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Objectives When managing partially defective restorations, dentists can choose between repair and replacement. We aimed to assess the long-term treatment costs of repairs and replacements. Methods Partially defective anterior and posterior composite restorations in permanent teeth had been repaired or replaced in a German university hospital and were retrospectively followed until censoring or one of the following events: (1) Extraction, (2) Major complications including placement of indirect restorations, endodontic treatments and extractions, or (3) Any complications including major complications and further direct restorations. Costs were estimated from a German mixed public-private-payer perspective. Cost-effectiveness differences were described using median-based incremental-cost-effectiveness ratios (ICERMEDIAN). Statistical analysis was performed using generalized linear mixed modeling (GLM), Chi2-test, and Wilcoxon rank-sum test (p Results A total of 616 repairs in 468 patients (follow-up: 4.9 ± 4.1 years) and 264 replacements in 218 patients (follow-up: 4.8 ± 4.3) were included. While replacements were associated with higher initial treatment costs, median annualized treatment costs did not significantly differ between repair (47.58 Euro [IQR: 24.41–107.04]) and replacement (50.64 Euro [IQR: 26.30–118.78]; p > 0.05), but were higher for molars (75.53 Euro [IQR: 24.41–92.18]) than incisors (45.03 Euro [IQR: 28.19–168.50]; p = 0.011). The difference in the % of extractions, major and any complications were minimal between both groups. The mean ICERMEDIAN of replacement vs. repair was -146.8 Euro/% when extractions were considered as outcomes. Regarding major and any complications, mean ICERMEDIAN amounted to 67.6 Euro/% and 23.9 Euro/%, respectively. Significance Repairs and replacements of partially defective restorations showed similar long-term costs and cost-effectiveness.

Objectives This study aimed to assess the survival of direct composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities. Materials and methods Survival of composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities was retrospectively analyzed. Failure was defined as the need for replacement of at least one surface of the original restoration or extraction of the tooth. Individual-, tooth-, and restoration-related factors were obtained from dental records. Five-year mean annual failure rate (mAFR) and median survival time were calculated (Kaplan-Meier statistics). The effect of potential risk factors on failure was tested using univariate log-rank tests and multivariate Cox-regression analysis (α = 5%). Results A total of 728 restorations in 101 patients were included in the analysis. The survival after 5 years amounted to 67.7% (5-year mAFR: 7.5%) and median survival time to 7.9 years. Results of the multivariate Cox-regression analysis revealed physical disability (HR: 50.932, p = 0.001) and combined intellectual/physical disability (HR: 3.145, p = 0.016) compared with intellectual disability only, presence of a removable partial denture (HR: 3.013, p < 0.001), and restorations in incisors (HR: 2.281, p = 0.013) or molars (HR: 1.693, p = 0.017) compared with premolars to increase the risk for failure. Conclusion Composite restorations placed under general anesthesia in adult patients with intellectual and/or physical disabilities showed a reasonable longevity as 67.7% survived at least 5 years. Clinical relevance Survival of composite restorations depends on risk factors that need to be considered when planning restorative treatment in patients with intellectual and/or physical disabilities. NCT04407520

Controversy exists regarding the effectiveness of delayed toothbrushing in decreasing erosive tooth wear (ETW). The purpose of this systematic review and meta-analysis was to assess the effects of delayed toothbrushing on ETW. This systematic review and meta-analysis was conducted according to the PRISMA statement and registered in PROSPERO (CRD42020200463). PubMed, Embase, and Web of Science databases were systematically searched with no publication year limits. Screening and data extraction were performed independently by two reviewers. In situ and in vitro studies comparing ETW after delayed and immediate toothbrushing following an erosive attack were included. Review Manager software 5.3 (The Cochrane Collaboration, Oxford, UK) was used for statistical analyses. Heterogeneity was assessed with the Cochran Q test and I2 statistics. Of the 565 potentially relevant studies, 26 full-text articles were assessed for eligibility. Twelve articles were included in the systematic review, and 11 were included in the qualitative analyses. No significant difference in the ETW of human enamel was observed between delayed and immediate toothbrushing (P = 0.13), whereas significantly less ETW of bovine enamel was observed after delayed toothbrushing (P

Objectives For an ORCA/EFCD consensus, this systematic review assessed the question “How to intervene in the caries process in proximal caries in adolescents and adults”. Material and methods Separating between the management of initial and cavitated proximal caries lesions, Medline via PubMed was searched regarding non-operative/non-invasive, minimally/micro-invasive and restorative treatment. First priority was systematic reviews or randomized controlled trials (RCTs), otherwise cohort studies. After extraction of data, the potential risk of bias was estimated depending on the study type, and the emerging evidence for conclusions was graded. Results Regarding non-invasive/non-operative care (NOC), no systematic reviews or RCTs were found. In cohort studies (n = 12) with a low level of evidence, NOC like biofilm management and fluoride was associated with a low proportion and slow speed of progression of initial proximal lesions. Minimally/micro-invasive (MI) treatments such as proximal sealants or resin infiltration (four systematic reviews/meta-analyses) were effective compared with a non-invasive/placebo control at a moderate level of evidence. Data on restorative treatment came with low evidence (5 systematic reviews, 13 RCTs); with the limitation of no direct comparative studies, sample size-weighted mean annual failure rates of class II restorations varied between 1.2 (bulk-fill composite) and 3.8% (ceramic). Based on one RCT, class II composite restorations may show a higher risk of failure compared with amalgam. Conclusions Proximal caries lesions can be managed successfully with non-operative, micro-invasive and restorative treatment according to lesion stage and caries activity. Clinical relevance Proximal caries treatment options like non-operative, micro-invasive and restorative care should be considered individually.

Introduction This retrospective study aimed to analyze the effect of repairing endodontic access cavities with composite on the survival of single crowns and retainer restorations of fixed or removable dental prostheses. Methods Dental records of patients attending a university dental clinic were retrospectively screened for single crowns and retainer restorations receiving endodontic treatment after crown placement. Survival (no further intervention) and failure (removal, loss or replacement of crown, replacement of access restoration, or recementation of restoration) of crowns and retainers with repaired endodontic access cavities were recorded. The mean annual failure rates were calculated, and the effect of individual-, tooth-, and restoration-related variables on survival was assessed by univariate log-rank tests and multivariate Cox regression analyses with shared frailty (P Results One hundred eighty repaired crowns/retainers placed in 151 patients were included (4.5 ± 3.3 years follow-up). Survival after 2, 5, 7, and 10 years amounted to 82.7%, 71.5%, 67.3%, and 48.8% (mean annual failure rate = 9.0%, 6.5%, 5.5%, and 6.9%), respectively. Although tooth type, kind of restoration, endodontic irrigant, repair conditioning methods, and kind of composite affected survival in the univariate regression analyses, only the kind of restoration (single crown vs retainer restoration) remained significant in the multivariate Cox regression model. Conclusions Repairing endodontic access cavities with composite increases the longevity of single crowns and retainer restorations.

Introduction Aim was to analyze and compare the efficacy of different bleaching agents typically used for internal bleaching of endodontically-treated discolored teeth. Methods Electronic databases (PubMed, Web of Science, Cochrane Library) were searched by two reviewers for clinical trials in which the color of endodontically-treated discolored teeth, before and after internal bleaching, was examined using shade guide units (ΔSGU) or a spectrophotometer/colorimeter (ΔE). The efficacies of the bleaching agents were compared using subgroup analyses. Statistical heterogeneity was assessed with Cochran’s Q and I2-statistic. Publication bias was evaluated using funnel-plots. Results Eight studies were included in the systematic review, out of which six could be included in the meta-analyses. Internal bleaching led to a significant change in tooth shade (ΔSGU: 6.27 [95%-CI: 5.36–7.17], ΔE: 12.83 [95%-CI: 9.46–16.20]). With regard to ΔSGU, the use of carbamide peroxide (35% or 37%), hydrogen peroxide (35%), and the combination of sodium perborate and hydrogen peroxide (3% or 30%) led to better bleaching effect than did sodium perborate (padj.≤0.026). Regarding ΔE, there were no significant differences between carbamide peroxide (37%), hydrogen peroxide (35%) and sodium perborate mixed with hydrogen peroxide (p=0.051). Risk of bias of included studies was classified as moderate to high. Conclusions Carbamide peroxide, hydrogen peroxide, and sodium perborate have a significant bleaching effect on discolored, root-canal-treated teeth. For a valid assessment of shade stability and comparison of bleaching agents resp. their concentrations, further studies with long term recalls are necessary.

BACKGROUND Smoking is one of the world's major health problems and dental professionals are in a unique position to promote smoking cessation. However, according to the current literature, neither dental students nor dentists feel adequately prepared to counsel smokers. The purpose of this study was to develop and implement a teaching intervention on smoking cessation for fourth-year dental students and assess its effectiveness in terms of learning outcome on knowledge, communication skills and attitudes. MATERIALS AND METHODS In this prospective intervention study, students in the intervention group (n = 28) participated in a teaching module consisting of a podcast, an interactive lecture, a seminar, and small-group sessions with role-play interactions. Knowledge, communication skills and attitudes were measured using written examinations and an objective structured clinical examination (OSCE) at the end of the module and 6 months later. Results were compared with data from a historical control group (n = 27) receiving standard teaching. RESULTS Compared with the control group, students in the intervention group had higher scores in the knowledge test (67.1% vs 41.8%; P

The study aimed to apply micro-computed tomography (micro-CT) and transverse microradiography (TMR) to measure dentine demineralization and to test the preventive effect of titanium tetrafluoride (TiF4 ) under microcosm biofilm. Sound dentine specimens from bovine root were treated for 6 h with: (i) 4.0% titanium tetrafluoride (TiF4 ) varnish [pH 1.0, 2.45% fluoride (F-); (ii) 5.42% sodium fluoride (NaF) varnish (pH 5.0, 2.45% F); (iii) 2% chlorhexidine (CHX) gel (pH 7.0); (iv) placebo varnish (pH 5.0); or (v) no agent (untreated). Dentine specimens were then exposed to human saliva mixed with McBain saliva for 8 h. Thereafter, McBain saliva containing 0.2% sucrose was applied daily, for 5 d, onto dentine specimens to stimulate formation of microcosm biofilm. Although a high correlation was found between the results of both methods regarding integrated mineral loss, the results of the methods did not show good agreement in Bland-Altman plots, with significant biases in calculations of lesion depth. Fluoride varnishes were able to reduce dentine demineralization (P < 0.05), while CHX failed to do so. Fluorides are still the best option to reduce dentine demineralization. Micro-CT may be used to measure dentine mineral loss, but not the lesion depth, for which TMR is superior.

While repairs are increasingly recommended to manage partially defective restorations, performing the repair (including bonding to different substrates) can be challenging, and dentists should adhere to established repair protocols. We aimed to systematically assess the consistency and quality of repair protocols.808 records were initially identified and 71 repair protocols based on 84 sources included. The number of published sources over time increased exponentially (p 0.001). Recommended treatment steps varied widely. Some treatment steps were only recommended by a minority of protocols, while others were consistently recommended (e.g. surface roughening, hydrofluoric acid etching of silicate ceramics, application of an adhesive/bonding agent). The overall quality of included sources was moderate (mean ± SD 3.7 ± 0.9 out of 7 points).Electronic databases (Medline via PubMed, Embase) were searched, hand searches using Google and Google Scholar conducted, and the reference lists of included full texts screened and cross-referenced.(Non-)systematic reviews, working instructions, and textbooks with protocols on direct composite repair restorations for partially defective (1) composite, (2) amalgam, (3) porcelain-fused-to-metal (PFMs) with exposed metal base, (4) ceramic/PFMs without exposed metal base, and (5) full metal restorations were included. Data synthesis was performed by tabulation of recommended treatment steps and descriptive statistics. The quality of included sources was assessed based on a checklist for guideline appraisal (MiChe).The main treatment steps were consistently reported across repair protocols.Dentists may want to adopt widely recommended treatment steps when performing repairs of different restoration materials in their daily practice.

This study evaluated the effect of three different NiTi instrumentation techniques on the incidence of microcracks after the preparation of straight and curved root canals using micro-CT. Roots from mandibular premolars and maxillary molars (n = 66) with the same mean canal curvatures were assigned to three groups of straight and three groups of curved roots (n = 11). After preoperative micro-CT scans, root canals were prepared with Reciproc, OneShape and ProTaper Next to size 25. Specimens were scanned again, and pre- and post-operative cross-sectional images (n = 75 263) were screened to identify the presence of dentinal microcracks. Overall, microcracks were detected in 2.97% (n = 2236) of the cross-sectional images. No new dentinal microcracks were observed after root canal instrumentation of straight and curved canals with the tested NiTi systems. Instrumentation with Reciproc, OneShape and ProTaper Next did not induce the formation of dentinal microcracks irrespective of canal curvature.

The aim of this systematic review and meta-analysis was to compare the bond strength between eroded and sound permanent enamel and dentin and to assess whether bonding performance (immediate and after aging) differs between etchrinse and self-etch adhesives and can be improved by surface pretreatment prior to bonding.Electronic databases (PubMed, Scopus, Embase, Web of Science, CENTRAL, LILACS, BBO) were searched by two reviewers. Random-effect meta-analyses were performed to compare bond strength to sound and eroded dental hard tissues without and with surface pretreatment prior to bonding, respectively. The effect of adhesive mode (etchrinse vs. self-etch) and aging (immediate vs. aged) was compared using subgroup analyses. Statistical heterogeneity was assessed using Cochran's Q and IFourty-seven studies (45 in vitro, 2 in situ) were included in the systematic review and meta-analyses. Erosion impairs bond strength to dentin (p0.001; mean difference: -10.2 MPa [95%CI: -11.9 to -8.6 MPa]), but not to enamel (p = 0.260). Surface pretreatment measures removing or stabilizing the collagenous matrix can improve dentin bond strength (maximum mean difference: +12.4 MPa). Etchrinse and self-etch adhesives did not perform significantly different on eroded enamel (p = 0.208) and dentin (p = 0.353). The majority of studies (32 of 47) presented a medium risk of bias.Data from in vitro and in situ studies showed that erosion impairs dentin bonding of etchrinse and self-etch adhesives and makes surface pretreatment prior to bonding of composite restorations necessary.

This study aimed to analyse if the erosion-protective potential of the salivary pellicle is different between female and male subjects. Bovine enamel and dentin specimens (each n = 3) were exposed to the oral cavity of healthy female or male volunteers (each n = 25, females: 25.8 ± 3.5 years, males: 26.7 ± 4.0 years) for 120 min to form a salivary pellicle. Subsequently, each 2 enamel and 2 dentin specimens were eroded with hydrochloric acid (pH 2.6, 60 s). Specimens of the control group (each n = 30) were eroded without presenting a salivary pellicle. Calcium release into the acid was determined photometrically. Additionally, total protein content in the pellicle (each n = 1 enamel and dentin specimen/volunteer) and different salivary parameters (flow rate, pH, buffer capacity, protein, albumin, calcium, phosphate, fluoride) were assessed. Statistical analyses were performed by one-way ANOVA, t tests, multiple linear regressions and Pearson correlations (p < 0.05). The erosion-protective capacity was not significantly different among female (calcium release [% of control]: enamel: 82.6 ± 28.1, dentin: 80.7 ± 24.0) and male (enamel: 76.0 ± 27.5, dentin: 87.1 ± 34.9) subjects. The protein content of the pellicle was not different between female and male subjects. The protein content and pH of unstimulated saliva were significantly reduced in female compared to male volunteers. Calcium release was neither correlated with the protein content of the salivary pellicle nor with salivary parameters. Under the conditions of the present study, the erosion-protective capacity of the salivary pellicle of female and male subjects is not different.

Background: To assess the knowledge of and attitudes towards erosive tooth wear among dental, medical, and non-medical university students of two Chinese universities. Methods: A questionnaire containing 15 questions on knowledge of erosive tooth wear and 10 questions on attitudes towards erosive tooth wear was designed, and its psychometric properties (reliability and validity) were analysed in a pilot study (n = 120 students). The following 3 groups of university students (n = 635) were recruited based on a convenience sampling technique and were distributed the questionnaire via an online survey system: Dental students (DSs), medical students (MSs), and non-medical students (NSs). Differences in the scores between groups and genders were analysed by one-way analysis of variance (ANOVA). The Pearson correlation coefficient was used to determine the association between the knowledge and attitude scores (P < 0.05). Results: The questionnaire was found to be reliable, valid and reproducible. A total of 435 students participated in this study (response rate: 69.6%). The knowledge score of the DSs (11.5 ± 3.4) was significantly higher than those of the NSs (5.5 ± 4.0) and MSs (6.1 ± 4.0) (P < 0.001). The attitude score of the DSs (45.2 ± 6.5) was significantly higher than those of the NSs (41.1 ± 6.9) and MSs (41.8 ± 6.4) (P < 0.001). The majority of DSs expressed attitudes that were more accurate and positive than those expressed by the other 2 groups. The attitude score was positively correlated with the knowledge score (r = 0.237, P < 0.001). Conclusions: Dental students had more accurate knowledge of and more positive attitudes towards erosive tooth wear than medical and non-medical students. In this population, a positive correlation was established between knowledge of and attitudes towards erosive tooth wear., BMC Oral Health, 20(1), art.no.110; 2020

Manufacturers offer single-file instrumentation systems with matching gutta-percha (GP) cones to simplify root canal preparation and obturation. The purpose of this study was to determine whether file diameters and tapers match with corresponding cone diameters and tapers (precision) as well as industry standards (accuracy).Twenty files and corresponding GP cones from each size of F360 (#25, #35, #45, #55 with .04 taper) and Reciproc (#25, #40, #50 with variable tapers) instruments were examined by using optical microscopy (×32) to determine their diameter and taper. Precision was evaluated by using one-way analysis of variance (α = 0.05) with Scheffé post hoc tests and t tests with Bonferroni correction. Accuracy was calculated by subtracting the nominal values from the measured values of all files and GP cones, and mean diameter and taper differences were compared by using one-way analysis of variance (α = 0.05) and Scheffé post hoc test for pairwise comparison.For F360, the majority of file and cone diameters were within the tolerance levels, but most of the file diameters were significantly larger than GP cone diameters (P .05), but the majority of all measured values were within the tolerance levels. For Reciproc, file and cone diameters at D1 and D3 mostly approached the nominal values. At the coronal end, file diameters #25 and #50 were significantly smaller than cone diameters (P .05). For both instrumentation systems, almost all file and cone tapers matched with the preset tolerance ranges. For Reciproc, significant differences between file and GP cone demonstrated either smaller cone or smaller file diameters and tapers, depending on the size. Most of the measured values were within the acceptable range, but diameters at the coronal end exhibited the highest percent difference from the nominal values.Despite the call for standardization, variability in diameter and taper dimensions between single-file instrumentation systems and their corresponding GP cones can be expected.

Objectives To identify potential changes in various aspects of teaching and to ascertain whether previously found inconsistencies in the teaching of criteria, indications and operative techniques for the repair of defective composite restorations at German dental schools have been resolved. Methods A validated questionnaire was used to gain the information sought. It was sent to all dental schools in Germany (n = 30). Whenever possible, data were compared to previous studies conducted in 2000 and 2009. Statistical analysis was performed using Fisher’s exact tests (p Results Twenty-nine schools responded to the survey – a response rate of 97%. All respondents indicated positive experiences with the repair of restorations. The teaching of repairs in 2018 (90%) was found to be comparable to the findings from the 2009 survey (88%, p = 1.000), but significantly increased since the 2000 survey (50%, p = 0.006). Main reasons reported for teaching repairs are tooth substance preservation (97%) and reduction of pulpal damage (79%). Main clinical indications are marginal defects and secondary caries. When performing repairs, almost all dental schools were found to teach both mechanical and adhesive substrate surface conditioning. Marked variation was observed in the method of mechanical surface treatment, with air abrasion having gained widespread popularity. The average expected longevity of repairs was 7.4 ± 3.0 years. Conclusions The teaching of the repair of resin composite restorations is widespread in dental schools in Germany. Aspects of this teaching were found to be more consistent between dental schools than in previous surveys, albeit variation in operative techniques still exists. Clinical significance Graduates from dental schools in Germany may be found to be well equipped with the knowledge and skills to perform repairs of defective resin based composite restorations in clinical practice.

INTRODUCTION Various scoring approaches for Multiple True-False (MTF) items exist. This study aimed at comparing scoring results obtained with different scoring approaches and to assess the effect of item cues on each scoring approaches' result. MATERIALS AND METHODS Different scoring approaches (MTF, Count-2, Count-3, "Vorkauf-Method," PS50 , Dichotomized MTF, "Blasberg-Method," Multiple response (MR), Correction for Guessing, "Ripkey-Method," Morgan-Method, Balanced Scoring Method) were retrospectively applied to all MTF items used within electronic examinations of undergraduate dental students at the University Medical Center Gottingen in the winter term 2016/2017 (1297 marking events). Item quality was evaluated regarding formal parameters such as presence of cues and correctness of content. Differences between scoring results of all scoring approaches and the differences between each methods' scoring results of items with and without cues were calculated by Wilcoxon rank sum tests (P

AIM To evaluate ex vivo the efficacy of ProTaper Universal Retreatment files (Dentsply Sirona, Ballaigues, Switzerland) in removing Thermafil, GuttaCore (both Dentsply Sirona) or vertically compacted gutta-percha from curved root canals using micro-CT. METHODOLOGY Sixty curved molar roots with the same mean canal curvatures and radii in two directions were prepared using ProFile instruments (Dentsply Sirona) to size 30 with .04 taper and obturated with either Thermafil, GuttaCore or vertically compacted gutta-percha and AH Plus (n = 20). Specimens were retreated using the ProTaper Universal Retreatment files D1, D2 and D3 to working length, and root canal preparation was completed with ProTaper Next (Dentsply Sirona) to size ×4. Percentages of residual filling material and dentine removal were assessed using micro-CT imaging. Working time and procedural errors were recorded. Statistical analysis was performed using Kruskal-Wallis and Wilcoxon tests. RESULTS No significant differences between carrier-based and warm vertical compaction regarding residual filling material (14.2-19.3%) and dentine removal (2.7-3.2 mm3 ) were detected (P > 0.05). Time to reach working length was significantly faster for canals filled with GuttaCore than that observed for Thermafil and warm vertical compaction (P

Objectives Repair instead of complete replacement is recommended to manage partially defective restorations. It is unclear if and why such treatment is taught at dental schools or practiced by dentists. We aimed to identify barriers and facilitators for repairs using a systematic review and meta- and qualitative analysis. Sources Electronic databases (PubMed, CENTRAL, Embase, PsycINFO) were searched. Study selection Quantitative studies reporting on the proportion of (1) dentists stating to perform repairs, (2) dental schools teaching repairs, (3) failed restorations having been repaired were included. We also included qualitative studies on barriers/facilitators for repairs. Random-effects meta-analyses, meta-regression and a thematic analysis using the theoretical domains framework were conducted. Data 401 articles were assessed and 29, mainly quantitative, studies included. 7228 dentists and 276 dental schools had been surveyed, and treatment data of 30,172 restorations evaluated. The mean (95% CI) proportion of dentists stating to perform repairs was 71.5% (49.7–86.4%). 83.3% (73.6–90.0%) of dental schools taught repairs. 31.3% (26.3–36.7%) of failed restorations had been repaired. More recent studies reported significantly more dentists to repair restorations (p = 0.004). Employment in public health practices and being the dentist who placed the original restoration were facilitators for repairs. Amalgam restorations were repaired less often, and financial aspects and regulations came as barriers. Conclusions While most dentists state to perform repairs and the vast majority of dental schools teach repairs, the proportion of truly repaired restorations was low. A number of interventions to implement repair in dental practice can be deduced from our findings. Clinical significance Partially defective restorations are common in dental practice. While repairs are taught and dentists are aware of the recommendation towards repairs, the actually performed proportion of repairs seems low.

This study aimed to analyze bond strengths of self-adhesive flowable composites on enamel, dentin and nano-hybrid composite. Enamel, dentin and nano-hybrid composite (Venus Diamond, Heraeus Kulzer, Germany) specimens were prepared. Three self-adhesive composites (Constic, DMG, Germany; Fusio Liquid Dentin, Pentron Clinical, USA; Vertise Flow, Kerr Dental, Italy) or a conventional flowable composite (Venus Diamond Flow, Heraeus Kulzer, Germany, etchrinse technique) were applied to enamel and dentin. Nano-hybrid composite specimens were initially aged by thermal cycling (5000 cycles, 5-55 °C). Surfaces were left untreated or pretreated by mechanical roughening, Al

SUMMARY Objectives: The aim of this study was to evaluate microleakage and shear bond strength of composite restorations under different cycling conditions. Methods and Materials: Class V cavities were prepared in the buccal and lingual surfaces of 30 human molars (n=60). A further 60 molars were used to prepare flat enamel and dentin specimens (n=60 each). Cavities and specimens were divided into six groups and pretreated with an adhesive (self-etch/Clearfil SE Bond or etch-and-rinse/Optibond FL). Composite was inserted in the cavities or adhered to the specimens' surfaces, respectively, and submitted to cycling (control: no cycling; thermal cycling: 10,000 cycles, 5°C to 55°C; thermal/erosive cycling: thermal cycling plus storage in hydrochloric acid pH 2.1, 5 minutes, 6×/day, 8 days). Microleakage was quantified by stereomicroscopy in enamel and dentin margins after immersion in silver nitrate. Specimens were submitted to shear bond strength testing. Statistical analysis was done by two-way analysis of variance and Kruskal-Wallis tests (p Results: Microleakage in enamel margins was significantly lower in the control group compared with thermal cycling or thermal/erosive cycling. Erosive conditions increased microleakage compared with thermal cycling (significant only for Clearfil SE Bond). No significant differences were observed in dentin margins. Bond strength of enamel specimens was reduced by thermal cycling and thermal/erosive cycling when Clearfil SE Bond was used and only by thermal/erosive cycling when Optibond FL was used. No differences were observed among dentin specimens. Conclusions: Thermal/erosive cycling can adversely affect microleakage and shear bond strength of composite resin bonded to enamel.

Clinical Relevance Contamination of enamel and dentin with repair surface conditioning measures should be avoided. SUMMARY Objectives: To analyze whether the contamination with different repair conditioning measures impairs the adhesive performance of a universal adhesive applied in etch-and-rinse mode (ER) or self-etch mode (SE). Methods and Materials: Bovine enamel and dentin surfaces (each subgroup n=16) were bonded with a universal adhesive in ER or SE after contamination with different repair conditioning measures (sandblasting, silica coating, hydrofluoric acid etching, self-etching ceramic primer). In half of the groups, sand-blasting, silica coating, and hydrofluoric acid etching was followed by the use of a universal primer. If the universal adhesive was applied in ER, contamination was performed either before or after phosphoric acid etching. If the universal adhesive was applied in SE, bonding was performed after contamination. In the control groups, no contamination was simulated. Shear bond strength (SBS) and failure modes of composite buildups were determined after thermal cycling (10,000 cycles, 5°C-55°C). Statistical analysis was performed using analyses of variance, Weibull statistics, and χ2 tests (p Results: In ER, sandblasting and silica coating significantly reduced SBS (control: enamel =25.7±4.2 MPa; dentin = 22.0±5.3 MPa) only when performed after phosphoric acid etching. Contamination with hydrofluoric acid impaired SBS on enamel but not on dentin. The self-etching ceramic primer reduced SBS, but not significantly. The contamination with the universal primer had no significant effect. In SE, all repair conditioning measures except the universal primer reduced SBS (control: enamel = 20.3±5.5 MPa; dentin = 23.0±4.0 MPa). Conclusion: Contamination of enamel and dentin by repair conditioning measures potentially affects bond strength.

Contains fulltext : 218124.pdf (Publisher’s version ) (Closed access) Our understanding of erosive tooth wear and its contributing factors has evolved considerably over the last decades. New terms have been continuously introduced, which frequently describe the same aspects of this condition, whereas other terms are being used inappropriately. This has led to unnecessary confusion and miscommunication between patients, professionals, and researchers. A group of 15 experts, selected by the European Organization for Caries Research (ORCA) and the Cariology Research Group of the International Association for Dental Research (IADR), participated in a 2-day workshop to define the most commonly used terms in erosive tooth wear. A modified Delphi method was utilized to reach consensus. At least 80% agreement was achieved for all terms discussed and their definitions related to clinical conditions and processes, basic concepts, diagnosis, risk, and prevention and management of erosive tooth wear. Use of the terms agreed on will provide a better understanding of erosive tooth wear and intends to enable improved communication on this topic.

Objectives Repairs are frequently taught at dental schools around the world. Various studies regarding the teaching of composite repairs were performed over the past 20 years. However, it is unclear if teaching reflects current evidence and if clinical recommendations have changed over time. Sources Electronic databases (Embase, Scopus, PubMed) were searched. Study selection Studies reporting on teaching concepts (i.e. recommended treatment steps) were included. Teaching was analysed regarding key treatment steps for conditioning of the repair surface (use of (1) diamond burs, (2) air abrasion/silica coating, (3) application of silane or universal primers, and (4) application of adhesives) using random-effects meta-analyses, meta-regressions, and an overall quality score. Data 63 records were assessed, and 12 studies having surveyed 331 dental schools were included. The mean (95%CI) proportion of dental schools teaching the use of diamond burs for roughening of the repair surface amounted to 83.0% (71.0-90.7%). Air abrasion / silica coating, the use of silane/universal primers and adhesives was taught by 29.8% (18.7-44.1%), 32.4% (21.1-46.2%), and 86.4% (73.5-93.6%), respectively. In recent years, dental schools more often taught the use of adhesives (padj. = 0.012) and the mean overall quality score of teaching improved (p = 0.007). Conclusions Share of dental schools recommending most of the key treatment steps did not significantly increase over the past 20 years. However, the overall quality of teaching improved, and teaching is nowadays more consistent with recently published recommendations. Clinical significance Repairs are not only frequently taught, but the mean overall quality score did improve in recent years.

Made available in DSpace on 2019-10-06T17:01:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Aim: The aim of this study was to compare microleakage assessment by micro-tomography (micro-CT) and conventional microscopy in class V restorations after different aging treatments. Methods: Class V cavities were prepared in sound human molars and restored with composite (Filtek Supreme XTE) after application of a self-etch adhesive (Clearfil SE Bond). Sealing ability was evaluated by assessing silver nitrate penetration along enamel and dentin margins either by micro-CT or by conventional stereomicroscopy. Class V cavities were divided in three groups (each n = 5): control: no aging, thermocycling: 10,000 cycles, 5–55 °C; thermo-erosive cycling: thermocycling with concomitant storage in HCl (pH 2.1, 5 min, 6×/day, 8 days). Penetration of silver nitrate was quantified by micro-CT and stereomicroscopy (25-fold magnification). Data for silver penetration assessed by stereomicroscopy and micro-CT were checked for normality and analyzed by Pearson or Spearman correlations. Differences between the aging effects were analyzed by one-way ANOVA (enamel) or Kruskal-Wallis tests (dentin) (p< 0.05). Results: For enamel, the correlations between stereomicroscopy and micro-CT data were not significant. For dentin, silver penetration depths obtained by stereomicroscopy and by micro-CT were moderately correlated (r=0.54, p=0.039), while volume of silver penetration (micro-CT) was not significantly correlated with penetration depth of silver (stereomicroscopy). Thermo-erosive cycling mostly increased microleakage compared with the control group and restorations submitted to thermocycling. Conclusions: Thermo-erosive aging increased the microleakage at enamel and dentin. The micro-CT analysis resulted in lower values of microleakage compared with the conventional stereomicroscope. Clinical significance: Microleakage is often used to evaluate the interfacial integrity of adhesives with dental hard tissues. The micro-CT analysis underestimated the dye penetration compared with the assessments made by the conventional stereomicroscopy, leading to lower microleakage values. Department of Preventive Dentistry Periodontology and Cariology University of Göttingen, Robert-Koch-Str. 40 Department of Restorative Dentistry Institute of Science and Technology São Paulo State University-UNESP Institute for Diagnostic and Interventional Radiology University of Göttingen Department of Restorative Dentistry Institute of Science and Technology São Paulo State University-UNESP FAPESP: #2015-08383-1

OBJECTIVES This study aimed to analyse loss of enamel worn against composite, leucite glass ceramic or enamel antagonists under non-erosive and alternating or simultanuous erosive-attritive conditions. MATERIALS AND METHODS Flat human enamel specimens were loaded (1 Hz, 300 g loading weight, each subgroup n = 12) with antagonists made from a hybrid-composite (Z250, 3 M Espe), a nano-composite (Filtek Supreme XTE, 3 M Espe), leucite glass ceramic (IPS Empress CAD LT, Ivoclar Vivadent) or enamel. Specimens were either submitted to mechanical loading in mineral solution (60 s) or to loading under alternating or simultaneous erosive conditions. For alternating erosion-attrition, specimens were eroded by citric acid (pH 2.6, 60 s) and then loaded with the respective antagonist for 60s. For simultaneous erosion-attrition, specimens were loaded with the respective antagonist while being immersed in citric acid (pH 2.6, 60 s). After each cycle, specimens were stored in water for 1 h. After 18 cycles, enamel loss was calculated profilometrically and statistically analysed by two-way ANOVA and Tukey's post-hoc tests (p < 0.05). RESULTS Enamel loss (μm, mean ± standard deviation) was significantly highest for simultaneous erosion-attrition (ceramic 9.4 ± 1.1, hybrid-composite 8.3 ± 0.7, nano-composite 7.8 ± 1.2, enamel 7.4 ± 0.8) followed by alternating erosion-attrition (ceramic 3.5 ± 0.5, hybrid-composite 2.1 ± 0.8, nano-composite 1.0 ± 0.2, enamel 2.5 ± 0.7) and attrition in mineral solution (ceramic 0.5 ± 0.3, hybrid composite 0.3 ± 0.1, nano composite 0.1 ± 0.2, enamel 0.1 ± 0.1). Ceramic antagonists resulted in significantly higher loss than the remaining antagonistic materials when alternating or simultaneous erosion-attrition was performed. CONCLUSION Erosive conditions had a massive impact on enamel worn against different antagonistic materials, with simultaneous erosive-attritive conditions being more detrimental than alternating erosive-attritive conditions. CLINICAL RELEVANCE Enamel wear by antagonistic restorative materials is significantly influenced by erosive conditions.

Objectives Repairing instead of replacing partially defective composite or amalgam restorations might reduce the initial treatment risks and costs, but could be less advantageous long-term due to repeated re-interventions being required. This study aimed to compare the cost-effectiveness of repairing versus replacing composite or amalgam restorations. Methods A mixed public-private-payer perspective from the German healthcare setting was adopted. A permanent molar with a three-surfaced partially defective composite or amalgam restoration in need of repair or replacement was modelled. Risks of complications after repair or complete replacement were derived by a rapid systematic literature review. The health outcome measure was tooth retention years. Costs were estimated from the German public and private fee catalogues. Monte-Carlo microsimulations were performed and incremental-cost-effectiveness ratios (ICERs) were used to express cost differences per gain or loss of effectiveness. Results Compared with complete composite replacement, composite repairs were marginally more costly and more effective (€326 versus €321; 24.7 versus 24.0 years; ICER: €7.14). Amalgam repairs were more costly and more effective than complete replacement (€467 versus €326; 24.3 versus 23.7 years; ICER: €235). If composite repair costs were € 166, composite repair was always cost-effective. This was not the case for amalgam repair. The size of the restoration, the reason for repair/replacement, and patients’ age were found to influence the cost-effectiveness. Conclusions Repair was found to be more effective, but not necessarily less costly than complete replacement of restorations. Clinical significance Repairing instead of replacing partially defective restorations is likely to retain teeth for longer compared with complete replacement. When considering cost-effectiveness, repairing composite can be recommended more strongly than repairing amalgam restorations.

OBJECTIVES The aims of this study were (1) to investigate prevalence, severity and distribution of erosive tooth wear in German kindergarten children aged 3-6 years in 2014/15 in comparison to an earlier survey from 2004/05 and (2) to identify and compare possible risk factors. METHODS 775 children aged 3-6 years from 27 kindergartens were examined in 2014/15 and compared to the data from 2004/05 (432 children/21 kindergartens). Erosive tooth wear was examined using the O'Sullivan-Index. Additionally, data were converted into the Basic Erosive Wear Examination (BEWE)-index. Information about dietary habits, chronic illness and oral hygiene practices were obtained by questionnaires. Statistical analyses were done by Chi(2)-, Mann-Whitney U Tests and regression analyses (p

The aim of the present study was to perform a representative survey among German dentists about attitudes, practice, and experience regarding single-tooth repair restorations.An anonymous questionnaire was designed and mailed to all registered dentists in Lower Saxony (n = 6600). Twenty-eight percent were returned (n = 1852), and n = 1805 could be analyzed. Statistical analyses were done by Wilcoxon signed-rank tests, Kruskal-Wallis tests, and ordered logistic regressions (p 0.05).Only 2.2 % of the dentists declared to never perform repair restorations. Composite restorations were repaired significantly more often than all other materials. Frequency of performing repair restorations was partially associated to dentist-related factors. The decision for repairing a restoration was dependent on several tooth- and restoration-associated variables. The main indications for repair were the partial loss of restoration or adjacent tooth structure as well as chipping and endodontic access cavities of crowns. Repair restorations were mostly done with composite using various different preconditioning techniques. Overall patients' acceptance was reported to be high. Most of the dentists considered repair restorations as permanent restoration with a moderate to high longevity. Estimated success of repair restorations depended significantly on the dentists' experiences (frequency and techniques of repair restorations).Repair restorations were often performed and were well accepted by dentists and patients, but indications for repair restorations as well as applied materials and techniques varied distinctly.Repairs of single-tooth restorations are well accepted and frequently performed, but indications, techniques, and materials require further research.

Objectives To investigate the effect of methacrylate polyhedral oligomeric silsesquioxane (POSS-8) particles on the polymerization process, dentin bond strength, and mineral precipitation of universal dental adhesives. Methods Five universal adhesives (Adhese Universal, CLEARFIL Universal Bond, Futurabond U, iBOND Universal, Scotchbond Universal) were filled with POSS-8 particles (10 wt%, additionally 2 wt% and 5 wt% in Scotchbond Universal). The particle size and dispersion in ethanol and acetone were examined by dynamic light scattering. Degree of conversion, linear shrinkage, and shear bond strength to dentin treated with the filled and pure adhesives (controls) were measured. Growth of calcium phosphate (Ca/P) precipitates on the adhesive specimens immersed in artificial saliva for up to 28 days was analyzed by energy-dispersive X-ray spectroscopy and scanning electron microscopy. Statistical analyses were performed using ANOVA and Tukey's post-hoc tests (p Results The hydrodynamic radius of the particles in acetone (1.4 ± 0.4 nm) and ethanol (1.1 ± 0.4 nm) revealed their good dispersion. POSS-8 did not change the degree of conversion and dentin bond strength of any adhesive. Ca/P precipitates formed on iBOND Universal specimens doped with POSS-8 after 4 weeks of immersion, but were not detected on the unfilled adhesive. The mineral precipitation of all other adhesives was not improved by POSS-8. Significance POSS-8 particles did not compromise polymerization and bonding of universal adhesives. Ca/P precipitation was stimulated by POSS-8 only in iBOND Universal.

To evaluate the efficacy of sonically and ultrasonically activated irrigation on removal of accumulated hard-tissue debris (AHTD) in mesial root canal systems of mandibular molars using micro-computed tomographic (micro-CT) analysis.Forty mesial roots of mandibular molars with two independent canals joined apically by an isthmus (Vertucci type II) were selected. The root canals were instrumented using Reciproc R25 instruments, and specimens were scanned at a resolution of 10.5 μm. Subsequently, n = 10 roots were assigned to each of the four final irrigation groups such that the group means and variances were almost identical: sonically activated irrigation with EndoActivator (EA) or EDDY (ED), ultrasonically activated irrigation (UAI) and manual irrigation without activation (MI). The final irrigation procedures were performed using a total of 5 mL 1% NaOCl and 5 mL 15% EDTA per canal over 5 min with activation time of 4 × 20 s. Reconstructed data sets were coregistered, and the mean percentage reduction of AHTD after final irrigation was compared statistically between groups using analysis of variance at a significance level set at 5%.A significant reduction of AHTD was achieved after final irrigation in all groups (P 0.05), ranging from 44.1% to 66.8%. The vol% of debris after irrigation was 3.7 ± 1.9% for EA, 3.3 ± 2.3% for ED, 2.1 ± 1.6% for UAI and 4.4 ± 2.3% for MI, with no significant difference between groups (P 0.05).None of the final irrigation protocols completely removed AHTD from mesial root canal systems in extracted human mandibular molars. Sonically and ultrasonically activated irrigation performed no better compared to manual irrigation.

A large consumption of fermentable carbohydrates, for instance the high intake of sweetened beverages, is an important risk factor for overweight and obesity. As lemonades and fruit juices present high sugar content and quite low pH-values, overweight and obese children might also have an increased risk for dental caries and erosive tooth wear.The aim was to analyze the prevalence and severity of erosive tooth wear and caries experience in children and adolescents with overweight, obesity and extreme obesity compared to children with normal weight and to determine a possible association between erosive tooth wear and caries experience.223 children (4-17 years, n = 1476 primary and n = 4110 permanent teeth) were examined using standardized dental indices (BEWE, ICDAS, DMFT). Demographic and socio-economic data, eating habits, oral hygiene, fluoride supply and details of medical history were obtained from a questionnaire. Weight classification was based on age- and gender-specific relative body mass indices (BMI). Statistical analyses were done by ChiErosive tooth wear and caries experience in primary and permanent teeth were significantly increased in children with obesity and extreme obesity compared to normal weight children (p 0.05). Higher BMI, age, gender, and the consumption of erosive snacks/beverages were identified as statistically significant risk factors for erosive tooth wear. Higher BMI, age, socio-economic factors, poor toothbrushing habits, and consumption of cariogenic beverages were identified as significant caries risk factors. Erosive tooth wear and caries showed a weak correlation in children with (extreme) obesity (Φ = 0.110 to 0.248).Higher BMI of children and adolescents is significantly associated with a higher risk for erosive tooth wear and caries.

The aim of the in-situ study was to determine fluoride uptake in non-fluoridated, demineralized enamel after application of fluoride varnishes on enamel samples located at various distances from the non-fluoridated samples. All enamel samples used were demineralized with acidic hydroxyethylcellulose before the experiment. Intra-oral appliances were worn by ten volunteers in three series: (1, Mirafluorid, 0.15% F; 2, Duraphat, 2.3% F and 3, unfluoridated controls) of 6 days each. Each two enamel samples were prepared from 30 bovine incisors. One sample was used for the determination of baseline fluoride content (BFC); the other was treated according to the respective series and fixed in the intra-oral appliance for 6 days. Additionally, from 120 incisors, each four enamel samples were prepared (one for BFC). Three samples (a-c) were placed into each appliance at different sites: (a) directly neighboured to the fluoridated specimen (=next), (b) at 1-cm distance (=1 cm) and (c) in the opposite buccal aspect of the appliance (=opposite). At these sites, new unfluoridated samples were placed at days 1, 3 and 5, which were left in place for 1 day. The volunteers brushed their teeth and the samples with fluoridated toothpaste twice per day. Both the KOH-soluble and structurally bound fluoride were determined in all samples to determine fluoride uptake and were statistically analyzed. One day, after fluoridation with Duraphat, KOH-soluble fluoride uptake in specimen a (=next) was significantly higher compared to the corresponding samples of both the control and Mirafluorid series, which in turn were not significantly different from each other. At all other sites and time points, fluoride uptake in the enamel samples were not different from controls for both fluoride varnishes. Within the first day after application, intra-oral-fluoride release from the tested fluoride varnish Duraphat leads to KOH-soluble fluoride uptake only in enamel samples located in close vicinity to the fluoridation site. peerReviewed

This study aimed to assess self- and proxy-rated changes in the oral health-related quality of life (OHRQoL) in adult patients with intellectual disabilities after dental treatment in general anesthesia. The OHRQoL in 52 adult patients with intellectual and developmental disabilities was assessed prior to dental treatment in general anesthesia (t0), 2 to 3 (t1) and 12 weeks (t2) postoperatively. Therefore, patients and primary cargivers were surveyed using either the 5-item short form of the Oral Health Impact Profile translated into easy language (OHIP-G5-easy, self-rating, n = 27) or the 14-item short form of the Oral Health Impact Profile (OHIP-G14, proxy-rating, n = 51), respectively. OHIP-G5-easy and OHIP-G14 summary scores were statistically analyzed with non-parametric mixed effects models and spearman correlation (p

Objectives This study aimed to analyse if children with untreated or treated caries (restorations/missing teeth) are perceived differently compared to children with healthy teeth and to explore possible differences in the perception by laypersons and dental experts. Methods Eye movements of female experts (n = 20) and laypersons (n = 18) were recorded by eye-tracking while paired images (neutral expression/teeth not visible; emotional expression/smiling, teeth visible) of children with healthy teeth, with visible untreated or treated caries (restorations/missing teeth as a consequence of caries treatment), each n = 13, were presented. First fixation, total fixation time and number of fixations on the areas of interest (eyes, nose, mouth) in the first two seconds of presentation were determined. Furthermore, the images were rated regarding arousal, valence and attractivity. Statistical analysis was performed using Mann-Whitney-U- and Kruskal-Wallis-tests (α = 0.05). Results Generally, laypersons spent more time exploring and fixating the eye region than the mouth, while dental experts more often first percept and longer and more often fixated the mouth region, especially in images with emotional expression. Dental experts, but not laypersons, were significantly longer fixating the mouth of children with untreated caries than the mouth of children with healthy teeth in images with emotional expression. When evaluating images with emotional expression, both dental experts and laypersons rated children with healthy teeth to be more attractive, pleasant and calm than children with untreated or treated caries. Conclusions Children with visible treated and untreated caries were differently perceived by laypersons and dental experts than children with healthy teeth.

The aim of this study was to evaluate dental students' retention of factual and procedural knowledge gained in a preclinical course in operative dentistry during a clinical dental curriculum. In 2017, all 157 seventh- to tenth-semester dental students at a dental school in Germany were asked to repeat the same written examination performed at the end of the preclinical course in the sixth semester. The examinations consisted of 30 multiple-choice questions covering factual and procedural knowledge. The percentage of correctly answered questions per exam and differences in correct answers between the original examination and the re-examination (per question) were analyzed. Students were also asked to self-rate their percentage of correctly answered questions and their knowledge in various disciplines of operative dentistry at the times of the original examination and the re-examination. After exclusions, data were analyzed for 129 students, for a participation rate of 82%. For the seventh- and tenth-semester students, the results on the original examination and the re-examination were not significantly different, while the eighth- and ninth-semester students performed significantly better on the original examination than the re-examination. In all semesters, procedural knowledge remained stable between the original examination and the re-examination, while factual knowledge decreased slightly. Their performance on the original examination was underestimated by the eighth- and ninth-semester students. All the students underestimated their performance on the re-examination. Students mostly rated their knowledge level significantly higher on the original examination than on the re-examination. Overall, this study found that factual and procedural knowledge gained in a preclinical course in operative dentistry was not increased during the clinical dental curriculum.

Aim To evaluate the effect of moisture content in root canal dentine on detection of microcracks using micro-computed tomography. Methodology Ten roots with and without craze lines or cracks (each n = 5) were selected and scanned six times with different moisture conditions of root dentine using a micro-CT scanner at a high resolution of 10.5 μm. Scanning conditions were as follows: 1. after 30 d wet storage, 2. after 2 h dry time, 3. after 48 h wet storage, 4. after 24 h dry time, 5. after 48 h wet storage, 6. after 2 h dry time. From each scan, cross-sectional images were obtained at intervals of 1 mm (total n = 708) and evaluated for the presence of dentinal microcracks twice by 5 calibrated blinded observers. Statistical analysis was performed by nonparametric analysis of variance for longitudinal data (P < 0.05). Results Intra-rater percentage agreement ranged between 92% and 98%, whereas inter-rater percentage agreement was 81% and 83%, respectively. No significant differences between all wet groups as well as between both groups with 2 h dry time were detected (P > 0.05). Almost no cracks were observed after wet storage with a significant increase of cracks after 2 h dry time (P < 0.001). Significantly more microcracks were identified after 24 h than after 2 h dry time (P < 0.004). Conclusions Moisture content of dentine influenced detection of microcracks when evaluated using micro-CT. Scanning should be performed on dried specimens to allow reliable identification of dentinal defects. Formation of new cracks during dry periods up to 24 h was disproved. This article is protected by copyright. All rights reserved.

Objectives To investigate the effect of saliva substitutes on enamel erosion in vitro. Methods A total of 204 bovine enamel samples were embedded in acrylic resin and allocated to 17 groups (n = 12). The specimens were eroded in an artificial mouth (3 days; 6 × 30 s/days, flow rate: 2 ml/min) using citric acid (pH: 2.5). Immediately after the erosive attacks, saliva substitutes (12 sprays, 3 gels) were applied. Between the erosive cycles the specimens were rinsed with artificial saliva (flowrate: 0.5 ml/min). A SnCl2/AmF/NaF-containing mouthrinse was used as positive control, water spray served as negative control. Enamel loss was measured profilometrically and the data were analyzed using one-way ANOVA followed by Scheffe’s post hoc tests (p Results Four saliva substitutes increased enamel erosion, probably due to the low pH or the content of citric acid. Several saliva substitutes were able to reduce enamel erosion significantly by 60–90% (in the range of the positive control). The protective potential of these products was in the range of the positive control (reduction of enamel loss to 30% of negative control). The erosion-protective potential of these high-viscous products is probably related to their film-forming properties, leading to a mechanical protection of the surface. Conclusion Saliva substitutes containing a very low pH exhibit a distinct erosive potential, while most high-viscous products present an erosion-protective effect. It can be recommended that patients suffering from xerostomia and at high risk for dental erosion should use high-viscous saliva substitutes, but should avoid saliva substitutes with low pH or containing citric acid. Clinical significance It can be recommended that patients suffering from xerostomia and at high risk for dental erosion should use high-viscous saliva substitutes, but should avoid saliva substitutes with low pH or containing citric acid.

This study aimed to evaluate the effect of differential learning of toothbrushing compared to habitual toothbrushing and instruction/demonstration of toothbrushing on plaque reduction and gingival inflammation of primary school children. Children (6–9 years) were subjected to a toothbrushing training consisting of 15 days (3 × 5 days, interval 2 days, 3 min/day) and randomly assigned to one of three groups (each n = 18): habitual toothbrushing/control, instruction/demonstration of toothbrushing, differential learning of toothbrushing. The differential learning approach comprised 15 different movement exercises (1/day), while instruction/demonstration of toothbrushing was based on repetitive practice of toothbrushing. Plaque (Turesky-modified Quigley-Hein plaque index (T-QHI)) and papilla bleeding (papilla bleeding index (PBI)) scores were assessed prior to the first toothbrushing (t0, baseline) and 21 (t1), 42 (t2) and 63 (t3) days after beginning of the study. Primary statistical analyses were performed with cumulative logit regression models with repeated measures. The global significance level was set to 5% two-sided. At all time points, PBI and T-QHI were significantly reduced by differential learning compared to instruction/demonstration of toothbrushing and habitual toothbrushing. Compared to baseline, differential learning improved PBI and T-QHI significantly at all time points. In the other groups, no significant reduction of PBI compared to baseline was observed. T-QHI was significantly reduced by habitual toothbrushing only at t1 and by instruction/demonstration of toothbrushing at t1 and t2. Differential learning had an improved effect on posterior compared to anterior teeth. Differential learning of toothbrushing improved plaque reduction and reduced gingival inflammation compared to habitual toothbrushing and instruction/demonstration of toothbrushing in 6- to 9-year-old children in mixed dentition. Toothbrushing skills of children might be improved by differential learning. ISRCTN14951343, https://www.isrctn.com/ISRCTN14951343?

This study aimed to analyse and compare the protective effect of buffered (pH 3.5) and native (pH 1.2) TiF4 in comparison with NaF solutions on enamel erosion. Bovine samples were pretreated with 1.50% TiF4 or 2.02% NaF (both 0.48 M F) solutions, each at a pH of 1.2 and 3.5. The control group received no fluoride pretreatment. Twenty samples per group were eroded with HCl (pH 2.6) for 10 × 60 s. Erosion was either investigated by profilometry (n = 10) or by determination of calcium release into the acid (n = 10). Additionally, the elemental surface composition was quantified by X-ray energy-dispersive spectroscopy in fluoridated but not eroded samples (6 samples per group). Scanning electron microscopy was performed prior and after erosion (2 samples per group). Cumulative enamel loss (μm) and calcium release (nmol/mm2) were analysed by repeated-measures ANOVA. The Ti and F surface composition was analysed by one-way ANOVA separately for each element. Only TiF4 at pH 1.2 reduced enamel surface loss significantly. Calcium release was significantly reduced by TiF4 and NaF at pH 1.2, but not by the solutions at pH 3.5. Samples pretreated with TiF4 at pH 1.2 showed a significant increase in Ti, while NaF increased F concentration significantly. Only TiF4 at pH 1.2 induced the formation of a glaze-like layer, which was still present after erosion. Enamel erosion can be significantly reduced by TiF4 at pH 1.2 but not at pH 3.5. TiF4 at pH 1.2 was more effective in protecting against enamel erosion than NaF.

OBJECTIVE: Toothbrush abrasion is significant in the development of tooth wear, particularly when combined with erosion. This in vitro study aimed to evaluate the impact of toothpaste slurry abrasivity and toothbrush filament stiffness on abrasion of eroded enamel. MATERIAL AND METHODS: Eroded enamel samples (hydrochloric acid, pH: 2.6, 15 s) were brushed with 40 strokes in an automatic brushing machine using manual toothbrushes with different filament stiffness (filament diameter: 0.15, 0.20, or 0.25 mm). A paste-free control slurry (relative enamel abrasion (REA) value 2) and toothpaste slurries with different abrasivity (REA values 6 or 9) were used for brushing. Erosion and abrasion were followed by storing the enamel samples in artificial saliva for 3 h. After each 4th cycle, the samples were stored in artificial saliva for 15 h. After 60 cycles, enamel loss was measured by profilometry and statistically analyzed by two-way and one-way ANOVA and Bonferroni/Dunn post-hoc tests. RESULTS: Loss of enamel (mean, microm) was influenced mainly by the abrasivity of the slurry and increased along with REA value (REA 2: 0.0-0.2, REA 6: 2.1-3.3, REA 9: 2.9-3.7). Abrasion of eroded enamel was also affected by filament stiffness of the toothbrush, but only groups brushed with toothpaste slurry of REA 6 showed any significant difference between the different toothbrushes. Thereby, toothbrushes with 0.2 mm filament diameter caused higher enamel loss than 0.15 and 0.25 mm filaments. CONCLUSIONS: Toothbrush abrasion of eroded enamel is influenced mainly by the abrasivity of the toothpaste slurry, but is also modified by toothbrush filament stiffness.

Made available in DSpace on 2018-12-11T17:27:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-03-01 The aim of this study was to evaluate the erosion-preventive effect of different artificial saliva formulations and human saliva in vitro compared to human saliva in situ. In the in vitro experiment, bovine enamel and dentin specimens were stored in artificial saliva (4 different formulations, each n = 20), deionized water (n = 20) or human saliva (n = 6 enamel and dentin specimens/volunteer) for 120 min. In the in situ experiment, each of the 6 enamel and dentin specimens was worn intraorally by 10 volunteers for 120 min. The specimens were then eroded (HCl, pH 2.6, 60 s). Half of the specimens were subjected to microhardness analysis (enamel) and the determination of calcium release into the acid (enamel and dentin), while the other half were again placed in the respective medium or worn intraorally, respectively, for 120 min before a second erosion was performed. Knoop microhardness of enamel and the calcium release of enamel and dentin into the acid were again determined. Statistical analysis was conducted by two-way repeated-measures ANOVA or two-way ANOVA (α = 0.05). Enamel microhardness was not significantly different between all test groups after the first and the second erosive challenge, respectively. Enamel calcium loss was significantly lower in situ compared to the in vitro experiment, where there was no significant difference between all test groups. Dentin calcium loss was significantly lower than deionized water only after the first and than all except one artificial saliva after the second erosion. Under the conditions of this experiment, the use of artificial saliva formulations and human saliva in vitro does not reflect the intraoral situation in dental erosion experiments adequately. Department of Preventive Dentistry Periodontology and Cariology University of Zurich Department of Restorative Dentistry Institute of Science and Technology UNESP - São Paulo State University, Av. Engenheiro Francisco Jose Longo, 777, Jd. Sao Dimas Department of Preventive Dentistry Periodontology and Cariology University of Göttingen Department of Restorative Dentistry Institute of Science and Technology UNESP - São Paulo State University, Av. Engenheiro Francisco Jose Longo, 777, Jd. Sao Dimas

Aim of the present study was to compare toothbrushing abrasion of eroded human and bovine enamel utilizing a toothpaste slurry. The surfaces of each 36 teeth from cattle and calves and from each 36 human wisdom teeth and deciduous teeth were polished. Each 12 specimens from the respective tooth type were used for assessing toothbrushing abrasion only (A), erosion only (E) and the combination of erosion and toothbrushing abrasion (EA). The EA samples were subjected to 20 cycles comprising a demineralization/remineralization procedure directly followed by toothbrushing abrasion (100 strokes, 300 g load, toothpaste slurry: 3 ml artificial saliva mixed with 1 g dentifrice). Demineralization in form of erosion was performed with 1% citric acid (1 min), remineralization with artificial saliva (15 min). Between the cycles, the samples were stored in artificial saliva. Wear of the treated surfaces with reference to untreated areas was determined profilometrically. The samples subjected to abrasion only (A) did not show a significantly different wear between the different kinds of teeth. The comparisons of substance loss between teeth of different species revealed that hard tissue loss of the human deciduous teeth was significantly lower as compared to calves’ teeth after both erosion and erosion–abrasion. Also, both erosion only and erosion–abrasion caused higher enamel loss in cattle's teeth than in human wisdom teeth. It is concluded that human eroded enamel offers better resistance against brushing than bovine enamel.

Objective Aim of the in vitro study was to evaluate the time period needed to re-establish enamel surface microhardness after bleaching with fluoridated (0.5% F − as NaF) and unfluoridated carbamide peroxide (CP) bleaching gels under a daily de- and remineralization protocol. Materials and methods Ninety enamel specimens were prepared from bovine incisors and prepared for Knoop microhardness determination. The samples were divided into five groups and bleached for 7 days (8 h per day) with experimentally designed neutral and acidic 10% CP gels: A (0.5% F − , pH 7.0), B (0.5% F − , pH 5.5), C (no F − , pH 7.0) and D (no F − , pH 5.5). Group E served as control and was not bleached. After each 8-h bleaching period the samples were subjected to a de- and remineralization protocol. In the following 5 days, the specimens were not bleached, but stored in artificial saliva for 8 h instead; the daily de- and remineralization cycles were maintained during this period. Knoop microhardness determinations were conducted at baseline, after each bleaching interval and after completion of each daily de- and remineralization cycle. A repeated measures two-way ANOVA statistical analysis and a comparison of confidence intervals was conducted to check for hardness recovery during the post-bleaching period. Results After completion of bleaching therapy on day 7 a statistically significant hardness loss was observed for all bleaching groups in the range of about 7–15% hardness reduction as compared to baseline. The fluoridated gels proved significantly less hardness loss than the unfluoridated gels. In the following period, from days 8 to 12 recovery of hardness to baseline data was observed in the fluoridated groups (A and B) after the first de-/remineralization cycle on day 8 (group A) and after the second 8-h remineralization period on day 9 (group B), respectively. Hardness of the specimens treated with the unfluoridated bleaching gel C returned to baseline values after day 10. The samples of group D did not show recover of hardness data during the 5-day post-bleaching period. Conclusion Fluoridated 10% carbamide peroxide bleaching gels support re-hardening of bleached enamel with a shorter period needed for hardness recover as compared to unfluoridated gels.

Objectives The purpose of this article was to review the fluoride release and recharge capabilities, and antibacterial properties, of fluoride-releasing dental restoratives, and discuss the current status concerning the prevention or inhibition of caries development and progression. Methods Information from original scientific full papers or reviews listed in PubMed (search term: fluoride release AND (restorative OR glass-ionomer OR compomer OR polyacid-modified composite resin OR composite OR amalgam)), published from 1980 to 2004, was included in the review. Papers dealing with endodontic or orthodontic topics were not taken into consideration. Clinical studies concerning secondary caries development were only included when performed in split-mouth design with an observation period of at least three years. Results Fluoride-containing dental materials show clear differences in the fluoride release and uptake characteristics. Short- and long-term fluoride releases from restoratives are related to their matrices, setting mechanisms and fluoride content and depend on several environmental conditions. Fluoride-releasing materials may act as a fluoride reservoir and may increase the fluoride level in saliva, plaque and dental hard tissues. However, clinical studies exhibited conflicting data as to whether or not these materials significantly prevent or inhibit secondary caries and affect the growth of caries-associated bacteria compared to non-fluoridated restoratives. Significance Fluoride release and uptake characteristics depend on the matrices, fillers and fluoride content as well as on the setting mechanisms and environmental conditions of the restoratives. Fluoride-releasing materials, predominantly glass-ionomers and compomers, did show cariostatic properties and may affect bacterial metabolism under simulated cariogenic conditions in vitro. However, it is not proven by prospective clinical studies whether the incidence of secondary caries can be significantly reduced by the fluoride release of restorative materials.

Objective The study aimed to evaluate the erosive effects of acids flowing with different velocities and duration on dentin previously pre-treated with distilled water or human saliva. Methods Bovine dentin surfaces were submitted to a 10 min demineralisation with hydrochloric or citric acid (pH 2.3, 37 °C) in an artificial mouth at flow rates of 3, 2.25, 1.5, 0.75 or 0.15 ml/min or in 30 ml of the respective acid without movement (each subgroup n = 16 specimens). Prior to the demineralisation, half of the specimens of each group were either pre-treated with distilled water or human saliva for 120 min. After 2, 5 and 10 min demineralisation, profilometric traces of dentin loss were performed perpendicular to the direction of acid flow at three sites (A–C) with intervals of 500 μm. The first profile (A) was taken in a distance of 1.5 mm from the acid starting to flow over the sample. Thus, median dentin loss at each site was calculated and statistically analysed by five-way ANOVA. Results Dentin loss increased with increasing acid flow rate and demineralisation time and was higher for demineralisation with citric acid compared to hydrochloric acid. For given flow rates of 0.15 to 3 ml/min, measurement of dentin loss yielded highest values for site A and decreasing values for sites B and C. For all groups, no significant differences of dentin loss were observed between specimens pre-treated with distilled water or human saliva. Conclusion Under the conditions of this study, both duration of demineralisation and acid flow rate but not pre-treatment with distilled water or saliva influence the extent of dentin erosion.

The study aimed to analyse the impact of olive oil and an olive-oil-containing fluoridated mouthrinse on enamel and dentin erosion.Bovine enamel and dentin specimens were submitted to 10 alternating demineralization and remineralization cycles each consisting of 5 min pretreatment with the test solutions, i.e. distilled water as negative control, 100% olive oil, 2% olive oil emulsion, 2% olive-oil-containing mouthrinse (Xerostom), acidic 13.2 mmol x l(-1) (250 ppm) fluoride solution as positive control, storage in artificial saliva (30 min), demineralization in citric acid (3 min, pH 2.3) and again storage in artificial saliva (60 min). Each group contained 10 enamel and dentin samples. Enamel and dentin loss was analyzed by profilometry after 10 cycles.Treatment with 100% olive oil was not effective in reducing enamel and dentin loss. Application of 2% olive oil or the olive-oil-containing mouthrinse also showed protection against erosion, but to a lesser degree compared to the positive control.Olive oil offered protection against enamel and dentin erosion when applied as 2% emulsion or 2% olive-oil-containing mouthrinse, but is not effective when applied as pure oil (100%). However, 2% olive oil emulsion is less effective in reducing erosion compared to the acidic 13.2 mol x l(-1) fluoride solution.

Objective This study evaluated the effect of fluoride gels, supplemented or not with sodium hexametaphosphate (HMP), on enamel erosive wear in situ. Methods Twelve healthy volunteers wore palatal appliances containing four bovine enamel discs. Subjects were randomly allocated into four experimental phases (double-blind, crossover protocol) according to the gels: Placebo (no fluoride or HMP), 1% NaF, 2% NaF, and 1% NaF + 9% HMP. Enamel discs were selected after polishing and surface hardness analysis, and treated only once with the respective gels prior to each experimental phase. Erosion (ERO) was performed by extra-oral immersion of the appliance in 0.05 M citric acid, pH 3.2 (four times/day, five minutes each, 5 days). Additional abrasion (ERO + ABR) was produced on only two discs by toothbrushing with fluoridated dentifrice after ERO (four times/day, 30 s, 5 days). The specimens were submitted to profilometry and hardness analysis. The results were analyzed by two-way ANOVA and the Student–Newman–Keuls test (p Results The 1% NaF + 9% HMP gel promoted significantly lower enamel wear for ERO compared to the other groups, being statistically lower than 1% NaF and Placebo for ERO + ABR. Similarly, the lowest values of integrated lesion area were found for 1% NaF + 9% HMP and 2% NaF, respectively, for ERO and ERO + ABR. Conclusion The addition of HMP to the 1% NaF gel promoted greater protective effect against ERO and ERO + ABR compared to the 1% NaF gel, achieving similar protective levels to those seen for the 2% NaF gel. Clinical significance Gel containing 1% NaF + 9% HMP showed a high anti-erosive potential, being a safer alternative when compared to a conventional 2% NaF gel.

Objective: To evaluate the recolonization pattern of Mutans streptococci (ms) on densely colonized teeth with fixed orthodontic appliances after treatment with a highly concentrated (36%) chlorhexidine varnish. Materials and Methods: Healthy subjects (n = 19) with fixed orthodontic appliances and high bacterial ms counts in saliva were recruited. In order to establish a baseline registration, plaque adjacent to brackets was sampled and cultivated on Dentocult® strips. Following professional tooth cleaning, chlorhexidine varnish was applied on all teeth for 8 minutes. The degree of recolonization with ms was assessed 2 weeks after varnish application in plaque around the brackets. For statistical analysis, the data were subjected to a repeated measures design. Results: After 2 weeks, ms counts were reduced as compared to baseline values. However, the reduction only weakly met statistical significance (P = .049). Conclusions: The application of a highly concentrated chlorhexidine varnish in patients with fixed orthodontic appliances does not result in a distinct reduction of ms numbers 2 weeks after treatment.

Objective Aim of the study was to evaluate the influence of carbamide peroxide (CP) on enamel fluoride uptake by comparing enamel fluoride uptake from a 1% amine fluoride (AmF) gel with the fluoride acquisition from a 10% carbamide peroxide agent supplemented with 1% AmF. Materials and methods Three enamel cylinders (4 mm in diameter) were prepared from the buccal surfaces of 60 bovine incisors. One sample of each tooth was used for determination of baseline fluoride content of the respective tooth. The two remaining samples were allocated to the experimental series 1 or 2, respectively. Each series consisted of five experimental groups (A–E, n = 12) and differed with respect to the length of the treatment period with the gels (A–D). The experimentally designed gels (pH 5.5) used in the study were as follows: A (10% CP), B (10% CP, 1% F− as AmF), C (1% F− as AmF), D (no CP, no F−) and were formulated on the same basis. The enamel samples were covered for 4 h with the respective gel at 37 °C and were then transferred to artificial saliva for 20 h (series 1). The samples of group E served as controls and were not treated with a gel. In series 2, treatment with the gels and storage in saliva was conducted seven times. Finally, the samples were assessed for KOH-soluble and structurally bound fluoride. Results Only the enamel samples treated with the fluoridated bleaching gel (group B) and with the amine fluoride gel (group C) exhibited significant fluoride acquisition. Thereby, both gels showed significantly lower uptake in series 1 as compared to series 2. Both KOH-soluble and structurally bound fluoride acquisition was significantly higher in group C than in group B. Conclusion Treatment with a carbamide peroxide gel supplemented with amine fluoride causes less fluoride acquisition in enamel than a pure amine fluoride gel. Under the conditions of the study, it is assumed that carbamide peroxide seems to influence enamel fluoride uptake.

The aim of the present study was to compare the recolonization pattern of mutans streptococci on densely colonized teeth with and without fixed orthodontic appliances after treatment with a 40 per cent chlorhexidine (CHX) varnish (EC 40, Explore). Healthy subjects free of carious lesions requiring fixed orthodontic appliance treatment but with high bacterial mutans streptococci saliva counts were recruited (n = 10). For baseline registration, plaque from buccal sites was sampled and cultivated on Dentocult strips. Following professional tooth cleaning, CHX varnish was applied to all teeth for 8 minutes. Subsequently, orthodontic brackets and bands were inserted in either the upper or lower arch. Eight weeks after varnish application the degree of recolonization with mutans streptococci was reassessed on the buccal sites. Statistical analysis showed that recolonization with mutans streptococci was significantly higher (P < 0.05) on teeth with orthodontic appliances. The results indicate that the use of fixed orthodontic appliances creates artificial environments suitable for the proliferation of mutans streptococci after CHX varnish suppression.