Bond strength of conventional versus modified methods for Class IV restorations in primary incisors: An in vitro study.

Background. Aesthetic restorations of severely decayed anterior primary teeth are challenging due to the small size of the teeth and the large pulp chambers. Therefore, this study evaluated and compared the tensile and shear bond strengths of conventional versus modified methods (slot technique) of Cl IV restorations in primary incisors. Methods. A total of 120 extracted intact maxillary primary central and lateral incisors were divided into two groups. In group A, conventional Cl IV cavities were prepared. In group B, after conventional cavity preparation, four and three incisal slots were prepared on the incisal edges of the central and lateral incisors, respectively. All the teeth were restored using composite resin, and then the tensile and shear bond strengths were evaluated. Results. A statistically significant increase in the tensile bond strength of restorations was recorded in the modified technique compared to the conventional method (P=0.001). Although an increase in the shear bond strengths was found in the modified method, the value did not reach a statistically significant level (P=0.158). The most frequent fracture type was adhesive in the conventional group and cohesive in the modified group, considering the tensile and shear bond strength tests. In both groups, the highest average tensile bond strength was recorded in teeth with the cohesive fracture in dentin, and the lowest average was seen in the adhesive type. Conclusions. Incisal slots could increase the tensile bond strengths of Cl IV composite resin restorations in primary teeth.

Assessing the Different Levels of Virtual Reality That Influence Anxiety, Behavior, and Oral Health Status in Preschool Children: Randomized Controlled Clinical Trial.

BACKGROUND: Compared with a traditional behavior management strategy and oral health training, virtual reality (VR) integrated with multisensory feedback possesses potential advantages in dentistry. OBJECTIVE: This study aimed to assess the impact of different levels of VR on anxiety, behavior, and oral health status. METHODS: This study was carried out in the Department of Pediatric Dentistry at the Tabriz University of Medical Sciences from December 2020 to June 2021. We randomly assigned 60 healthy children aged 4 years to 6 years to 4 groups, each consisting of 15 children. The study consisted of 2 consecutive sessions. During the first visit, the plaque index was calculated, and oral health education was carried out in all groups using Immersive VR (group I), Semi-immersive VR (group II), Nonimmersive VR (group III), and tell-show-do (TSD; group IV). In the second session, an amalgam restoration was performed in all groups. Participants' anxiety and behavior were recorded using the face version of the Modified Child Dental Anxiety Scale (MCDAS[f]) and Frankl scale. The plaque index was recorded in 2 follow-up sessions. RESULTS: The greatest prevalence of positive behavior (P=.004) and the lowest anxiety (P<.001) were recorded in group I, followed by group II, group III, and group IV. The plaque index scores showed a reduced trend between the first session and follow-up sessions (P<.001), but the values did not differ significantly between the 4 groups during the 3 sessions (P=.28, P=.54, P=.18). CONCLUSIONS: The most positive behavior was observed in the Immersive VR group, followed by the Semi-immersive VR, Nonimmersive VR, and TSD groups. Moreover, oral health education using VR resources can improve oral health status in children. TRIAL REGISTRATION: Iranian Registry of Clinical Trials 20210103049926N1; https://www.irct.ir/trial/53475.