Traumatic injuries to an immature permanent tooth may result in cessation of dentin deposition and root maturation. Novel revascularisation endodontic procedure (REP) has been considered as an option for treatment of immature teeth with damaged pulp tissue. The continuous development of the root and the root canal has been recognised as a major advantage of this technique over traditional apexification approach. Traditional apexification procedures may resolve pathology but have not been able to prove tooth survival due to absence of continued root development and risk of root fracture. A successful REP results in resolution of signs and symptoms of pathology, radiographic signs of healing, proof of continued root development as well as presence of pulp vitality due to the regeneration of pulp tissue in the root canal. Currently, repair rather than true regeneration of the ‘pulp-dentine complex’ is achieved and further root maturation is variable. According to Glossary of Endodontic terms published by American Association of Endodontists, REP’s are biologically based procedures designed to physiologically replace damaged tooth structures, including dentin and root structures, as well as cells of the pulp-dentin complex.1,2 Apexification treatment has been a routine procedure to treat and preserve such teeth for many decades.3 Apexification is the process by which a suitable environment is created within the root canal and periapical tissue to allow for the formation of a calcific barrier across the open apex. Calcium hydroxide [Ca(OH)2] has been the material of choice for apexification as Frank reported its capacity to induce physiological closure of immature pulpless teeth in 1966.4 However, this technique has several disadvantages, including the unpredictability of apical barrier formation and the long duration of treatment, which often requires multiple visits.5 A retrospective study by Jeruphuaan et al.6 has shown a higher survival rate with regenerative endodontic treatment when compared to both mineral trioxide aggregate (MTA) and Ca(OH)2 apexification. The first evidence of regeneration of dental tissues was in 1932 by G.L. Feldman, who showed evidence of regeneration of dental pulp under certain optimal biological conditions.7 In 1971, a pioneer study in regenerative endodontics conducted by Nygaard-Ostby concluded that bleeding induced within a vital or necrotic canal led to resolution of signs and symptoms of necrotic cases and in certain cases, apical closure.8 According to Windley et al. (2005), the successful revascularisation of immature teeth with apical periodontitis is mainly dependent upon: 1. Canal disinfection 2. Scaffold placement in the canal for the growing tissues 3. Bacteria-tight sealing of the access opening.9 The purpose of this case report is to illustrate the outcome of a revascularisation endodontic procedure in a non-vital immature young permanent central incisor.

Dental materials are essential for most of dental treatment modalities. Understanding the science and chemistry behind the materials and their properties can enable the operator to employ the dental material to its maximum advantage. Contemporary dental materials have evolved significantly from the conventional variety, but there is always room for refinement since the inadequacies of the current dental materials in function are recognized only with the advent of advanced dental materials testing methods. As a result, continuous improvement and modification of dental materials is essential. Caries is a process of continuous demineralization and re-mineralization. Recurrent caries is a common occurrence around the tooth-restoration margin. It most likely indicates that the current dental materials are inadequate in their applications. As a result, augmenting conventional dental materials with additional advantageous properties is critical. This chapter aims to reflect on the empirical status of direct restorative materials frequently used in the field of restorative dentistry.

Aim-The purpose of this study was to study the amount of apically extruded debris, axis modification and centering ability using CBCT in relatively curved root canals with WaveOne and One Shape single file systems. Method-Forty extracted human adult teeth with curvatures were selected. Experimental study groups were divided as Group I-WaveOne (n=20) and Group II-One Shape (n=20). To evaluate the axis modification and centering ability, pre and post-operative views were analyzed in longitudinal and axial sections which were taken using RVG and CBCT respectively. For evaluating the amount of debris extrusion, the difference between the pre-instrumentation and postinstrumentation weight of eppendorf tubes were calculated. For intergroup comparison, ANOVA followed by Post-Hoc test were used. Results-WaveOne and One Shape single file systems showed statistically non-significant modification of root canal axis and centering ability. WaveOne single file system non-significantly generated more debris as compared to One Shape. Conclusion-It was concluded that WaveOne single file reciprocating systems demonstrated better centering ability as compared to OneShape single file rotary systems in curved root canals.

Introduction: A four-walled access cavity plays a vital role in successful endodontic treatment. The materials used for preendodontic restoration are flowable composites, restorative composite resins, packable composite resins, silver amalgam, or glass ionomer cement. Researchers have claimed that exposure of composite resins to low pH liquids and root canal irrigants can have a deleterious effect on their physical and mechanical properties. Aim: To evaluate the microhardness of a bulk-fill restorative composite resin material before and after being exposed to distilled water, 1% sodium hypochlorite, 3% sodium hypochlorite, and 5% sodium hypochlorite. Materials and Methods: This was an in-vitro experimental study that was conducted at the Department of Conservative Dentistry and Endodontics, M.G.M Dental College and Hospital, Mumbai, Maharashtra, India, over a period of eight months from January 2021 till August 2021. Total 32 disc-shaped samples were made from a bulk-fill restorative composite resin, 3MTM Filtek Bulk fill posterior restorative composite resin (3MTM, St. Paul, MN, USA). Each disc was prepared using polytetrafluoroethylene (Teflon) molds of 10 mm inner diameter and 4 mm depth. The bulkfill composite resin discs were randomly divided into four main groups, group 1 (distilled water), group 2 (1% NaOCl), group 3 (3% NaOCl), and group 4 (5% NaOCl), with eight samples in each group. Baseline Vickers hardness testing was performed for each group using a 100 gram load and a dwell time of 10 seconds before being immersed in the irrigation solution. Pre and post immersion microhardness measurements were done on the same surface of each sample (top surface). Data obtained were subjected to normality tests. Further statistical analysis was done using one-way Analysis of Variance (ANOVA) followed by the Games-Howell test for pair-wise comparisons. Results: Irrespective of the different concentrations of sodium hypochlorite irrigant, all samples showed a reduction in microhardness of bulk-fill composite restorative resin. The post immersion microhardness mean values were highest in group 1 (63.06) and lowest in group 4 (58.42), and the difference was statistically significant (p<0.001). No statistical difference was seen between group 3 and group 4. On intragroup comparison, all the groups show statistically highly significant difference between pre and post immersion microhardness values {Paired-t test (p<0.05)}. Conclusion: Microhardness of bulk-fill composite restorative resin was lowered by different concentrations of sodium hypochlorite irrigant.

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