Outcome of novel pulp capping modalities after full pulpotomy in teeth diagnosed with irreversible pulpitis: A prospective randomized clinical trial.

Objective: The study aimed to compare and evaluate the effect of biodentine (BD) alone, BD along with Lyophilised freeze dried platelet rich concentrate (LPC + BD), and BD along with low-level laser therapy (BD + LLLT) after pulpotomy in mature permanent molars with irreversible pulpitis. Materials and Methods: The study was designed as a randomized, pragmatic, parallel, double-blinded clinical trial registered under the Clinical Trial Registry-India (CTRI/2020/02/023245). 120 permanent molars fulfilling the inclusion and exclusion criteria with symptoms of irreversible pulpitis were randomized after performing pulpotomy into three pulp capping groups: Group 1, BD; Group 2, lyophilized freeze-dried platelet-rich concentrate + BD (LPC + BD); and Group 3, Low level laser therapy + BD Group 3, LLLT + BD. The intergroup comparison was done using one-way analysis of variance followed by the Bonferroni test. The level of significance and confidence interval were 5% and 95%, respectively. Interobserver reliability was measured using Cohen's kappa analysis. Results: At 1 week, there was a significant difference (P < 0.005) observed in the mean postoperative pain levels between the three groups with Group 1 (BD) exhibiting the highest postoperative pain followed by Group 2 (LPC + BD) and least pain was exhibited by Group 3 (LLLT + BD). A similar pattern was observed regarding the analgesic intake with maximum frequency in Group 1 (BD) and least with Group 3 (LLLT + BD). No significant difference in success rates was reported among the groups. Conclusion: Pulpotomy as a treatment option for mandibular molars with irreversible pulpitis has an acceptable clinical success rate; however, long-term overall success rate remains questionable. The outcomes of incorporating adjunctive modalities with BD are remarkable and show tremendous potential for continued development and research.

Comparative evaluation of dentinal tubule penetration and push-out bond strength of new injectable hydraulic calcium disilicate based root canal sealer: A single blinded in vitro study.

Objective: To evaluate and compare dentinal tubule penetration and push-out bond strength of BIO-C ION+, AH Plus and NanoSeal-S using Confocal Laser Scanning Microscopy (CLSM) and Universal Testing Machine (UTM). Materials & method: Sixty human mandibular premolars were prepared using ProTaper Gold till F3. Samples were then divided into 3 groups: Group I (n = 20) BIO-C ION + sealer, Group II (n = 20) AH Plus and Group III (n = 20) NanoSeal-S sealer. Groups were then sub-divided into two sub groups: In Subgroup A (n = 10) samples were obturated using single-cone with 0.1 % Rhodamine B dye and in Subgroup B (n = 10) samples were obturated using single cone. The samples were then transversely sectioned into coronal, middle and apical segments, samples in subgroup A & B were then submitted to CLSM analysis and UTM respectively. Results: The Bond Strength data showed following means (MPa): Group I Subgroup B: (BIO-C ION+) coronal (1.64), middle (1.25), apical (0.93); Group II Subgroup B: (AH Plus) coronal (2.20), middle (1.85) apical (1.38) and Group III Subgroup B: (NanoSeal-S) coronal (1.26), middle (0.94), apical (0.58). The dentinal tubule penetration data showed following means: (µm) Group I Subgroup A (BIO-C ION+) coronal (1184.69), middle (997.03), apical (637.26); Group II Subgroup-A AH Plus (864.14) and NanoSeal-S (495.64). Statistical analysis (two-way ANOVA, Tukey's Post Hoc Test) showed significant difference among sealers (p < 0.001) and root canal thirds (p < 0.001). Conclusion: The results of the study concluded that BIO-C ION + sealer showed maximum dentinal tubule penetration and AH Plus demonstrated maximum push-out bond strength.

Comparative evaluation of treatment outcome of partial pulpotomy using different agents in permanent teeth-a randomized controlled trial.

AIM: To compare and evaluate the clinical and radiographic performance, post-operative pain, and anti-inflammatory intake after partial pulpotomy (PP) with calcium hydroxide (CH), mineral trioxide aggregate (MTA), Biodentine (BD), and Emdogain (EMD) as pulp capping agents in mature permanent molars with definitive diagnosis of reversible pulpitis. MATERIALS AND METHODS: As part of this prospective, randomized clinical trial with four parallel arms (CTRI Registration No.: CTRI/2020/11/029329 dated 24/11/2020), hundred and ten permanent molars with a clinical diagnosis of reversible pulpitis and normal apical tissues, from patients between the ages of 15 and 45 years, were recruited and randomly assigned to four groups-CH, MTA, BD, and EMD. Operative procedure was performed under local anesthesia and dental dam isolation. After carious pulpal exposure, 2 mm of superficially inflamed coronal pulp tissue was amputated and either of the four pulp capping materials was placed. The outcome assessment was carried out at 1, 3, 6, and 12 month(s) and was categorized as success (asymptomatic patients with PAI score = 1) or failure (symptomatic patients or PAI score > 1). RESULTS: There was a significant difference in post-operative pain and anti-inflammatory medication intake after partial pulpotomy with Emdogain vis-à-vis other three capping agents. No difference in both clinical and radiographic performances was observed among the four capping agents. CONCLUSION: Partial pulpotomy when performed following evidence-based guidelines results in high success rates regardless of capping agent employed. EMD can be considered a valid and suitable pulp capping agent in PP. CLINICAL RELEVANCE: Meticulous examination and removal of superficially inflamed pulp under magnification and complete asepsis lead to successful pulpal healing regardless of capping agent employed.

Evaluating the Concentration of MMP-9 and TNF- α in Pulpal Blood at Various Stages of Pulpal Inflammation in Diabetics: A Cross Sectional Study.

OBJECTIVE: To investigate the concentration of Matrix metalloproteinases-9 (MMP-9) and Tumor necroses fac- tor-alpha (TNF- α) in pulpal blood at various stages of pulpal inflammation in diabetics and to establish the relationship between these two biomarkers. METHODS: 77 patients, each having a tooth with pulpal exposure due to caries presenting with distinct stages of pulpitis were grouped into 2 main study groups as based on the HbA1c Levels-Group 1: Non-Diabetics (Control Group) (HbA1c < 5.6%) and Group 2: Type 2 Diabetics (Experimental Group) (HbA1c>6.5%; Random Plasma Glucose > 200) and diabetes mellitus with less than 10-year history. Depending on the radiological and clinical diagnosis, these two groups were again sub-divided into 2 subgroups: Sub-group A: Tooth with Symptomatic Irreversible Pulpitis. Sub Group B: Tooth with Reversible Pulpitis. Thus, for comparison purposes, a total of 4 sub-divisions were formed: Sub-group 1A- Non-Diabetic, Symtomatic Irreversible Pulpitis, Sub- group 1B: Non-Diabetic, Reversible Pulpitis, Sub-group 2A: Diabetic, Symptomatic Irreversible Pulpitis, Sub- group 2B: Diabetic, Reversible Pulpitis. Blood sample was collected from pulp chamber after partial pulpo- tomy was done. The total levels of MMP-9 and TNF-α were assessed by enzyme linked immunosorbent assays (ELISA). Inter-group comparison in levels of MMP-9 and TNF- α were conducted using the Kruskal Wallis test and pairwise comparison was done Mann-Whitney U test. RESULTS: The inter-group comparison in levels of MMP-9 and TNF- α were conducted using the Kruskal Wallis test and pairwise comparison was done using Mann-Whitney U test. Pearson correlations were conducted in order to investigate correlations between the paired TNF-α and MMP-9 values and also their correlation with the blood sugar levels within the pulp diagnosis groups. MMP-9 and TNF-α levels were significantly higher (p<0.005) in irreversible pulpits than reversible pulpits and also in Type-2 diabetics than non-diabetics. High- est level of MMP-9 and TNF-α was found in Group 2A (Diabetic, symptomaticirreversible pulpitis) and lowest in Group 1B (Non-Diabetic, reversible pulpitis). There exists a very high significant positive correlation between MMP-9 and TNF-α (p<0.005). CONCLUSION: These findings show that the inflammatory mediators MMP-9 and TNF-α are significantly in- creased in pulpal blood samples of diabetic patients. Also, in diabetic patients diagnosed with reversible pul- pitis, higher levels of inflammatory pulpal biomarkers were reported that could compromise the success of Vital Pulp Therapy (VPT) and may necessitate endodontic intervention. MMP-9 and TNF- α were reported to have a positive correlation. (EEJ-2023-01-04).

Evaluation of Bacterial Reduction at Various Stages of Endodontic Retreatment After Use of Different Disinfection Regimens: An In Vivo Study.

OBJECTIVE: The present study was conducted to evaluate the presence of aerobic bacteria, anaerobic bacteria, E. faecalis, F. nucleatum, Propionibacteria sp., Actinomyces sp., and their reduction at various stages of endodontic retreatment with the use of conventional protocol (5.25 % Sodium Hypochlorite (NaOCl) as the irrigant along with Calcium Hydroxide (Ca (OH)2) as intracanal medicament and advocated protocol (SmearOFF as the irrigant along with 2% Chlorhexidine (CHX) gel as intracanal medicament). METHODS: Twenty eight patients fulfilling the eligibility criteria were selected for root canal retreatment and randomly allocated into two groups. Group 1: Final irrigant as SmearOFF+Chlorhexidine 2% gelas intracanal medicament (n=14). Group 2: Final irrigant as 5.25% NaOCl+Ca(OH)2 as intracanal medicament (n=14). With aseptic environment, access opening was performed followed by Gutta Percha (GP) removal and sample S1 was collected for bacterial analysis. The biomechanical preparation was done by using Reciproc system with additional finishing with XP-Endo Finisher R. Sample S2 was then collected for bacterial analysis after the final irrigation protocol in the respective groups. Intracanal medicaments were placed for one week and sample S3 was collected. All the samples were subjected to qualitative analysis using PCR and quantification was done by Colony Forming Unit (CFU) analysis. RESULTS: Aerobic [28/28], Anaerobic [28/28], Propionibacterium sp. [20/28] and F. nucleatum [24/28] were the most frequently isolated in S1 sample followed by Actinomyces sp. [16/28] and E. faecalis sp. [19/28]. Chemico-mechanical preparation followed by irrigation (S2 sample) resulted in significant reduction of all types of bacteria in both groups. Group-1 (SmearOFF as the final irrigant) had significantly superior efficacy against aerobic bacteria, E. faecalis and F. nucleatum (P<0.05) as compared to Group-2 (NaOCl). After medicament placement, significant differences between the groups were noted only for the E. Faecalis group. For the S3 samples, the mean bacterial reduction was significant in Aerobic and F. nucleatum in S3 samples for Group 1 and Group 2. CONCLUSION: Chemico-mechanical preparation followed by irrigation resulted in significant reduction in bacterial load irrespective of the final irrigant. SmearOFF was significantly better than NaOCl in minimizing bacterial load of E. faecalis and F. nucleatum. 2% Chlorhexidine gel has superior antimicrobial efficacy against E. faecalis and may be recommended in secondary endodontic treatment.

Comparative evaluation of microleakage and hardness of newer posterior restorative materials.

Background: The physical properties of restorative materials are critical when restoring posterior teeth. Restorative materials are continuously evolving in the quest for creating long lasting restorations. Aim and objective: To compare and evaluate microleakage and hardness of three different posterior restorative materials: Cention N, Zirconomer Improved and Solare Sculpt. Materials and methods: For micro leakage evaluation, 40 extracted human third molars were randomly divided into three experimental groups of 10 teeth each and two control group of 5 teeth each. Standardized box shaped class II cavity preparation was done in Group I, II, III and V. In Group V, cavity was prepared but left unrestored. No cavities were prepared in Group IV. Cavities in Group I, II, and III were restored with Cention N, Zirconomer Improved, Solare Sculpt respectively. Teeth were thermocycled together for 500 cycles. All the samples were placed in 2% methylene blue for 24 h. Microleakage evaluation was done using stereomicroscope. For hardness evaluation ten standardized discs of each material were prepared and evaluated using vicker's hardness test. Results: All the groups showed some amount of microleakage. The mean micro-leakage score was significantly more among Group II compared to Group I. There was no significant difference in mean micro-leakage score between Groups I and III. The mean hardness value was significantly more among Groups I and II compared to Group III. Conclusion: No material was able to completely eliminate microleakage. Cention N showed high hardness among the materials tested.

Effect of dental acid etchant-mediated photodynamic therapy on bacterial reduction and microshear bond strength of composite to dentin - An in vitro study.

OBJECTIVE: The objective of this study was to assess the effect of dental acid etchant (DAE)-mediated photodynamic therapy on bacterial reduction and microshear bond strength of composite to dentin. MATERIALS AND METHODS: Eighty permanent third molars after sample preparation were exposed to a cariogenic challenge with Streptococcus mutans. After incubation, specimens were randomly divided into four groups (n = 20): Group I - DAE, Group II - low-level laser (LLL), Group III - diode laser + methylene blue (MB + L), and Group IV - diode laser + DAE (DAE + L). Half of the specimens from each group were selected for bacterial reduction assessment and the other half for microshear bond strength. All the samples for assessment of bacterial reduction (before and after intervention) were seeded onto the surface of mitis-salivarius-bacitracin medium. After incubation, the viable bacterial count was determined in colony-forming unit/mL. For microshear bond strength assessment, samples were subjected to various treatment modalities and then bonding and debonding procedure was performed for blocks of composite and values were recorded. RESULTS: Significant reductions in S. mutans were observed in all the groups - Group I (DAE) 68.50%, Group II (LLL) 55.90%, Group III (MB + L) 88.60%, and Group IV (DAE + L) 87% with comparable bacterial reduction between Group III (MB + L) and Group IV (DAE + L). Furthermore, a significant difference in bond strength values was seen in Group III (MB + L) 10.99 MPa and Group IV (DAE + L) 17.99 MPa whereas an insignificant difference was found between Group I (DAE) 20.74 MPa, Group II (LLL) 18.27 MPa, and Group IV (DAE + L). CONCLUSION: DAE caused a comparable reduction in bacterial count to MB-assisted PDT and also there was no adverse effect on bond strength values. PDT can be performed while acid etchant containing MB dye is being applied in the cavity, thus reducing operative time and enhancing cavity disinfection.

Evaluation of the effect of natural versus synthetic matrix metalloproteinase silencers in preservation of dentin collagen and long-term bond strength of total etch adhesive.

AIM: This study investigated the effect of various synthetic (galardin [Gal] and benzalkonium chloride [BAC]) and natural agents (hesperidin [HES] and epigallocatechin gallate) on the stability of dentin collagen matrix to resist collagenase degradation and improve long-term microtensile bond strength. MATERIALS AND METHODS: Ten sound-impacted third molars were collected and manual removal of pulp, periodontal ligament, cementum, and enamel was done. Remaining dentin fragments were pulverized under liquid nitrogen to obtain dentin powder. 2 mg aliquot of dentin powder was allocated to each of the test solutions and subjected to hydroxyproline assay. Another 60 sound human third molars were collected and occlusal enamel was ground flat to reach dentinoenamel junction. Class I cavities were prepared in dentin, followed by etching using 37% phosphoric acid for 15 s. Samples were then subjected to surface treatment with different agents for 60 s, followed by application of Optibond S and restoration with P 60 composite resin. Samples of all groups except control were subject to thermocycling. Samples were sectioned to 1 mm thick slabs which were subject to universal testing machine to determine ultimate tensile strength. One-way analysis of variance and Bonferroni post hoc test with a significance level of P < 0.05 were used to analyze data. RESULTS: HES resulted in maximum resistance to collagen degradation, followed by epigallocatechin gallate (EGCG), Gal, and BAC with a significant difference among the groups. Samples of Gal group showed the highest microtensile bond strength values, followed by HES, EGCG, BAC with a significant difference between the groups except HES and EGCG where the difference was nonsignificant. CONCLUSION: The use of matrix metalloproteinase silencers could improve the mechanical properties of collagen and resist enzymatic degradation, leading to an improved long-term intimate restoration.

Influence of type of cement and their thickness on stress distribution at dentin-cement interface of computer-aided designed glass fiber post: A three-dimensional finite element analysis.

AIM: This study aims to evaluate the effect of type of cement, and their thickness on stress distribution at dentin-cement interface of computer-aided designed glass fiber post using three-dimensional finite element analysis. MATERIALS AND METHODS: Nine 3D models of endodontically treated maxillary second premolar were divided into three groups according to the adhesive cement used PermaCem (Group I), Variolink II (Group II), and ParaCore (Group III). Each group was further divided into subgroup a, b, and c on the basis of the thickness of the adhesive cement 50 µm, 200 µm, and 300 µm, respectively. All the models were simulated to be cemented with computer-aided designed glass fiber post and core followed by zirconia crown. The core was modeled with incomplete ferrule. The load of 200N at 45° at lingual and central fossa was applied. Maximum von Mises stresses distribution was calculated. RESULTS: Maximum and minimum stresses in dentin were seen in the Ic and IIIa, respectively. Maximum and minimum stresses in cement were seen in IIIc and Ia, respectively. CONCLUSION: The von Mises stresses in dentin can be minimized by keeping the cement thickness minimum and selecting the cement whose modulus of elasticity is closest to that of dentin.

Evaluation of the effect of calcium hydroxide and endodontic irrigants on the push-out bond strength of fiber post - an in vitro study.

BACKGROUND: In recent years, fibre-reinforced composite posts have been proposed for the restoration of root filled teeth as an alternative to pre-fabricated posts or metal dowels. AIMS AND OBJECTIVES: The aim of the study was to analyze the effect of endodontic irrigants used for removal of calcium hydroxide on the push-out bond strength of fiber posts to root canal dentin. METHODS: Forty human permanent single-rooted mandibular premolars with relatively straight roots were taken and access cavities were prepared and biomechanical preparation done using Rotar Y protaper file till size F2. The samples were divided into Experimental group and Control group. In Experimental groups Intracanal dressing of calcium hydroxide was removed by 2.5% NaOCl and 17% EDTA (Group1), MTAD (Group II) and Qmix (Group III). Control group did not receive Intracanal calcium hydroxide dressing. Canals were obturated using size F2 protaper gutta-percha points and AH plus sealer. After storage for 24 hours, post space was prepared. Forty Tenax fiber post (Coltene) were cemented with Rely X U200 resin. The roots were then transversally sectioned into 3 slices of 1mm thickness corresponding to cervical, middle and apical third. The slices obtained were subjected to micro-push-out bond strength test using a universal testing machine. The data obtained was subjected to statistical analysis using One-Way ANOVA test. P value of .05 was considered as statistically significant level. RESULTS: The mean push-out bond strength values for controls, NaOCl/EDTA, MTAD and QMIX group at cervical third were 10.17, 15.84, 20.39 and 20.98 whereas at apical third 4.78, 8.85, 11.66 and 12.10. CONCLUSION: Qmix showed higher push-out bond strength values followed by MTAD and NaOCl/EDTA. All the groups showed lowest push-out bond strength values in the apical third followed by middle and the maximum in the cervical region.

Effect of potential remineralizing agent and antioxidants on color stability of bleached tooth exposed to different staining solutions.

AIM: The aim of the study was to evaluate the effect of staining solutions, remineralizing agent, and antioxidant on color stability of tooth during and after bleaching. MATERIALS AND METHODS: Ninety human central incisors were bleached using 35% hydrogen peroxide (Pola office) and allocated to three groups (n = 30). Group I stained with cola-based soft drinks, Group II stained with pomegranate juice, and Group III stained with turmeric. The groups were then divided into three subgroups (n = 10): subgroup A - control (artificial saliva), subgroup B - remineralizing agent (Vantej), and subgroup C - antioxidant (grape seed extract [GSE]). Specimens were bleached according to the manufacturer's recommendations. Color variation measurement was performed using a photoreflectance spectrophotometer before bleaching, during each bleaching session (2-times/week), and after (7 and 15 days) the cessation of bleaching. Artificial saliva was used as the storage medium for the specimens except when measurements were to be recorded. The results were then subjected to statistical analysis. RESULTS: Freshly bleached teeth exposed to Vantej and GSE and significantly lowered the stain absorption. CONCLUSION: Among the experimental agents, Vantej performed statistically better at all time intervals.

Effect of different antioxidants on reversing compromised resin bond strength after enamel bleaching: An in vitro study.

OBJECTIVE: The effect of 10% sodium ascorbate, 10% α-tocopherol, 10% grape seed extract, and 10% guava seed extract solutions on the shear bond strength (SBS) of composite resin to bleached enamel was evaluated. MATERIALS AND METHODS: Labial enamel surfaces of 72 extracted maxillary central incisors were bleached using 37.5% hydrogen peroxide. Sixty-four specimens were divided into four experimental groups (Group I-IV) comprising 16 specimens each and remaining eight specimens were placed in Group V. Groups I-IV were further divided into 2 subgroups: A (10 min) and B (120 min) comprising 8 specimens each. Eight unbleached specimens served as control (Group VI). Immediately following bleaching, Groups IA-IVA and IB-IVB specimens were treated with respective antioxidants for 10 min and 120 min. All specimens were then bonded with composite resin. Specimens were stored in distilled water for 24 h. SBS testing was done. Data were tabulated and subjected to statistical analysis using ANOVA and Tukey's honest significant difference test. RESULTS: Group VI (unbleached) showed the highest SBS followed by Group IV (10% guava seed extract). CONCLUSION: Use of antioxidants effectively reversed the compromised bond strength of bleached enamel. About 10% guava seed extract application after bleaching showed best bond strength.

Efficacy of different irrigation regimes on the push-out bond strength of various resin-based sealers at different root levels: An in vitro study.

AIM: This study aims to evaluate and compare the efficacy of various irrigation regimens on push-out bond strength of AH Plus/gutta-percha, Real Seal/Resilon, and MetaSeal/gutta-percha at three different root levels. MATERIALS AND METHODS: Single-rooted mandibular premolars (n = 120) were prepared and divided into four groups (n = 30) based on irrigation regimen used: I: 5.25% sodium hypochlorite (NaOCl)-17% ethylenediaminetetraacetic acid (EDTA); II: 5.25% NaOCl-2.25% Peracetic acid (PAA); III: 5.25% NaOCl-18% 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) (Etidronic Acid); and IV: Distilled Water. Each group was further divided into three subgroups (n = 10); A: AH Plus/gutta-percha; B: MetaSEAL/gutta-percha; C: RealSeal/Resilon. After obturation, roots were sectioned at 3 levels and push-out tests were performed. One-way ANOVA with post hoc Tukey-honestly significant difference tests were applied to assess the significance among various groups. RESULTS: Among irrigants, 2.25% PAA showed significantly lower values when compared with rest of the irrigants. There was no significant difference found among EDTA and HEBP. The push-out bond strength of AH Plus was significantly higher among all sealers. The bond strength values were significantly decreased in apico-coronal direction. CONCLUSIONS: There was superior efficacy of EDTA and HEBP on the bond strength of AH Plus at apical root level when compared with other irrigants and sealers at various root levels.

Effect of saliva and blood contamination on the shear bond strength of fifth-, seventh-, and eighth-generation bonding agents: An in vitro study.

AIM: To evaluate the bond strength of different adhesives after contamination with saliva and blood at various steps of application. MATERIALS AND METHODS: Buccal surfaces of 180 human premolars were sliced to expose dentin. The specimens were randomly divided into six groups (n = 30), in which saliva and blood were used as contaminants in three groups each. The groups were further divided according to the generation (fifth - OptiBond Solo Plus Kerr, USA; seventh - OptiBond All-In-One Kerr, USA; eighth - Futurabond DC, Voco, Germany) of the adhesive used. Effect of contaminant application both before and after polymerization of the adhesive was evaluated. Composite cylinders were fabricated on exposed dentinal surfaces and were subjected to shear bond strength test. The results were subjected to one-way analysis of variance and t-test. RESULTS: The eighth-generation adhesive showed the highest mean shear bond strength, followed by fifth- and seventh-generation adhesive. Salivary contamination resulted in greater decrease of bond strength when contaminated before polymerization. However, the results were vice versa when blood contamination was done, except in the case of fifth-generation adhesive. Blood contamination produced the lowest shear bond strength in all conditions. CONCLUSION: The eighth-generation adhesives showed the highest and blood contamination the lowest bond strength in all conditions.

To evaluate and compare the effect of different light-curing modes and different liners on cuspal deflection in premolar teeth restored with bulk filled or incrementally filled composite measured at different time intervals.

AIM: The aim of this study is to evaluate and to compare the effect of different light-curing modes and different liners on cuspal deflection in premolar teeth restored with bulk filled or incrementally filled composite measured at different time intervals. MATERIALS AND METHODS: The study was divided into two parts (Part 1-different curing modes, Part 2-different liner) each with sixty extracted human upper premolar teeth with standardized large mesio-occlusal-distal cavities prepared. Each part was divided into two groups according to the composite used (Group A-Filtek Z350 XT, Group B-Sonic fill). Each group was then divided into three subgroups according to the light-curing modes (soft-start, pulse, and continuous curing mode) and liner (Filtek Z350 XT Flowable, Vitremer) used. The cuspal deflection was then measured with a digital micrometer gauge and subjected to statistically analysis using analysis of variance and Tukey's post hoc test. RESULTS: Sonic fill composite, resin-modified glass ionomer cement (RMGIC) liner and curing with soft-start/pulse curing mode had significantly lower cuspal deflection compared to Filtek Z350 XT, flowable liner, and continuous curing mode, respectively. CONCLUSION: Sonic fill composite, RMGIC liner under the restorations and composites cured with soft start/pulse curing mode resulted in reduced cuspal deflection.

Comparative evaluation of the microtensile bond strength of bulk fill and low shrinkage composite for different depths of Class II cavities with the cervical margin in cementum: An in vitro study.

AIM: The aim of this study was to evaluate the microtensile bond strength (µTBS) of bulk fill and low shrinkage composite for different depths of Class II cavities with the cervical margin in cementum. MATERIALS AND METHODS: Standardized conservative box-shaped Class II cavities were prepared on sixty sound-impacted human third molars. The samples were randomly divided into two groups: Group I (n = 30) - horizontal incremental technique and Group II (n = 30) - bulk fill technique (SonicFill). They were further subdivided into three subgroups of (n = 10) samples each according to the different occluso-gingival height: subgroup (A - 4 mm, B - 5 mm, and C - 6 mm). The gingival margins for all the samples were located 1 mm below the cementoenamel junction. The restored samples were subjected to thermocycling (500 cycles) followed by µTBS testing. The scores were statistically analyzed using ANOVA and post hoc test using SPSS software version 16. RESULTS: Subgroups IA and IB showed lower µTBS than subgroups IIA and IIB (P < 0.05) whereas subgroup IC showed higher µTBS than subgroup IIC (P < 0.05). SonicFill showed a significant reduction in µTBS as the depth increased. CONCLUSION: SonicFill should be used in two increments for cavities with a depth of more than 5 mm.

Effect of ceramic type, thickness, and time of irradiation on degree of polymerization of dual - cure resin cement.

AIM: The aim of the study is to evaluate the effect of ceramic type, thickness, and time of irradiation on degree of polymerization of dual-cure resin cement. MATERIALS AND METHODS: Dual-cure resin cement (SoloCem) was used to prepare disk-shaped samples (0.5 mm thick × 5 mm diameter). Study group samples (n = 5) were light-cured for 40, 60, and 80 s through all ceramic leucite-reinforced (Cergo Kiss), lithium disilicate-reinforced (IPS e.max), and monolithic zirconia-reinforced (Ziecon) of three thicknesses (2, 3, and 4 mm). Negative control group samples were cured through metal disks and positive control samples were cured without the presence of ceramic. The degree of conversion (DC) was evaluated by Fourier transform infrared spectrometer. The recorded data were subjected to one-way analysis of variance, followed by post hoc analysis (Tukey HSD). RESULTS AND CONCLUSION: Greatest light transmission and DC were seen through Cergo Kiss, followed by IPS e.max Press and Ziecon, with insignificant difference between the latter two. The attenuation of light irradiance increased with increasing thickness of ceramic disks, with statistically significant values between 3 and 4 mm. Increasing time of irradiation to cure dual-cure resin cement did not always result in greater degree of polymerization.

An in vitro comparison of effect on fracture strength, pH and calcium ion diffusion from various biomimetic materials when used for repair of simulated root resorption defects.

AIM: The aim of this study was to compare the effect on fracture strength, pH and calcium ion diffusion from mineral trioxide aggregate (MTA) Fillapex, iRoot SP, and Ultracal when used for repair of simulated root resorption defects. MATERIALS AND METHODS: Three sets of 40 teeth each were used, and biomechanical preparation was done. Resorption cavity was made at 5 mm from the apex. Teeth were filled with different experimental materials. In control group, saline was used. Samples of fracture resistance were stored in an incubator for 3 months and then subjected to the universal testing machine. To evaluate the pH and calcium ion release were checked at 1 day and 1, 2, 3, and 4 weeks intervals. Data were recorded and statistical analysis done by one-way analysis of variance followed by post-hoc Tukey test. RESULTS: Highest fracture resistance was seen in MTA Fillapex followed by iRoot SP, control, and then Ultracal group. Teeth filled with iRoot SP showed highest pH and calcium ion release followed by MTA Fillapex and Ultracal group. CONCLUSION: Bioceramic sealers showed high pH, calcium ion release, and good root reinforcement potential. Initial dressing of calcium hydroxide followed by obturation with Gutta-percha and bioceramic sealer may be considered as an alternative treatment modality for inflammatory resorption.

Apical extrusion of Enterococcus faecalis using three different rotary instrumentation techniques: an in vitro study.

AIMS: To compare the apical extrusion of Enterococcus faecalis after instrumentation with three different Ni-Ti rotary instruments- An in vitro study. SETTINGS AND DESIGN: In vitro study Methods and Material: Forty freshly extracted mandibular premolars were mounted in bacteria collection apparatus and root canals were contaminated with a suspension of Enterococcus faecalis. The contaminated teeth were divided into 4 groups of 10 teeth each according to rotary system used for instrumentation: Group1: Hyflex files, Group 2: GTX files, Group 3: Protaper files and Group 4: control group (no instrumentation). Bacteria extruded after preparations were collected into vials and microbiological samples were incubated in BHI broth for 24 hrs. The colony forming units were determined for each sample. STATISTICAL ANALYSIS USED: Statistical analysis was done using one way ANOVA followed by post hoc independent " t" test. RESULTS: GTX files extruded least amount of bacteria followed by Hyflex files. Maximum extrusion of E. faecalis was seen in rotary Protaper group. CONCLUSION: Least amount of extrusion was seen with GTX files followed by Hyflex files and then rotary Protaper system.