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PURPOSEThere is insufficient data regarding the durability of porcelain laminate veneers bonded to existing composite fillings. The aim of the present study was to evaluate the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with existing composite fillings.MATERIALS AND METHODSThirty maxillary central incisors were divided into three groups (for each group, n=10): intact teeth (NP), teeth with class III composite fillings (C3) and teeth with class IV cavities (C4). Porcelain laminate veneers were made using IPS-Empress ceramic and bonded with Panavia F2 resin cement. The microleakage of all of the specimens was tested before and after cyclic loading (1 × 106 cycles, 1.2 Hz). The fracture resistance values (N) were measured using a universal testing machine, and the mode of failure was also examined. The statistical analyses were performed using one-way ANOVA and Tukey post hoc tests (α=.05).RESULTSThere was a significant difference in the mean microleakage of group C4 compared with group NT (P=.013). There was no significant difference in the fracture loads among the groups.CONCLUSIONThe microleakage and failure loads of porcelain laminate veneers bonded to intact teeth and teeth with standard class III composite fillings were not significantly different.

Objectives: Endocrown restorations were introduced for endodontically treated teeth as a conservative treatment. However, data about the effect of preparation design on marginal integrity and fracture resistance of endocrowns are lacking. The purpose of this systematic review was to investigate the effect of preparation design of endocrown restorations on marginal integrity and fracture resistance. Materials and Methods: Based on PICO question and the search terms, PubMed, Embase, Scopus, and the Cochrane Library were searched. After including studies matched to predefined inclusion and exclusion criteria, the extracted data were tabulated in a table provided by the authors. Two reviewers assessed the methodological quality of each included study independently. Ten articles were selected for extracting the quantitative data. All included studies were in vitro. The potential risk of bias of the selected studies was assessed using the modified MINORS scale. Results: Four studies assessed the marginal adaptation, five studies evaluated the fracture resistance and just one investigated both the marginal integrity and fatigue resistance of the specimens. The evaluated influencing items in preparation design were as follows: cavity depth, occlusal thickness, ferrule effect, internal divergence angle, type of finish line, and adding vents inside pulp chamber. Meta-analysis could not be done due to heterogeneity of preparation designs and evaluation methods. Conclusion: Marginal discrepancy of endocrowns is intensified with adding preparation features, higher cavity depth and increasing the divergence. Fracture resistance of endocrowns is increased with more occlusal reduction and cavity depth. However, it is still beyond the normal clinical force range.

Background: The present study was conducted to develop a standard questionnaire to assess the knowledge and practice of prosthodontists regarding the diagnosis and treatment of obstructive sleep apnea syndrome (OSA). Materials and Methods: This study had questionnaire designing and cross-sectional-descriptive phases. Questionnaire domains were identified by a panel of eight experts. The face and content validity of the questionnaire was assessed by experts and four laypeople. The internal consistency reliability of the questionnaire was checked using Cronbach's alpha coefficient. Moreover, its stability was tested using the test–retest method. The questionnaire was completed online by 282 Iranian prosthodontists and the relationship between different variables and scores of knowledge and practice of them with simple and multiple linear regression tests was were analyzed. Results: A 32-item questionnaire was designed. The Scale Content Validity Index was >0.8 for clarity, simplicity, and necessity in all domains and the content validity of all questions was above 0.8. As for reliability, Cronbach's alpha coefficient was above 0.7 on average. Faculty members had more knowledge (P = 0.04) and better practice (P = 0.001) compared to others. Prosthodontists who participated in sleep disorders training courses had higher scores in knowledge (P = 0.001) and practice (P = 0.001). Prosthodontists who referred patients to sleep disorders clinics had higher knowledge (P = 0.001) and practice (P = 0.001) than those who did not. Conclusion: The questionnaire developed in this study can be considered a comprehensive and executable scale with appropriate reliability and validity. There is a positive relationship between being exposed to information and the level of knowledge and practice of prosthodontists about OSA.

Cranial radiotherapy has several side effects. One of the most important complications is radiation caries that endangers the treatment prognosis. In the literature, the use of crowns and bridges for irradiated patients has been suggested as a contraindication. In addition, due to the risk of osteoradionecrosis (ORN), there are doubts about tooth extraction and implant placement. Here, we present a treatment sequence and recalls for an irradiated young patient. For irradiated patients, it is recommended to replace teeth with implants when there is no possibility for supragingival prosthetic margin.