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INTRODUCTION: There is growing interest in colour stability of aesthetic restorations. So far few studies have been reported. AIM: This study was designed to investigate the effects of different common food colourants i.e., Turmeric and Carmoisine (orange red dye) consumed by patients in Asian countries on a recent nano hybrid composite resin. MATERIALS AND METHODS: A total of sixty disk shaped specimens measuring 10 mm in diameter and 2 mm in thickness were prepared. The samples were divided into two groups {Z 100 (Dental restorative composite) Filtek Z 250 XT (Nano hybrid universal restorative)}. Baseline colour measurement of all specimens were made using reflectance spectrophotometer with CIE L*a*b* system. Specimens were immersed in artificial saliva and different experimental solutions containing food colourants (carmoisine solution and turmeric solution) for three hours per day at 37°C. Colour measurements were made after 15 days. Colour difference (ΔE*) was calculated. Mean values were compared by one-way analysis of variance (ANOVA). Multiple range test by Tukey Post-hoc test procedure was employed to identify the significant groups at 5% level. RESULTS: Z 100 showed minimum staining capacity when compared to Z 250 XT in both the colourant solutions. CONCLUSION: The nanohybrid composite resin containing TEGDMA showed significant colour change when compared to that of microhybrid composite resin as a result of staining in turmeric and carmoisine solution.
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INTRODUCTION: M-Wire and reciprocating motion of WaveOne and controlled memory (CM) wire) of HyFlex were the recent innovations using thermal treatment. Therefore, a study was planned to evaluate the shaping ability of reciprocating motion of WaveOne and HyFlex using cone beam computed tomography (CBCT). METHODOLOGY: Forty-five freshly extracted mandibular teeth were selected and stored in saline until use. All teeth were scanned pre- and post-operatively using CBCT (Kodak 9000). All teeth were accessed and divided into three groups. (1) Group 1 (control n = 15): Instrumented with ProTaper. (2) Group 2 (n = 15): Instrumented with primary file (8%/25) WaveOne. (3) Group 3 (n = 15): Instrumented with (4%/25) HyFlex CM. Sections at 1, 3, and 5 mm were obtained from the pre- and post-operative scans. Measurement was done using CS3D software and Adobe Photoshop software. Apical transportation and degree of straightening were measured and statistically analyzed. RESULTS: HyFlex showed lesser apical transportation when compared to other groups at 1 and 3 mm. WaveOne showed lesser degree of straightening when compared to other groups. CONCLUSION: This present study concluded that all systems could be employed in routine endodontics whereas HyFlex and WaveOne could be employed in severely curved canals.
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BACKGROUND: There is a growing interest in chemomechanical excavation (papain) in permanent molar teeth. There are several studies dealing with primary molar teeth. AIM: The aim of this study was to evaluate the influence of conventional method and Carie-care (chemomechanical method) on the microshear bond strength (µSBS) and the type of failure of an adhesive system to caries-affected dentin of permanent molar teeth. MATERIALS AND METHODS: Twenty permanent molar teeth with carious lesions extending into the dentin were selected. Through the center of the carious lesion, teeth were sectioned mesiodistally and divided into two groups based on the method of caries excavation (conventional and chemomechanical method). The time required for the completion of excavation procedure was noted. Samples were again divided into two subgroups in each according to the method of restoration (Ketac N100 and Filtek Z350 composite). The bonded interface was subjected to µSBS testing in a universal testing machine. Fractured surfaces were examined under a stereomicroscope, and representative specimens were examined under scanning electron microscope for the type of failure. STATISTICAL ANALYSIS: It was achieved with unpaired t-test and Kruskal-Wallis H-test at 5% level of significance. RESULTS: The µSBS values of Carie-care groups were similar to that of the conventional method. The µSBSs of resin composite were significantly (P < 0.001) more than that of resin glass ionomer bonded irrespective of the method of caries excavation. CONCLUSION: A papain-based chemomechanical agent can be used safely as a method for caries removal when employing conventional adhesive systems.
ABSTRACT
Hemisection refers to sectioning of a mandibular molar into two halves followed by removal of the diseased root and its coronal portion. Hemisection of a mandibular molar may be a suitable treatment option when the decay is restricted to one root and the other root is healthy. The retained root is endodontically treated and the furcation area is made self-cleansable. Retained tooth structure is restored as premolar which helps to reduce the masticatory load. Hemisection of mandibular molar was often referred to as premolarization. Studies showed that the remaining coronal structure influenced the fracture resistance of endodontically treated maxillary first premolars. Clinical experience showed the viability of tunnel restoration as an alternative to class II conventional cavity preparation in initial proximal lesion. This article discusses a case that presents the novel technique involved in restoration of the remaining hemisected tooth using modified tunnel restoration.
