Survival of molar teeth in need of complex endodontic treatment: Influence of the endodontic treatment and quality of the restoration.

OBJECTIVES: The objective of this retrospective practice-based study was to evaluate the survival of molar teeth and endodontic success after complex endodontic treatment up to 89 months. METHODS: Endodontically (Endodontic Treatment Classification (ETC) scores II and III) treated first and second molars treated between January 2011-October 2017 within a referral setting were included. Open apices, combined surgical treatment, ETC score I, patients <18 years or with an ASA-score >2 were excluded. Cumulative survival estimates and Cox regression analysis were performed for tooth survival and endodontic healing according to the Glossary of Endodontic Terms. Restoration quality was assessed using the FDI criteria. Alpha was set at 0.05. RESULTS: 279 endodontically treated molars in 245 patients were included for survival analysis and 268 molars for endodontic success. After 89 months, the cumulative survival was 91.7 % [95 % CI: 86.8 %-94.9 %]. Absence of adjacent teeth and deviance in root canal morphology significantly decreased the probability of tooth survival. Cumulative endododontic healing rates after 48 and 89 months were 82.2 % [95 %CI: 75.7 %-87.1 %] and 51.1 [95 % CI: 20.2 %-75.5 %] respectively. Deviance in root canal morphology and inadequate coronal seal significantly decreased the probability of endodontic healing. Indirect restorations obtained higher esthetic and biological FDI scores, however no difference between direct and indirect restorations was found concerning the functional FDI score. CONCLUSIONS: After 89 months, cumulative survival of molars in need of complex endodontic treatment was 91.7 % [95 % CI: 86.8 %-94.9 %]. CLINICAL SIGNIFICANCE: Within daily clinical practice, the dilemma of performing a complex endodontic (re)treatment or to explore other treatment options for molar teeth in need of reintervention is still urgent. Tooth survival of molar teeth with complex endodontic (re)treatment seems satisfactory up to 89 months.

Digital assessment of a retentive full crown preparation-An evaluation of prepCheck in an undergraduate pre-clinical teaching environment.

INTRODUCTION: Acquiring practical skills is essential for dental students. These practical skills are assessed throughout their training, both formatively and summatively. However, by means of visual inspection alone, assessment cannot always be performed objectively. A computerised evaluation system may serve as an objective tool to assist the assessor. AIM: The aim of the study was to evaluate prepCheck as a tool to assess students' practical skills and as a means to provide feedback in dental education. METHODS: As part of a previously scheduled practical examination, students made a preparation for a retentive crown on the maxillary right central incisor-tooth 11. Assessments were made four times by two independent assessors in two different ways: (a) conventionally and (b) assisted by prepCheck. By means of Cohen's kappa coefficient, agreements between conventional and digitally assisted assessments were compared. Questionnaires were used to assess how students experienced working with prepCheck. RESULTS: Without the use of prepCheck, ratings given by teachers differed considerably (mean κ = 0.19), whereas the differences with prepCheck assistance were very small (mean κ = 0.96). Students found prepCheck a helpful tool for teachers to assess practical skills. Extra feedback given by prepCheck was considered useful and effective. However, some students complained about too few scanners and too little time for practice, and some believed that prepCheck is too strict. CONCLUSION: prepCheck can be used to assist assessors in order to obtain a more objective outcome. Results showed that practicing with feedback from both prepCheck and the teacher contributes to an effective learning process. Most students appreciated prepCheck for learning practical skills, but introducing prepCheck requires enough equipment and preparation time.

Performance of ceramic laminate veneers with immediate dentine sealing: An 11 year prospective clinical trial.

OBJECTIVE: In this prospective clinical trial the survival, success rate and patient satisfaction of ceramic laminate veneers with special interest on existing restorations, immediate dentin sealing and endodontically treated teeth was evaluated. METHODS: A total of 104 patients (mean age: 42.1 years old) received 384 feldspathic ceramic laminate veneers on maxillary anterior teeth. Veneer preparations with incisal overlap were performed using a mock up technique. Existing resin composite restorations of acceptable quality were not removed but conditioned using silica coating and silanization. Immediate dentin sealing (IDS) was applied when more than 50% of dentin was exposed during preparation. Endodontically treated teeth were not excluded. After adhesive cementation, restorations were evaluated by calibrated evaluators at baseline and final follow-up using modified USPHS criteria. RESULTS: 225 Laminate veneers were bonded onto teeth without existing restorations, 159 on teeth with pre-existing resin composite restorations, 87 to teeth with more than 50% of exposed dentin surface and 43 to endodontically-treated teeth. In total, 19 failures were observed in form of debonding (n = 3), fracture (n = 15) and extraction due to endodontic complications (n = 1). In teeth with more than 50% of dentin exposure, a significant increase in survival rate was observed when IDS was used (96.4% versus 81.8%). No significant difference was found between teeth with and without pre-existing composite resin restorations (84.6% versus 95.5%) or between vital and non-vital teeth (95.6% versus 88.1%). Laminate veneers luted to endontically-treated teeth had a significant mis-match in color compared to vital teeth. Patients who smoked presented with significantly more marginal discoloration, but no intervention was needed. Patients scored favorably values on the Oral Health Impact Profile questionnaire and were generally satisfied with the treatment. In this clinical trial, the ceramic laminate veneers had a relatively high survival rate. SIGNIFICANCE: Teeth with more than 50% of dentin exposure significantly benefit from IDS. Pre-existing restorations or endodontic treatments do not have an effect on the survival rate of ceramic laminate veneers. However, smoking habits and previous endodontic treatments negatively affect the success rate due to color changes. CLINICAL TRIAL REGISTRATION NUMBER: NCT03645551.

Loss of Accuracy of Torque Wrenches Due to Clinical Use and Cleaning Procedure: Short Communication.

PURPOSE: The aim of this study was to investigate the way intensive use and multiple cleanings of torque wrenches may interfere with accurary over time. MATERIALS AND METHODS: Three different brands (one spring-style and two friction-style types) were tested at baseline and after enduring mechanical testing (1,000 cycles) and cleaning in a thermal disinfector (150 cycles). Torque wrenches were tested at a predetermined value of 30 Ncm at given intervals, and true values were registered by means of a digital torque gauge. RESULTS: All measured values varied between 28.3 Ncm and 31.1 Ncm. Only the spring-style torque wrench revealed values that differed significantly from baseline after both mechanical testing (P < .001) and cleaning (P < .05). CONCLUSION: The spring-style torque wrench produced values that changed significantly after multiple mechanical and multiple cleaning cycles. However, the differences were small and the measured values from all tested specimens were close to the predetermined value of 30 Ncm.

Temperature rise during removal of fractured components out of the implant body: an in vitro study comparing two ultrasonic devices and five implant types.

BACKGROUND: Ultrasonic instrumentation under magnification may facilitate mobilization of screw remnants but may induce heat trauma to surrounding bone. An increase of 5°C is considered detrimental to osseointegration. The objective of this investigation was to examine the rise in temperature of the outer implant body after 30 s of ultrasonic instrumentation to the inner part, in relation to implant type, type of ultrasonic equipment, and the use of coolants in vitro. METHODS: Two ultrasonic devices (Satelec Suprasson T Max and Electro Medical Systems (EMS) miniMaster) were used on five different implant types that were provided with a thermo couple (Astra 3.5 mm, bone level Regular CrossFit (RC) 4.1 mm, bone level Narrow CrossFit (NC) 3.3 mm, Straumann tissue level regular body regular neck 3.3 mm, and Straumann tissue level wide body regular neck 4.8 mm), either with or without cooling during 30 s. Temperature rise at this point in time is the primary outcome measure. In addition, the mean maximum rise in temperature (all implants combined) was assessed and statistically compared among devices, implant systems, and cooling mode (independent t-tests, ANOVA, and post hoc analysis). RESULTS: The Satelec device without cooling induces the highest temperature change of up to 13°C, particularly in both bone level implants (p < 0.05) but appears safe for approximately 10 s of continuous instrumentation, after which a cooling down period is rational. Cooling is effective for both devices. However, when the Satelec device is used with coolant for a longer period of time, a rise in temperature must be anticipated after cessation of instrumentation, and post-operational cooling is advised. CONCLUSIONS: The in vitro setup used in this experiment implies that care should be taken when translating the observations to clinical recommendations, but it is carefully suggested that the EMS device causes limited rise in temperature, even without coolant.