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Objective: This study aimed to compare the wear behavior of a microhybrid composite vs. a nanocomposite in patients suffering from severe tooth wear.Methods: A convenience sample of 16 severe tooth wear patients from the Radboud Tooth Wear Project was included. Eight of them were treated with a microhybrid composite (Clearfil APX, Kuraray) and the other eight with a nanocomposite (Filtek Supreme XTE, 3M). The Direct Shaping by Occlusion (DSO) technique was used for all patients. Clinical records were collected after 1 month (baseline) as well as 1, 3 and 5 years post-treatment. The maximum height loss at specific areas per tooth was measured with Geomagic Qualify software. Intra-observer reliability was tested with paired t-tests, while multilevel logistic regression analyses were used to compare odds ratios (OR) of “large amount of wear”.Results: Intra-observer reliability tests confirmed that two repeated measurements agreed well (p > 0.136). For anterior mandibular teeth, Filtek Supreme showed significantly less wear than Clearfil APX; in maxillary anterior teeth, Clearfil APX showed significantly less wear (OR material = 0.28, OR jaw position = 0.079, p < 0.001). For premolar and molar teeth, Filtek Supreme showed less wear in bearing cusps, whereas Clearfil APX showed less wear in non-bearing cusps (premolar: OR material = 0.42, OR bearing condition = 0.18, p = 0.001; molar: OR material = 0.50, OR bearing condition = 0.14, p < 0.001).Significance: Nanocomposite restorations showed significantly less wear at bearing cusps, whereas microhybrid composite restorations showed less wear at non-bearing cusps and anterior maxillary teeth.

Objective The study aimed to evaluate survival and failure behavior of Direct Composite Restorations (DRC) and Indirect Composite Restorations (ICR) on molars and anterior teeth, in a Randomized Controlled Trial (RCT). Methods Patients with generalized severe tooth wear were included, and randomly assigned to one of 2 protocols: (1) DCR: All teeth were restored with directly applied micro-hybrid composite restorations (Clearfil AP-X, Kuraray) for load bearing areas and nano-hybrid composite restorations (IPS Empress Direct, Ivoclar Vivadent) for buccal veneers; (2) ICR: First molars were restored with indirect composite ‘tabletop’ restorations and maxillary anterior teeth were restored with indirect palatal veneer restorations (Clearfil Estenia C&B, cemented with Panavia F, Kuraray). Remaining teeth were restored directly. Restorations were evaluated after 3 years, focusing on clinical acceptability. Statistical analysis was performed using Kaplan Meier curves, Annual Failure Rates (AFRs), and univariate Cox regression analyses (p Results 41 patients (age: 36.6 ± 6.6y) were evaluated after 3 years (40.0 ± 2.2 m). 408 restorations on first molars and palatal veneers on maxillary anterior teeth were part of this RCT, with 220 DCRs and 188 ICRs. No differences in survival between treatment modality for palatal veneers for any failure criteria were found. Tabletop restorations on first molars showed a considerable higher failure rate for ICR compared to DCR (p = 0.026, HR: 3.37, 95%CI = 1.16–9.81). Significance In this RCT, directly applied composite restorations showed superior behavior compared to the indirect composite restorations, when used in the molar region.

Contains fulltext : 235568.pdf (Publisher’s version ) (Open Access) BACKGROUND: The Tooth Wear Evaluation System (TWES) is a type of tooth wear index. To date, there is the lack of data comparing the reliability of the application of this index on gypsum cast records and digital greyscale intra-oral scan records. OBJECTIVES: A comparative evaluation between the use of gypsum cast records and digital greyscale intra-oral scan records with the reliability of tooth wear scoring using the TWES amongst a group of patients with tooth wear. METHODS: Records for 10 patients with moderate to severe tooth wear (TWES ≥ 2) were randomly selected from a larger clinical trial. TWES grading of the occlusal/incisal, buccal and palatal/lingual surfaces was performed to determine the levels of intra- and interobserver agreement. Intra-observer reproducibility was based on the findings of one examiner only. For the interobserver reproducibility, the findings of two examiners were considered. One set of models/ records were used per patient. Cohen's weighted kappa (κ(W) ) was used to ascertain agreement between and within the observers. Comparison of agreement was performed using t tests (P

Contains fulltext : 238755.pdf (Publisher’s version ) (Open Access) OBJECTIVES: To evaluate the 5.5-year performance of direct resin composite restorations, prescribed for patients with severe tooth wear, requiring full-mouth rehabilitation. METHODS: A convenience sample of 34 patients were recruited to a prospective trial between December 2010 and June 2013. The participants were provided 1269 full-mouth direct resin composite restorations (Clearfil AP-X) by 5 experienced operators, using the DSO-technique. Treatment resulted in an increase in the vertical dimension of occlusion (VDO). Failure was assessed at three levels. Frequencies of failure were analysed using Kaplan Meier survival curves and the effects of the relevant variables calculated with a multifactorial Cox regression (p < 0.05). RESULTS: Annual failure rates (for all levels of failure, 'Level 3- ') of ≤ 2.2% and ≤ 2.9% were respectively reported for the anterior and posterior restorations with a mean observation time of 62.4 months. The completion of an anterior restoration with the need for further appointments resulted in significantly more Level 2- & 3- failures. An evaluation of the performance of the premolar and posterior maxillary restorations showed significantly lowered risks of certain types of failures, compared to the molar and posterior mandibular restorations. CONCLUSIONS: At 5.5 years, 2.3% of the overall restorations displayed catastrophic, (Level 1) failures. Molar restorations, posterior mandibular restorations and the anterior restorations requiring two further sessions for completion, were associated with significantly higher risks for failure. CLINICAL SIGNIFICANCE: Direct resin composite can offer an acceptable medium-term option for the treatment of severe, generalized tooth wear; molar restorations may require higher maintenance.

Objectives To investigate the effects of the level of pre-treatment tooth wear and increasing the VDO on the performance of direct resin composite restorations for the rehabilitation of pathological tooth wear. Methods Full-mouth (pre-treatment) grading was performed on digital greyscale scan records for 34 participants (35.3 ± 8.4 years) with signs of moderate-to-severe generalised tooth wear, using the Tooth Wear Evaluation System and the Basic Erosive Wear Examination. Each participant received full-mouth direct resin composite restorations, with increased VDO. The post-treatment increase in the VDO was determined. Recalls were planned after 1 month, and after 1, 3, and 5 years. Three ‘levels’ of restoration failure were described. The effects of the variables on the frequencies of restoration failure were calculated with a multivariable Cox regression, (p Results 1269 restorations were placed with a mean observation period of 62.4 months. Increasing the VDO by 1 mm significantly reduced the risks of all levels of anterior restoration failure (HR ≤ 0.62, p ≤ 0.025). A higher anterior BEWE surface score was associated with increased risks of Level 2- & 3- failures, (HR ≥ 1.29, p ≤ 0.019). Premolar restorations showed lower risks of Level 2- & 3- failure, compared to the molar restorations, (HR ≤ 0.5, p ≤ 0.005). Conclusion Levels of pre-treatment wear and the applied change in the VDO significantly affected failure risk. Clinical relevance Direct resin composite restorations for the rehabilitation of wear should be made as voluminous as possible, respecting the presenting biological, functional, and esthetic constraints.

Objective Fracture is one of the main causes for failure of resin-based composite restorations. To overcome this drawback, self-healing resin-based composites have been designed by incorporation of microcapsules. However, the relationship between their self-healing capacity and microcapsule and resin parameters is still poorly understood. Therefore, the objective of this study was to systematically investigate the effect of initiator concentration (in the resin) and microcapsule size and concentration on the self-healing performance of commercially available flowable resin-based composites. Methods Poly(urea-formaldehyde) (PUF) microcapsules containing acrylic healing liquid were synthesized in small (33 ± 8 μm), medium (68 ± 21 μm) and large sizes (198 ± 43 μm) and characterized. Subsequently, these microcapsules were incorporated into a conventional flowable resin-based composite (Majesty Flow ES2, Kuraray) at different contents (5–15 wt%) and benzoyl peroxide (BPO) initiator concentrations (0.5–2.0 wt%). Fracture toughness (KIC) of test specimens was tested using a single edge V-notched beam method. Immediately after complete fracture (KIC-initial), the two fractured parts were held together for 72 h to allow for healing. Subsequently, fracture toughness of the healed resin-based composites (KIC-healed) was tested as well. Results The fracture toughness of healed dental composites significantly increased with increasing microcapsule size and concentration (2 wt% BPO, p Significance commercially available resin-based composites can be rendered self-healing most efficiently by incorporation of large microcapsules (198 ± 43 μm). However, long-term tests on fatigue and wear behavior are needed to confirm the clinical efficacy.

Background Three-dimensional scans are increasingly used to quantify biological topographical changes and clinical health outcomes. Traditionally, the use of 3D scans has been limited to specialized centers owing to the high cost of the scanning equipment and the necessity for complex analysis software. Technological advances have made cheaper, more accessible methods of data capture and analysis available in the field of dentistry, potentially facilitating a primary care system to quantify disease progression. However, this system has yet to be compared with previous high-precision methods in university hospital settings. Objective The aim of this study was to compare a dental primary care method of data capture (intraoral scanner) with a precision hospital-based method (laser profilometer) in addition to comparing open source and commercial software available for data analysis. Methods Longitudinal dental wear data from 30 patients were analyzed using a two-factor factorial experimental design. Bimaxillary intraoral digital scans (TrueDefinition, 3M, UK) and conventional silicone impressions, poured in type-4 dental stone, were made at both baseline and follow-up appointments (mean 36 months, SD 10.9). Stone models were scanned using precision laser profilometry (Taicaan, Southampton, UK). Three-dimensional changes in both forms of digital scans of the first molars (n=76) were quantitatively analyzed using the engineering software Geomagic Control (3D Systems, Germany) and freeware WearCompare (Leeds Digital Dentistry, UK). Volume change (mm3) was the primary measurement outcome. The maximum point loss (μm) and the average profile loss (μm) were also recorded. Data were paired and skewed, and were therefore compared using Wilcoxon signed-rank tests with Bonferroni correction. Results The median (IQR) volume change for Geomagic using profilometry and using the intraoral scan was –0.37 mm3 (–3.75-2.30) and +0.51 mm3 (–2.17-4.26), respectively (P Conclusions As expected, the method of data capture, software used, and measurement metric all significantly influenced the measurement outcome. However, when appropriate analysis was used, the primary care system was able to quantify the degree of change and can be recommended depending on the accuracy needed to diagnose a condition. Lower-resolution scanners may underestimate complex changes when measuring at the micron level.

This study investigated the effect of bulk-fill composites on proximal contact tightness (PCT) of composite restorations using different matrix systems. 150/standardized-MO-ivorine cavity preparations were divided into 5 groups; Smart Dentin Replacement (SDR), SonicFill (SF), Tetric EvoCeram Bulk-Fill (TEB), G-aenial Universal Flo (GF) and Tetric EvoCeram (TE). Each group was subdivided into 3 sub-groups (n=10); Dixieland band in Tofflemire retainer, FenderMate and Palodent plus matrix systems. PCT was measured 24 h post-curing using Tooth Pressure Meter. PCT means were calculated and statistically-analyzed using ANOVA and Tukey's post-hoc test (p

Background/Aim: The underlying mechanism of the development of cups and grooves on occlusal tooth surfaces is still unclear. The aim of this study was to evaluate factors contributing to in vitro cup formation, in order to elucidate the clinical process. Methods: A total of 48 extracted human molar teeth were exposed to acidic aqueous solutions at pH of 4.8 and 5.5 in constant motion, in combination with different loading conditions: no load (0N group, control), 30 N (30N group) or 50 N (50N group) (n = 8 per group). Before and after 3 months of exposure (1,422,000 loading cycles), the samples were scanned using a non-contact profilometer. Pre- and post-exposure scans were subtracted and height loss and volume tissue loss were calculated. Representative samples with wear and cupping lesions were imaged using scanning electron microscopy, light microscopy and micro-computed tomography. Results: Average height and volume tissue loss at pH 5.5 was 54 µm and 3.4 mm3 (0N), 52 µm and 3.4 mm3 (30N) and 58 µm and 3.7 mm3 (50N), respectively, with no statistically significant differences. Average height and volume loss at pH 4.8 were 135 µm and 8.7 mm3 (0N), 172 µm and 12.6 mm3 (30N) and 266 µm and 17.8 mm3 (50N), respectively, with a statistically significant difference between 0N and 50N (p < 0.002). Cup-shaped lesions had formed only at pH of 4.8, in the 30N and 50N groups. Conclusion: The study showed that a cup can arise fully in enamel and that mechanical loading in addition to erosive challenges are required.

Evaluate the effect of a full rehabilitation, including an increase of vertical dimension of occlusion (VDO), in patients with severe tooth wear on changes in facial appearance.Patients with severe tooth wear were restoratively treated using direct composite restorations, including an increase of the VDO. Before and one month after treatment 3D stereophotographs were taken and facial changes were measured with the use of 3D cephalometric landmarks. Cast models were used to determine the Tooth Wear Index (TWI) and the VDO-increase. The Orofacial Esthetic Scale-questionnaire was used to evaluate subjective happiness with appearance. Paired Student's t-tests were used to evaluate the changes after full rehabilitation. The relation between the facial changes, VDO-increment and TWI-score were analyzed using multiple regression models (p 0.05).44 Patients (35 men, 9 women, mean age: 38.2 ± 7.1 y) participated in this study. Mean TWI-score at baseline was 3.3 ± 0.5 and the mean increase in VDO was 1.6 ± 0.9 mm. Lower face height increased by 1.9 mm (p ≤ 0.001). Patients reported a significant improvement in orofacial appearance: OES-summary score of 34.3 ± 11.2 before and 59.9 ± 6.8 one month after treatment (p 0.001). The increase of VDO resulted in an increase in Lower Face Height (p ≤ 0.002), whereas the TWI-score at baseline had no effect on the facial changes. The applied increase in VDO and TWI-score were not related to changes in OES-scores.A full rehabilitation with an increase in VDO resulted in objective differences in facial height as measured with 3D stereophotogrammetry.In patients with severe tooth wear, receiving a full rehabilitation including an increase in vertical dimension of occlusion, an objectively change will occur in the Lower facial height, but this effect will be subjectively judged as a positive change.

Clinical research of restorative materials is confounded by problems of study designs, length of trials, type of information collected, and costs for trials, despite increasing numbers and considerable development of trials during the past 50 years. This opinion paper aims to discuss advantages and disadvantages of different study designs and outcomes for evaluating survival of dental restorations and to make recommendations for future study designs. Advantages and disadvantages of randomized trials, prospective and retrospective longitudinal studies, practice-based, pragmatic and cohort studies are addressed and discussed. The recommendations of the paper are that clinical trials should have rational control groups, include confounders such as patient risk factors in the data and analysis and should use outcome parameters relevant for profession and patients.

Contains fulltext : 225358.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To investigate the impact of an e-training resource with the consistency of tooth wear scoring using the Basic Erosive Wear Examination (BEWE). METHODS: Gold standard (GS) BEWE scores were attained from a trained examiner using the photographic and dental cast records for three conveniently selected cases representing low, medium and severe tooth wear. Four successive cohorts of first year post-graduate students, (n = 76, mean age, 35.4 years) undertook a training exercise. Each was given written guidance on using the BEWE. Following e-training, scoring was repeated, and the results expressed as mean, confidence Intervals, (95% ci) and p-values (values

Objective To investigate the relationship between levels of tooth wear scored using the Basic Erosive Wear Examination (BEWE) and the impact on the quality of life of adult dental patients. Methods BEWE assessments were performed on 319 new dentate adult patients attending the practices of 5 trained recruiters based in primary care in Malta (120), Australia (118) or the UK (81). Oral impacts on the quality of life were measured using a shortened form of the Oral Health Impact Profile (OHIP-26). Regression analysis were performed, adjusted for age, to estimate the relationship between the variables. Data were expressed as Confidence Intervals (95 % CI), p-values (values Results Overall, the sample had a mean age of 42.6 ± 17.1 (range, 18–93 years), a mean cumulative BEWE score of 6.7 ± 4.4 and a mean total OHIP-26 score of 1.84 ± 0.59. For the cumulative sextant BEWE scores, 68.0 % of the participants scored ≤ 8, 24.5 % between 9 and 13 and 7.5 %, ≥ 14. A significant association was found between increasing BEWE score and the overall OHIP-26 total score (effect = 0.028; p = 0.002), implying a higher BEWE to be associated with a larger impact of oral conditions on daily life. Conclusion Higher levels of tooth wear were significantly associated with a deteriorating oral-health related quality of life amongst the participants. Clinical relevance When treatment planning for patients with tooth wear, it is appropriate to consider the psycho-social impact of the condition alongside other clinical findings.

Contains fulltext : 220535.pdf (Publisher’s version ) (Closed access) OBJECTIVES: Recent software advancements have facilitated quantification of erosive tooth wear progression using intraoral scans. This paper investigated if wear on commonly affected surfaces (central incisors and first molars) was representative of wear on the full arch. METHODS: Bimaxillary digital intraoral scans (True Definition, 3 M, USA) of patients (n = 30) from the monitoring arm of the Radboud Tooth Wear Project, were taken at baseline and at 3 years (+/-10months). The occlusal/incisal surface of each tooth (excluding 3rd molars) was analysed for volume change and volume change per mm of analysed surface area in WearCompare (www.leedsdigitaldentistry.com/Wearcompare) following previously published protocols. Data were normal, descriptives and multi-level linear regression analysis was performed in Stata v15.1 taking patient level and surface type data into account. RESULTS: Data from 556 surfaces in 29 patients were included in analysis. Per patient, mean volume loss (95 % CI) was -0.91mm(3)(-1.28,-0.53) on all surfaces, -1.85mm(3)(-2.83,-0.86) on index surfaces, -2.53mm(3)(-3.91,-1.15) on molar surfaces and -0.83 mm(3)(-1.34,-0.31) on upper central incisal surfaces. Statistical differences were observed between analysing all surfaces and index teeth(p = 0.002) in addition to molar surfaces(p < 0.0001). Mean volume loss per mm(2) of surface analysed was -0.024 mm(3) (-0.031,-0.017), -0.028mm(3) (-0.041,-0.014), -0.030mm(3) (-0.046,-0.013) and -0.025mm(3) (-0.041,-0.010) for all surfaces, index surfaces, first molar surfaces and central incisor surfaces respectively with no statistical differences between groups. CONCLUSIONS: Wear on upper central incisors was not statistically different to full arch wear analysis. If the surface area is standardised, wear on both index surfaces are statistically similar to wear on the full arch. CLINICAL SIGNIFICANCE: These results suggest that analysing rates of wear on index teeth can be a resource-saving substitute for analysing rates of wear on the entire dentition, provided the surface area is standardised. If whole surfaces are analysed, the molar surfaces will show greater rates of wear.

Objective The aim of this study was to evaluate changes in speech characteristics and self-perceived quality of speech in tooth wear patients, after occlusal rehabilitation. Materials and methods Patients with tooth wear were included in this study after informed consent. The amount of tooth wear was scored with Tooth Wear Evaluation System (TWES). To assess the perspective of the patient, the Dutch Speech Handicap Index was used (SHI). Acoustic analysis was performed to evaluate changes with the use of voice recordings. These were made before treatment, T0; directly after treatment, T1; 1 month after treatment, T2. With the use of PRAAT software, the spectral characteristic centre of gravity (COG) was evaluated for the sounds /s/, /f/, /v/, /d/, /t/, /m/. Results Recordings of 17 patients (14 men, 3 women, mean age 41.2 ± 10.4 years) were included. SHI scores did not change significantly between T0 and T2 (p = 0.054). A multiple regression model showed that for all sounds the intercept was negative, but statistically significant only for /s/ and /f/ between T0 and T1. The effect of the initial change (between T0 and T1) on the change between T1 and T2 was clearly negative for all sounds (p Conclusion Tooth wear patients perceive improvement in speech function after treatment. Clinical significance Clinicians may explain to patients that speech is likely to alter for a short period due to treatment but that there will be a good adaption to the new situation.

Contains fulltext : 169646.pdf (Publisher’s version ) (Closed access) OBJECTIVES: Composite resin restorations present high survival rates and when a failure occurs repair is often possible. The aim of this study was to assess the effect of various repair techniques on indirect restorations. METHODS: LAVA Ultimate (3M), and Clearfil Estenia blocks (Kuraray) were repaired with our without surface roughness treatments, silane application and artificial ageing. Micro-shear bond stress tests were performed, while cohesive strength served as positive control. ANOVA was used for cohesive strength and effect of ageing, and linear mixed models to evaluate the effect of treatment variables on repair strength. RESULTS: Both materials reacted differently on surface treatments. Untreated (no treatment, no silane) repair strength was 16.3+/-6.3MPa for LAVA Ultimate and 19.0+/-4.3MPa for Estenia. Thermal cycling resulted in a 14-58% reduction of cohesive strength. Without cycling, all treatments resulted in a significant increase of bond strength in LAVA Ultimate (p

Contains fulltext : 172856.pdf (Publisher’s version ) (Open Access) The service life of defective direct or indirect restorations could be prolonged by repair or relayering actions where durable adhesion of resin-based composite materials is established for longevity of repairs. The advances in adhesive technologies have introduced several surface conditioning concepts to adhere resin composites onto different restorative materials. The purpose of this report is to summarize reasons for failure, survival of repaired reconstructions, elaborate upon types and mechanisms of available surface conditioning methods, and present operative dentists with practical guidelines for intraoral repair procedures.

This study investigated by means of a systematic review of the literature and meta-analysis the impact of physical and/or chemical surface treatments on the repair bond strength of methacrylate-based dental composites. Three international databases (Medline/PubMed, Scopus, and Web of Science) were searched. Studies that evaluated the repair bond strength of aged control composites (untreated or treated with abrasives) and aged composites subjected to surface treatments before repair (physical, chemical, or physical + chemical) were included. In total, 777 articles were found, 129 were selected for full-text reading, and 15 studies were included in the qualitative and quantitative synthesis. Meta-analyses were conducted using random effects model to calculate pooled mean differences between control and treated composites, according to the different groups of surface treatments. Statistical heterogeneity was assessed using the Cochrane Q statistic and I 2 test. Risk of bias of all included studies was assessed. Application of chemical or physical + chemical surface treatments of aged composites was shown to generally improve their repair bond strengths. Silane coupling agents appeared to have a minor role as compared to adhesive agents in improving repair potential. Airborne-particle abrasion alone was found not to contribute significantly to the repair bond strengths. High heterogeneity was observed in most statistical analyses; the analysis of risk of bias also indicated potential problems associated with reporting in the studies. Therefore, suggestions for future in vitro studies on the repair bond strength of dental composites are given.

Objective The purpose of this study was to evaluate the 3D-stereophotogrammetry technique to detect differences in facial appearance after a simulated rehabilitation. Materials and Methods Eleven volunteers without tooth wear participated. A 3D-stereophotograph was taken in five different situations: resting position, teeth in occlusion, and teeth in occlusion with a 1 mm-, 3 mm- or 5 mm resin block between the first molars. Cephalometric measurements were performed on the 3D-stereophotographs using the software program Maxilim® (Medicim NV Mechelen, Belgium). Four anatomical parameters were analyzed: (1) Subnasale–Gnathion, (2) Subnasale–Stomion, (3) Stomion–Gnathion, and (4) Masseter right–Masseter left. A paired Student's T-test was applied to detect significant differences (p

Objective The restorative treatment of generalized tooth wear involves an increase in vertical dimension of occlusion and a comprehensive alteration of occlusal morphology. The aim of this study was to assess the impact of a direct adhesive restorative treatment on masticatory performance parameters. Materials and methods A sample of 23 fully dentate adult generalized tooth wear patients (17 male, 6 female, age 41.7 ± 8.3 years) undergoing direct composite restorative treatment was selected. Before and one month after restorative treatment with resin bonded composite restorations, masticatory performance was evaluated using 1) a comminution test, 2) a maximum voluntary bite force recording and 3) the sum score of five items related to eating and chewing from the Oral Health Impact Profile (OHIP-49) questionnaire. Statistical analysis was performed using a paired t-test, and analysis per OHIP item was done by a McNemar test (p Results There was no statistically significant difference in median particle size (X50) calculated before and after treatment (4.19 ± 0.97 and 4.03 ± 0.76, respectively, p = 0.327). Maximum voluntary bite force decreased significantly after treatment (baseline 389 ± 90 N, one month recall 323 ± 173 N, p = 0.028). The sum score of the five OHIP items significantly decreased after treatment (baseline 10.6 ± 4.8, one month recall 6.6 ± 2.5, p = 0.001), with the item regarding unsatisfactory diet showing the largest significance (p = 0.029). Conclusions This study indicates that the restorative treatment of generalized tooth wear using direct resin bonded composite has no significant short-term effect on masticatory performance as measured with a comminution test, although the self-reported ability to eat and chew, as measured by the sum score of all pertaining OHIP items, did significantly improve. Clinical significance On individual level, food comminution could be influenced by restorative treatment with increase of vertical dimension of occlusion, but at group level no significant effect is observed. Nevertheless, tooth wear patients do perceive improved ability to eat and chew foods, which is clinically relevant.

Biomaterials are being applied in increasingly complex areas such as tissue engineering, bioprinting, and regenerative medicine. For these applications, challenging-or even contradictory-combinations of biomaterial properties are often required which cannot be met by conventional biomaterials. During the past decade, several new concepts have been developed to render biomaterials self-healing, thereby offering new opportunities to improve the functionality of traditional biomaterials in terms of their mechanical, handling, and biological properties. Consequently, various types of self-healing polymeric, ceramic, or composite biomaterials have been developed. Nevertheless, despite the rapid emergence of the field of self-healing biomaterials, this field of research has not been reviewed during the recent years. Therefore, this article provides a critical overview of recent progress in the field of self-healing biomaterials research by discussing both extrinsic and intrinsic self-healing systems. While the extrinsic self-healing section focuses on self-healing dental materials and orthopedic bone cements that rely on release of healing liquids from embedded microcapsules, the section on intrinsic self-healing materials mainly discusses concepts for self-healing of polymeric biomaterials that are either hydrated (hydrogels) or nonhydrated (e.g., films and coatings). Finally, benefits of the self-healing feature for biomaterials are discussed, and directions for future research and developments are outlined.

In 2016, a European consensus meeting was held regarding the treatment of severe tooth wear. This meeting resulted in the publication of the European statement of consensus on the treatment of severe tooth wear in 2017. In the statement, new definitions of physiological and pathological tooth wear are described, recommendations for diagnosis and taking preventive measure are presented, and advice for counseling and monitoring is offered to better elucidate the underlying aetiological factors causing tooth wear in the patient. The decision whether restorative treatment is appropriate is multifactorial and partially dependent on the severity and the consequences of the wear and on the aesthetic and functional wishes of the patient. Restorative intervention should be delayed as long as possible, but when such intervention is indicated, the preference is for minimally invasive techniques using direct, indirect or hybrid treatment methods.In 2016 vond een Europese consensusbijeenkomst plaats over de behandeling van ernstige gebitsslijtage. Deze bijeenkomst resulteerde in 2017 in de publicatie van de Europese consensusverklaring over de behandeling van ernstige gebitsslijtage. In de verklaring worden nieuwe definities van fysiologische en pathologische gebitsslijtage beschreven en aanbevelingen gegeven voor diagnostiek, het nemen van preventieve maatregelen en wordt aanbevolen te counselen en te monitoren om de onderliggende etiologische factoren van gebitsslijtage bij een patiënt beter in beeld te krijgen. Het besluit of restauratief moet worden ingegrepen is multifactorieel en is mede afhankelijk van de ernst, de gevolgen van de slijtage en esthetische of functionele hulpvraag van de patiënt. Een restauratieve behandeling moet zo lang mogelijk worden uitgesteld, maar op het moment dat een restauratieve behandeling is geïndiceerd, gaat de voorkeur uit naar minimaal invasieve technieken, waarbij gebruikgemaakt wordt van directe, indirecte of hybride behandelmethoden.

Chewing, drinking, and occasional tooth grinding will result in physiological tooth wear during a lifetime. Extreme challenges, such as bruxism or habitual chewing on foreign objects, may lead to excessive wear. Recently, the role of erosion in accelerating mechanical tooth wear has been recognized, but the interplay between chemical and mechanical wear processes has not been extensively studied. Our laboratory recently introduced a novel oral wear simulation device, the Rub&Roll, that enables the user to perform wear and loading studies separately or simultaneously in an erosive and/or abrasive environment. This manuscript describes an application of the device: the combined mechanical and erosive loading of extracted human (pre)molars in a simulated chewing movement, with a controlled application of force, velocity, fluid, and time, and the application of non-contact profilometry in visualizing and measuring the resulting wear pattern. The occlusal morphology that was created in the experiment with the highest loading level is very similar to the clinical presentation of erosive wear.

Objectives To evaluate the mid-term clinical performance of direct composite restorations placed in patients with pathological tooth wear needing full rehabilitation with an increase of vertical dimension of occlusion. Methods In a prospective trial 34 patients (34.0 ± 8.4 years; 25 males, 9 females) were treated with a minimal invasive additive technique using composite restorations. The restorative treatment protocol was to provide all teeth with composite build-up restorations in an increased vertical dimension of occlusion (VDO) using the DSO-technique. Recall appointments were planned after 1 month, 1 and 3 years after treatment. Restorations were scored for clinically acceptability (FDI-criteria) and scores 4 and 5 were recorded as clinically unacceptable. Frequencies of failures and Kaplan Meier survival curves are presented and effect of relevant variables was calculated with a multifactorial Cox regression (p Results 1256 Restorations were placed, 687 anterior, 324 premolar, and 245 molar restorations. After a mean observation time of 39.7 months a total of 69 failures were observed, of which 61 restorations were repaired (score 4) and 8 were replaced (score 5). Most common reasons for failure were (chip) fractures (n = 43) and caries (n = 11). Placement of anterior restorations in two sessions led to significant 4.6 times more failures then placed in one session. Conclusions In patients with severe tooth wear a full rehabilitation, in an increased vertical dimension of occlusion, direct composite resin restorations show a 94.8% success and 99.3% survival rate after a period of 3.5 years.

Objective Masticatory performance is influenced by a number of variables such as age, gender, bite force, and occlusal units. Tooth wear may also play a role due to changes in occlusal area and in vertical dimension of occlusion. The aim of this study was to evaluate the effect of tooth wear on masticatory performance, using a communition test. Materials and Methods Patients with different degrees of tooth wear, referred by their general dental practitioners, and included in the Radboud Tooth Wear Project, were approached for this study and included after informed consent. The amount of post canine wear was scored with the Tooth Wear Index (TWI). The number of occluding posterior units was quantified and the bite force was measured using a transducer. Masticatory performance was measured with a communition test, with the median particle size (X50) after 20 chewing cycles as outcome measure. A multiple regression model was used to assess the relation between TWI, age, gender, bite force, occlusal units and X50. Results 52 participants (40 male, 12 female, mean age: 40 ± 8.2y) were included in the study. The post canine TWI-score was between 1.0-3.3. The average number of occlusal units per participant was 11.9 ± 1.4 and the mean bite force 369 ± 172 N. The mean X50 was 4.2 ± 1.1. The results showed no significant relation between post canine TWI-score, age, gender, bite force, and occlusal units upon the X50 (p > 0.13). Conclusion This study showed that the degree of tooth wear could not be observed to have an effect on masticatory performance. Clinical significance On individual level an effect could be present but looking at a larger group of patients, the degree of tooth wear did not have a relation with masticatory performance as measured with a communition test.

Objective: The purpose of this study was to identify the level of oral health-related quality of life and orofacial appearance in patients with moderate to severe tooth wear. Patients with and without a request for restorative treatment were included. Methods: One hundred twenty-four patients (98 men, 26 women, mean age: 40.5 ± 8.8 years) with moderate to severe tooth wear were included. Patients without a request for help received a non-restorative treatment of counseling and monitoring. Patients with a request for restorative treatment were treated with a full rehabilitation using composite resin restorations. Oral Health Impact Profile (OHIP-NL) and Orofacial Esthetic Scale (OES-NL) questionnaires were filled in at baseline and after 1 year. Results: Counseling and monitoring group: baseline OHIP-NL score was 0.4 ± 0.3, baseline summary score of OES-NL was 48 ± 7.0, and baseline impression score was 7.1 ± 1.2. Scores had not changed significantly after 1 year (p = 1.00 after Bonferroni correction).Restoration group: baseline OHIP-NL score was 0.8 ± 0.6, baseline summary score of OES-NL was 38 ± 10, and baseline impression score was 5.9 ± 1.5. Scores had improved significantly after 1 year (p < 0.001 after Bonferroni correction). Conclusions: Counseling and monitoring did not result in a significant deterioration and restorative treatment resulted in a significant improvement of oral health-related quality of life (OHRQoL) and orofacial appearance in this patient group. Clinical significance: In patients with moderate to severe tooth wear, without functional and esthetical problems, counseling and monitoring may be an appropriate treatment option. Restorative treatment in patients with a need for treatment results in an improved OHRQoL. OHIP and OES questionnaires may be used to monitor changes in clinically relevant symptoms.

This case report shows the treatment of a severe traumatic tooth injury. For the maxillary right central incisor, the trauma was considered a complicated crown-root fracture. The level of the fracture line, the length of the remaining root segment, and the presence and condition of the tooth fragment determined the type of therapy. Traumatized teeth with fractures below the alveolar crest are often considered hopeless. As this report shows, the treatment of a complicated crown-root fracture in the esthetic region can be challenging. Orthodontic extrusion and crown-length surgery were performed to bring the fracture line above the alveolar bone crest. A multidisciplinary approach was required for complete rehabilitation of the traumatized maxillary incisor. Suggestions are made to improve treatment planning of complicated crown-root fractures.

Item does not contain fulltext This paper explains a conservative, pragmatic and minimally invasive intervention concept for the treatment of severe tooth wear patients based on the Radboud Tooth Wear Project in the Netherlands. Guidelines and flowcharts for management of severe tooth wear patients and rehabilitation in increased vertical dimension of occlusion are presented. We concluded that: (a) Restorative treatment is not always indicated, even for patients with severe tooth wear. (b) If the patient has no complaints, counselling and monitoring is probably the best option. (c) Minimally invasive and adhesive restorative strategies are preferred when severe tooth wear patients are to be treated in increased vertical dimension, especially when young patients are involved. (d) Clinical evidence for a suitable restorative treatment protocol is limited to five-year follow up for direct composites. This material seems to be suitable for rehabilitation in increased vertical dimension on the middle long term. Clinical results for indirect techniques are not available yet. (e) Restorations, including those that are considered 'definitive' may prove to have a limited lifetime in patients with severe tooth wear due to bruxism and erosion. Explanation of the possible treatment options and expected complications should be included in the informed consent.

Contains fulltext : 172086.pdf (Publisher’s version ) (Open Access) This paper describes the application technique of direct shaping by occlusion (DSO) for large composite restorations including the entire occlusal surface. For this technique, matrix bands and wedges are inserted without interference with antagonists in the desired occlusion. The final increment of soft-composite resin is shaped by letting the patient occlude on the uncured composite. Due to the nature of the technique, special care has to be taken for moisture control and handling of contamination. The procedure, advantages, and limitations of the technique are discussed.

Item does not contain fulltext The aim was to investigate in vitro the marginal overhang in Class II composite restorations placed with various separation rings and placement techniques. A total of 180 Mesial-Occlusal [MO] preparations in artificial molar teeth were divided into nine groups (n=20). After placement of the sectional matrix, one of three ring systems was applied: Contact Matrix System (Danville Materials), Composi-Tight Gold (Garrison), and V-Ring (Triodent). In each group, rings were placed according to four different techniques (V-Ring placed with technique no. 2 only): 1) occlusally of the wedge, 2) on back end of the wedge, 3) between adjacent tooth and wedge, and 4) between treated tooth and wedge.After application of the adhesive resin, preparations were restored with composite Clearfil AP-X (Kuraray) and polymerized in increments. After matrix removal, overhang was measured on a standardized digital macroscopic image in millimeters squared. For analysis, analysis of variance and Tukey B were used (p

Item does not contain fulltext OBJECTIVES: In search for clinically effective composite repair protocols, the effect of various etching protocols on the surface roughness of composite resins with different filler composition were investigated. METHODS: Of two composite resins (hybrid-filled Clearfil AP-X; nano-filled Filtek Supreme XT) specimens of 3mm thick with a diameter of 7 mm were prepared (n=24). The top surface was polished with 4000-grit SiC-abrasive paper and subjected to one of eight surface treatments: (n=3): negative control (NC), 37% phosphoric acid for 20s (37PA-20s), 3% hydrofluoric acid for 20s (3HF-20s), for 120 s (3HF-120 s), 9.6% hydrofluoric acid for 20s (9.6HF-20s), for 120 s (9.6%HF-120 s), 37PA-20s followed by 9.6%HF for 120 s (37PA-20s/9.6HF-120 s) and 9.6%HF for 120 s followed by 37PA-20s (9.6HF-120s/37PA-20s). Roughness (S(a)) was measured using a 3D noncontact optical interferometer (WYKO) and surface topography imaged by SEM. Multilevel models were used to estimate the variances within a sample and between samples in each group. Using the resulting overall variances and the means for each group, the eight groups were compared consecutively using t-tests (p

Contains fulltext : 88267.pdf (Publisher’s version ) (Closed access) Hydrofluoric acid can be used for intra-oral repair of restorations. Contamination of tooth substrate with hydrofluoric acid cannot always be avoided. OBJECTIVES: To investigate the bonding effectiveness to hydrofluoric acid contaminated dentin by, micro-tensile bond strength testing, SEM and TEM. METHODS: For this study, 15 molar teeth were used of which dentin surfaces were subjected to five, different etching procedures. Group A, 37.5% phosphoric acid (Kerr Gel) (control group); group B, 37.5% phosphoric acid followed by 3% hydrofluoric acid (DenMat); group C, 37.5% phosphoric acid, followed by 9.6% hydrofluoric acid (Pulpdent); group D, 3% hydrofluoric acid followed by 37.5%, phosphoric acid; group E, 9.6% hydrofluoric acid followed by 37.5% phosphoric acid. After the bonding procedure (OptiBond FL, Kerr) a composite resin build-up (Clearfil AP-X, Kuraray), was made. After 1 week storage, specimens were prepared for micro-tensile bond testing, SEM- and, TEM-analysis. Data were analyzed using ANOVA and post hoc Tukey's HSD (p

Contains fulltext : 70756.pdf (Publisher’s version ) (Closed access) OBJECTIVES: To compare the marginal ridge fracture strength of Class II composite resin restorations placed with a straight or contoured matrix band using composite resins with different modulus of elasticity. METHODS: In 60 artificial first molars standardized MO-preparations were ground. Two matrix systems were used: (1) A straight matrix (Standard Tofflemire Matrix, KerrHawe) in Tofflemire retainer (Produits Dentaire). (2) A contoured matrix (Standard matrix, Palodent, Dentsply). In both groups, a wooden wedge and separation ring (Composi-Tight Gold, GDS) were placed and the matrix was burnished against the adjacent tooth. Three composite resins together were used (Filtek Supreme: e-modulus 13.3 GPa (3M ESPE), Clearfil AP-X: 16.6 GPa (Kuraray) and Clearfil Majesty Posterior: 22.0 GPa (Kuraray)), resulting in six groups (n=10). Teeth were mounted into a MTS servo hydraulic testing machine (Mini Bionix II, MTS, USA) with stylus placed on the marginal ridge. Samples were loaded at a crosshead speed of 1.0mm/min until fracture occurred. Fracture resistance data were statistically analyzed using ANOVA and Scheffe's post hoc test for multiple comparison of groups (p

Contains fulltext : 172526.pdf (Publisher’s version ) (Open Access) This article gives an overview of the state of the art of different restorative treatment procedures and techniques needed for placing extended posterior resin composite restorations. Clinical aspects related to the procedure are discussed and reviewed based on the current literature, such as the use of proper adhesive restorative materials, use of liners and bases, moisture control, reconstruction of proximal contacts, extended resin composite restorations, and techniques to address restoring teeth with deep subgingival margins.

Item does not contain fulltext OBJECTIVES: The aim of this systematic review was to evaluate the treatment performance/longevity of dental materials/techniques indicated to restore teeth with severe wear. MATERIALS AND METHODS: A systematic literature search was conducted to select retrospective studies (cohort and case series) and prospective studies that evaluated or compared techniques/materials to restore teeth with severe wear. A search was conducted in Medline (via Pubmed - June 2015) with no limits for publication year or language to identify clinical studies. Two reviewers independently selected studies, extracted data and assessed the risk of bias of randomized controlled trials included. The annual failure rate (AFR%) of restorations was calculated for each study. RESULTS: A total of 511 articles were found and 23 studies were eligible for full-text analysis; hand search included 7 more papers. From the 30 studies, 12 were eligible for the review. Most of these studies presented good performance of the restorations in teeth with severe wear. AFR ranged from 0.4% (microhybrid) to 26.3% (microfilled) for direct resin composite, 0% to 14.9% for indirect resin composite and 2.7% for porcelain veneers. CONCLUSION: There is no strong evidence to suggest that any material is better than another. Direct or indirect materials may be feasible options to restore severely worn teeth.

Contains fulltext : 58422.pdf (Publisher’s version ) (Closed access) OBJECTIVES: To investigate the survival over a five-year period of posterior resin composite restorations placed by students. METHODS: Class I and II resin composite restorations placed by second-fourth year dental students were evaluated. Patients attended the dental school every 6 months for a regular check-up during which all restorations were checked on their clinical acceptability. In case of replacement or repair of a restoration, this was registered in the patient's record. From each record the survival time and reasons for failure of resin composite restorations were gathered. RESULTS: Seven-hundred three posterior resin composite restorations in 382 patients (49% female and 51% male, age 22-78) were evaluated. At 5 years 560 of the 703 restorations were still considered to be "clinically acceptable". Forty-nine restorations were considered as "functionally present", of which 44 were restored with a crown and four had received a new restoration adjacent to the existing restoration without its removal. Ninety-four restorations had failed. The main reasons for failure were restoration fracture, caries, endodontic treatment, defective margin and lack of proximal contact. The survival rate of the restorations was 87% at 5 years, resulting in an annual failure rate of 2.8%. CONCLUSIONS: Dental students are able to place resin composite restorations in posterior teeth with an acceptable mean annual failure rate.

Contains fulltext : 57995.pdf (Publisher’s version ) (Closed access) OBJECTIVES: To review the change in teaching of Restorative Dentistry at Nijmegen dental school over the period 1986 to the present. KEY POINTS: In 1986, class I and II resin composite restorations were included in the pre-clinical program. However, these courses still started with class I and II amalgam restorations. From 1990 on, the number of amalgam restorations placed in the clinic gradually decreased while the number of resin composite restorations increased. Meanwhile, resin composite had become the first choice for treatment of primary caries (class I and class II) lesions. Finally in 1994, the pre-clinical training started with resin composite restorations before dental amalgam was taught and the advantage of a minimal preparation was further emphasized. Since 2001 the teaching of dental amalgam ceased at the dental school. This was not an abrupt change but the result of a long transitional stage during which it was gradually substituted by resin composite. This step-by-step introduction allowed the acceptance of composite resin by the staff as an alternative for dental amalgam in posterior restorations. As in 2001 students placed only 2.5 amalgam restorations before graduation, it was decided to stop with the pre-clinical training program. CONCLUSIONS: The introduction of resin composites meant an important change in teaching restorative dentistry at Nijmegen dental school. It was not just a change in materials and techniques but also a change in treatment philosophy. The reduced need for preparation and the strengthening effect on the remaining tooth were the principal reasons for the shift from dental amalgam to adhesive dentistry with resin composite at Nijmegen dental school.

Bij een porseleinfractuur of bij een onesthetische kroonrand van een goed functionerende kroon of brug kan in de meeste gevallen worden gekozen voor een intraorale reparatie of correctie met composiet. Om retentie te bereiken aan metaal, porselein, kunsthars en composiet zijn macromechanische, micromechanische en/of chemische retentievormen beschikbaar. Voor het verkrijgen van macromechanische retentie is het prepareren van putten, groeven en/of ondersnijdingen nodig. Onder micromechanische retentie wordt verstaan het op microscopisch niveau verruwen van het oppervlak door etsen of zandstralen. Voor de chemische retentiemethoden worden speciale primers gebruikt die een chemische reactie kunnen aangaan met de diverse materialen. De keuze van de meest geëigende methode wordt bepaald door het restauratiemateriaal en de uitvoerbaarheid van de methode.

Item does not contain fulltext The aim was to evaluate retrospectively the influence on restoration longevity of a repair and to evaluate longevity of repaired restorations. MATERIALS AND METHODS: In a practice, 1202 amalgam and 747 composite resin restorations were placed. 407 restorations failed (amalgam 293, composite 114), 246 restorations were repaired with composite resin using an etch-and-rinse technique. Of repaired restorations reason for failure and number of surfaces of original restoration, repair date, and date of patients' last visit were recorded. Whenever a new treatment was necessary, this was considered failure. Data were analysed by Kaplan-Meier statistics and log-rank tests (p

SUMMARY Background Proximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and technique of placement. However, the effect of volumetric shrinkage of resin and intensity of curing light has yet to be determined. Thus, the aim of this study was to identify the influence of these factors on the proximal contact tightness when restoring class II cavity preparations in vitro. Methods Sixty artificial molars were restored with either a low-shrinkage (Filtek Silorane, 3M ESPE) or a conventional (Z100, 3M ESPE) composite and polymerized with low-intensity (Smartlite IQ2, Dentsply) or high-intensity light curing units (DemiTM, Kerr). Proximal contact tightness was measured using the Tooth Pressure Meter. Data were statistically analyzed using one-way analysis of variance and Tukey post hoc test. Results Use of low-shrinkage composite (Filtek Silorane) resulted in significantly tighter proximal contacts compared to the use of conventional composite (Z100) when cured with the same polymerization unit (p Conclusions Low-shrinkage resin composite and low curing light intensity is associated with tighter proximal contact values.

Item does not contain fulltext OBJECTIVES: To investigate the influence of cavity preparation (MO/DO/MOD) and type of matrix system on proximal contact tightness of direct posterior composite restorations. MATERIALS AND METHODS: 85 patients in need of a two- or three surface Class II direct composite restoration were randomly divided into two treatment groups. Group 1 was treated with a sectional matrix system combined with a separation ring (Palodent); Group 2 was treated with a circumferential matrix system in combination with a retainer (Tofflemire). Proximal contact tightness was recorded before treatment and directly after finishing the restoration. RESULTS: For the two-surface cavities use of the separation ring resulted in a statistically significantly tighter proximal contacts at both the mesial and distal site (MO: 2.51+/-0.81 N; DO: 2.82+/-1.14 N) compared to the use of the circumferential (MO: -1.08+/-1.04 N; DO: -0.22+/-0.87 N) (p=0.01). Regarding the three-surface (MOD) cavities no statistically significant differences were found between the mesial and distal site, nor was there an effect of the used matrix system. No statistically significant influence of cavity design (mesially/distally) was recorded for all cavities (MO, DO and MOD). CONCLUSIONS: Use of the sectional matrix system in two-surface Class II cavities resulted in statistically significantly tighter proximal contacts than the use of the circumferential matrix system. For the three-surface no statistically significant differences in contact tightness were found between the different matrix systems. Location of the cavity (mesially or distally) did not show to have any statistically significant effect on the obtained proximal contact tightness.

Item does not contain fulltext OBJECTIVES: The aim of this study was to investigate the effectiveness of a variety of techniques to bond new composite to artificially aged composite of different compositions. METHODS: Composite resin blocks were made of five different commercially available composites (n=30) (Clearfil AP-X, Clearfil PhotoPosterior, Photo Clearfil Bright, Filtek Supreme XT and HelioMolar). After aging the composite blocks (thermo-cycling 5000x), blocks were subjected to one of 9 repair procedures: no treatment (control), diamond bur, sandblasting alumina particles, CoJet, phosphoric acid, 3% hydrofluoric acid 20s or 120s, 9.6% hydrofluoric acid 20s or 120s. In addition, the cohesive strength of the tested composites was measured. Two-phase sandwiches ('repaired composite') were prepared using each of the 9 repair protocols, successively followed by silane and adhesive (OptiBond FL) treatment, prior to the application of the same composite. Specimens were subjected to micro-tensile bond strength testing. Data were analyzed using ANOVA and Tukey's HSD (p

Contains fulltext : 89725.pdf (Publisher’s version ) (Closed access) Information about the long-term clinical survival of large amalgam and composite restorations is still lacking. This retrospective study compares the longevity of three- and four-/five-surface amalgam and composite restorations relative to patients' caries risk. Patient records from a general practice were used for data collection. We evaluated 1949 large class II restorations (1202 amalgam/747 composite). Dates of placement, replacement, and failure were recorded, and caries risk of patients was assessed. Survival was calculated from Kaplan-Meier statistics. After 12 years, 293 amalgam and 114 composite restorations had failed. Large composite restorations showed a higher survival in the combined population and in the low-risk group. For three-surface restorations in high-risk patients, amalgam showed better survival. 01 oktober 2010

Contains fulltext : 81668.pdf (Publisher’s version ) (Closed access) OBJECTIVES: The objective of the study was to compare in vitro interproximal overhang formation of Class II composite resin restoration when using different matrix systems. METHODS: 240 lower left molar phantom head teeth with an MO-preparation were divided into 12 groups (n=20). In six groups a circumferential matrix (Tofflemire X-thin matrix, HaweNeos 1001-c, SuperCap) was used, combined with either a hand-instrument (PFI49 or OptraContact) or separation ring (Composi-Tight Gold). In the other six groups two sectional matrix systems were used (flexible and dead-soft), with three separation rings (Composi-Tight Gold, Contact Matrix, Palodent BiTine). Matrices were secured with wooden wedges and preparations were restored with composite resin Clearfil AP-X (Kuraray) placed and polymerized in increments. After matrix removal overhang was measured on a standardized digital macroscopic image in mm(2). For analysis a multiple linear regression model was used. RESULTS: Use of circumferential matrices resulted in less overhang than sectional matrices (-0.85 mm2, p

Contains fulltext : 71051.pdf (Publisher’s version ) (Closed access) The purpose of this study was to investigate long-term clinical effectiveness of treating painful cracked teeth with a direct bonded composite resin restoration. The hypothesis tested was that cracked teeth treated with or without cuspal coverage showed the same performance. Forty-one patients attended a dental practice with a painful cracked tooth that was restored with a direct composite resin restoration. Twenty teeth were restored without and 21 with cuspal coverage. After 7 years, 40 teeth could be evaluated. Three teeth without cuspal coverage needed an endodontic treatment, of which 2 failed as a result of fracture. No significant differences were found for tooth or pulp survival. Three more repairable restoration failures were recorded. Mean annual failure rate of restorations without cuspal coverage was 6%; no failures in restorations with cuspal coverage occurred (P = .009). A direct bonded composite resin restoration can be a successful treatment for a cracked tooth.

Contains fulltext : 52502.pdf (Publisher’s version ) (Closed access) The effect of interdental separation of a special separation ring and wooden wedge was investigated. In a split-mouth design, 27 patients were randomly assigned to one of two groups (W or S). In 11 patients, an interdental wooden wedge (Hawe-Neos) was placed (group W), and in 16 patients, a separation ring (Composi-Tight Gold) was placed at the contact between teeth 4/5 and 5/6. Simultaneously, in both groups, a wooden wedge, combined with a separation ring (Composi-Tight Gold), was placed on the contact between teeth 4/5 and 5/6 (reference group W+S). To measure proximal contact tightness, frictional forces were recorded at the removal of a 0.05 mm thick metal matrix band inserted between adjacent teeth. Contact tightness was measured at contacts 4 and 5 and at 5 and 6 in the third and fourth quadrant using the Tooth Pressure Meter prior to applying separation devices (TO) five minutes after application (T1) and five minutes after removal of the devices (T2). The effect of separation was determined by calculating the differences between contact tightness before application and contact tightness with the devices in situ (T1-T0). Interdental recovery was calculated by the difference in contact tightness before application and after removal of the devices (T2-T0). To assess the presence of statistically significant differences between these measurement times, paired t-tests were applied. With each patient, either a comparison between W and W+S or S and W+S was made. For both W versus W+S and S versus W+S, paired t-tests were applied to compare differences (T1-T0 and T2-T0) between the separation devices. Within a patient, groups W and S could not be compared, therefore, to compare separation achieved between these two devices, unpaired t-tests were used. The increase in contact tightness measured at contact 4 and 5 for group W (0.98 +/- 0.26 N) was statistically significantly less compared to the increase in group S (5.48 +/- 0.88 N) (p < 0.001) or group W+S (4.62 +/- 0.68 N) (p = 0.02). No significant differences were found between groups S and W+S (p = 0.77). For all groups, five minutes after removal of the devices, the contact tightness at contact 4 and 5 and at contact 5 and 6 were still significantly weaker compared to the tightness at baseline (p < 0.02). When separation is required for restorative procedures, such as at placement of a Class II resin composite restoration, special separation rings may be more useful than wooden wedges.