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AIM AND OBJECTIVE This study aimed to evaluate the effect of ozonated water used as an irrigant and dentin-cleaning solution on the bond strength of fiberglass pins in vitro, comparing it with the commonly used solutions. MATERIAL AND METHODS Seventy-seven bovine roots were randomly divided into seven groups according to the irrigant and dentin-cleaning solution to be used: HP/HP, 2.5% sodium hypochlorite; DA/DA, distilled water; CHX/CHX, 2% chlorhexidine; OA/OA, 4 ppm ozonated water; HP/DA; HP/CHX; and HP/OA. In each group, the root canals were endodontically prepared by using the corresponding irrigant and stored in DA; after 7 days, they were cleared and cleaned with the corresponding cleaning solution. The fiberglass pins were cemented by using self-adhesive cement. After 7 days, the roots were sectioned (six discs each) and submitted to the push-out test. The type of fracture was analyzed with a 4.5x stereoscopic magnifying glass. The data were analyzed by the analysis of variance and the Tukey test at a 5% significance level. RESULTS The OA/OA (11.67), HP/HP (11.21), and HP/OA (9.71) groups showed the highest mean push-out bond strength (MPa) in the cervical third. The same trend was maintained in the middle and apical thirds. CONCLUSION Ozonated water and 2.5% sodium hypochlorite are the most relevant solutions for root dentin treatment. CLINICAL RELEVANCE Teeth treated with ozonated water, sodium hypochlorite, and a combination of the two showed greater bond strength than those treated with other solutions.

Resumo: A cárie radicular é uma patologia progressiva e dinâmica que ocorre na interface biofilme e cemento/dentina radicular, com maior taxa de prevalência na população idosa. O uso profissional de agentes fluoretados consiste na intervenção minimamente invasiva, capaz de prevenir e inativar as Lesões de Cárie Radicular (LCRs). Desta forma, o presente estudo objetivou identificar os diferentes agentes terapêuticos fluoretados de uso profissional que agem na inativação/paralisação da cárie radicular. Para tanto, foi realizado levantamento bibliográfico dos últimos cinco anos por meio de análise criteriosa de artigos científicos. Os idiomas foram, predominantemente o português, inglês e espanhol. Como critérios de inclusão foi considerado os trabalhos relacionados com o objetivo do presente estudo, estudos disponíveis na integra, artigos publicados entre 2016 e 2021, sendo descartados artigos que não estavam em consonância com o objetivo deste estudo, teses e dissertações. Conclui-se que o Diamino Fluoreto de Prata (DFP) é o agente fluoretado que apresentou maior eficácia na prevenção e paralização das LCRs. Contudo, sugere-se que mais estudos sejam realizados, com foco na intervenção minimamente invasiva, que tragam protocolos clínicos de atendimento adequado ao tratamento da cárie radicular Palavras-chave: Cárie; Cárie radicular; Agentes fluoretados.Abstract: Root caries is a progressive and dynamic pathology that occurs at the biofilm and cementum/root dentin interface, with a higher prevalence rate in the elderly population. The professional use of fluoridated agents is a minimally invasive intervention capable of preventing and inactivating Root Caries Lesions (CRLs). Thus, the present study aimed to identify the different fluoride therapeutic agents for professional use that act in the inactivation/paralysis of root caries. Therefore, a bibliographic survey of the last five years was performed through a careful analysis of scientific articles. The languages were predominantly Portuguese, English and Spanish. As inclusion criteria, works related to the objective of this study were considered, studies available in full, articles published between 2016 and 2021, and articles that were not in line with the objective of this study, theses and dissertations were discarded. It is concluded that Silver Diamino Fluoride (DFP) is the fluoridated agent that showed the greatest effectiveness in preventing and paralyzing CSFs. However, it is suggested that more studies be carried out, focusing on minimally invasive intervention, which bring clinical protocols for adequate care for the treatment of root caries. Keywords: Caries; Root caries; Fluoridated agents.

OBJECTIVES This study aimed to assess the effect of application of QMix and common root canal irrigating solutions on the bond strength of fiber post to root dentin. MATERIAL AND METHODS In this in-vitro study, 60 extracted incisor teeth were decoronated such that 15 mm of root length remained. The canals were prepared with ProTaper rotary system to F5 and filled with gutta-percha and AH26 sealer. Prior to post placement, the teeth were divided into four groups based on the type of final irrigating solution namely saline, 5.25% NaOCl, 2% chlorhexidine, and QMix. The fiber posts were then cemented with Panavia F2 resin cement. The roots were sectioned perpendicular to their longitudinal axis, and four sections with 1 mm thickness were made at the middle and coronal thirds of the roots. The push-out bond strength of fiber posts was measured by a universal testing machine in megapascals. Data were analyzed by two-way ANOVA and Tukey's test. RESULTS The maximum and minimum bond strength values were noted in QMix and NaOCl groups in both the middle and coronal third of the root, respectively. But, there was no significant difference between the push-out bond strength in the middle or coronal third of the root (p = 0.054). Adhesive failure was the most common mode of failure in all groups. CONCLUSION Use of QMix for post space irrigation does not compromise the bond strength of fiber post to root dentin, and can be used for final rinsing of the post space.

This systematic review (PROSPERO - CRD42020150722) was performed to answer the following question: Does the use of chelating agents affect the dislodgment resistance of epoxy resin-based root canal sealers? A search was conducted in PubMed, EMBASE, Scopus, LILACS and Web of Science, hand searching of two endodontic journals and grey literature until September 2020. Extracted data included: teeth used, sample size, root canal preparation, irrigant, chelating solution, neutralisation solution, type of resin-based sealer and obturation approach, storage method and duration, root third and slice thickness, plunger dimension and loading direction and the push-out testing parameters and values. The search retrieved a total of 2.389 studies. After analysis, 12 studies fulfilled the eligibility criteria and were included. Most of the final irrigation protocols with chelating agents had a positive impact and promoted an improvement in the dislodgment resistance of epoxy resin-based sealers to the root dentin.

Made available in DSpace on 2022-04-28T17:22:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Objective: To evaluate the effects of mechanical versus chemical cleaning protocols for cleaning the root dentin surface before cementation of fiberglass posts for their effect on the bond strength, failure mode, and dentinal penetration of the cementing agent using an etch-and-rinse adhesive system on dentin prepared to receive a fiberglass post. Methods: Forty roots of bovine teeth were endodontically treated and prepared for fiber post cementation. The specimens were randomized into 4 groups of 10: Control group (CO) - irrigation with 2.5% NaOCl; DW group- irrigation with distilled water; RB group - rotating brush for cleaning root canals, and CUI group - continuous ultrasonic irrigation. The fiberglass posts were cemented, and the specimens were immersed in distilled water for 6 months. A push-out test was performed on the cervical, middle, and apical thirds of the samples. Dentinal penetration of the cementing agent and the fracture pattern were evaluated by laser confocal microscopy. Statistical analysis was performed using analysis of variance (ANOVA) and post hoc Tukey tests (alpha=0.05). Results: The RB and CUI groups showed significantly higher bond strength values when compared to the Control and DW groups (p

Objective To develop a new method to test the fracture strength of endodontically-treated root dentin. Method Bovine tooth roots were transversely cut into 2-mm thick sections and the root canals were enlarged with a taper of 0.06. An outer layer of resin composite was bonded to each section to make the root canal-to-outer radius ratio smaller than 1/3. The resulting discs were treated with irrigants at the inner surface and then fractured by inserting through the center a steel rod of the same taper attached to a universal test system. Fracture strength was calculated by using Lame’s equations for thick-walled cylinders. Micro-indentation was performed to evaluate the depth of dentin affected by irrigation. Finite element analysis (FEA) was performed to verify the reasonableness of using resin composite to surround the dentin section as well as the analytical solution. Results The fracture strength of endodontically-treated root dentin based on the analytical solution for a homogeneous section was 139.69 ± 32.59 MPa. However, FEA that took into account root canal softening caused by the irrigants showed that this was overestimated by about 33.5%. The corrected fracture strength of treated dentin was 114.58 ± 26.74 MPa. By incorporating the layer of affected dentin into the analytical solution, the difference in the fracture-causing stress between the analytical and numerical solutions dropped to around 9.5%. Significance A relatively simple but clinically relevant method has been developed for measuring the fracture strength of endodontically-treated root dentin. The method could be applied to root dentin that is treated by conventional canal opening and irrigation.

Aim. This study aimed to determine the residual filling material and the reestablishment of working length and apical patency after retreatment of TotalFill® BC Sealer.Materials and methods. Thirty maxillary incisors were used in a single cone obturation technique with TotalFill BC Sealer (FKG, Switzerland) and randomly divided into 6 groups according to the retreatment technique. The samples were scanned by micro-CT before and after retreatment in order to evaluate the residual filling material on the root dentin walls. Data were analyzed statistically with the Kruskal-Wallis tests (p < 0.05).Results. No instrumental protocol was able to remove all obturation material from the root canals. The differences in reduction in the total volume of filling material percentage were statistically significant (p < 0.05) among groups with and without ultrasound or sound activation in retreatment protocol.Conclusions. The most effective root canal retreatment was determined with D-Race + XP-endo Shaper + XP-Endo Finisher R + US (3.0 W) protocol; it was found that the efficiency of filling material removal was more than 92%.

Background: This study aimed to assess the effects of calcium hydroxide, Biodentine, calcium-enriched mixture (CEM) cement, and mineral trioxide aggregate (MTA) on root dentin flexural strength after a 30-day exposure period. Methods: This in vitro experimental study evaluated 25 freshly extracted sound human incisors with no caries or restorations. The apical 5 mm and the coronal two-thirds of the crowns were cut such that all samples had 10 mm length. Dentin samples (n=20 in each group) were then exposed to 2 mm thickness of calcium hydroxide, Biodentine, CEM cement, MTA, or saline (control) in petri dishes for 30 days. Finally, dentin samples were subjected to a three-point bending test after the intervention, and the flexural strength data were analyzed using one-way ANOVA, Tukey’s test, and t test. Results: Thirty-day exposure to all four biomaterials decreased the flexural strength of root dentin (P0.05). Conclusions: In general, all four tested biomaterials decrease the dentin strength although this reduction is more prominent by calcium hydroxide.

To evaluate the effect of ionizing radiation and cariogenic biofilm challenge using two continuous flow models, normal and reduced salivary flow, on the development of initial root-dentin caries lesions. Microcosm biofilms were grown under two salivary flow rates (0.06 and 0.03 mL min−1) and exposed to 5% sucrose (3 × daily, 0.25 mL min−1, 6 min) dripped over non-irradiated and irradiated root-dentin blocks for up to 7 days. The vibration modes of root dentin, matrix/mineral (M/M), and carbonate/mineral (C/M) ratios were evaluated by FTIR. The mineral density was assessed by micro-CT. With normal salivary flow, FTIR revealed an increase in the organic matrix (amide III) and a decrease in the mineral phase (ν4, ν2 PO43−, AII + ν2 CO32−, C/M) in caries lesions. Irradiated dentin exhibited a reduction in the mineral phase (ν1, ν3 PO43−, ν2 CO32−, C/M). Differences in mineral densities were not significant. With reduced salivary flow, FTIR also revealed increased organic matrix (amide III) for irradiated caries lesions and decrease in mineral phase (v4, v2 PO43−, v2 CO32−, and C/M) in caries lesions. ν1, ν3 PO43− precipitated on the surface of irradiated dentin and a lower mineral density was observed. Initial caries lesions differed between non-irradiated and irradiated dentin and between normal and reduced salivary flow rates. Significant mineral loss with exposure of the organic matrix and low mineral density were observed for irradiated dentin with a reduced salivary flow rate. Ionizing radiation associated with a reduced salivary flow rate enhanced the progression of root-dentin caries.

Made available in DSpace on 2022-04-29T08:29:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 Background: The aim of this study was to evaluate the effects of surface treatments with 1% peracetic acid (PA), solution containing 17% EDTA (SmearClear, Kerr Endodontics), solution containing a combination of 17% EDTA with 2% chlorhexidine (QMix, Dentsply Sirona) on the post-space root dentin compared to 2.5% sodium hypochlorite (NaOCl) on bond strength and resin tags length in dentin. Material and Methods: Forty human-canine roots were endodontically treated and the post space was prepared. The specimens were randomised into four groups (n = 10): control - irrigation with 2.5% NaOCl solution, PA - irrigation with 1% PA, SmearClear - irrigation with SmearClear solution, and QMix - irrigation with QMix solution. The fibre posts were cemented using a self-adhesive resin system (Relyx U200, 3M ESPE). After six months, the specimens were cross-sectioned and subjected to push-out and confocal laser microscopy tests. One-way ANOVA and Tukey's tests were used to analyse the data (a= 0.05). Results: PA and QMix presented the highest bond strength values compared to the other groups (p < 0.05). There was no significant difference between the resin tags length in dentin by the groups (p = 0.75). Conclusions: Irrigation of the post space with 1% PA and QMix showed a positive clinical impact on the adhesion between the fiber post and root dentin. However, these materials had no influence on resin tags length in dentin by self-adhesive resin cement. Department of Restorative Dentistry Araraquara School of Dentistry São Paulo State University (UNESP) School of Dentistry Federal University of Para (UFPA) Department of Restorative Dentistry Bauru School of Dentistry University of Sao Paulo (USP) Department of Restorative Dentistry Araraquara School of Dentistry São Paulo State University (UNESP)

The objective of this study was to evaluate the effect of different concentrations of NaOCl with and without passive ultrasonic irrigation (PUI) on mechanical properties of human dentin for applications in regenerative endodontics (RE). Sixty single-rooted teeth were sectioned into 2 halves (n = 120). Dentin bars were produced from one half for flexural strength and the other half was used for microhardness. Specimens were randomly assigned into 10 groups: G1 and G2 (control): distilled water for 30 and 60 min, respectively; G3: 1.5%NaOCl for 30 min; G4:1.5%NaOCl for 60 min; G5: 1.5%NaOCl + PUI for 30 min; G6: 1.5%NaOCl + PUI for 60 min; G7: 5.25%NaOCl for 30 min; G8: 5.25%NaOCl for 60 min; G9: 5.25%NaOCl + PUI for 30 min; G10: 5.25%NaOCl + PUI for 60 min. An increase in NaOCl concentration showed highly significant reduction in mechanical properties. There was no significant difference between 1.5% NaOCl and control group except for specimens treated with PUI for 60 min. NaOCl in concentrations recommended for RE did not have a significant effect on mechanical properties of dentin. However, PUI with increased irrigation time might have an effect even with low NaOCl concentration.

Background: In an oval-shaped canal, no single instrumentation systems were effective in absolute removing obturation. Aim: The aim of the study was to evaluate the performance of ProTaper Universal Retreatment (PTUR) system, XP-endo Shaper (XPS), XP-endo Finisher (XPF), and XP-endo Finisher-R (XPF-R) in removing root-canal filling material and preservation of sound dentin during retreatment procedure. Methodology: Root-canal preparation was performed on 60 mandibular premolars with oval-shaped canals using the ProTaper Gold file system. Preobturation scans were performed to measure canal volume of the canal and recorded. Obturation was performed and the samples were randomly assigned into four groups according to the retreatment protocol used (n = 15): H-file, PTUR files, PTUR followed by XPF file, and XPS supplemented with XPF-R file. After retreatment, the specimens were re-scanned and volumetric analysis of remaining root filling material, volume of the canal space were measured using EZ-3Di Software Version 5.0.0.2. All the data were subjected to one-way ANOVA and post hoc Tukey's test with a significance of 5%. Results: XPS + XPF-R showed promising results in the removal of obturating material and preservation of root dentin than any other group. The difference is statistically significant. Conclusion: XPS + XPF-R removed gutta-percha more significantly without sacrificing the sound dentin along with instrumentation.

This study aimed to evaluate (1) the effect of irrigating solutions and intracanal medicaments on the release of transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF) from cervical root dentin and (2) the effect of associating triple antibiotic paste (TAP) and calcium hydroxide paste (CH) with 2% chlorhexidine (CHX) on TGF-β1 release.First, 119 specimens from roots (cervical thirds) were obtained and were distributed into 5 groups: 2% CHX, 2.5% sodium hypochlorite, TAP, CH, and 10% EDTA by each growth factor (TGF-β1 [n = 8] and VEGF [n = 8]). Then, specimens were distributed as follows (n = 13): TAP + 2% CHX, CH + 2% CHX, and 10% EDTA and treated with irrigating solutions and intracanal medicaments. After the treatments, the specimens were immersed in 10% EDTA (20 minutes), and the solution was analyzed using the enzyme-linked immunosorbent assay. The data were submitted to normality, homogeneity of variance, and Mann-Whitney tests (P.05).Significant differences were found between the irrigating solutions (P.05) and intracanal medicaments for TGF-β1 (P.05). No VEGF release was detected for any group. Our results showed no significant differences among the TAP + 2% CHX and EDTA groups for TGF-β1 but a significant difference between CH + 2% CHX and the other groups (P.05).The use of 2% CHX as the irrigating solution, CH as the intracanal medicament, and 10% EDTA as the final irrigation provides higher TGF-β1 release from the cervical root dentin, whereas VEGF was not detected. Moreover, TAP and 2% CHX with 10% EDTA as the final irrigation resulted in greater TGF-β1 release from cervical root dentin than CH + 2% CHX.

Root resorption of the tooth is defined as a pathologic or physiologic process resulting in loss of hard tissue such as root dentin, cementum and bone. Root resorption is of two types external and internal root resorption. Management of internal root resorption has always been a challenge to the endodontists. It may occur in cases with chronic pulpal inflammation, following caries or due to traumatic injuries. Prevalence of internal root resorption is more in anterior teeth, because of their susceptibility to trauma. For successful treatment outcome early diagnosis, removal of the cause, proper treatment of the resorbed root is mandatory. This paper summarizes the management of internal root resorption through two cases of non-perforating and perforating internal resorption, which were successfully managed and showed good healing after a follow up of 6 months to 1 year. Keywords: Root resorption, Nonperforating internal root resorption, Perforating internal root resorption.

This study aims to identify the optimal concentrations of triple antibiotic paste (TAP), modified triple antibiotic paste (mTAP) and double antibiotic paste (DAP) that could completely eradicate Enterococcus faecalis in dentinal tubules. One hundred and ninety extracted human premolars inoculated with E. faecalis were medicated with calcium hydroxide and mixed antibiotic pastes (TAP, mTAP and DAP at 0.1, 1.25, 5, 10 and 20 mg mL-1 of each drug) for seven days before being frozen, pulverised and cultured. Specimens treated with the lowest concentration of the mixed antibiotics capable of eradicating E. faecalis were examined using scanning electron and confocal laser scanning microscopy to confirm the eradication of the microbial. TAP at 10 mg mL-1 of each drug was able to completely eliminate bacteria inside dentinal tubules, whereas mTAP and DAP required 20 mg mL-1 of each drug. Calcium hydroxide was not effective in eradicating E. faecalis inside dentinal tubules.

This study aimed to evaluate the effect of ultrasonic activation (UA) of endodontic sealers on dentin tubule penetration and the bond strength to root dentin.One hundred single-rooted teeth were prepared with 40.06 nickel-titanium instruments and divided into 2 groups: with or without UA. Three resin-based sealers (MTA Fillapex [Angelus Dental Solutions, Londrina, PR, Brazil], Sealer Plus [MK Life Medical and Dental Products, Porto Alegre, RS, Brazil], and AH Plus [Dentsply, DeTrey GmbH, Konstanz, Germany]; n = 20) and 2 calcium silicate-based sealers (Sealer Plus BC [MK Life Medical and Dental Products] and EndoSequence BC [Brasseler, Savannah, GA], n = 20) were used and subdivided (n = 10) according to the protocols. Fluo-3 (Thermo Fisher Scientific, Waltham, MA) and rhodamine B dyes were added to the calcium silicate- and resin-based sealers, respectively. In the UA groups, the activation was performed for 40 seconds followed by lateral compaction. Samples were transversely sectioned to evaluate the dentin tubule penetration and the bond strength to root dentin. The penetration data were analyzed with the Student t test, 1-factor analysis of variance, and Bonferroni tests. Bond strength was evaluated using the Student t test, Kruskal-Wallis, and Dunn post hoc test.Resin-based sealers showed the highest tubule penetration without UA (P.05). UA significantly enhanced MTA Fillapex and Endosequence BC dentin tubule penetration (P.05). AH Plus and Sealer Plus BC improved their bond strength to root dentin after UA (P.05). AH Plus/UA, Sealer Plus/UA, and Sealer Plus BC/UA presented the highest bond strength values (P.05). Adhesive failures were predominant in all groups regardless of the use of ultrasound.UA interferes with tubule penetration and the bond strength to root dentin of resin- and calcium silicate-based sealers.

To determine the effect of a natural extract of of 2.5% concentration on the of root canal when used as an irrigating solution. This was an in comparative study where and twenty intact single-rooted teeth were selected and with a diamond bur to get an apical-coronal length of 10 mm and were randomly separated into three groups as per the used; Group 1 (control): Irrigation with Normal saline, Group 2: Irrigation with Smear Clear solution, Group 3: Irrigation with 2.5% extract solution. were prepared using Pro Taper Universal Rotary Files with intermittent irrigation with the respective irrigating solution. The teeth were then embedded in acrylic resin and subjected to Vicker's Hardness test, and the data obtained were analyzed using one way ANOVA. When Group 2(51.80±9.80 VHN and 52.66±5.28 VHN) was compared with Group 3(44.98±4.34 VHN and VHN) the values showed a statistically significant difference (p< 0.05).When Group 3 (44.98±4.34 VHN and VHN) was compared with Group 1(65.37±8.80 VHN and 67.74±9.56 VHN), the values did show a statistically significant difference (p> 0.05). Within the limitations of this study, teeth irrigated with normal saline showed the least reduction in followed by irrigation with leaf extract solution and Smear Clear.

Evaluate the influence of different surface treatment protocols on the bond strength of bulk fill restorative material to root dentin using the push-out test after cyclic loading. Forty intact human premolars, freshly extracted for orthodontic purpose with straight canals and fully developed apices, were selected for this study. The coronal portion of the teeth were cut perpendicular to the long axis of the teeth at the cement-enamel junction. All root canals were instrumented, cleaned, and obturated; then, a space of 3 mm in depth was prepared below the orifice level in both canals in each tooth to receive direct core bulk fill material; the specimens were classified according to the surface treatment protocol into four groups (n = 30). Group 1: no surface treatment (control group); group 2: surface treatment using Er,Cr:YSGG laser; group 3: surface treatment using chlorhexidine; and group 4: surface treatment using 17% EDTA solution. Restorations were bonded using universal adhesive following the same protocol. The roots were sectioned and three 1-mm-thick slices were obtained representing the length of the restorations inside the canals. The specimens were thermocycled, then subjected to push-out testing. A specimen from each group was examined using scanning electron microscope. Data was analyzed statistically using Kruskal-Wallis test and pairwise comparisons were carried out. The results showed that laser group was significantly higher than EDTA and chlorhexidine groups, and also higher than the control group with no significant difference. Also, the control group was significantly higher than EDTA and chlorhexidine group. However, chlorhexidine group was higher than EDTA group with no significant difference recorded (p

Transforming growth factor beta 1 (TGF-β1) is a key morphogen in regenerative endodontics; yet, its location within the hard tissue phase of dentin and its availability in mature roots have not been fully elucidated.Young mature (n = 8) and immature (n = 11) roots from sound premolars were obtained from 13 orthodontic patients aged 17 ± 1 and 12 ± 1 years, respectively. Roots were cleaned of organic remnants in 5% sodium hypochlorite. The width of the minor foramen was measured using a digital microscope. TGF-β1 distribution was assessed in 3 roots per group by immunostaining combined with confocal laser scanning microscopy. The root dentin of the remaining 13 roots was powdered and decalcified in 17% EDTA to determine the overall levels of hard tissue-embedded TGF-β1 by enzyme-linked immunosorbent assay. Data were compared between groups using the Student t test (α = .05).The minor foramen was 168 ± 49 μm versus 557 ± 295 μm in mature compared with immature roots (P.05). TGF-β1 was highly stainable toward the pulp space in both groups. It was clearly associated with peritubular dentin and apparently absent in nontubular outer dentin. TGF-β1 content was 115 ± 31 pg and 74 ± 35 pg/100 mg mature versus immature root dentin, respectively (P.05).TGF-β1 is deposited into the peritubular dentin. It should be possible to release this molecule in regenerative endodontic procedures from young mature roots as well as immature roots.

Microtissue engineering root canal dentin with biopolymeric nanoparticles has the potential to improve mechanical properties of iatrogenically compromised root dentin. This study aims to characterize the surface mechanical property, bulk biomechanical response, and fatigue resistance of microtissue-engineered root dentin using photodynamically (photodynamic-activated [PDA]) cross-linked chitosan nanoparticles (CSnps).Experiments were conducted in 3 parts: part 1, root canal dentin sections were subjected to nanoindentations before/after treatment with CSnps and chemically (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide [EDC] cross-linked CSnps) and photodynamically cross-linked CSnps to determine the properties of treated surfaces (n = 84 points/group); part 2, root canal dentin specimens treated with PDA cross-linked CSnps were subjected to strain analysis using customized moiré interferometry (n = 5/group); and part 3, root canal dentin specimens treated with EDC cross-linked CSnps, PDA cross-linked CSnps, and instrumented controls were tested using an accelerated fatigue loading protocol to evaluate the sustained loads and cycles at failure (n = 15/group). Data were analyzed using the paired sample t test, trend analysis, and Kaplan-Meier with log-rank tests at a significance of .05 in each experiment.Root dentin microtissue engineered with PDA cross-linked CSnps showed a 16.8% increase in elastic modulus and a conspicuous decrease in strain distribution in cervical root dentin (P.01). There was a significant reduction in the tensile strain formed at the apical region of the instrumented root dentin after treatment (P.05). Survival analysis showed a statistically significant difference (P.05) among evaluated conditions in fatigue resistance (ie, PDA cross-linked CSnpsEDC cross-linked CSnpscontrol).This study highlighted the potential of root canal dentin microtissue engineering with PDA cross-linked CSnps to diminish radicular strain distribution and improve resistance to fatigue loads in endodontically treated teeth.

Background When a phosphoric acid is used, before applying an adhesive system, it is known that obtaining an effective adhesion to the root canal walls is a challenge. The aim of the present study was to evaluate the influence of phosphoric acid viscosity and application mode on the push-out bond strength (BS) values of fiberglass post to root dentin. The conditioning pattern on the root dentin was also evaluated. Materials and Methods The roots of 44 endodontically treated premolars were divided into 4 groups, of eleven teeth each, according to the combination of the main factors: phosphoric acid viscosity (liquid or gel) and application mode (passive or sonic). After application of the two-step etch-and-rinse adhesive system, the fiberglass posts were cemented with a dual-cure resin-cement. Roots were sectioned transversely into six 1-mm slices for push-out BS test at 0.5 mm/min. Some roots of each group were selected for evaluation of the conditioning pattern by scanning electron microscopy. BS results (three-way ANOVA and Tukey's test) and the conditioning pattern (Kruskal-Wallis test and Mann-Whitney test) were statistically evaluated (α= 0.05). Results The highest BS value was observed with a liquid phosphoric acid under sonic application mode (p < 0.05), being all other groups similar to one another (p < 0.05). Also, the highest BS value was observed in the cervical third, followed by the medium and the apical thirds (p < 0.05). The sonic application produced better smear layer removal and opening of dentinal tubules for both viscosities (p = 0.015). Conclusion A better bonding of fiberglass posts to root canals can be achieved when the post spaces are conditioned with a liquid phosphoric acid under sonic application.

Background: Residual root dentin thickness (RDT) in endodontically treated teeth is a major factor that is responsible for longevity of treated tooth. Aims and Objectives: To evaluate and compare the amount of RDT during endodontic treatment using manual K-files and rotary Mtwo, ProTaper Next, and Hero shaper instruments. Settings and Design: Anin vitro study was carried out on a sample of 100 freshly extracted human single straight rooted mandibular first premolar teeth. Methodology: The teeth were divided into five groups of twenty each and mounted on wax rims for a preoperative cone beam computed tomography scan to calculate the dentin thickness 3 and 6 mm from the apex. All the teeth were treated according to their groups. Statistical Analysis: The observations were then statistically analyzed using one-way ANOVA to evaluate the difference among four groups followed by post hoc test for pairwise comparison. Results: Maximum preservation of dentin was seen in Group V (cleaning and shaping done with rotary Hero shaper files) at 3 and 6 mm from the apex, whereas minimum preservation of dentin was seen in Group IV at 3 mm (cleaning and shaping done with rotary ProTaper Next files) and Group II at 6 mm (cleaning and shaping done with hand K-stainless steel files) from the apex. Overall there was a statistically significant difference in RDT values between Group V and Groups I, II, III, IV both at 3 and 6 mm from the apex. Conclusion: Cleaning and shaping with rotary Hero shaper files preserved more amount of dentin when compared to hand K-files, rotary Mtwo, ProTaper Next.

Aim: To estimate the age by evaluating the length of dentin translucency in ground sections of extracted teeth using digital scanner and tools of GIMP 2.8 software for dental age estimation. Materials and Methods: Fifty extracted single-rooted permanent teeth from 50 different individuals and their 0.25-mm thick sections were prepared. Each tooth section was scanned and the length of dentin translucency was measured in GIMP 2.8 software. Results: A linear relationship was observed between dentin translucency and age in the regression analysis. Pearson's correlation analysis showed that there was positive correlation (r = 0.93, P = 0.001) between dentin translucency and age, and the difference between the chronologic age and real age is ± 4.88 years. Conclusion: Dentin translucency in the apical part of the tooth can be used for estimating the age of an individual. A method to digitally select and measure translucent root dentin length was used here. This software method is easy to use and less time-consuming. The measurements obtained using this method are more precise and thus help in more accurate age estimation. Considering these benefits, this study recommends the use of digital method to assess translucency for forensic purpose.

Aim This study aimed to evaluate the effect of the prior application of intracanal medicaments on the bond strength of OrthoMTA (mineral trioxide aggregate) and iRoot SP to the root dentin. Materials and methods Thirty single-rooted mandibular premolars were standardized and prepared using ProTaper rotary files. The specimens were divided into a control group and two experimental groups receiving Diapex and Odontopaste medicament, either filled with iRoot SP or OrthoMTA, for 1 week. Each root was sectioned transversally, and the push-out bond strength and failure modes were evaluated. The data were analyzed using Kruskal Wallis and Mann-Whitney U post hoc test. Results There was no significant difference between the bond strength of iRoot SP and OrthoMTA without medicaments and with the prior placement of Diapex (p value > 0.05). However, iRoot SP showed significantly higher bond strength with the prior placement of Odontopaste (p value 0.05) and between failure mode and root filling materials (p value > 0.05). The prominent failure mode for all groups was cohesive. Conclusion Prior application of Diapex has no effect on the bond strength of iRoot SP and OrthoMTA. However, Odontopaste improved the bond strength of iRoot SP. Clinical significance Dislodgment resistance of root canal filling from root dentin could be an indicator of the durability and prognosis of endodontic treated teeth.

Aim: The present in-vitro study evaluated the influence of different organic and inorganic root canal irrigants used during chemomechanical preparation on the push-out bond strength of an Epoxy-resin based AH Plus sealer and a Bioceramic Endosequence BC sealer. Materials and Methods: Eighty extracted permanent human mandibular single rooted premolar teeth were used and randomly assigned to four major groups [according to irrigation protocol using sodium hypochlorite (NaOCl) with MTAD (mixture of tetracycline, acid and detergent) or ethylenediaminetetraacetic acid (EDTA) or phosphoric acid or normal saline (NS) as control group]. The root canals were instrumented using rotary nickel-titanium Hyflex® CM file system to size 30/0.06 taper, at the working length, as final shaping and finishing file, following different irrigation protocols, as per group allocation. The samples were further subdivided into two groups, with ten samples each (n=10), based on endodontic sealer; roots were obturated with gutta-percha and test sealers (AH-Plus or Endosequence Bioceramic sealer). The teeth were decoronated and obtained samples of eighty obturated roots of eight groups were cut to obtain 2mm thick coronal root slices (10 root section in each group), using hard tissue microtome. Bond strength of sealers was then measured by subjecting each root section to a compressive load via Instron Universal testing machine. The data were tabulated and statistically analyzed using analysis of variance (ANOVA) and Tukey’s HSD along with Bonferroni’s post-hoc test and level of significance set at a p value Results: The highest mean push-out bond strength of 5.38 MPa for AH Plus sealer was obtained in Group 2A followed by 3.94 MPa for Endosequence BC sealer (Group 2B), when phosphoric acid was used as chelating agent. However, mean bond strength of AH Plus sealer was significantly decreased (p Conclusion: The Bioceramic based Endosequence BC sealer and gutta-percha core combination was n

The aim of this study was to evaluate the influence of final irrigation protocols and endodontic sealer on bond strength of root filling material on root dentin previously treated with photodynamic therapy (PDT).One hundred root canals were prepared up to #F3 file of Pro-Taper system to receive the root filling material. All samples were submitted to PDT and randomly divided into five groups (n = 20) according to final irrigation protocols: Group 1-distilled water + ultrasonic activation (US); Group 2-17% EDTA; Group 3-QMix; Group 4-17% EDTA + US; Group 5-QMix + US. Each group was randomly divided into two subgroups (n = 10), according to the endodontic sealer used for cementation of gutta-percha points: AH Plus or MTA Fillapex. The bond strength was evaluated by a push-out test. The patterns of failure were observed under optical microscopy. The bond strength was evaluated using a two-way Anova followed by the Tukey post-hoc test, and the failure mode was evaluated using the chi-square test (α = 5%).The use of 17% EDTA and QMix associated or not to US improved the bond strength of root filling material with either endodontic sealer (p 0.05). AH Plus showed higher bond strength than MTA Fillapex (p 0.05). There was a higher predominance of cohesive failure in all groups, regardless of the tested final irrigation protocols and endodontic sealer (p 0.05).The use of 17% EDTA and QMix, regardless of association with US, and the use of AH Plus improve the bond strength of the root filling material on root dentin previously treated with PDT.

Lasers are used for preventing demineralization, but there are no studies that report the compositional changes on root dentin irradiated with Er,Cr:Ysgg (2.78µm) laser in an erosive process. In this in vitro study, fifty dentin slabs were distributed in 5 groups to be treated with Er,Cr:YSGG laser associated or not with application of acidulated phosphate fluoride gel (APF-gel); then, a 10-days erosion regimen was conducted and the composition changes were monitored by Fourier transform infrared spectroscopy. The data suggest a synergistic effect between laser irradiation and APF-gel, with a greater preventive effect when APF-gel was applied after irradiation.

Objective The aim was to compare Photodynamic therapy (PDT) as an adjunct to NaOCl and EDTA on the extrusion bond strength (EBS) of AH Plus (AH), Sealapex (SA) and MTA Fillapex (MF) root canal sealers. Materials and method Root canal treatment for human teeth (n = 60) using protaper universal system was performed followed by irrigation with NaOCl/ EDTA. Samples were divided (n = 30) based on disinfection technique, NaOCl/EDTA and NaOCl/EDTA with PDT (Curcumin-PS-CP) as an adjunct. Specimens were divided in three subgroups (n = 10) based on sealers used (Gp 1-Na-E-AH, Gp 2-Na-E-PDT-AH, Gp 3-Na-E-SA, Gp 4-Na-E-PDT-SA, Gp 5-Na-E-MF & Gp 6-Na-E-PDT-MF). Canals were dried and obturated followed by sectioning at coronal and middle third. EBS testing was performed using a universal testing machine (UTM) and modes of failure were assessed. Analysis of variance (ANOVA) and Tukey multiple comparison tests were used to compare the means of EBS. (p Results Sealers showed a significant influence on EBS, as Gp 1 (Co: 9.21 ± 0.62, Mid: 8.54 ± 0.55) and Gp 2 (Co: 7.11 ± 0.68, Mid: 7.30 ± 0.37) showed higher EBS than Gp 3 (Co: 5.21 ± 0.63, Mid: 4.36 ± 0.83) and Gp 4 (Co: 5.39 ± 0.72, Mid: 4.46 ± 0.74). Gp 5 (Co: 9.04 ± 0.13, Mid: 8.14 ± 0.91) and Gp 6 (Co: 8.67 ± 0.42, Mid: 8.07 ± 0.07) exhibited higher EBS than Gp 3 and Gp 4 specimens. Adjunctive use of PDT for AH sealer (Gp 2) showed decreased EBS compared to Gp 1 specimens. EBS remained comparable for both MTA-Fillapex and Sealapex with and without PDT. Conclusion AH Plus (Gp 1 and 2) and MTA-Fillapex (Gp 5 and 6) sealers displayed better EBS compared to Sealapex (Group 3 and 4). Adjunctive Application of PDT (CP) did not show a significant improvement in bond strength of sealers to root dentin.

This study evaluated the ability of different types of silver diammine fluoride (SDF) to inhibit dentin demineralization using micro-focused X-ray computed-tomography (µCT). Dentin specimens were divided into five groups (n=10); no-treatment (control), 3.8% SDF (RC), 38% SDF, 38% SDF with potassium iodide (SDF/KI), and potassium fluoride (KF). The treated-dentin surfaces were subjected to demineralization for 7-days and assessed using µCT to determine mineral loss (ML) values. Specimens were also analyzed with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The ML values of the SDF and KF groups were significantly lower than those of the RC and SDF/KI groups. EDS detected fluoride ions in the SDF and KF groups but not in the RC and SDF/KI groups. It was concluded that 38% SDF demonstrated a high ability to inhibit dentin demineralization while additional application of KI may diminish the inhibitory effect of SDF. The amount of dentin demineralization with SDF treatments was material dependent.

This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn’s post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 μm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

Aim To evaluate the push-out bond strength of resin-based sealer to root dentin after a final flush of three different irrigants. Materials and methods Thirty extracted human mandibular premolars were sectioned 4 mm below the cement-enamel junction and 60 horizontal disks of 2 mm from middle one-third of the root were prepared. The disks were immersed in 3% sodium hypochlorite for 1 minute, and after drying the disks, they were finally flushed with the following irrigants: group I-Chitosan solution, group II-Morinda citrifolia juice (MCJ), and group III-ethylenediaminetetraacetic acid (EDTA). The disks were filled with AH Plus sealer, and after 7 days, the disks were subjected to push-out bond strength using a universal testing machine. Results EDTA had the highest push-out bond strength followed by MCJ and then chitosan. Conclusion Chitosan and MCJ can be used as alternative irrigants as a final flush during the cleaning and shaping of the root canals. Clinical significance EDTA, chitosan solution, and MCJ are efficient in smear layer removal which thereby increases better sealer penetration and prevents the dislocation of obturating materials.

Objectives Surface pre-reacted glass-ionomer (S-PRG) fillers release antibacterial borate and fluoride ions. We fabricated nanoscale S-PRG fillers (S-PRG nanofillers) for antibacterial coating of tooth surfaces and assessed the antibacterial effects of this coating in vitro. In addition, we creating a canine model of periodontitis to evaluate the effectiveness of S-PRG nanofiller application on tooth roots and improvement of periodontal parameters. Methods Human dentin blocks were coated with S-PRG nanofiller (average particle size: 0.48 μm) and then characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX), and ion-releasing test. Antibacterial effects of dentin blocks coated with S-PRG nanofiller were examined using bacterial strains, Streptococcus mutans and Actinomyces naeslundii. Next, we created an experimental model of periodontitis in furcation of premolars of beagle dogs. Then, S-PRG nanofiller coating was applied onto exposed tooth root surfaces. Periodontal parameters, gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL), were measured from baseline until 4 weeks. In addition, bone healing was radiographically and histologically examined. Results SEM and EDX revealed that S-PRG nanofillers uniformly covered the dentin surface after coating. Dentin blocks coated with S-PRG nanofiller showed ion-releasing property, bacterial growth inhibition, and sterilization effects. In the experimental periodontitis model, S-PRG nanofiller coating significantly reduced clinical inflammatory parameters, such as GI (P < 0.01) and BOP (P < 0.05), compared to uncoated samples. In addition, PPD and CAL significantly decreased by S-PRG nanofiller coating (2 weeks: P < 0.05; 3 and 4 weeks: P < 0.01), suggesting the improvement of periodontitis. Micro-CT and histology revealed that bone healing of furcation defects was enhanced by S-PRG nanofiller coating. Conclusion S-PRG nanofiller coating provides antibacterial effects to tooth surfaces and improves clinical parameters of periodontitis., Actinomyces naeslundii; Animal model; Antibacterial activity; Anti-inflammatory; Class II furcation defect; Ion-releasing; Periodontitis; Root dentin; Streptococcus mutans; Surface pre-reacted glass-ionomer (S-PRG) filler.

Introduction: Intracanal Medicaments (ICMs) play a major role in disinfection of root canal system. The use of interappointment ICM during endodontic treatment may affect the mechanical properties of dentin which results in decreased fracture resistance of teeth. The use of synthetic medicament is associated with many limitations such as antibiotic overdose, side effects and cytotoxic reactions. In order to overcome this, recent research has been directed towards herbal ICMs with better efficacy and lesser side effects. Aim: To evaluate the effect of a novel herbal ICM Calendula officinalis L. (CO) on fracture resistance of root dentin in comparison to Calcium Hydroxide (CH). Materials and Methods: This in vitro study was conducted in the Department of Conservative Dentistry and Endodontics, SRM Dental College and Hospital, Ramapuram, Chennai, Tamil Nadu. Thirty freshly extracted single rooted human premolar teeth were selected for the in vitro study and randomly assigned into three groups: Group 1: No medication (Control group) (n=10), Group 2: CH (n=10), Group 3: CO (n=10). The samples were decoronated and biomechanical preparation was done followed by placement of respective ICMs in the root canal space, sealed with glass ionomer cement and immersed in saline for a storage period of 7 and 14 days. Each group was subdivided into 5 teeth, depending on the storage period. After each storage period, ICMs were removed and samples were subjected to fracture resistance test using universal testing machine. Data were analysed using One-way Anova followed by Tukey HSD post-hoc test with level of statistical significance set at p

This study investigated the anti-demineralization effects of surface pre-reacted glass-ionomer (S-PRG) filler-containing varnishes. Thirty-five bovine root specimens were divided into five treatment groups, with seven specimens each coated with 1) MI varnish (MIV), 2) F varnish (FV), 3) PRG varnish I (PV), 4) PRG varnish II (with sodium fluoride added, PVF), and 5) acid-resistant nail varnish (Control). A 3×1 mm area of the dentin surface adjacent to each varnish was demineralized for one week at 37°C. Integrated mineral loss (IML) of these lesions was determined by transverse microradiography, as was the amount of fluoride released by each material. IML was significantly lower in the PV and PVF groups than in the Control group, and was significantly lower in the PVF than in the MIV and FV groups. These findings indicated that S-PRG filler-containing varnishes, especially varnish containing sodium fluoride, had superior anti-demineralization effects on root dentin.

Background: Human Dentition presents as the most durable and resilient part of the skeletal system inthe body subjected to wide range of physiological changes with increase in age such as attrition, cementalapposition. Among several functional changes dental root translucency is often considered to be morereliable parameter for estimation.Methodology: The literature search for articles written in the English language in PubMed, MEDLINE,Embase and Google Scholar database by using MeSH terms “Dentin Translucency”, “Age Estimation”,“Forensic Method” “Dentin in Forensics”, “Digital Method of Age Estimation”, “Dentin Age estimation”was retrieved. The present evaluation is to provide a broad literature review on “Dentin translucency” as atool in age estimation with emphasis on the most substantial method obtainable for identification.Observations: It was observed both traditional and digital method are significant and reliable foridentification of age by root dentin translucency. The custom built software program is commerciallyavailable and extensively used image editing software program. Moreover, digital method is easy to use,precise and less time consuming. Considering these benefits, the present study recommends the use of digitalmethod to assess root dentin translucency for age estimation.Conclusion: Though conventional sectioning of teeth with observation using caliper or under microscopewas gold standard, due to advancement in technology and more precise results digital method could possiblyserve as more reliable where estimation of age plays a vital role in identification process in the field offorensics.

Attempting exploration at the expense of dentin tissue to reveal anatomical variation is still a common practice in root canal treatment, mainly because it relies on bi-dimensional radiographic images and clinical assessments to comprehend root morphology and root canal anatomy. The main purpose of this chapter is to understand the role of technological advances in finding the appropriate resources and maneuvers to (a) completely treat root canal anatomy avoiding residual intracanal infection, (b) balancing the size of the access cavity and the degree of root canal enlargement with the requirements of irrigation methods to achieve optimum disinfection, and (c) preserving root dentin during instrumentation to maintain the mechanical integrity of the root, minimizing the risk of fractures, all of them considered relevant causes of endodontic treatment failure.

This study evaluated the syringe/needle (SN), passive ultrasonic irrigation (PUI) and XP-endo Finisher (XP) in the removal of Ca(OH)2 -based paste and the bond strength (BS) values of an epoxy resin (AH Plus) and silicate (MTA)-based sealers to root dentin. Eighty lower premolars were assigned: control group (CT), SN, PUI and XP, and subdivided according to the sealer (n = 10) for BS. SN has the lowest removal followed by PUI and XP. AH Plus had higher BS for CT compared with SN in all root thirds. CT and XP presented similar BS in the apical and middle thirds and higher than SN and PUI. For MTA, similar BS was observed in the cervical and apical thirds, and in the middle third, CT, PUI and XP presented similar values and higher than SN. PUI and XP methods presented higher efficiency in the Ca(OH)2 removal, and the residual Ca(OH)2 provides a reduction in BS of the AH Plus.

Objectives This study investigated the incidence of root dentin defects after the use of different post space preparation (PSP) drills. Materials and Methods Seventy-two bovine incisors were selected and obtained 14-mm-long root sections. Twelve roots served as controls with no intervention (G1). The 60 root canals remaining were instrumented using the crown-down technique with the ProTaper Next system and obturated using the lateral condensation technique. Specimens were randomly distributed into 5 groups (n = 12) according to the operative steps performed: G2, root canal instrumentation and filling (I+F); G3, I+F and PSP with Gates-Glidden drills; G4, I+F and PSP with Largo-Peeso reamers; G5, I+F and PSP with Exacto drill; and G6, I+F and PSP with WhitePost drill. Roots were sectioned at 3, 6, 9, and 12 mm from the apex, and digital images were captured. The presence of root dentin defects was recorded. Data were analyzed by the χ2 test, with p < 0.05 considered to indicate statistical significance. Results Root dentin defects were observed in 39.6% of the root sections. No defects were observed in G1. G5 had significantly more cracks and craze lines than G1, G2, and G3 (p < 0.05), and more fractures than G1, G2, G3, and G4 (p < 0.05). When all root sections were analyzed together, significantly more defects were observed at the 12-mm level than at the 3-mm level (p < 0.05). Conclusions PSP drills caused defects in the root dentin. Gates-Glidden drills caused fewer root defects than Largo-Peeso reamers and Exacto drills.

Adhesion science is one of the greatest contributions to restorative dentistry. Adhesion not only established the current principles of tissue preservation, but also allowed for the production of more hermetic and long-lasting restorations. Although adhesive strategies are routinely used in most clinical situations, adhesion to root dentin is still a major challenge. The presence of humidity together with less intertubular dentin are factors that limit the adhesive potential of root dentin. This situation is more unfavorable in endodontically treated teeth prepared for prefabricated or custom-made intraradicular posts; these procedures may alter the mechanical properties of teeth by modifying the viable dentin surface for adhesion. Also, contaminants deposited on the dentin surface are difficult to remove through conventional techniques. Moreover, root canal morphology has a very unfavorable C-factor, bringing undesirable effects resulting from polymerization contraction of resin-based materials. However, the differences between coronal and root dentin are not a barrier for dentin adhesion. Standardization of procedures and care during clinical steps are fundamental to the success of adhesion to coronal or intraradicular dentin. Thus, it is essential to know the anatomy of the root structure, the factors that interfere with intraradicular adhesion, as well as the current adhesive materials and techniques.

The aim of the study was to evaluate the cytotoxicity of different glycolic acid concentrations (GA) and its effects on dentinal microhardness. Cytotoxicity was evaluated after inoculation of test irrigants in the lymphocyte primary culture for 3 min. The tested substances were distilled water(DW); 17% EDTA; QMix; 10% GA; 17% GA; and 25% GA. Counting of total, live and dead cells was performed, obtaining the average percentage of dead cells of each group. For microhardness evaluation, 60 root dentin samples were divided into the same tested groups (n = 10) and immersed in test irrigants for 3 min. Dentin microhardness was evaluated by Vicker test. Specific statistical analysis was made in both tests. Results showed significant lower cytotoxicity for QMix and 10% GA (P 0.05). Moreover, all test irrigants presented similar values of microhardness than the control group (P 0.05). In conclusion, lower GA concentration can be an alternative for final irrigation on endodontics.

This study compared the effect of experimental polymer-based desensitizers with NaF and oxalic acid (OA) for preventing root demineralization via observation using micro-CT. Bovine root dentin surfaces were treated with coating materials: no treatment; MS0(+) (MS Coat One®); MS3000(+) (MS Coat®); MS0(-); MS3000(-); MS7000(+/-); fluoride gel (NaF9000). MS; MS polymer, 0-7000; NaF concentrations, (+/-); OA. The specimens were scanned using micro-CT before and after demineralization (pH4.5, 10 h). Following this, the mean mineral loss (ML) after demineralization was calculated, and the specimens were observed under a scanning electron microscope (SEM). The ML values of MS3000(+), MS7000(-), MS7000(+) and NaF9000 were significantly lower than the other groups (p

Background and purpose This systematic review documents the up-to-date evidence on the efficacy of photodynamic therapy (PDT) on the push-out bond strength of fiber posts cemented to root dentin. Materials and methods The focused PICO question was: “What impact does PDT have on the push-out bond strength of fiber posts cemented to root dentin?” This systematic review followed the guidelines and recommendations reported in the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines chart. An electronic search was performed in MEDLINE/PubMed, SCOPUS, Web of Science, and Embase from January 1980 up to and including January 2020. Heterogeneity was calculated for push-out bond strength by means of the Chi-square test and I2 statistics. For meta-analyses, if the I2 was higher than 50 %, a random effects model was used, otherwise a fixed effects model for I2 ≤50 % was applied. A p-value Results In total, ten studies were included, all of wich demonstrated medium risk of bias. All studies tested the push-out bond strength by means of a universal testing machine with applying a load ranging between 0.5 and 1 mm/min speed. Of the 10 studies, nine (90 %) indicated that PDT had no effect on push-out bond strength of fiber posts to root dentin. Only one study indicated that PDT significantly improved the bond strength when compared with other control groups. The overall mean difference for push out bond strength showed no statistically significant difference between PDT and the control group (SMD = -1.11 [-3.25, 1.02], Z=-1.02, p = 0.305). Conclusion This systematic review concludes that PDT has no effect on improving the push-out bond strength of fiber posts to root dentin.

Objective: To evaluate anti-demineralization effects of dentin desensitizer containing sodium fluoride and methacrylate-co-p-styrene sulfonic acid (MS polymer) on root dentin using transverse microradiography (TMR). Material and methods: Twenty-four dentin specimens were divided into four groups: MSO (no fluoride), MSF (3000 ppm F), FJL (9000 ppm F), and Control. In MSO and MSF, each desensitizer was rubbed into the dentin surfaces for 10 s then left for 20 s. In FJL, paste containing 9000 ppm F was applied onto the surface for 30 s. All specimens, including the Controls, were rinsed with deionized water, dried and an area of their surface exposed to pH 5.0 acidic solution, refreshed every 24 h, for 4 days. Sections 300-µm-thick were assessed by TMR. Mineral profiles and integrated mineral loss (IML) of lesions were analyzed by dedicated software. IML was analyzed with one-way ANOVA and Tukey’s test. Results: MSF and FJL specimens showed high mineral volume % at the surface and in lesions, and significantly lower IML than the other groups (p

Background Evaluate the fracture resistance of endodontically treated teeth after cervical preflaring and root canal preparation and to assess the volume of the root canal and the amount of remaining root dentin before and after cervical preflaring. Methods Forty-four mandibular incisors were selected using micro-CT scanning and distributed into 4 groups (n = 11) according to the instrument used for cervical preflaring: control group - no cervical preflaring; Gates Glidden – burs size #2 and #3; WXN – 25.07 Navigator instrument; and Easy – 25.08 ProDesign S instrument. Coronal opening was performed, and the canals were prepared with Wave One Gold Primary and filled with an epoxy-resin based sealer and gutta-percha cones. Micro-CT scans were performed before and after root canal instrumentation. All images were reconstructed and assessed for the thickness of mesial and distal root dentin at 3 mm and 5 mm from the cement -enamel junction and for the volume of cervical portion of the canal after preparation. Fracture resistance test was performed applying compressive loads at a crosshead speed of 0.5 mm/min, applied on the palatal aspect of specimens at 135° along the long axis of the tooth. The data were analyzed using ANOVA and Tukey’s test (P = .05). Results Cervical preflaring and canal preparation reduced the dentin thickness (P P P Conclusions All instruments reduced the dentin thickness and increased the canal volume in the cervical at 3 mm and 5 mm. Gates Glidden reduced fracture resistance of mandibular incisors submitted to cervical preflaring, whereas NiTi instruments did not. Clinical relevance Cervical preflaring assumes particular importance previously to the root canal preparation because it minimizes the occurrence of operative accidents, and permits more accurate determination of working length and the apical diameter.

This study aimed to evaluate the anti-caries effect of a fluoridated milk-based drink on a root caries model by assessing mineral loss and both biofilm microbial viability and acidogenicity under increasing concentrations of fluoride supplementation.Streptococcus mutans UA159 biofilms were grown on root dentin slabs for five days. The slabs were randomly assigned to following groups: milk-based drink (G1) and milk-based drink supplemented with 5-ppm NaF (G2), 10 ppm NaF (G3), and 20 ppm NaF (G4). A 10% sucrose and 0.9% NaCl solution were used as positive and negative-caries controls, respectively. Slabs/biofilms were exposed to the different treatments 3 times/day for 5 min. To estimate biofilm acidogenicity, the pH of the spent media was serially measured to calculate the area above the curve. Viable bacteria and dentin demineralization were assessed after the experimental phase. Results were compared using ANOVA followed by the Tukey test.G1 exhibited slightly lower acidogenicity than the positive caries control group (p 0.05). G2, G3, and G4 induced lower acidogenicity than 10% sucrose and the non-supplemented milk-based drink. The lowest acidogenicity was found in G4 (p 0.05). Fluoride-supplemented milk-based drinks (G2, G3, and G4) resulted in lower bacterial counts (p 0.05) and induced lower demineralization (p 0.05) than the positive caries control and non-supplemented milk-beverage (G1). There was a dose-dependent inhibition of demineralization with fluoride-supplemented milk-based drinks.Fluoride supplementation of a milk-based drink for older adults may reduce its cariogenicity in root dentin.

Proanthocyanidin-rich plant-derived agents have been shown to increase dentin biomechanical properties and resistance of dentinal collagen to degradation. This study investigated the effects of proanthocyanidin-rich extract (grape seed extract, GSE; Vitis vinifera) on the mechanical properties of demineralized dentin matrix, and the bond strength and stability of the adhesion of fiber posts to the root dentin. Demineralized dentin beams (n = 15) were incubated with 6.5% or 10% GSE for 30, 60, or 120 s. The modulus of elasticity (E) and the fold increase in E were determined by comparing specimens at baseline and after treatment. The data were analyzed by two-way ANOVA and Tukey post hoc tests (α = 0.05). For the bond strength test, single-rooted human teeth were randomly divided into seven groups: control group, no treatment; and experimental groups as described for the modulus of elasticity. Fiber posts were cemented with RelyX U200. Each group was randomly divided into two subgroups: 24 hours of water storage and 12 months of water storage. All roots were sectioned transversely in the coronal, middle, and apical regions, producing 1-mm thick slices, and the push-out test was performed. The failure modes were observed, and the bond strength means were analyzed by ANOVA (α = 0.05). For E test, no significant difference was observed among the incubation times (P > 0.05); however, high concentration of GSE (10%) resulted in a statistically higher fold increase in E compared to 6.5% (P 0.05), irrespective of the GSE concentration, time of treatment, and root regions (P > 0.05); however, the use of GSE contributed to a significant reduction in adhesive failure mode. The results indicate that 10% GSE exhibits a high cross-linking potential for dentin extracellular matrix. Moreover, the bond strength of fiber posts luted to root dentin with RelyX U200 remained stable after 12 months of water storage, with or without pre-treatment with GSE.