Influence of two remineralizing agents on bleached enamel surface morphology and mineral composition - An In Vitro study.

Aim: To investigate the effects of bleaching with 35% hydrogen peroxide on the structure of tooth enamel and the role of two remineralizing agents for their potential to remineralize any damaged regions of enamel. Materials and Methods: Freshly extracted 32 mature permanent central incisors were selected and sectioned at the level of the cemento-enamel junction. The teeth were divided into four groups consisting of eight teeth each: No bleaching (control) [Group 1], bleaching with 35% hydrogen peroxide [Group 2], bleaching with 35% hydrogen peroxide followed by application of casein phosphopeptide amorphous calcium phosphate fluoride paste [Group 3], and bleaching with 35% hydrogen peroxide followed by application of xylitol-coated calcium phosphate fluoride varnish [Group 4]. The enamel surfaces were analyzed under the scanning electron microscope and quantitative energy dispersive X-ray analysis. Results: Results were statistically analyzed by one-way analysis of variance and Tukey's posthoc test. Group 2 revealed changes in enamel surface morphology and a statistically significant decrease in mineral content. Groups 3 and 4 showed statistically significant remineralization potential. Intergroup comparison showed that samples in Group 4 had a higher mineral content compared to Group 3. Conclusions: The application of the tested remineralizing agents following bleaching was effective in repairing the enamel surface morphology with higher efficacy for the fluoride varnish product. Since bleaching regimes with high concentrations of hydrogen peroxide adversely affect the enamel surface, these findings can translate to clinical practice to reduce the long-term damaging effects of tooth bleaching.

Shear bond strength evaluation of an alkasite restorative material to three different liners with and without using adhesive system: An in vitro study.

AIMS: The aim of the study is to compare and evaluate the bonding ability of alkasite restorative material to TheraCal LC™ (TLC), Biodentine™ (BD), resin-modified glass ionomer cement (RMGIC) using an universal adhesive and characterizing their failure modes. SUBJECTS AND METHODS: Ninety extracted intact human molars were divided into three groups of (n = 30) as Group I (TLC), Group II (RMGIC), and Group III (BD). Each group was subdivided into two based on application of universal adhesive. Cention N was bonded to each sample. Shear bond strength analysis was performed. The data were analyzed using SPSS version 22 software. RESULTS: No significant difference was observed between Group I and Group II (P < 0.05) while Group III showed the least bond strength (P < 0.05). The modes of failure were predominantly cohesive in Groups I and III (TLC and BD) while RMGIC showed mixed and adhesive failures. CONCLUSIONS: The bond strength of Cention N to TLC and RMGIC was similar and significantly higher than that of BD following application of universal adhesive.

Spectrophotometric Analysis of Coronal Discolouration Induced by ProRoot MTA, Biodentine and MTA Repair HP Used for Pulpotomy Procedures.

OBJECTIVE: To assess and quantify coronal tooth discolouration by ProRoot MTA, Biodentine and MTA repair HP as pulpotomy agents and to identify colour stability of these materials in presence of blood contamination. METHODS: 120 human premolar teeth were used in the study. The teeth were sectioned horizontally 1 mm apical to the cementoenamel junction. A retrograde cavity extending within 2 mm of the incisal edge was prepared. The specimens were randomly distributed as; Control: Group 1, ProRoot MTA: Group 2, Biodentine: Group 3 and MTA repair HP: Group 4. The groups werefurther subdivided on basis of exposure to saline (subgroup A) or blood (subgroup B). The access was sealed with light cured Glass ionomer cemet and the specimens were stored in artificial saliva at 37°C. The Colour change was evaluated with a spectrophotometer at: day 0 (T0), day 1 (T1), day 7 (T7), 1 month (T30), 2 months (T60), and 6 months (T180). The colour measurements were recorded using the Commission Internationale de l'Eclairage L*a*b* value. RESULTS: For all groups, there was a sharp increase in L* parameter at T1. At 6 months, Group 1B (Control + blood) showed maximum decrease in luminosity followed by Group 2A (ProRoot + saline) > Group 4B (MTA repair HP + blood) > Group 2B (ProRoot + blood). Group 3A (Biodentine + saline) showed the least amount of decrease in luminosity followed by Group 4A (MTA repair HP + saline) and Group 3B (Biodentine + blood). No significant difference was found in ∆E change between any of the groups from baseline to 180 days (P>0.05). CONCLUSION: Relative to L* parameter, it was possible to observe a statistically significant decrease in luminosity in the Group1B (Control + blood) followed by ProRoot MTA (Group 2A and 2B) and MTA repair HP (Group 4A and 4B). Biodentine (Group 3A and 3B) showed least tooth discolouration in terms of L* parameter.

Effect of bromelain enzyme on the microleakage of composite resin restorations after external tooth bleaching: An in vitro study.

AIMS: The aim of this study is to evaluate in vitro the effect of application of bromelain enzyme on the microleakage of composite resin restorations after external tooth bleaching using spectrophotometric evaluation. SUBJECTS AND METHODS: Buccal Class V cavities were prepared on the surface of fifty intact premolars, which were randomly divided into five groups. All cavities were filled with composite resin. Group I: Teeth were not bleached but restored (n = 10). External bleaching with 35% hydrogen peroxide was carried out for the rest of the specimensGroup II: Cavities were restored immediately after bleaching (n = 10)Group III: Cavities were restored after a delay of 3 weeks (n = 10)Group IV: Cavities were treated with sodium ascorbate after bleaching and then restored (n = 10)Group V: Cavities were treated with bromelain enzyme solution after bleaching and then restored (n = 10). Microleakage was assessed by the dye extraction method using a spectrophotometer. STATISTICAL ANALYSIS USED: The data were analyzed statistically by comparison of mean microleakage and post hoc test using SPSS 2.0 software. RESULTS: Group I displayed the least amount of microleakage, whereas Group II showed the greatest amount of microleakage (P < 0.05). Groups III, IV, and V showed a significantly lower amount of microleakage compared to Group II (P < 0.05). There was no statistically significant difference between Groups IV and V. CONCLUSIONS: Microleakage increased significantly after external bleaching with 35% hydrogen peroxide, and decreased when the bleached teeth were treated with antioxidants. Ten percent bromelain enzyme was effective in decreasing microleakage; however, its efficacy was similar to 10% sodium ascorbate.

Assessment of Enamel Remineralisation After Treatment with Four Different Remineralising Agents: A Scanning Electron Microscopy (SEM) Study.

INTRODUCTION: Decades of research has helped to increase our knowledge of dental caries and reduce its prevalence. However, according to World Oral Health report, dental caries still remains a major dental disease. Fluoride therapy has been utilised in a big way to halt caries progression, but has been met with limitations. This has paved the way for the development of newer preventive agents that can function as an adjunct to fluoride or independent of it. AIM: The purpose of the present study was to evaluate the ability of Casein Phosphopeptide-Amorphous Calcium Phosphate Fluoride (CPP ACPF), Bioactive Glass (BAG), fluoride enhanced Hydroxyapatite (HA) gel and self-assembling peptide P11-4 to remineralise artificial carious lesions in enamel in vitro using a 30 day pH cycling model through surface microhardness analysis and SEM. MATERIALS AND METHODS: Sixty enamel samples were divided into five groups of 12 samples each. The control Group A consisted of intact enamel samples, Group B: CPP-ACPF (Tooth Mousse Plus), Group C: BAG (SHY- NM), Group D: fluoride enhanced HA gel (ReminPro) and Group E: Self-assembling peptide P11-4 (Curodont Protect). All groups excluding the control group were subjected to demineralisation following which four of these groups were remineralised using the four remineralising agents. The treated groups were subjected to pH cycling over a period of 30 days. This was followed by assessment of surface microhardness and SEM for qualitative evaluation of surface changes. The results were analysed by One-Way Analysis Of Variance (ANOVA). Multiple comparisons between groups were performed by paired t-test and post-hoc Tukey test. RESULTS: The results of the study revealed that remineralisation of enamel was the highest in samples of Group E (Self assembling peptide P11-4) followed by Group B (CPP-ACPF), Group C (BAG) and Group D (fluoride enhanced HA gel). There was a significant difference (p<0.05) in the remineralising ability between the self assembling peptide P11-4 group and BAG and fluoride enhanced HA gel group. Although no significant difference was observed between the self assembling peptide P11-4 and CPP-ACPF group, the self assembling peptide P11-4 remineralised the enamel lesions more effectively. SEM photomicrographs of the test groups demonstrated either amorphous crystals or particles scattered on the surface or lines of remineralisation along the prismatic borders. CONCLUSION: Self assembling peptide P11-4 demonstrated promising results by effectively and significantly remineralising the enamel lesions as compared to other test agents.

A cone-beam computed tomography assessment of the efficacy of different irrigation devices for removal of silicone oil-based calcium hydroxide from root canal system.

BACKGROUND: Most often used intracanal medicament is calcium hydroxide (Ca(OH)2). Removal of Ca(OH)2 before obturation is mandatory. Different irrigation solutions and devices were tested in the previous study for this purpose. AIM: The aim of this study was to evaluate the comparative efficacy of different irrigation techniques in removing intracanal medicament using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Cleaning and shaping was carried out in 42 freshly extracted single-rooted mandibular first premolars using Protaper Rotary Files. Intracanal medicament (silicone oil-based Ca(OH)2 paste) was placed and left for 2 weeks in the root canal. Medicament was then removed by five different irrigation techniques: EndoActivator, EndoVac, ultrasonic irrigation with Endo-U-File, F-file, and Max-i-Probe needle. Changes in volume percentage were measured using CBCT and results were statistically analyzed using Levene's statistics and ANOVA. RESULTS: Remnants of Ca(OH)2 were found in all experimental groups. No significant difference was detected among the groups. F-file showed maximum removal efficacy of approximately 48%. CONCLUSION: (1) There is no statistically significant difference between any irrigation technique for removal of oil-based Ca(OH)2. (2) F-file demonstrated better results among all the other systems.

A novel technique of sculpting Biodentine in the restoration of iatrogenic dentin loss.

Excessive tooth structure loss is a common iatrogenic error encountered during endodontic practice. Conservative treatment planning is essential to maintain the structural integrity in such teeth. This case report elucidates a novel approach in sculpting Biodentine as a dentin substitute followed by internal bleaching and restoration with fiber-reinforced composite.

Fibre reinforcement in a structurally compromised endodontically treated molar: a case report.

The reconstruction of structurally compromised posterior teeth is a rather challenging procedure. The tendency of endodontically treated teeth (ETT) to fracture is considerably higher than vital teeth. Although posts and core build-ups followed by conventional crowns have been generally employed for the purpose of reconstruction, this procedure entails sacrificing a considerable amount of residual sound enamel and dentin. This has drawn the attention of researchers to fibre reinforcement. Fibre-reinforced composite (FRC), designed to replace dentin, enables the biomimetic restoration of teeth. Besides improving the strength of the restoration, the incorporation of glass fibres into composite resins leads to favorable fracture patterns because the fibre layer acts as a stress breaker and stops crack propagation. The following case report presents a technique for reinforcing a badly broken-down ETT with biomimetic materials and FRC. The proper utilization of FRC in structurally compromised teeth can be considered to be an economical and practical measure that may obviate the use of extensive prosthetic treatment.

Endodontic Management of a Mandibular First Molar with Radix Entomolaris and Conservative Post-endodontic Restoration with CAD/CAM Onlay: A Novel Clinical Technique.

This case report describes a novel technique of restoring endodontically treated teeth. Hidden caries causing irreversible pulpitis in a mandibular molar with Radix Entomolaris (RE) was evident. The intact occlusal surface anatomy was duplicated before preparing an access cavity to replicate the original occlusal surface in the post endodontic restoration using (Computer-Aided Design and Computer-Aided Manufacturing) CAD/CAM technique. This report highlights uniquely designed onlay utilizing the benefits of contemporary materials and advanced technology.

Bilateral dens invaginatus in the mandibular premolars - Diagnosis and treatment.

Dens invaginatus (DI) is a developmental anomaly that results from an infolding of the dental papilla during tooth development and simulates the appearance of a tooth within another tooth. It shows a wide spectrum of variations in morphology and usually affects the maxillary lateral incisors. This study presents an unusual case of an Oehlers' Type I DI involving the bilateral mandibular first and second premolars, which presented as an incidental radiographic finding in the first premolars and was associated with a periapical lesion in the second premolars which was successfully treated using nonsurgical endodontics.

Assessment of apical seal obtained after irrigation of root end cavity with MTAD followed by subsequent retrofilling with MTA and Biodentine: An in vitro study.

INTRODUCTION: The present study is designed to assess the apical seal obtained after root end cavity irrigation with MTAD and retrograde filling with mineral trioxide aggregate (MTA) and Biodentine. MATERIALS AND METHODS: Sixty extracted maxillary central incisors were instrumented and obturated. Apical 3 mm of all the roots were resected and retrograde preparations of 3 mm were made in all the teeth using ultrasonic tips. Thirty root end preparations were irrigated with MTAD for 5 min (Group 1), while 30 were irrigated with saline for 5 min (Group 2). Each main group was subdivided into two subgroups containing 15 samples each. Samples under each subgroup were then filled either with MTA (1A and 2A) or Biodentine (1B and 2B). The amount of microleakage was assessed using a UV spectrophotometer. RESULTS: Statistical analysis suggest a significant difference (P < 0.005) between group 1A and 2A and between the groups 1B and 2B (P < 0.1). There was a significant difference (P < 0.005) between group 1A and 1B and also between group 2A and 2B. CONCLUSION: Irrigation with MTAD significantly improved the apical seal of Biodentine, but it increased the microleakage in MTA-filled root end cavities. Also the apical seal obtained with Biodentine was superior to that obtained with MTA.

Treatment of combined endodontic: periodontic lesion by sealing of palato-radicular groove using biodentine.

INTRODUCTION: Palatoradicular groove is a developmental anomaly which is predominantly found in maxillary lateral incisors. It provides a susceptible alcove for the progression of localised periodontal inflammation which can further cause pulpal involvement. This case report describes the successful treatment of a large periodontic - endodontic lesion usingnon surgical endodontic therapy and biodentine for the sealing of the palatoradicular groove.

An in vitro comparison between the apical sealing abilities of resilon with Epiphany sealer and gutta-percha with AH plus sealer.

CONTEXT: The study assesses the apical sealing ability of two obturating materials (resilon and gutta-percha) with their sealants by means of the dye penetration method using India ink. AIMS: To compare the resistance to apical dye penetration between resilon (with Epiphany sealer; Epiphany, Pentron clinical technologies, USA) and gutta-percha (with AH Plus sealer; Dentsply, Maillefer, Germany). It was hypothesized that there would be no difference between the two groups with regard to apical dye penetration. SETTINGS AND DESIGN: Hundred mandibular first premolars from individuals aged between 20 to 25 years were selected after their lengths were standardized. MATERIALS AND METHODS: Instrumentation was performed with NiTi hand protaper files (Dentsply, Maillefer) using EDTA paste and copious irrigation with 2.5% sodium hypochlorite. Experimental group 1 consisted of roots that were treated with Epiphany primer and obturated with resilon (with Epiphany sealer). Experimental group 2 consisted of those obturated with gutta-percha using AH Plus sealer. The samples were immersed in blue India Ink and cleared using 5% nitric acid. Dye penetration was assessed under a stereomicroscope. STATISTICAL ANALYSIS: Mann-Whitney U test. RESULTS: Roots obturated with resilon core material and Epiphany sealer exhibited lesser mean apical dye penetration (1.281 mm; SD: 0.742) in comparison to those obturated with gutta-percha and AH plus sealer (2.154 mm; SD: 0.814). The difference was found to be highly significant (P<0.0025). CONCLUSION: Resilon (with Epiphany sealer) provided better radicular apical sealing in comparison to gutta percha (with AH Plus sealer).

In vitro study comparing fracture strength recovery of teeth restored with three esthetic bonding materials using different techniques.

Reattachment of the fractured fragment of a traumatized tooth (whenever available and usable) has become the treatment of choice in cases of uncomplicated crown fractures. Despite the presence of various bonding materials and techniques, laboratory data evaluating the biomechanical aspects of such procedures is largely lacking in the literature. The objective of this in vitro study was to evaluate the fracture strength recovery of incisors, following fragment restoration with three different techniques. A total of 90 extracted human maxillary central incisors were subjected to crown fractured under standard conditions. This was carried out by applying a compressive force from the buccal aspect of the clinical crown using a universal strength testing machine. The fractured teeth were equality distributed in three groups, defined on the basis of the technique used for reattachment: i) overcontour, ii) internal dentinal groove and iii) direct buildup. Each group was further subdivided into three subgroups on the basis of the intermediate restorative material used for reattachment, namely: i) hybrid composite (Filtek Z100 Universal Restorative, ii) nanocomposite (Filtek Z350) and iii) Ormocer (Voco Admira). Following reattachment, the crowns were re-fractured under standard conditions. The force required for fracture was recorded and was expressed as a percentage of the fracture strength of the intact tooth. The data was expressed as a percentage of the fracture strength of the intact tooth. The data was analyzed using two-way ANOVA and Bonferroni tests for pair-wise comparison. The results showed no statistically significant differences in fractures strength between the three groups (P > 0.05). However, comparison of the subgroups revealed statistically significant higher strength recovery percentages for the hybrid and the nanocomposite compared with the Ormocer material (P < 0.05). It was concluded that material properties have a significant influence on the success of reattachment procedures.