Journal of Conservative Dentistry最新文献

Aim: The aim of this study was to assess the impact of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin following plasma application at different steps of dentin bonding in total-etch and self-etch adhesive systems.

Materials and methods: Ninety extracted third molars were taken, and the occlusal surfaces were removed until the exposure of the dentin. Samples were distributed into two main groups: Group T: total-etch adhesive system and Group S: self-etch adhesive system. Groups are further subdivided (n = 10) based on plasma application at different steps of dentin bonding. T1: surface etching with 37% phosphoric acid and bonding agent application. T2: plasma application and bonding agent application. T3: plasma application, etching, and bonding agent application. T4: etching, plasma application, and bonding agent application. T5: etching, plasma application, bonding agent application, and again plasma application. S1: self-etch bonding agent application. S2: plasma application and bonding agent application. S3: Bonding agent application and plasma application. S4: plasma application, bonding agent application, and again plasma application. For all the samples, composite resin buildup was done, and shear bond strength (SBS) was measured. The contact angle was measured at different steps of dental adhesive systems.

Statistical analysis: Two-way analysis of variance and the post hoc Tukey's test were used for analysis, regarding P < 0.05 as statistically significant.

Results: Among all groups of total-etch and self-etch adhesives, Group T4 (48.81 Mpa) and Group S2 (36.59 Mpa), respectively, have demonstrated significantly greater bond strength values than the corresponding control groups.

Conclusion: NTAP enhanced the composite resin's SBS when plasma treatment was done before bonding agent application and significantly reduced the contact angles of the distilled water.

Aim: Using confocal laser scanning microscopy (CLSM), the current study assessed the impact of nonthermal atmospheric plasma (NTAP) on the dentinal tubule penetration of bioceramic and epoxy resin-based root canal sealers (CLSM).

Materials and methods: Forty human mandibular premolar teeth with a single root that had just undergone extraction were chosen and biomechanical preparation of root canals was done with ProTaper Gold rotary Nickel-titanium instruments. Samples were divided into four groups (n = 10). Group 1: Bioceramic sealer (BioRoot RCS); Group 2: Epoxy resin-based sealer (AH Plus) without application of NTAP; Group 3: Bioceramic sealer (BioRoot RCS); and Group 4: Epoxy resin-based sealer (AH Plus) with the application of NTAP for 30 s. In Groups 3 and 4, all of the samples underwent obturation with the appropriate sealers following NTAP application. For determination of the sealer's dentinal tubule penetration values, slices with a thickness of 2 mm were taken from the middle third of sample's root and examined using CLSM. The acquired data were statistically analyzed with one-way analysis of variance and the Post hoc Tukey's test. The cutoff for statistical significance was P < 0.05.

Results: In comparison to other groups, the maximum sealer penetration values into dentinal tubules were significantly higher in Group 3 for Bioceramic sealer with NTAP application and Group 4 for Epoxy resin-based sealer with NTAP application.

Conclusion: NTAP application increased the dentinal tubule penetration of bioceramic and epoxy resin-based sealers in comparison to groups without NTAP application.

Objectives: The objective of the study was to evaluate and compare the surface topographies of WaveOne Gold (WOG), FlexiCON X1, and EdgeOne Fire (EOF) reciprocating files before and after root canal instrumentation using different irrigating solutions.

Materials and methods: Forty-eight extracted mandibular molars were selected and randomly assigned into three groups (n = 16) based on the file system used and each group was divided into two subgroups based on the irrigants used during root canal treatment. (Group-1: WOG; Group-2: FlexiCON X1; Group-3: EOF; Subgroup-A: 3% sodium hypochlorite [NaOCl] +17% ethylenediaminetetraacetic acid [EDTA]; Subgroup-B: Citra wash as irrigating solutions). The surface topography of the files was analyzed using atomic force microscope before and after instrumentation. Average roughness and root mean square roughness were calculated. Independent and paired t-tests and one-way analysis of variance with Tukey's post hoc were used for statistical analysis.

Results: Atomic force microscopy results showed an increase in surface roughness after instrumentation, EOF showing the highest roughness. Citra wash showed more roughness compared to NaOCl and EDTA together. However, the surface roughness between the experimental groups WOG and EOF are statistically insignificant and this insignificance was also seen among subgroups (P>0.05).

Conclusion: Instrumentation with various irrigating solutions affected the surface topography of EOF, WOG, and FlexiCON X1 reciprocating files.

Maxillary central incisor is considered the tooth with least anatomical variations. In literature, the prevalence of single root and single canal in maxillary central incisor has been reported as 100%. Only a handful of case reports suggesting more than one root or one canal are available and are mostly associated with developmental anomalies such as gemination and fusion. This article describes a rare case report of retreatment of a maxillary central incisor with two roots with normal clinical crown which was confirmed by cone-beam computer tomography (CBCT). A 50-year-old Indian male patient presented with pain and discomfort on a root canal-treated anterior tooth. Pulp sensibility testing of left maxillary central incisor was negative. Intraoral periapical digital radiograph revealed an obturated canal with suspected outline of a second root which got confirmed with cone shift technique. The tooth was treated under dental operating microscope during which two canals were located and retreatment was completed. Postobturation, CBCT was performed to study the root and canal morphology. Clinically and radiographically, all the follow-up examinations revealed an asymptomatic tooth without any active periapical lesion. The present case report emphasizes the fact that clinicians should approach each case with an open mind having a thorough knowledge of the normal tooth anatomy and should suspect variations in every case to ensure successful endodontic outcome.

Background: Optimal biomechanical preparation, thorough irrigation, proper disinfection, and finally, well-sealed obturation is a must to attain definitive success in root canal procedure. Proper preparation of the root canal is all the more imperative to establish a hermetic apical seal with adequately placed filling materials. The present study was conducted for comparing the Cleaning Efficiency of F360 system and the WaveOne Gold (WOG) system of rotary NiTi instrumentation for a root canal.

Materials and methods: One hundred freshly extracted noncarious mandibular canines were obtained. Access cavity of standard size was made followed by the establishment of working length. Afterward, random division of all the specimens was done into two study groups: group A: the group in which F360 system was used for instrumentation and group B: the group in which the WOG system was used for instrumentation. Irrigations of all the specimens of both the study groups were done followed by root canal shaping by the instrument system of their respective study groups. Scanning electron microscope (SEM) was used for assessment after specimens were cut buccolingually. Debris score and residual smear layer score were used for assessment.

Results: Among group A specimens, the mean smear layer score at the coronal third, middle third, and apical third was 1.76, 2.39, and 2.65, respectively. Among group B specimens, the mean smear layer score at the coronal third, middle third, and apical third was 1.34, 1.59, and 1.92, respectively. While analyzing statistically, it was seen that the mean smear layer score was significantly higher among specimens of group A in comparison to group B. While analyzing statistically, it was seen that the mean debris score was significantly higher among specimens of group A in comparison to group B.

Conclusion: The cleaning effectiveness of WOG instruments was significantly enhanced in comparison to F360 equipment.

Contemporary paradigms of dental caries management focus on the biological approaches to treating the disease and its principal symptom, the carious lesion. This narrative review traces the evolution of carious lesion management from the operative and invasive approaches of G. V. Black's era to the current period of minimally invasive biological approaches. The paper explains the rationale for adopting biological approaches to dental caries management and lists the five core principles of this management approach. The paper also details the aims, features, and the most recent evidence base for the different biological carious lesion management approaches. Based on current practice guidelines, collated clinical pathways for lesion management are also presented in the paper to aid clinicians in their decision-making. It is hoped that the biological rationale and evidence summarized in this paper will bolster the shift to modern biological carious lesion management approaches among dental practitioners.

Dental fluorosis is caused by ingestion of excessive fluoride during tooth development resulting in hypomineralization of the enamel and can present as white or brown intrinsic lesions. This case report describes a combination of minimally invasive techniques: microabrasion, bleaching, and resin infiltration to address brown enamel fluorosis present on the maxillary anterior teeth of a young patient. Before resin infiltration, air microabrasion was targeted at subsurface lesions located on the maxillary central and lateral incisors, and chairside bleaching was done with 37% hydrogen peroxide (Opalescence). After which, hypoplastic lesions on the buccal surfaces were etched before being treated with two sessions of resin infiltration (ICON and DMG). Following treatment, satisfactory esthetic outcomes were achieved. Accurate diagnosis, depth of lesions, and understanding the effectiveness and limitations of each technique are essential to select the appropriate type of treatment to obtain the best esthetic outcome. In conclusion, the conservative management of varying severity of dental fluorosis may require the appropriate use of combination treatment modalities, such as microabrasion, bleaching and resin infiltration, when clinically indicated, to address the treatment needs and achieve a desired outcome.

Context: Elucidating the effects of leachates from composite resins (CRs) on cells by examining the transcription level of detoxification genes and the antioxidant-responsive element (ARE), would be helpful in clinical practice.

Aims: The aim of the study is to investigate the cytotoxicity of commercially available CRs, we used a reporter assay system to evaluate intracellular stress based on ARE-mediated transcription.

Setting and design: The study design was an in vitro study.

Materials and methods: Seven kinds of CRs were each placed in four-well plates to which culture medium was added and then light-cured. The prepared samples were used either immediately (sample A) or after incubation at 37°C for 24 h (sample B) in the subsequent ARE-luciferase reporter assay, in which HepG2 cells stably expressing an ARE-regulated luciferase reporter gene (HepG2-AD13 cells) were cultured for 6 h in culture media with the CR eluate (samples A or B) or without (control) (n = 4). In the cell viability assay, cell viability in various solutions with the same incubation time was confirmed by MTT assay (n = 4). Statistical analysis was performed using the paired t-test and one-way analysis of variance.

Results: All CR solutions showed an increase in ARE activation rate; a CR with spherical nanofillers showed the highest ARE activation rate of 108.5-fold in sample A. Cell viability was not significantly reduced for any of the CRs in sample A. However, the CR-containing bisphenol A-glycidyl methacrylate (Bis-GMA) caused a significant decrease in cell viability in sample B.

Conclusions: The intracellular stress in the viable cells differed among the CRs, depending on the type of monomer used. In particular, Bis-GMA-containing hydroxyl groups showed high cytotoxicity.

Introduction: The study evaluated the influence of coronal restoration after pulpotomy on the strength of electrical stimulus reaching the radicular pulp using an electric pulp test (EPT).

Materials and methods: The pulp tissue from ten freshly extracted mandibular premolar teeth was removed and replaced with an electroconductive gel. The cathode probe of Powerlab was inserted into the pulp space and the anode probe was attached to the EPT handpiece. The EPT probe coated with electro-conducting material was positioned in the middle third of the buccal crown surface. The EPT stimulus reaching the pulp space of an intact tooth at 40 numerical readings was recorded. The tooth was removed from model and endodontic access was made. The 2-mm thick mineral trioxide aggregate was placed at the cementoenamel junction followed by composite resin restoration. The experimental setup was re-established and postpulpotomy EPT stimulus data were recorded. The data collected were compared using the Wilcoxon signed-rank test.

Results: There was a statistically significant difference (P = 0.038) between observed between the strength of EPT stimulus reaching the pulp space in prepulpotomy (mean 91.18 ± 101.02 V and median 25.79 V) and postpulpotomy (mean 58.49 ± 77.13 V and median 13.75 V) tooth samples.

Conclusion: The placement of the restoration and pulp capping agent after pulpotomy dampens the strength of EPT stimulus reaching the pulp canal space.