed followed by a sequence of 4 Sof-lex polishing discs (3M); Group 3, 30-blade tungsten carbide bur in high speed followed by Enhance tips (Dentsply). All groups were subdivided into (a) unpolished; (b) polished with aluminum oxide paste; and (c) polished with water slurry of fine pumice. Subsequently, the enamel surface was assessed and statistical analysis was carried out. RESULTS: There were statistically significant differences in enamel roughness and removal time among all groups. Groups 3a, 3b and 3c appeared to be the most efficient methods of removing resin with low damages to enamel. Groups 2a, 2b and 2c were the most time consuming procedures, and Group 2a caused more damages to enamel. CONCLUSION: The suggested protocol for resin removal is the 30-blade tungsten carbide bur in high speed followed by Enhance tips and polishing with aluminum oxide paste. This procedure seems to produce less damages and is less time consuming. OBJETIVO: avaliar a superfície do esmalte, por meio de microscopia eletrônica de varredura, após descolagem de braquetes e o polimento do esmalte, com diferentes técnicas de remoção de resina, bem como comparar o tempo necessário para a realização do procedimento. MÉTODOS: foram utilizados 180 dentes bovinos decíduos. A superfície do esmalte dos dentes foi preparada e realizada a colagem dos braquetes com resina Transbond XT. Os braquetes foram removidos em máquina de ensaio mecânico. Foram formados, aleatoriamente, nove grupos, de acordo com o tipo de remoção da resina e de polimento, sendo: Grupo 1, broca de tungstênio de 30 lâminas em alta rotação; Grupo 2, broca de tungstênio de 30 lâminas em alta rotação e sequência de quatro discos Soflex (3M); Grupo 3, broca de tungstênio de 30 lâminas em alta rotação e pontas de acabamento Enhance (Dentsply). Todos os grupos foram subdividido em (a) sem polimento, (b) polimento com pasta de óxido de alumínio e (c) polimento com pedra-pomes. As superfícies foram avaliadas e foi realizada análise estatística. RESULTADOS: houve diferença estatística entre os grupos em relação à rugosidade de superfície e ao tempo de remoção. Os grupos 3a, 3b e 3c demonstraram ser os métodos mais eficientes de remoção da resina, promovendo pouco dano à superfície do esmalte. Os grupos 2a, 2b e 2c consumiram maior tempo de procedimento, e o grupo 2a causou maior dano ao esmalte. CONCLUSÃO: sugere-se como protocolo de remoção o uso de broca de tungstênio de 30 lâminas para remoção do maior volume da resina, pontas de acabamento Enhance e polimento com a pasta de óxido de alumínio, por produzirem menor dano.

Objectives The aim of the present study was to measure the polymerization shrinkage, modulus, and shrinkage stress of bulk-fill and conventional composites during polymerization and to investigate the relationship between tooth-composite interfacial debonding and shrinkage stress of the composites. Methods Polymerization shrinkage, dynamic modulus, and shrinkage stress of two high-viscosity bulk-fill (SonicFill (SF)/Tetric N-Ceram Bulk-Fill (TNB)) and two low-viscosity bulk-fill composites (Filtek Bulk-Fill (FB)/SureFil SDR Flow (SDR)) as well as one high-viscosity conventional (Filtek Z250 (Z250)) and one low-viscosity conventional composite (Filtek Z350 XT Flowable (Z350F)) were measured using custom-made instruments. Acoustic emission (AE) analysis was performed to evaluate the tooth-composite interfacial debonding during polymerization of the composites in Class 1 cavities on extracted third molars. Results The low-viscosity composites exhibited higher shrinkage and lower modulus than the high-viscosity composites. Polymerization shrinkage at 10 min ranged between 2.05% (SF) and 3.53% (Z350F). Polymerization shrinkage stress values at 10 min ranged between 1.68 MPa (SDR) and 3.51 MPa (Z350F). The number of AE events was highest in Z350F and lowest in SDR. Conclusions Composites that exhibited greater polymerization shrinkage stress generated more tooth-composite interfacial debonding. In contrast to similar outcomes among the high-viscosity composites (conventional: Z250, bulk-fill: TNB and SF), the low-viscosity bulk-fill composites (FB and SDR) demonstrated better results in terms of polymerization shrinkage stress and tooth-composite interfacial debonding than did the low-viscosity conventional composite (Z350F). Clinical significance Despite the better performance by some of the bulk-fill composites, clinicians should be aware that the bulk-fill composites are not perfect substitutes for conventional composites.

Objective: This study was done to compare the intrapulpal temperature change generated by different energy levels of Er:YAG laser used during debonding of ceramic brackets and find the most suitable level for clinical use. Material and methods: Eighty polycrystalline alumina brackets were bonded on bovine incisor teeth, which were randomly divided into 4 groups of 20. One group was assigned as control. In the study groups, after laser exposure with 2, 4, or 6 Watt energy levels, brackets were debonded using an Instron Universal Testing machine. Adhesive remnant index (ARI) scores were recorded to evaluate the site of debonding. To assess intrapulpal thermal increase, 60 human premolar teeth that were prepared in the same way, at the same energy levels, by a thermocouple were used. Results: When the debonding forces, intrapulpal temperature increases, and ARI of the groups were examined, statistically significant difference was observed between the groups. Mean temperature increases of 0.67°C ± 0.12°C, 1.25°C ± 0.16°C, and 2.36°C ± 0.23°C were recorded for the 2, 4, and 6 Watt laser groups. The mean shear bond strength was 21.35 ± 3.43 megapascals (MPa) for the control group, whereas they were 8.79 ± 2.47, 3.28 ± 0.73, and 2.46 ± 0.54 MPa for the 2, 4, and 6 Watt laser groups, respectively. Conclusions: Four watts is the most efficient and safe energy level to be used, utilizing Er:YAG laser with water cooling spray for 6 sec by scanning method during debonding of polycrystalline alumina brackets without any carbonization effects and detrimental temperature changes at debond sites. © 2018, Mary Ann Liebert, Inc.

This study investigated temperature increases in dental pulp resulting from laser-assisted debonding of ceramic brackets using a 445-nm diode laser.Eighteen ceramic brackets were bonded in standardized manner to 18 caries-free human third molars. Pulpal fluid circulation was simulated by pumping distilled water at 37°C through the pulp chamber. The brackets were irradiated with a 445-nm diode laser. Temperatures were measured using a thermal camera at points P1 (center of the pulp) and P2 (in the hard dental tissue) at the baseline (T0), at the start and end of laser application (T1 and T2), and the maximum during the sequence (TSignificant differences in the temperatures measured at P1 and P2 were observed among T0, T1, T2, and TOn the basis of the laser settings used, there is no risk to the vitality of dental pulp during laser-assisted debonding of ceramic brackets with a 445-nm diode laser.

Amaç: Bu çalışma lösit ve lityum disilikat tam seramik restorasyonların mine ve dentin yüzeylerinden çıkarılmasında Er:YAG lazer kullanımının makaslama bağlanma dayanımına etkisini değerlendirmek ve lazer ile çıkarılan restorasyonların tekrar simantasyonu sonrasında makaslama bağlanma dayanımı değerlerindeki değişimi araştırmak ve karşılaştırmak amacıyla yapılmıştır. Bununla birlikte, beyazlatma ajanı uygulamasının, lityum disilikat veneerlerin simantasyon sonrasındaki bağlanma dayanımına etkisi de incelenmiştir.Gereç ve yöntem: 120 adet çekilmiş maksillar santral diş örnekler 2'ye ayrılarak 60'ı mine 60'ı dentin seviyesinde olacak şekilde prepare edilmiştir. 60 adet lösit seramik disk (IPS Empress Esthetic; Ivoclar Vivadent, Schaan, Liechtenstein) ve 60 adet lityum disilikat seramik disk (IPS e.max Press; Ivoclar Vivadent, Schaan, Liechtenstein) 1 mm kalınlığında ve 5 mm çapında üretilmiştir. Her bir seramik disk, dual-cure rezin siman (Variolink N; Ivoclar Vivadent AG, Schaan, Liechtenstein) kullanılarak hazırlanmış 60 adet mine ve 60 adet dentin yüzeyine simante edilmiştir (mine yüzeyine 30 lösit, dentin yüzeyine 30 lösit, mine yüzeyine 30 lityum disilikat, dentin yüzeyine 30 lityum disilikat). Her grup kendi içerisinde kontrol veya lazer uygulanmayan grup ve lazer uygulanan grup olmak üzere 2 alt gruba ayrılmıştır (n = 15). Böylece, her farklı seramik ve preparasyon yüzeyi için 4 kontrol grubu ve 4 lazer debonding grubu elde edilmiştir. İlk 4 grup kontrol grubu olarak planlanmış ve lazer uygulaması yapılmamıştır. İkinci 4 grubun örneklerine Er: YAG lazer, 3W gücünde (10Hz, 300mJ) ve 9 saniye süreyle uygulanmıştır. Er: YAG lazer ile çıkarılmış seramik diskler ve diş yüzeylerindeki artık simanların kaldırılmasından sonra aynı örnekler tekrar simante edilmiş ve rebonding grubu olarak tanımlanmıştır. Beyazlatmanın bağlanmaya etkisini araştırmak üzere; beyazlatma işlemi uygulanmadan, beyazlatmayı takiben hemen ve 7 gün sonra olacak şekilde 3 farklı grup oluşturulmuştur (n=15). Her grubun makaslama bağlanma dayanımı değerleri universal bir test cihazı (AG-5 kNG,Shimadzu, Tokio, Japan) kullanılarak ölçülmüştür. Standart tanımlayıcı istatistiksel hesaplanmasına ek olarak tekrarlı ölçümler varyans analizi (Repeated measures ANOVA) kullanılmıştır (p

Amaç: Bu çalışmanın amacı, bonding sonrası çürük lezyonu oluşturulmuş dişler ile sağlıklı dişlerde, debonding sonrası meydana gelen yüzey değişikliklerini seramik ve metal braket gruplarında karşılaştırmalı olarak incelemektir.Materyal ve Metod: Çalışmada 60 adet sağlıklı premolar diş metal ve seramik braket uygulanmak üzere iki gruba ayrılmıştır. Braket türlerinin yanı sıra beyaz nokta lezyonunun mine hasarına olan etkisinin incelenebilmesi için hafif dereceli lezyonlu(n=10), ileri dereceli lezyonlu(n=10) ve lezyon oluşturulmamış kontrol grubu(n=10) oluşturulmuştur. Tüm dişlere aynı bonding protokolü uygulanmıştır. Uygulama öncesi (T0), debonding sonrası(T1) ve yüzeyin temizlenmesinden sonra(T2) steromikroskobik inceleme ile mine yüzey değişiklikleri incelenmiştir.Bulgular: Seramik braket grubunda debonding sonucunda diş yüzeyinde kalan yapışık adeziv miktarı metal braket grubuna göre anlamlı derecede fazla bulunmuştur. Metal braket grubunda, T0 zamanındaki toplam çatlak uzunluğu ortalaması ile T2 zamanındaki toplam çatlak uzunluğu ortalaması arasındaki farkın istatistiksel olarak anlamsız olduğu belirlenmiştir. Seramik braket grubunda, T0 zamanındaki toplam çatlak uzunluğu ortalaması ile T2 zamanındaki toplam çatlak uzunluğu ortalaması arasındaki farkın istatistiksel olarak anlamlı olduğu belirlenmiştir. Çürük seviyesi hafif olduğunda hem metal hem de seramik braket grubunda T1 zamanındaki toplam kavitasyon alanı ortalaması ile T2 zamanındaki toplam kavitasyon alanı ortalaması arasındaki fark istatistiksel olarak anlamsızdır. Çürük seviyesi ileri olduğunda hem metal hem de seramik braket grubunda T1 zamanındaki toplam kavitasyon alanı ortalaması ile T2 zamanındaki toplam kavitasyon alanı ortalaması arasındaki fark istatistiksel olarak anlamlıdır. Sonuçlar: Seramik braketlerin debondinginde çatlak boyu ortalamasında artış meydana gelmiştir. Braketin tüm yüzeyini saran beyaz nokta lezyonu debonding esnasında kavitasyon riski taşımaktadır. Kavitasyonlar özellikle adeziv artıklarının temizlenmesi esnasında meydana gelmektedir.Anahtar Kelimeler: Debonding, mine çatlağı, beyaz nokta lezyonu. Aim: The aim of this study is to compare the surface changes after debonding in the ceramic and metal bracket groups in healthy teeth with and teeth with caries lesion created after bonding.Materiel and Method: In the study, 60 healthy premolar teeth were separated to two groups for application of metal and ceramic brackets. Mild lesion (n = 10), advanced lesion (n = 10) and non lesion control group (n = 10) were established in order to examine the effect of white spot lesions on enamel damage as well as bracket species. All teeth underwent the same bonding protocol. Enamel surface changes were examined by steromicroscopic examination before application (T0), after debonding (T1) and after surface cleaning (T2).Results: The amount of adhesive adhered on the tooth surface as a result of debonding in the ceramic bracket group was significantly higher than the metal bracket group. In the metal bracket group, it was determined that the difference between the total crack length average at T0 and T2 was statistically insignificant. In the ceramic bracket group, it was determined that the difference between the total crack length average at T0 and T2 was statistically significant. When the caries level is mild, the difference between the total cavitation area average at T1 and T2 is statistically insignificant in both the metal and ceramic bracket groups. When the caries level is advanced, the difference between the total cavitation area average at T1 and T2 is statistically significant in both the metal and ceramic bracket groups. Conclusion: Debonding of ceramic brackets increased the average crack size. The white point lesion surrounding the entire surface of the bracket carries the risk of cavitation during debonding. Cavities come into play especially during the cleaning of adhesive residues.Key Words: Debonding, enamel crack, white spot lesion. 103

Background and objectives The purpose of this in vitro study was to evaluate the bond strength of the laser-etched base bracket, site of bond failure, and evaluate for enamel remnants on the bracket base after debonding, when compared to foil mesh base bracket. Materials and methods Sixty noncarious, human premolar extracted for the orthodontic treatment were used for this study. The teeth were randomly divided into two groups containing 30 teeth each, which were bonded with laser-etched base bracket and mesh base bracket using light cure resin. The tensile and mechanical bond strength was tested after 24 hours using TIRA. The forces recorded during debonding were measured in Newton and final readings were tabulated in megapascals (MPa). After debonding, the amount of residual adhesive and enamel detachment on the bracket base were assessed according to adhesive remnant index (ARI) and enamel detachment index (EDI) using stereomicroscope and energy dispersive X-ray spectrometer. Results The laser-etched base bracket showed statistically significant higher results than mesh base bracket. Mann-Whitney test indicated that laser-etched base bracket had significantly higher tensile bond strength of 8.47 MPa (SD ± 0.84), fatigue strength of 7.75 MPa (SD ± 0.79) compared to mesh base bracket with tensile bond strength of 5.53 Mpa (SD ± 0.89) and fatigue strength of 5.17 MPa (SD ± 1.15). Adhesive remnant index score indicated that laser-etched base bracket had ARI score of 3 for most of the bracket, when compared to mesh base bracket. This was statistically significant. Enamel detachment index scores indicated that less than 10% of enamel detachment occurred in both the types of brackets, which was not statistically significant. Conclusion Laser-etched base bracket showed superior bond strength, when compared to the foil mesh base bracket. The site of bond failure of these laser-etched base bracket was at the interface of enamel-adhesive and did not induce any significant enamel detachment. Thus, we can conclude that laser-etched base bracket is a promising step toward achieving an ideal bracket base design for successful bonding. How to cite this article Rajesh RNG, Girish KS, Sanjay N, Scindhia RD, Kumar SG, Rajesh S. Comparison of Bond Strength of Brackets with Foil Mesh and Laser Structure Base using Light Cure Composite Resin: An in vitro Study. J Contemp Dent Pract 2015;16(12):963-970.

The objective of this study was to assess the effect of a UV light-based auxiliary illumination on adhesive remnant (AR) removal after orthodontic debonding. Sixty human molars were divided according to the adhesive used for bonding: O-opaque; LF-low fluorescence; and HF-high fluorescence. After debonding, the teeth were subdivided according to the AR removal method: No UV light or With UV light. After AR removal, the teeth were polished. Direct visual analysis, scanning electron microscopy (SEM) and time quantification for AR removal analyses were performed (Fisher-Freeman-Halton, Fisher’s exact, chi-square trend, ANOVA, and independent t-tests; α = 5%). Concerning the adhesives, there was no significant difference among direct visual, SEM and time analyses for AR removal (p ≥ 0.05). Regarding AR removal methods, a similarity among the subgroups was verified for direct visual and SEM analyses (p≥0.05). However, a significant trend was verified for the with UV light method to produce greater marks, and the no UV light method, to produce a greater rate of samples with AR before polishing (p = 0.015). AR removal with light was significantly quicker in comparison with the no UV light method (p < 0.0001). The use of UV light may aid orthodontists in removing AR more thoroughly and in less time. However, they should receive special training to apply this technology, and should never dismiss the final polishing procedure.

To investigate debonding of full crowns made of CAD/CAM composites, CAD/CAM technology was applied to manufacture standardized test abutments to increase the reproducibility of human teeth used in in vitro studies. A virtual test abutment and the corresponding virtual crown were designed and two STL data sets were generated. Sixty-four human third molars and CAD/CAM blocks were milled using a CNC machine. Crowns of four different composite blocks (Lava Ultimate (LU), Brilliant Crios (BC), Cerasmart (CS), Experimental (EX)) were adhesively bonded with their corresponding luting system (LU: Scotchbond Universal/RelyX Ultimate; BC: One Coat 7 Universal/DuoCem; CS: G-PremioBond/G-Cem LinkForce; EX: Experimental-Bond/Experimental-Luting-Cement). Half of the specimens were chemical-cured (CC) and the others were light-cured (LC). Afterwards, specimens were artificially aged in a chewing simulator (WL-tec, 1 million cycles, 50–500 N, 2 Hz, 37 °C). Finally, a dye penetration test was used to detect debonding. For inspection, the specimens were sliced, and penetration depth was measured with a digital microscope. Data were analyzed with the Mann-Whitney U test. No cases of total debonding were observed after cyclic loading. However, the LC specimens showed a significantly lower amount of leakage than the CC ones (p

An easy debonding method for ceramic brackets using a light-cured Bis-GMA resin containing heat-expandable microcapsules and COCeramic brackets are used frequently in orthodontic treatment because of their desirable esthetic properties. However, the application of heavy force to ceramic brackets in debonding can fracture the tooth enamel and ceramic brackets, causing tooth pain.In total, 60 freshly extracted bovine permanent mandibular incisors were divided randomly into 10 groups of 6 specimens each, corresponding to the number of variables tested. Ceramic brackets were bonded to bovine permanent mandibular incisors using an orthodontic bonding agent containing heat-expandable microcapsules at different levels (0-30 wt%) and resin composite paste, and cured by a curing device. The bond strengths were measured before and after COWith COFrom these results, it seems likely that the combined use of a light-cured orthodontic bonding agent containing microcapsules and a CO

Debonding procedure is a fundamental stage in the orthodontic treatment (1). Adhesive removal should lead to a complete polished enamel in order to prevent the plaque accumulation and enamel injures (2). Aim of this study is to evaluate in vitro by use of Scanning Electron Microscopy (SEM) the enamel surface after the bracket removal and the enamel polishing with four different techniques. Two groups of teeth, group A (n=12) and group B (n=12) were evaluated. The images were analyzed by the Image J software. After the debonding procedure the two groups were subcategorized in four groups (1A, 1B, 2A, 2B 3A, 3B and 4A, 4B, n.=3). The discriminant between the two main categories was the use of a magnification system (Group A) during the polishing stages. From the qualitative and quantitative images analysis the most conservative technique resulted to be the use of tungsten carbide bur, followed by the final polishing using the soft-polisher tip for composites. In group A, the percentage of the residual adhesive resulted 8% and the damages on the enamel surface showed to be 7%. In group B the percentage of the residual adhesive resulted 35% and the damages on the enamel surface showed to be 15%. This analysis showed how the use of a magnification system aids in significant way during the debonding procedures in the enamel surfaces’ preservation.The authors are grateful to Dr. M. Gianmatteo and to Dr. E. Nazaj, University of L’Aquila, for their help in the sampling and microscopy procedures., Italian Journal of Anatomy and Embryology, Vol. 121, No. 1 (Supplement) 2016

The safest and least traumatic means of removing a cemented restoration is to cut a slot and pry the crown or retainer loose, sacrificing the restoration. However, various techniques and instruments for intact removal of permanently cemented cast restorations have been described in the literature. This literature review explores conservative and semiconservative techniques that are useful for preserving permanently cemented restorations during removal. Richwil resin, ultrasonic energy, and crown tractors can be considered preferred methods for removal of temporarily cemented restorations. Patients should be informed regarding the risks and benefits before removal of a cemented restoration.

Submitted by Fabio Salomão (salomaofm@me.com) on 2017-10-25T13:11:58Z No. of bitstreams: 1 TESE FINAL - POS DEFESA OK.pdf: 22130957 bytes, checksum: 001852660d064b7d48732b95f0767def (MD5) Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-31T16:03:04Z (GMT) No. of bitstreams: 1 salomao_fm_dr_araca.pdf: 22130957 bytes, checksum: 001852660d064b7d48732b95f0767def (MD5) Made available in DSpace on 2017-10-31T16:03:04Z (GMT). No. of bitstreams: 1 salomao_fm_dr_araca.pdf: 22130957 bytes, checksum: 001852660d064b7d48732b95f0767def (MD5) Previous issue date: 2017-08-28 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Objetivo: Avaliar através de simulação clínica a efetividade da remoção de resíduos fluorescentes do esmalte dental bovino, após remoção de bráquetes ortodônticos, utilizando dispositivos emissores de luz branca e fluorescente. Materiais e Métodos: 180 dentes bovinos anteriores hígidos foram seccionados em discos de esmalte/dentina. A remoção do material resinoso cimentante foi realizada por três operadores. Os dentes foram divididos em quatro grupos de estudo. Os fatores em estudo foram: a fonte de iluminação empregada durante a remoção dos materiais resinosos cimentantes de bráquetes ortodônticos em 4 níveis (n = 45): Convencional (C), LED branco (W), LED fluorescente (F) e fotopolimerizador com filtro fluorescente (FL). Foram consideradas como variáveis de resposta: o tempo para remoção dos resíduos das amostras; a área de remanescente resinoso fluorescente superficial e a mensuração da altura de material adesivo fluorescente remanescente (PICO) e a profundada de esmalte desgastado (VALE). Na comparação entre as técnicas empregou-se o teste Kruskal-Wallis seguido do pós-teste Mann-Whitney U (P≤0,05). Resultados: As Técnicas F e FL apresentaram-se, estatisticamente, semelhantes e as menores medianas de tempo consumido para a remoção do resíduo resinoso. As técnicas C e W apresentaram estatisticamente, a presença de maiores e semelhantes medianas de áreas fluorescentes remanescentes e de PICO (altura do remanescente), com relação as técnicas F e FL; enquanto que as técnicas FL e F postaram, estatisticamente, uma maior mediana de VALE que a técnica C. Conclusões: A associação de emissor de luz fluorescente com um material resinoso fluorescente, colaborou significativamente e de forma eficaz, na redução do tempo consumido para remoção e evidenciação dos resíduos resinosos cimentantes fluorescentes, possibilitando uma remoção efetiva, após a remoção dos bráquetes ortodônticos. Objective: Evaluate, through clinical simulation, the effectiveness on the removal of fluorescent resin residues from bovine dental enamel after brackets debonding using white and fluorescent light emitting devices. Materials and Methods: 180 healthy anterior bovine teeth were sectioned on enamel / dentin disks. The removal of the resinous material was performed by three operators. The teeth were divided into four groups. The factors studied were: the light source used to remove orthodontic resin residue in 4 levels (n = 45): Conventional (C), white LED (W), fluorescent LED (F) and photocuring unit with Fluorescent filter (FL). Response variables were: the time spent to remove the sample residues; The surface area of the fluorescent remaining resin and the depth measurement of the remaining fluorescent adhesive thickness (PEAK) and the enamel thickness removed (VALLEY). In the comparison between the techniques, the Kruskal-Wallis test was used, followed by the Mann-Whitney U post-test (P≤0.05). Results: In terms of time, the groups F and FL were similar to each other and statistically different for groups C and W. The techniques C and W presented statistically, the presence of larger and similar medians of remaining fluorescent areas, in relation to te F and FL techniques. The techniques C and W presented, statistically, a larger and similar median of peaks than the F and FL techniques. The FL technique statistically demonstrated a higher median of valleys than the C technique. The W, F and FL techniques were statistically similar to each other, as were C and W techniques. Conclusions: Fluorescent light with a fluorescent resinous material, signicantly and removal of fluorescent resin residues, allowing an efficient removal after removal of orthodontic brackets. CAPES: 1294804

Aim: To visually compare, using microscope, two different techniques for removing adhesive remnants after orthodontic bracket debonding. Methods: Twenty healthy third molars were used. One molar did not undergo any procedures and served as a control. After bracket bonding and immersion of the teeth in saline solution for 12 days, the attachments were debonded. One of the molars was not stripped of the attachments, while the others (n=18) were randomly divided into two groups according to the adhesive removal technique: Group 1, use of a high-speed 18-blade bur and a fine-grain sandpaper disc; and Group 2, use of a high-speed 18-blade bur, a fine-grain sandpaper disc, and enamel microabrasion. Tooth fragments were collected for inspection under a field emission scanning electron microscope for a qualitative analysis of the adhesive remnants. Results: A substantial amount of adhesive residue remained on the enamel surface of the molars in Group 1. The procedures performed in Group 2 were more effective in removing the adhesive remnants but resulted in greater enamel wear and ledge formation. Conclusion: The combined use of a multiblade bur and the microabrasion technique was the most effective method of removing adhesive remnants and returning the enamel to its pre-treatment appearance.

Objective: To measure enamel surface changes after ceramic bracket debonding and after cleanup. Materials and Methods: Forty extracted teeth were scanned in three dimensions using an optical scanner (baseline). Two ceramic bracket systems were placed (19 metal-reinforced polycrystalline ceramic brackets; 21 monocrystalline ceramic brackets). Seven days later, brackets were debonded and teeth scanned (post-debond). Adhesive remnants and bracket fragments were recorded. Tooth surfaces were cleaned using a finishing carbide bur and scanned again (post-cleanup). Post-debond and post-cleanup scans were aligned with the baseline, and surface changes were quantified. Results were statistically compared using t-tests and Mann-Whitney tests (α = .05). Results: The depth of enamel loss (mean ± standard deviation) post-debond was 21 ± 8 µm and 33 µm and post-cleanup was 28 ± 14 µm and 18 ± 8 µm (P = .0191); the post-debond remnant thickness was 188 ± 113 µm and 120 ± 37 µm (P = .2381) and post-cleanup was 16 ± 5 µm and 15 µm for polycrystalline and monocrystalline ceramic brackets, respectively. The monocrystalline ceramic brackets predominantly left all adhesive on the tooth; the polycrystalline ceramic brackets were more likely to leave bracket fragments attached. Conclusion: Both systems allowed successful removal of the brackets with minimal enamel loss. However, the polycrystalline ceramic brackets left more fragments on the tooth, which complicated cleanup efforts.

WOS: 000340846900007, PubMed ID: 25102408, Objective: The purpose of this study was to investigate the effects of various surface pretreatments in the ridge lap area of acrylic resin denture teeth on the shear bond strength to heat-polymerized polymethylmethacrylate (PMMA) denture base resin. Background data: Tooth debonding of the denture is a major problem for patients with removable prostheses. Methods: A total of 84 central incisor denture teeth were used in this study. Seven test groups with 12 specimens for each group were prepared as follows: untreated (control, group C), ground, with a tungsten carbide bur (group H), airborne-particle abrasion (group AA), primed with methyl methacrylate (group M), treated with izobutyl methacrylate (group iBMA), Eclipse Bonding Agent applied (group E), and Er:YAG laser irradiated (group L). Test specimens were produced according to the manufacturers' instructions and mounted to a universal testing machine for shear testing with a crosshead speed of 1 mm/min. Data were evaluated by one way variance analysis (ANOVA) and Tukey's test (alpha = 0.05). Results: Similar bond strength values were found between groups L and M, and these were the highest shear bond strengths among the groups. The lowest one was observed in group E. All surface treatments, except group E, exhibited significant difference when compared with group C (p < 0.05). Conclusions: Lasing of the ridge lap area to enhance the bond strength of acrylic resin denture teeth to PMMA denture base resin might be an alternative to wetting with MMA monomer. To overcome tooth debonding, surface treatment of the ridge lap area should be performed as part of denture fabrication.

Objective This study investigates monitored micro-crack growth and damage in the ceramic/enamel adhesive interface using the acoustic emission (AE) technique with optical coherence tomography (OCT) under fatigue shear testing. Methods Shear bond strength (SBS) was measured first with eight prepared ceramic/enamel adhesive specimens under static loads. The fatigue shear testing was performed with three specimens at each cyclic load according to a modified ISO14801 method, applying at 80%, 75%, 70%, and 65% of the SBS to monitor interface debonding. The number of cycles at each load was recorded until ceramic/enamel adhesive interface debonding occurred. The AE technique was used to detect micro-crack signals in static and fatigue shear bond tests. Results The results showed that the average SBS value in the static tests was 18.07 ± 1.72 MPa (mean ± standard deviation), expressed in Newton's at 56.77 ± 5.40 N. The average number of fatigue cycles in which ceramic/enamel interface damage was detected in 80%, 75%, 70% and 65% of the SBS were 41, 410, 8141 and 76,541, respectively. The acoustic behavior varied according to the applied load level. Events were emitted during 65% and 70% fatigue tests. A good correlation was observed between the crack location in OCT images and the number of AE signal hits. Significance The AE technique combined with OCT images as a pre-clinical assessment tool to determine the integrity of cemented load bearing restored ceramic material. Sustainable cyclic load stresses in ceramic/enamel bonded specimens were substantially lower than the measured SBS. Predicted S–N curve showed that the maximum endured load was 10.98 MPa (about 34.48 N) passing 106 fatigue cyclic.

The purpose of this study was to analyze the initial changes in salivary mutans streptococci levels after orthodontic treatment with fixed appliances.Our subjects consisted of 58 adults. Whole saliva and simplified oral hygiene index values were obtained at 4 time points: at debonding (T1), 1 week after debonding (T2), 5 weeks after debonding (T3), and 13 weeks after debonding (T4). Repeated measures analysis of variance was used to determine the time-related differences in salivary bacterial levels and the simplified oral hygiene index values among the 4 time points after quantifying the salivary levels of Streptococcus mutans, Streptococcus sobrinus, and total bacteria with real-time polymerase chain reaction.Simplified oral hygiene index values and total bacteria significantly decreased, but salivary mutans streptococci levels significantly increased after orthodontic treatment. The amounts of total bacteria in saliva significantly decreased at T3 (T1, T2T3, T4), and the simplified oral hygiene index values decreased at T2 (T1T2, T3, T4). However, salivary S mutans and S sobrinus significantly increased at T3 and T4, respectively (T1, T2T3T4). Furthermore, the proportion of mutans streptococci to total bacteria significantly increased at T4 (T1, T2, T3T4).This study suggests that careful hygienic procedures are needed to reduce the risk for dental caries after orthodontic treatment, despite overall improved oral hygiene status.

Introduction The aim of this study was to retrospectively assess the frequency and localizations of bond failures (BFs) in patients treated with either lingual (TOP-Service fur Lingualtechnik GmbH, a 3M Company, Bad Essen, Germany) or buccal (Mini Diamond brackets/Accent molar tubes; Ormco, Orange, Calif) full multibracket appliances in both dental arches. Methods Data were acquired by an independent investigator from the patient records of 3 practitioners. To establish a standardized observation period, the first year of treatment was analyzed for each patient. Statistical analysis comprised the Kruskal-Wallis, Wilcoxon, Mann-Whitney U, and Fisher exact tests. The significance level was set at P Results The mean number of BFs per patient in the first year of treatment did not differ significantly between the lingual group (n = 59; mean age, 31.1 years; mean BFs per patient, 2.63; SD, 2.77; minimum, 0; maximum, 13) and the buccal group (n = 44; mean age, 15.14 years; mean BFs per patient, 2.61; SD, 3.41; minimum, 0; maximum, 14) ( P = 0.428) or with respect to sex (lingual group, P = 0.251; buccal group, P = 0.414) or practitioner (lingual group, P = 0.755; buccal group, P = 0.060), but molar attachments were more prone to BFs than were premolar brackets (lingual group, P = 0.015; buccal group, P = 0.049), and premolar brackets were more prone to BF than anterior brackets (lingual group, P = 0.005; buccal group, P = 0.004). Conclusions With both appliances, a mean of 2.62 BFs per patient in the first year of treatment can be expected; this benchmark provides a reference for patient briefing, which is very important considering the large interindividual variances and budgeting considerations.

BACKGROUND:When implants are restored with cement-retained restorations, prosthetic retrievability can be difficult and often requires sectioning using rotary instruments. Sometimes repeated removals of a cement-retained implant crown are needed such as for treatment of peri-implantitis or immediate implant provisionalization. The purpose of this study was to evaluate the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser as a non-invasive treatment modality to remove lithium disilicate crowns from zirconia implant abutments following long-term cementation, repetitive debonding and re-cementation, and short-term retrieval. MATERIAL AND METHODS:Twenty identical lithium disilicate crowns were cemented onto zirconia prefabricated abutments using composite resin cement. Ten cemented crowns were removed at 48 hours after cementation as a short-term group (ST), while another 10 were removed 6 months after cementation as a long-term group (LT). To mimicking repetitive recementation and retrieval, the LT crowns were then recemented and removed after 48 hours as a long-term recemention (LTR) group. The LTR crowns were then again recemented and removed after 48 hours as a long-term repeated recemention (LTRR) group. Er:YAG laser was used to facilitate the retrieval of these crowns. recorded and analyzed using ANOVA and t-test. The surfaces of the crown and the abutment were further examined using light microscopy and scanning electron microscopy (SEM). Temperature changes of the abutment and crown upto 10 minutes were also measured and statistically analyzed (paired t-test). RESULTS:The average times of crown removal from zirconia abutments were 4 minutes (min) and 42 second (sec) in LT to 3 min 24 sec in LTR, and 3 min 12 sec in LTRR and ST groups. LTR took the longest time to remove, statistically (ANOVA and t-test, p < .001). No statistical differences were observed among the removal times of LTR, LTRR, and ST groups (t-test, p = .246, .246 and 1). SEM examination of the material surface showed no visual surface damaging from treatment with Er:YAG laser. The temperatures during irradiation ranged from 18.4°C to 20°C and 22.2°C to 24.5°C (Paired t-test, p < .0001) for the abutment and the crown during irradiation from 1 min to 10 mins. CONCLUSIONS:Long-term cementation can increase time in lithium disilicate crown removal from zirconia abutment using Er:YAG. Er:YAG laser is a non-invasive tool to remove cement-retained implant prostheses and should be considered as a viable alternative to rotary instruments.

4-Methacryloyloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butylborane (4-META/MMA-TBB) resin is widely used as a direct bonding adhesive for orthodontic appliances because of its strong bonding ability. However, its clinical disadvantages include long setting times and difficult debonding with subsequent residual adhesive left on the enamel surface. To resolve these problems, thermal heating was applied to orthodontic appliances. The setting time was dramatically reduced by thermal heating (160°C for 5 s), with the shear bond strength remaining the same as that stated in the manufacturer's instructions. Debonding of appliances following thermal heating (160°C for 20 s) could be easily performed, decreasing the amount of adhesive left on enamel. These conditions were not accompanied by an increase in the heat pain threshold of pulpal dentin. These results suggest that the use of thermal heating in the bonding/debonding of 4-META/MMA-TBB resin may resolve its clinical weaknesses, making its ease of use similar to light-cured resin.

Aim: To evaluate the histological changes following electrothermal debonding (ETD) of ceramic brackets. Materials and Methods: A total of 50 first premolar teeth from 14 patients were divided into two groups: Group I consisted of 20 teeth which served as control, and the brackets were debonded using conventional pliers. (7 teeth were extracted 24 hours after conventional debonding, 7 teeth were extracted 28 to 32 days after conventional debonding and 6 teeth were extracted 56-60 days after conventional debonding). Group II consisted of 30 teeth and the brackets were debonded using the ETD unit. (10 teeth were extracted 24 hours after ETD, 10 teeth were extracted 28 to 32 days after ETD and 10 teeth were extracted 56-60 days after ETD. Immediately after extraction, the teeth were sectioned and prepared for histological examination. Results: The pulp was normal in most samples of the control group. In group II, mild inflammation was observed in the 24 hour sample while the 28 to 32 day sample showed signs of healing. The 56-60 day sample showed that the pulp was similar to the control group in 6 out of the 10 samples. Conclusion: The ETD of ceramic brackets did not affect the pulp and the changes which were observed, were reversible in nature.

Objective: The aim of this study was to determine the erbium-doped yttrium aluminum garnet (Er:YAG) laser transmission ratio through different dental ceramics with different thicknesses. Background data: Laser debonding procedure of adhesively luted all-ceramic restorations is based on the transmission of laser energy through the ceramic and the ablation of resin cement, because of the transmitted laser energy. Methods: Five different dental ceramics were evaluated in this study: sintered zirconium-oxide core ceramic, monolithic zirconium-oxide ceramic, feldspathic ceramic, leucite-reinforced glass ceramic, and lithium disilicate-reinforced glass ceramic. Two ceramic discs with different thicknesses (0.5 and 1mm) were fabricated for each group. Ceramic discs were placed between the sensor membrane of the laser power meter and the tip of the contact handpiece of an Er:YAG laser device with the aid of a custom- made acrylic holder. The transmission ratio of Er:YAG laser energy (500mJ, 2Hz, 1W, 1000s) through different ceramic discs was measured with the power meter. Ten measurements were made for each group and the results were analyzed with two way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests. Results: The highest transmission ratio was determined for lithium disilicate-reinforced ceramic with 0.5mm thickness (88%) and the lowest was determined for feldspathic ceramic with 1mm thickness (44%). The differences among the different ceramics and between the different thicknesses were significant (p

After orthodontic treatment, brackets are debonded and residual adhesive is removed, causing iatrogenic enamel damage. The aim of this study was to review the methods of orthodontic adhesive removal, find clear evidence, and provide a rationale for this procedure. A literature search was performed in PubMed, Dentistry and Oral Sciences, Scopus, Cochrane, Google, and Google Scholar using keywords: orthodontic adhesive removal, orthodontic debonding, orthodontic clean-up. Studies concerning human enamel roughness or loss from debonding and adhesive removal were considered. Forty-four full-text articles were analyzed and 3 were rejected after detailed reading; finally 41 papers were included. Fifteen qualitative studies, 13 studies based on indices of enamel surface, and 13 quantitative studies were found. No meta-analysis could be performed due to a lack of homogenous quantitative evidence. The most popular tools were tungsten carbide burs, which were faster and more effective than Sof-Lex discs, ultrasonic tools, hand instruments, rubbers, or composite burs. They remove a substantial layer of enamel and roughen its surface, but are less destructive than Arkansas stones, green stones, diamond burs, steel burs, and lasers. Multi-step Sof-Lex discs and pumice slurry are the most predictable enamel polishing tools. Arkansas stones, green stones, diamond burs, steel burs, and lasers should not be used for adhesive removal. The use of tungsten carbide bur requires multistep polishing. Further efforts should be made to find tools and methods for complete removal of adhesive remnants, minimizing enamel loss and achieving a smooth surface.

In this, the third part of the series, aesthetic orthodontic treatment will be considered. The previous two articles have looked at invisible orthodontics with Invisalign and lingual brackets. This article will discuss the properties and use of aesthetic brackets, along with examples of orthodontic treatment cases using the aesthetic brackets. Clinical Relevance: Increasing demand for aesthetics during orthodontic treatment has resulted in a significant increase in the use of aesthetic brackets. Clinicians need to be aware of the benefits and drawbacks of aesthetic brackets.

Objective: To determine patient experience of pain during treatment with fixed orthodontic appliances, expectations of pain during debond and whether biting on a soft acrylic wafer during debond decreases pain experience. Design: Multicentre randomized controlled trial. Setting: Three UK hospital based orthodontic departments: Mid-Staffordshire NHS Foundation Trust, Birmingham Dental Hospital and University Hospital of North Staffordshire. Materials and methods: Ninety patients were randomly allocated to either the control (n = 45) or wafer group (n = 45). A visual analogue scale-based questionnaire was completed pre-debond to determine pain experience during treatment and expectations of pain during debond. The appliances were debonded and those in the wafer group bit on a soft acrylic wafer. A second questionnaire was completed post-debond to assess the pain experienced. Results: Biting on an acrylic wafer significantly reduced the pain experienced when debonding the posterior teeth (P≤0·05). Thirty-nine per cent found the lower anterior teeth the most painful. The expected pain was significantly greater than that actually experienced (P≤0·0001). Greater pain during treatment correlated with increased expectations and increased actually experienced pain (P≤0·0001). Conclusions: Biting on a soft acrylic wafer during debond of the posterior teeth reduces the pain experienced. The lower anterior teeth are the most painful. The pain expected is significantly greater than actually experienced. Patients who had greater pain during treatment expected and experienced greater pain at debond.

OBJECTIVE: The purpose of this study was to evaluate, in vitro, the bond strength of brackets bonded to premolars previously subjected to bleaching with a 35% hydrogen peroxide. METHODS: Twenty one healthy premolars were selected and randomly divided into three groups (n = 7). Group I (G1) included teeth that were not submitted to bleaching. The enamel surfaces of Groups II (G2) and III (G3) were submitted to a bleaching process with 35% hydrogen peroxide (Whiteness HP Maxx). On Group II (G2), after bleaching, the teeth were stored for 24 hours in distilled water at 98.6 ºF, and then, premolar metallic brackets were bonded using Transbond XT (3M) resin. Group III (G3) was submitted to the same procedure seven days after bleaching. After bonding, all teeth were stored in distilled water at 98.6 ºF for 24 hours. All groups were submitted to a traction test using an EMIC DL2000 universal testing machine at a speed of 0.5 mm/min. RESULTS AND CONCLUSION: The bracket resistance to debonding was compared between the groups by the Kruskal-Wallis nonparametric test (p < 0.05) and it was verified that the bleaching agent significantly reduced bracket adhesion when bonded 24 hours after bleaching. However, seven days after bleaching, there was no significant difference on the resistance to debonding among groups G1 (19,52 kgf) and G3 (18,44 kgf), meaning that it is necessary to wait longer after bleaching to bond brackets. OBJETIVO: o propósito do presente estudo in vitro foi avaliar a resistência de união de braquetes colados em pré-molares previamente submetidos ao clareamento com peróxido de hidrogênio a 35%. MÉTODOS: foram estudados 21 dentes pré-molares hígidos, divididos aleatoriamente em três grupos (n = 7). O grupo I (G1) incluiu os dentes que não foram submetidos ao clareamento. As superfícies de esmalte dos grupos II (G2) e III (G3) foram submetidas ao processo de clareamento com peróxido de hidrogênio a 35% (Whiteness HP Maxx). No grupo II (G2), após o clareamento, os dentes foram armazenados por 24 horas em água destilada a 37ºC e, em seguida, braquetes metálicos para pré-molares foram colados utilizando resina Transbond XT (3M). O grupo III (G3) também foi submetido ao mesmo procedimento, sete dias após o clareamento. Após a colagem, todos os dentes foram armazenados em água destilada a 37ºC por 24 horas. Todos os grupos foram submetidos ao teste de tração utilizando-se máquina universal de ensaios Emic DL2000 a uma velocidade 0,5mm/min. RESULTADOS E CONCLUSÃO: a resistência à descolagem dos braquetes foi comparada entre os grupos por meio da utilização do teste não paramétrico Kruskall Wallis (p < 0,05), verificando-se que o agente clareador reduziu significativamente a adesão dos braquetes quando colados 24 horas após o clareamento. No entanto, 7 dias após o clareamento, não houve diferença na resistência à descolagem entre os grupos G1 (19,52kgf) e G3 (18,44kgf), sendo necessário, portanto, aguardar um maior tempo após o clareamento para a colagem de braquetes.

OBJECTIVE: To evaluate the influence of bonding and debonding of orthodontic brackets on dental in-home bleaching, taking into account three different adhesive systems. METHODS: Forty-four bovine incisors were divided into four groups according to the primer system used for orthodontic bracket bonding. Following the debonding of orthodontic brackets, the teeth were stored in staining solution for 96 hours. Then, teeth were whitened using 10% carbamide peroxide for two weeks at a 6-hour-a-day regime. Standardized digital photographs were taken at the following intervals: T0 (initial); T1 (after debonding); T2 (after pigmentation); T3, T4 and T5 representing 1, 7, and 14 days of bleaching. Repeatability and stability tests were carried out to check the method accuracy. Images were analyzed using Adobe Photoshop 7.0 software considering (L*a*b*)color coordinate values and a modified color difference total (Δ;E'). RESULTS: The results of this study (ANOVA and Tukey; p < 0.01) demonstrated that after 7 days of bleaching, experimental groups showed significantly less teeth whitening compared to the control group. However, there were no significant color differences between the groups after 14 days, according to values of lightness (L*). CONCLUSIONS: Regardless of the adhesive primer system applied, bonding and debonding of orthodontic brackets alters the outcome of tooth whitening in the first 7 days of bleaching, however it has no influence on the whitening of the dental structure after 14 days of in-home dental bleaching with 10% carbamide peroxide. OBJETIVO: o objetivo desse estudo foi avaliar a influência da colagem e descolagem de braquetes ortodônticos no clareamento caseiro, considerando três diferentes sistemas adesivos. MÉTODOS: quarenta e quatro incisivos bovinos foram divididos em quatro grupos, de acordo com o sistema adesivo utilizado para colagem dos braquetes. Após a descolagem dos braquetes, os dentes foram pigmentados por 96 horas e depois clareados com peróxido de carbamida a 10% por 6 horas diárias, durante duas semanas. Foram realizadas fotografias digitais padronizadas nos tempos: T0 (inicial); T1 (após descolagem); T2 (após pigmentação); T3, T4 e T5 representando 1, 7 e 14 dias de clareamento. Testes de repetitividade e de estabilidade foram realizados para avaliar a acurácia do método. As imagens foram avaliadas pelo software Adobe Photoshop 7.0, considerando os parâmetros de cor (L*a*b*) e a diferença total de cor adaptada para esse estudo (Δ;E'). RESULTADOS: os resultados do presente estudo (ANOVA e Tukey; p < 0,01) demonstraram que, após uma semana de clareamento, os grupos experimentais apresentaram uma resposta mais lenta ao clareamento que o grupo controle. Contudo, após 14 dias, não houve diferença cromática significativa entre os grupos, observada pelos valores de luminosidade (L*). CONCLUSÕES: independentemente do sistema adesivo utilizado, a colagem e descolagem de braquetes ortodônticos altera os resultados de obtenção de cor com sete dias de avaliação. Contudo, após 14 dias não se observa nenhuma diferença de cor na estrutura dentária clareada pela técnica caseira.

The usefulness of erbium-doped yttrium aluminum garnet laser irradiation for debonding ceramic brackets is assessed using a single laser pulse. Damon Clear brackets were chosen for their 85% transmission of 2.94 μm radiation and were bonded to 20 human third molars using the Blugloo adhesive system. Laser parameters comprised of 600 mJ pulse energy with 800 μs duration, 1.3 mm fiber tip. Light microscopy was used to assess Adhesive Remnant Index (ARI) scores, and scanning electron microscope (SEM) images were taken of the cross-section of the enamel-adhesive interface. Nineteen brackets (95%) were successfully debonded with a single laser pulse, while one bracket (5%) required eight pulses for debonding. For all teeth, the SEM analysis showed no signs of damage to the enamel, and ARI scores of three were observed, supporting the result that the laser effect is confined in the adhesive. The presented laser parameters are able to rapidly debond suitable brackets. The debonding mechanism was concluded to be thermomechanical ablation for single pulse debonding.

Objective The Primekote® (TP) polymer was incorporated to the of Orthodontic Bracket mesh base to improve bond strength and make it more efficient. The purpose of this study was to assess the shear bond strength and adhesive remnant index (ARI) of these brackets. Material and method The test sample consisted of thirty bovine incisors divided into 2 groups: with a group with TP® brackets (n=15), and a control group with Morelli® brackets (n=15) without Primekote® technology. The TransbondTM XT was used as adhesive system in both groups, following the same protocol and manufacturer’s instructions. Specimens were stored in distilled water for 24 hours and then submitted to shear bond strength test in a universal testing machine (EMIC DL2000). The assessment of ARI was performed under stereomicroscope by two calibrated examiners. Result No significant differences (p>0.05) in shear bond strength were found between the two groups according to the independent t-test. The Wilcoxon test was used to assess ARI data and statistical difference was found between Morelli® and TP® Nu-Edge brackets; the last one left less remaining adhesive on tooth surface. Conclusion TP® brackets had higher adherence to the adhesive system as shown by lower ARI scores, but this does not improve its clinical performance. Resumo Objetivo Avaliar a resistência ao cisalhamento e o índice de remanescente adesivo (IRA) dos bráquetes que tiveram o polímero Primekote® incorporado a suas bases. Material e método Foram confeccionados trinta corpos de prova com incisivos bovinos, divididos em dois grupos: o colado com bráquete TP® Nu-Edge(n=15) e grupo controle com bráquetes Morelli® (n=15) sem tratamento na base. O sistema adesivo TransbondTM XT foi utilizado nos dois grupos seguindo o mesmo protocolo de colagem e respeitando as instruções do fabricante. Os corpos de prova foram armazenados em água destilada por 24 horas, e posteriormente submetidos ao teste de cisalhamento na máquina de ensaios universais (EMIC-DL2000). O IRA foi avaliado por dois examinadores calibrados utilizando lupa estereoscópica com aumento de 20 vezes. Resultado Na resistência ao cisalhamento o teste T-independente mostrou não haver diferença estatisticamente significante entre os grupos (p>0,05), ambos tiveram desempenho semelhante. O teste Wilcoxon foi utilizado nos valores obtidos no IRA revelando diferença estatística, sendo que os bráquetes TP® deixaram menos remanescente adesivo na superfície dental que os bráquetes Morelli®. Conclusão Bráquetes TP® apresentaram maior adesão ao sistema adesivo pois foi encontrado menor IRA nos mesmos, porém esta característica não reflete em melhora no desempenho clínico.

Background The purpose of this study was to evaluate orthodontic debonding methods by comparing the surface roughness and enamel morphology of teeth after applying two different debonding methods and three different polishing techniques. Methods Forty eight human maxillary premolars, extracted for orthodontic reasons, were randomly divided into three groups. Brackets were bonded to teeth with RMGIC (Fuji Ortho LC, GC, Tokyo, Japan) (two groups, n = 18 each) after acid etching (30s), light cured for 40 s, exposed to thermocycling, then underwent 2 different bracket debonding methods: debonding pliers (Shinye, Hangzhou, China) or enamel chisel (Jinzhong, Shanghai, China); the third group (n = 12) comprised of untreated controls, with normal enamel surface roughness. In each debonded group, three cleanup techniques (n = 6 each) were tested, including (I) diamond bur (TC11EF, MANI, Tochigi, Japan) and One-Gloss (Midi, Shofu, Kyoto, Japan), (II) a Super-Snap disk (Shofu, Kyoto, Japan), and (III) One-Gloss polisher. The debonding methods were compared using the modified adhesive remnant index (ARI, 1–5). Cleanup efficiencies were assessed by recording operating times. Enamel surfaces were qualitatively and quantitatively evaluated with scanning electron microscopy (SEM) and surface roughness tester, respectively. Two surface roughness variables were evaluated: Ra (average roughness) and Rz (10-point height of irregularities). Results The ARI scores of debonded teeth were similar with debonding pliers and enamel chisel (Chi-square = 2.19, P > 0.05). There were significant differences between mean operating time in each group (F = 52.615, P

Sve češća potražnja za estetskim restauracijama rezultirala je povećanim korištenjem potpuno keramičkih dentalnih nadomjestaka, primjerice onih od cirkonijeva oksida. Time se pojavljuje izazov osiguravanja vezne čvrstoće ortodontskih bravica na različite keramičke materijale. Na snagu veze može utjecati vrsta bravice, odnosno materijal od kojega je izrađena i površina njezine baze ili način retencije. Svrha rada: Željela se provesti komparativna analiza posmične čvrstoće metalnih i keramičkih ortodontskih bravica zalijepljenih na cirkonij-oksidnu keramičku površinu kakva se nalazi na protetičkim nadomjestcima, te procijeniti način loma tih dviju vrsta ortodontskih bravica. Materijali i metode: Pripremljeno je 20 uzoraka/polukrunica od keramike na koje su zalijepljene ortodontske bravice – 10 metalnih i 10 keramičkih. Posmični test obavljen je u univerzalnoj kidalici s opterećenjem uzrokovanim klipom oštrog vrha koji se kretao pri fiksnoj brzini od 1 mm/min do loma. Sila potrebna za odljepljivanje bravica bilježena je u Newtonima, nakon čega je posmična čvrstoća izračunata u MP-ima. Osim toga, uzorci su analizirani pod digitalnim mikroskopom kako bi se ustanovio indeks ostatka ljepila (ARI). Statistički podatci obrađeni su t-testom, a razina značajnosti postavljena je na α = 0,05. Rezultati: Pokazali su da je vezna čvrstoća metalnih bravica vezanih na cirkonij-oksidne krunice veća u usporedbi s keramičkim bravicama sa statistički značajnom razlikom. Tijekom istraživanja dvije keramičke bravice su djelomično ili potpuno oštećene. Zaključak: Čini se da metalne bravice u usporedbi s keramičkima stvaraju jaču vezu s cirkonij-oksidnim površinama zbog boljeg načina retencije. Keramičke bravice su i krhkije tijekom uklanjanja., An increasing demand for esthetic restorations has resulted in an increased use of all-ceramic restorations, such as zirconium. However, one of the challenges the orthodontist must be willing to face is how to increase bond strength between the brackets and various ceramic restorations. Bond strength can be affected by bracket type, by the material that brackets are made of, and their base surface design or retention mode. The aim of this study was to perform a comparative analysis of the shear bond strength (SBS) of metallic and ceramic orthodontic brackets bonded to all-zirconium ceramic surfaces used for prosthetic restorations, and also to evaluate the fracture mode of these two types of orthodontic brackets. Material and methods: Twenty samples/semi-crowns of all-zirconium ceramic, on which orthodontic brackets were bonded, 10 metallic and 10 ceramic polycrystalline brackets, were prepared for this research. SBS has been tested by Universal Testing Machine, with a load applied using a knife edged rod moving at a fixed rate of 1 mm/min, until failure occurred. The force required to debond the brackets was recorded in Newton, then SBS was calculated to MPa. In addition, the samples were analyzed using a digital camera magnifier to determine Adhesive Remnant Index (ARI). Statistical data were processed using t-test, and the level of significance was set at α = 0.05. Results: Higher shear bond strength values were observed in metallic brackets bonded to zirconium crowns compared to those of ceramic brackets, with a significant difference. During the test, two of the ceramic brackets were partially or totally damaged. Conclusion: Metallic brackets, compared to ceramic polycrystalline brackets, seemed to create stronger adhesion with all-zirconium surfaces due to their better retention mode. Also, ceramic brackets showed higher fragility during debonding.

IntroductionThe aims of this study were to describe bacterial load and diversity of the aerosol created during enamel cleanup after the removal of fixed orthodontic appliances and to assess the effect of a preprocedural mouth rinse.MethodsThe study involved the sampling of ambient air adjacent to the patient's mouth during adhesive removal using a slow-speed handpiece and a spiral fluted tungsten carbide bur without water irrigation. Sampling was carried out during enamel cleanup with or without a preprocedural mouth rinse of either sterile water or chlorhexidine. Airborne particles were collected using a viable inertial impactor simulating the human respiratory tree. The bacteria collected were analyzed using both culture and molecular techniques.ResultsBacteria produced during debond and enamel cleanup can reach all levels of the respiratory tree. The use of a preprocedural mouth rinse, either sterile water or chlorhexidine, increased the numbers and diversity of the bacteria in the air.ConclusionsWhen using a slow-speed handpiece and a spiral fluted tungsten carbide bur for enamel cleanup after orthodontic treatment, the bacterial load and diversity of the aerosol produced are lower when a preprocedural mouth rinse is not used.

After orthodontic treatment with fixed appliances, bonded brackets and residual adhesive must be removed. This procedure should lead to restitutio ad integrum of the enamel or, at least, restore the enamel surface as closely as possible to its pre-treatment conditions. The purpose of this study is the in vivo assessment at a microscopic resolution of enamel surfaces after bracket debonding while avoiding the tooth extraction. Nine orthodontic patients who had brackets removed at the conclusion of orthodontic treatment were enrolled. In vivo reflectance confocal microscopy imaging of dental enamel surface after debonding was performed for each patient. Eighteen upper incisors were analyzed, 10 in which the enamel demineralization appeared after the treatment and 8 in which the demineralization was present before the treatment. RCM analyses showed some speckled or roundish dark areas within the enamel. Moreover enamel alterations were detected at different levels of depth. The present in vivo microscopic study allowed for highlighting structural features in dental enamel, after debonding, at a microscopic resolution in real-time and in a non-invasive way, without the need for extraction or processing of the samples. After orthodontic treatment with fixed appliances, bonded brackets and residual adhesive must be removed. This procedure should lead to restitutio ad integrum of the enamel or, at least, restore the enamel surface as closely as possible to its pre-treatment conditions. The purpose of this study is the in vivo assessment at a microscopic resolution of enamel surfaces after bracket debonding while avoiding the tooth extraction. Nine orthodontic patients who had brackets removed at the conclusion of orthodontic treatment were enrolled. In vivo reflectance confocal microscopy imaging of dental enamel surface after debonding was performed for each patient. Eighteen upper incisors were analyzed, 10 in which the enamel demineralization appeared after the treatment and 8 in which the demineralization was present before the treatment. RCM analyses showed some speckled or roundish dark areas within the enamel. Moreover enamel alterations were detected at different levels of depth. The present in vivo microscopic study allowed for highlighting structural features in dental enamel, after debonding, at a microscopic resolution in real-time and in a non-invasive way, without the need for extraction or processing of the samples.

Clinical procedures when shear forces are applied to brackets suggest adhesion forces between 2.8 and 10.0 MPa as appropriate. In this study dental enamel was evaluated by scanning electron microscopy (SEM) before and after removing the brackets. Thirty bicuspids (previous prophylaxis) with metallic brackets (Roth Inovation 0.022 GAC), Transbond Plus SEP 3M Unitek adhesive and Transbond XT 3M resin were used. The samples were preserved to 37°C during 24 hr and submited to tangential forces with the Instron Universal machine 1.0 mm/min speed load strength resistance debonding. Also the Adhesive Remanent Index (ARI) test was made, evaluating the bracket base and the bicuspid surface. All the bracket SEM images were processed with AutoCAD to determine the enamel detached area. The average value was 6.86 MPa (SD ± 3.2 MPa). ARI value 1= 63.3%, value 2= 20%, value 3= 13.3% and 33% presented value 0. All those samples with dental enamel loss, presented different situations as fractures, ledges, horizontal, and vertical loss in some cases, and some scratch lines. There is no association between the debonding resistance and enamel presence. Less than half of the remanent adhesive on the dental enamel was present in most of the samples when the ARI test was applied. When the resin area increases, the debonding resistance also increases, and when the enamel loss increases, the resin free metallic area of the bracket base decreases in the debonding.

Following the debonding of orthodontic brackets, the removal of residual adhesive from the enamel surface is required. Published adhesive removal protocols present conflicting advice.The present study evaluated the surface roughness of enamel after debonding and instrumentation with non-traditional orthodontic polishing systems.The facial aspects of 35 extracted human incisor teeth were scanned with a surface profilometer for surface roughness prior to the bonding of orthodontic brackets. After debonding, residual adhesive was removed with a 12-fluted titanium carbide bur. The teeth were randomly divided into seven groups (N = 5 per group) and the enamel surface was polished with one of seven products. All samples were re-scanned for surface roughness and subjectively evaluated via SEM.There was no significant difference in enamel surface roughness between the groups when compared using surface profilometry. Visual observations from the SEM evaluations demonstrated differences in the enamel surface at the microscopic level that were not detected by profilometric analysis.The present study found no statistically significant difference in mean enamel smoothness change from pretreatment to post-treatment between the seven polishing methods studied via profilometer surface reading measurements. An SEM analysis showed visual differences in enamel striations viewed at 1000x magnification in a comparison of traditional versus non- traditional polishing methods.

The objective of the present study was to determine which of six bonding protocols yielded a clinically acceptable shear bond strength (SBS) of metal orthodontic brackets to CAD/CAM lithium disilicate porcelain restorations. A secondary aim was to determine which bonding protocol produced the least surface damage at debond.Sixty lithium disilicate samples were fabricated to replicate the facial surface of a mandibular first molar using a CEREC CAD/CAM machine. The samples were split into six test groups, each of which received different mechanical/chemical pretreatment protocols to roughen the porcelain surface prior to bonding a molar orthodontic attachment. Shear bond strength testing was conducted using an Instron machine. The mean, maximum, minimal, and standard deviation SBS values for each sample group including an enamel control were calculated. A t-test was used to evaluate the statistical significance between the groups.No significant differences were found in SBS values, with the exception of surface roughening with a green stone prior to HFA and silane treatment. This protocol yielded slightly higher bond strength which was statistically significant.Chemical treatment alone with HFA/silane yielded SBS values within an acceptable clinical range to withstand forces applied by orthodontic treatment and potentially eliminates the need to mechanically roughen the ceramic surface.

The aim of the study was to evaluate the influence of Er:YAG laser irradiation on the debonding of metal and ceramic brackets and enamel damage ex vivo.The principle of safe bracket debonding is to degrade the adhesive resin strength connecting the tooth and bracket. Removal of adhesive resin from tooth surfaces without iatrogenic damage (enamel loss) is generally the main problem of the otherwise very successful method of aesthetic straightening of teeth.Forty ceramic and metal brackets (Clarity™ Advanced and Victory Series™; 3M Unitek, Monrovia, CA) were standardly bonded to buccal polished enamel surfaces of 30 caries-free human third molars. Two types of adhesive resins (Transbond™ XT Light Cure Adhesive; 3M Unitek, and Variolink II Professional Set; Ivoclar Vivadent AG) were used. Before debonding, the brackets in the laser group were irradiated with the Er:YAG laser (FJFI CVUT) 280 mJ, 250 μs long, repetition rate 6 Hz, spot focus 1 mm, and 140 sec. The control group was debonded without the laser irradiation. During the bracket irradiation, temperature changes inside the tooth were monitored using a thermal image infrared camera. The enamel surface was investigated by SEM.It has been observed that bracket removal was easier after the Er:YAG laser irradiation, and temperature rise was limited (from 2.0°C to 3.2°C) also for metal brackets. As against the nonirradiated samples, SEM investigation has confirmed no damage to enamel.Irradiation with Er:YAG laser radiation before debonding of ceramic brackets significantly decreases the bonding failure and amount of remaining adhesive.

Aim The aim of the study is to evaluate the immediate and delayed effects of diode laser on debonding of ceramic brackets. Materials and methods A total of 60 human extracted premolar teeth were randomly assigned to three different treatment groups. All teeth were bonded with adhesive precoated (APC) ceramic brackets (3M Unitek). A total of 20 teeth were debonded without lasing (group 1), 20 immediately after lasing (group 2), and 20 1 hour after lasing (group 3). For the lasing groups (groups 2 and 3), access cavity was prepared on the occlusal surface to a 2 mm diameter. A transbond plus self-etching primer (3M Unitek, Monrovia, CA, USA) and APC PLUS clarity advanced brackets (3M, Unitek, Monrovia, CA, USA) were used. The shear bond strength (SBS) and adhesive remnant index (ARI) were measured. The internal pulpal wall temperature was noted for the laser groups. Results The mean SBS was 15.4, 11.57, and 11.79 MPa for groups 1 to 3 respectively. Post hoc test showed significant difference (p < 0.001) between the control group and the lased groups. For groups 2 and 3, the rise in temperature was at an average of 1.4 and 1.3°C respectively. Conclusion The SBS of APC brackets decreased by 33.3% on application of diode laser without increasing the internal pulp chamber wall temperature significantly. Shear bond strength remains more or less the same whether debonding is done immediately after lasing or 1 hour after lasing. Diode lasers increased the ARI scores and thus decreased the risk of enamel fracture. How to cite this article Anand P, Anand PB, Prabhakar R, Rajvikram N, Rajakumar P, Atali VR, Saravanan R. Immediate and Delayed Effects of Diode Laser on Debonding of Ceramic Brackets: An in vitro Study. J Contemp Dent Pract 2016;17(4):275-281.

This study investigated enamel smoothness after debonding. A smooth surface would intuitively seem to be a good outcome, but there is little evidence about the variables of debonding technique whic...

Background The aim of this prospective in vitro study was to evaluate the effect of nanohydroxyapatite (nanoHAP) serum on the enamel surface roughness and tooth color stability after orthodontic debonding procedure. Methods The crowns of 30 premolars were embedded in acrylic blocks with a 4 mm × 5-mm-sized window on the middle third of buccal surfaces. Primary roughness values were evaluated by an atomic force microscope (AFM). After bracket debonding, and polishing procedures, the second roughness parameters were recorded. Specimens were then randomly assigned to two equal groups. NanoHAP serum and HAP toothpaste were applied for 10 days in the first and second groups, respectively. Then, after the third AFM, initial color parameters were measured. Following 1-week immersion in the coffee solution, second color assessment was performed. The fourth AFM was registered after 2 months of aging process. Results All roughness parameters were elevated following debonding procedure. There was no statistically significant reduction in roughness parameters after 10 days of nanoHAP serum or HAP toothpaste application. Both groups showed significant color change after immersion in the coffee solution. Conclusions NanoHAP serum with the protocols used in this study could not restore enamel surfaces to their original condition.

Lasers have the potential for reducing the required debonding force and can prevent the mechanical damage given to the enamel surface as a result of conventional debonding procedure. However, excessive thermal effects limit the use of lasers for debonding purposes. The aim of this study was to investigate the optimal parameters of 1940-nm Tm:fiber laser for debonding ceramic brackets. Pulling force and intrapulpal temperature measurements were done during laser irradiation simultaneously. A laser beam was delivered in two different modes: scanning the fiber tip on the bracket surface with a Z shape movement or direct application of the fiber tip at one point in the center of the bracket. Results showed that debonding force could be decreased significantly compared to the control samples, in which brackets were debonded by only mechanical force. Intrapulpal temperature was kept equal or under the 5.5°C threshold value of probable thermal damage to pulp. Scanning was found to have no extra contribution to the process. It was concluded that using 1940-nm Tm:fiber laser would facilitate the debonding of ceramic brackets and can be proposed as a promising debonding tool with all the advantageous aspects of fiber lasers.

Jeon H., Lee S. J., Kim T. W., Donatelli R. E. Three-dimensional analysis of lip and perioral soft tissue changes after debonding of labial brackets Orthod Craniofac Res 2013; 16: 65–74. © 2012 John Wiley & Sons A/S Structured Abstract Objectives – To evaluate the possible soft tissue changes after debonding of labial brackets using three-dimensional (3D) images acquired by a laser scanner. Methods – On the same day, 3D facial scans were taken immediately before debonding (T1) and immediately after debonding (T2) from 53 patients, and follow-up scans were taken 3 months after debonding (T3) from 31 patients. To compare the scans, superimpositions were performed and shell-to-shell deviations were used for quantitative analysis. Results – Shell-to-shell deviation map showing warm colors in lip and perioral tissue represented the retrusion of soft tissue after bracket removal. Soft tissue retrusion was significant for all landmarks immediately after debonding (T1–T2) and 3 months after debonding (T1–T3). Gender, bracket type, and the lip thickness variables did not show a clinically significant influence on the amount of soft tissue retrusion at the T1–T3 period. Lip corners and vermilion borders were significantly retruded at the T1–T3 period more than other perioral areas. A negative linear relationship was found in the amount of soft tissue retrusion immediately after debonding (T1–T2) and from debonding to 3 months after debonding (T2–T3). Conclusion – Three-dimensional imaging showed significant changes in lip and perioral soft tissue after debonding of labial brackets. Clinically significant changes, approximately 2 mm of retrusion, occurred in the mouth corners bilaterally. Vermilion border landmarks also demonstrated significant changes in more than 1 mm. However, it was not possible to predict the soft tissue changes. A wide range of individual variability in the response to treatment and soft tissue adaptation was noted.