Evaluation of volumetric substance loss and precision in targeted endodontic re-treatment with guided versus conventional access cavity preparations: An in vitro study.

Introduction: Root canal retreatment is typically viewed as an "all or nothing" approach. Whether there is periapical pathosis or not, it is advised that all restorative and obturation materials be removed from all roots. Selective root retreatment, a new therapeutic strategy, allows retreatment to be restricted to a single root or multiple roots exhibiting periapical pathosis. To address the issues, "guided endodontics," a unique guided technique for the preparation of apically extended access cavities, was introduced. Materials and Methods: In this in vitro experimental study, 22 freshly extracted two-rooted maxillary first premolars were selected and divided into two groups (n = 11). Pretreatment cone-beam computed tomography imaging of all teeth was performed. Root canal treatment was performed for all samples followed by postendodontic composite restorations with the occlusal stamp technique. Then targeted endodontic retreatment (TER) was done with the conventional method and guided method respectively. The tooth substance loss was measured and evaluated using Ez3D-i-3D-software (VATECH) and work precision was determined by calculating the dentinal loss. Statistical data analysis was done by Independent t-test for substance loss measurement and Chi-square test was used to measure the dentinal loss. Results: TER with conventional method showed significantly higher substance loss with t = 4.591 (P < 0.05) and significantly higher dentinal loss measured in conventional method (P < 0.05). Conclusion: In comparison to traditional TER, TER using a customized bur and three dimensions (3D)-guide results in much less substance loss. The dentinal loss was much lower in 3D-guided approach.

Internal root resorption: A rare complication of vital pulp therapy using platelet-rich fibrin.

Internal root resorption (IRR) is a specific type of pulp disease categorized by the loss of dentin as a consequence of the action of clastic cells stimulated by pulpal inflammation. It is one of the rare complications following a vital pulp therapy (VPT) procedure. Reported here is a case of IRR as a complication of VPT platelet-rich fibrin pulpotomy procedure in a mature permanent tooth. Diagnosed using cone-beam computed tomography and management of the resorptive defect using biodentin with a follow-up of 1 year.

Quantitative Polymerase Chain Reaction Analysis of Cariogenic Streptococcus mutans in Saliva of Oral and Laryngeal Cancer Patients Undergoing Radiotherapy: A Clinical Study.

CONTEXT: Radiotherapy leads to radiation-induced caries. There is limited knowledge about the quantification of cariogenic bacteria in the saliva of irradiated cancer patients. OBJECTIVE: The aim of this study is to check salivary pH, flow rate, and the assessment of Streptococcus mutans in the saliva of irradiated oral and laryngeal cancer patients using quantitative real-time polymerase chain reaction (qRT-PCR). SETTINGS AND DESIGN: This was time-bound study which consisted of 26 cancer patients undergoing radiotherapy (13-oral cancer 13-laryngeal cancer). SUBJECTS AND METHODS: Resting saliva samples were gathered from oral (Group-I) and laryngeal (Group-II) cancer patients immediately before radiotherapy and after completion of radiotherapy (dose-60 Gy). pH of saliva and the salivary flow rate was measured. S. mutans were analyzed using qRT PCR. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS software 20. Paired t-test was used to evaluate salivary pH, flow rate, and amount of S. mutans pre- and post-radiotherapy for Group I and II. Independent t-test was used to compare salivary pH, flow rate, and S. mutans pre- and post-radiotherapy between Group I and II. RESULTS: Salivary pH and flow rate significantly reduced postradiotherapy in oral and laryngeal cancer patients (P < 0.001). The amount of S. mutans statistically increased postradiotherapy in oral cancer patients (P = 0.001). While S. mutans count was statistically insignificant in laryngeal cancer patients (P = 0.091). There was a significant increase in the amount of S. mutans in Group I when compared with Group II (P = 0.002). CONCLUSION: Amount of S. mutans increased postradiotherapy in oral cancer patients. While the salivary pH and salivary flow rate reduced postradiotherapy.