Comparative evaluation of pH and Ca + ion release from MTA on interaction with platelet-rich fibrin and blood clot: an in vitro study.

Background: 'Regenerative endodontics' using host-derived scaffolds and biomaterials (MTA) is popular in the management of teeth with open apex. Alkaline pH and bioactivity contribute to tissue healing and remineralization. We assessed the influence of PRF and Blood Clot on the pH and Ca + ion release from MTA. Methods: A total of 15 single-rooted human extracted teeth were sectioned at the level of the cementoenamel junction. Based on the type of scaffolds used, samples were divided into three groups. Group 1 (MTA+ PRF), Group 2 (MTA + Blood Clot), Group 3 (control MTA). The prepared specimens were transferred to a fresh falcon tube containing 10mL of distilled water and the collected solutions were analysed for pH and Ca + ion release at 3h, seventh day and 14 th day. Results: It was observed that the mean pH and Ca + ion release were significantly lower in the experimental groups as compared to the control group. Though there was an increase in the pH recorded in Group 1 and 2 at all time periods, the difference was not significant. Ca + ion release peaked at Day 7 (Group3 > Group2 > Group1) and reduced significantly on the 14 th day for all groups. Conclusions: Within the limitations of the study, it can be concluded that PRF and blood clot influence the pH and Ca + ion release from MTA.

Evaluation of the effect of remineralization with strontium-doped nanohydroxyapatite with noncollagenous protein analog: Chitosan on the shear bond strength of resin composite to dentin - An in vitro study.

Context: The resin-dentin interface is less durable, which reduces the longevity of tooth-colored restorations. To encounter this shortcoming, the use of nanotechnology to mimic biomineralization proves beneficial. Aims: This study was conducted to evaluate the effect of remineralization with strontium-doped nanohydroxyapatite (Sr-nHAp) with chitosan on shear bond strength of resin composite to dentin. Materials and Methods: Sixty five extracted human premolars were divided into five groups (n = 13) based on remineralization protocol as: Group A - 20% (Sr-nHAp) with chitosan, Group B - 10% (Sr-nHAp) with chitosan, Group C - 20% (Sr-nHAp) with simulated body fluid, Group D - 10% (Sr-nHAp) with simulated body fluid, and Group E - control. Following bonding, resin composite of specified dimension was built and was subjected to shear bond strength test after 24 h and 1 week using Universal Testing Machine, and mode of failure was assessed. ANOVA and paired sample t-test were used for analyzing the data, and the level of significance was set at 5%. Results: The highest value of shear bond strength was obtained from Group A after aging for a week, and there is a significant increase in the value of all the groups as compared to the control group after 1 week of storage than 24 h. Conclusions: Remineralization with Sr-nHAp and chitosan has positively improved the bond strength of resin to dentin at the end of 1 week.

Effect of nano-hydroxyapatite with biomimetic analogues on the characteristics of partially demineralised dentin: An in-vitro study.

BACKGROUND: Research on dentin remineralisation protocols in particular 'biomimetic remineralisation' has gained huge momentum. Aim of this study was to evaluate if biomimetic analogs, incorporated in n-HAp, as an experimental formulation could aid in remineralization of artificial caries-like dentin and have anti-microbial effect on cariogenic bacteria, S mutans. MATERIALS AND METHODOLOGY: An experimental paste was formulated using nano-hydroxyapatite (nHAp) with Non-Collagenous Protein analogs- polyacrylic acid (PAA), sodium tri-poly phosphate (STPP) with Simulated Body Fluid. Partially demineralised dentin specimens were divided into three groups (n=10) based on the remineralisation treatment as, Group A- n-HAp paste, Group B- n-HAp and NCP analogues and Group C (Control) - no treatment. At the end of the experimental period, the specimens were assessed using SEM-EDS analysis and Vickers microhardness testing. Further, the antimicrobial efficacy of the paste was assessed. STATISTICAL ANALYSIS: The results were statistically analyzed using ANOVA with post-hoc Bonferroni test. RESULTS: Dentin specimens treated with the experimental paste revealed greater tubular occlusion, with intra tubular deposits and increased mineral content. Specimens treated with n-HAp alone had higher microhardness values and inhibitory effect on the cariogenic bacteria. CONCLUSION: Non-Collagenous Protein analogs incorporated in n-HAp could remineralize the demineralised dentin and had antibacterial efficacy against S mutans.

The efficacy of transdermal and oral diclofenac for post-endodontic pain control: A randomised controlled trial.

OBJECTIVE: The aim of the present study was to compare the effect of transdermal diclofenac patch against oral diclofenac for post-endodontic pain control. MATERIALS AND METHODS: Thirty-two patients with symptomatic irreversible pulpitis in single-rooted premolar teeth of either arch were treated endodontically in a single visit by a single endodontist. Oral diclofenac (50 mg twice daily) for group I and transdermal diclofenac patch (100 mg once daily) for group II were administered as post-endodontic analgesics for two days. Visual analogue scale (VAS) chart was used to record pain intensity scores preoperatively and at intervals of 4, 8, 12 and 24 h postoperatively for 2 days. Paracetamol 650 mg tablets were provided as rescue medication. RESULTS: There was a significant decrease in the postoperative pain intensity scores for both groups. The postoperative scores gradually decreased from day 1 to day 2 in both groups. Twelve out of sixteen patients who had received diclofenac tablets complained of gastric discomfort. CONCLUSION: Transdermal diclofenac patch was as effective as an oral diclofenac tablet and can be used as an alternative and effective analgesic for post-endodontic pain management, especially in patients with gastric discomfort.

Evaluation of vascular endothelial growth factor - A release from platelet-rich fibrin, platelet-rich fibrin matrix, and dental pulp at different time intervals.

BACKGROUND: Lack of collateral blood supply and the low compliance environment of pulp makes its healing, a challenge. Vascular endothelial growth factor (VEGF) is a primary angiogenic growth factor. Knowledge of dose and time-dependent expression of VEGF from platelet concentrates, namely platelet-rich fibrin (PRF) and PRF matrix (PRFM), along with vital pulp can aid in developing strategies to improve the outcome of vital pulp therapy and regenerative procedures. Hence, the aim of this study was to compare VEGF kinetics of PRF, PRFM, and dental pulp. MATERIALS AND METHODS: The PRF, PRFM, and vital dental pulp were placed in culture media for a week; the supernatant was collected from these samples at days 1, 4, and 7. VEGF-A expression was evaluated using ELISA and compared with the weight of the sample so as to quantify the release of VEGF-A per milligram of sample. RESULTS: PRF exhibited maximum VEGF-A release on day 4 and was sustained till day 7. In contrast, PRFM and dental pulp showed no significant release of VEGF-A till day 7. However, on day 7, there was a rapid increase in VEGF-A expression from dental pulp that was comparable to PRF. On comparing the release of VEGF-A per milligram of tissue, pulp exhibited the maximum values. CONCLUSION: Among the platelet concentrates, differential expression of VEGF-A was superior in PRF. The use of PRF in partial pulpitis should be explored in order to restore pulp vascularity and hasten pulpal healing.

Study of antibacterial and antifungal efficacy of platelet-rich fibrin and platelet-rich fibrin matrix.

BACKGROUND: Platelet concentrates are extensively utilized in the medical and dental field to promote tissue regeneration. The profusion of endogenous growth factors in platelets α-granules transmit their use for enhanced wound healing. However, little attention has been given to study their antimicrobial potential. This study was conducted to assess the antibacterial and antifungal property of platelet-rich fibrin (PRF) and PRF matrix (PRFM). MATERIALS AND METHODOLOGY: Blood samples were obtained from 16 participants, PRF and PRFM were processed as per the protocol prescribed by Choukroun et al. and Lucarelli et al., respectively. The susceptibility test against microbiota in the root canal and Candida albicans was assessed through minimum inhibition zone by agar diffusion technique. RESULTS: PRF showed an effective antibacterial property, however, did not perform well against C. albicans strains. PRFM did not show any antibacterial or antifungal properties. CONCLUSIONS: The antibacterial efficacy of PRF may prove beneficial when used in the revascularization procedure of immature necrotic teeth.

Isolation and genetic characterization of mutans streptococci associated with dental caries in rural field practice of a dental institution: In vivo study.

BACKGROUND: Streptococcus mutans is well-known causative microorganism in the development of dental caries because they drop the plaque pH and produce acids from carbohydrates and survive in the acidic environment. It is now evident that knowledge of the bacteria enforces empirical approach to therapy, then specific antimicrobial therapy that might allow more conservative treatment options. Over the past few decades, there has been a remarkable increase in the prevalence rate of dental caries among children and the elders. Genotypic methods help in the detection and manipulation of nucleic acids which allows microbial genes to be examined directly. AIM: The aim of this study is to isolate and characterize S. mutans from rural population and to obtain genomic DNA and screen DNA band pattern. METHODOLOGY: A total of 80 plaque samples were collected from the buccal surfaces of maxillary and lingual surfaces of mandibular first molar with carious teeth in patients at a rural outreach center in Chikkaballapur district, Karnataka. Among these, 48 clinical isolates of S. mutans were recovered. Further, genomic DNA was extracted from all the positively isolated strains including the standard strain (microbial type culture collection 497), and stored at 4°C in tris EDTA buffer (TE). To analyze the molecular heterogeneity of the clinical strains, polymerase chain reaction (PCR), and restriction fragment length polymorphism was performed using restriction enzymes Hind III and Hae III. Using agarose gel electrophoresis, genomic DNA band pattern was analyzed. RESULTS: Statistically significant difference was seen in the "dex" gene collected from sample DNA and standard DNA in three different parameters (S. mutans 497). CONCLUSION: Genomic DNA of S. mutans was successfully isolated from the rural population. Dex gene was successfully amplified using PCR. Hae III enzymes successfully digested PCR amplicons and the fragments exhibited visible heterogeneity.

Evaluation of Histological and pH Changes in Platelet-Rich Fibrin and Platelet-Rich Fibrin Matrix: A In vitro Study.

BACKGROUND: The autologous platelet concentrates (PCs), such as platelet-rich fibrin (PRF) and platelet-rich fibrin matrix (PRFM), are processed through different centrifugation protocols, which can affect their biological properties and in turn influence treatment outcome. The pH value can influence the process of wound healing directly or indirectly. Hence, a study was conducted to evaluate fibrin network pattern, initial pH of obtained matrix, and its changes during degradation matrix and to determine platelet and leukocyte count in PRF and PRFM. MATERIALS AND METHODS: Blood from the volunteers was collected in blood vacutainers for processing PRF and PRFM. It was centrifuged as per the standard protocol. Serum from PRF and PRFM was subjected for analysis of platelet and leucocyte concentration using Hemo-Analyzer. The pH of PRF and PRFM were evaluated over 5 days using a pH meter. PRF and PRFM were subjected to histological and scanning electron microscopic analysis. RESULTS: There was no significant variation in the platelet and leukocyte count between PRF and PRFM. A steady rise in the level of pH with respect to PRFM was observed, whereas there was a decrease in the pH levels in PRF. Fibrin network was denser in PRF compared to PRFM. CONCLUSION: The PCs undergo variation in pH upon degradation. Formation of fibrin matrix is influenced by the method of preparation. Fibrin pattern is crucial to facilitate adhesion of cells and transport of nutrients to enable proliferation and differentiation of mesenchymal cells and better wound healing.

Cone-beam computed tomographic evaluation of remaining dentin thickness in bifurcated roots of maxillary first premolars after rotary instrumentation and post space preparation: An in vitro study.

BACKGROUND: Intraradicular procedures remove radicular dentin and jeopardizing longevity of a tooth. Traditional in vitro methods used to determine the remaining dentin thickness (RDT) have limitations. AIM: The aim is to evaluate, using cone-beam computed tomography (CBCT), RDT following rotary instrumentation and post space preparation in buccal and palatal roots of maxillary first premolars. MATERIALS AND METHODS: Twenty-three maxillary first premolars with two roots were selected. CBCT images were taken preoperatively, after instrumentation and Parapost 3 and 4 preparation (CBCT 1, 2, 3, and 4). RDT was measured 5 mm above apex, 1 mm below furcation, and 1 mm above furcation (Levels 1, 2, and 3). Data were analyzed using ANOVA and post hoc Tukey's test (P = 0.05). RESULTS: Rotary instrumentation and post space preparation reduced RDT in all walls of buccal and palatal roots. Post space preparation with Parapost 3 and 4 reduced RDT in the palatal wall of buccal root to <1 mm and Parapost 4 reduced all walls to 1 mm of dentin. CONCLUSION: Post space preparation in maxillary first premolars should be performed cautiously. It is safer to place a post in the palatal root of this tooth and limit preparation to Parapost 3.

Clinical evaluation of mineral trioxide aggregate and biodentine as direct pulp capping agents in carious teeth.

BACKGROUND: Root canal treatment has been a routine treatment option for carious exposure of the dental pulp. In the context of minimally invasive dentistry, direct pulp capping (DPC) procedure with a reliable biomaterial may be considered as an alternative provided the pulp status is favorable. Mineral trioxide aggregate (MTA), a bioactive cement with excellent sealing ability and biocompatibility is capable of regenerating relatively damaged pulp and formation of dentin bridge when used as DPC agent. Biodentine is comparatively a new biomaterial claimed to possess properties similar to MTA and is currently explored for vital pulp therapy procedures. AIM: The aim of the present study was to evaluate the clinical response of pulp-dentin complex after DPC with MTA and biodentine in carious teeth. SUBJECTS AND METHODS: Twenty-four permanent molars with carious exposure having no signs and symptoms of irreversible pulpitis were selected and assigned to one of the two groups, Group I - MTA and Group II - biodentine. Patients were recalled at 3 weeks, 3 months, and 6 months for clinical and radiographic evaluation. Fisher's exact test was used along with Chi-square test for statistical analysis. RESULTS: Over a period of 6 months, MTA and biodentine showed 91.7% and 83.3% success rate, respectively, based on the subjective symptoms, pulp sensibility tests, and radiographic appearance. CONCLUSION: MTA and biodentine may be used as DPC agents when the pulpal diagnosis is not more than reversible pulpitis.

Effect of Desensitization Using Bioactive Glass, Hydroxyapatite, and Diode Laser on the Shear Bond Strength of Resin Composites Measured at Different Time Intervals: An In vitro Study.

BACKGROUND: Dentin desensitizers may change the properties of smear layer and have adverse effects on the bonding performance of adhesive systems. AIM: The aim of this study was to compare the effect of bioactive glass (BG), hydroxyapatite, and diode laser desensitization on shear bond strength of resin composites to dentin at different time intervals. MATERIALS AND METHODS: Seventy-two caries-free maxillary premolars were selected. Buccal surfaces were flattened to expose dentin. Teeth were divided into four groups (Groups 1, 2, 3, and 4) according to treatment modality (control with no pretreatment, Sensodyne Repair and Protect, Teethmate Desensitizer, diode laser). Bonding was performed using self-etch adhesive followed by composite buildup. Universal testing machine was used to determine shear bond strengths immediately after bonding, after 3 months, and 5 months storage in artificial saliva. RESULTS: Pretreatment with BG and hydroxyapatite desensitizers increased, whereas diode laser decreased mean shear bond strength of composite to dentin as compared to control group. No statistical significant difference in shear bond strength values was seen in groups after storage. CONCLUSION: Desensitizing toothpastes incorporating remineralizing agents not only occluded open dentinal tubules but also increased shear bond strength of composite to dentin.

Cone beam computed tomographic evaluation of two access cavity designs and instrumentation on the thickness of peri-cervical dentin in mandibular anterior teeth.

BACKGROUND AND OBJECTIVES: The aim of the study was to determine the effect of two access cavity designs on the peri-cervical dentin thickness before and after instrumentation using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Sixty mandibular anterior teeth were divided into two groups of thirty teeth each: Group I: conventional access cavity preparation, where access was prepared just above the cingulum and Group II: incisal access cavity preparation, where access was prepared in proximity to the incisal edge. CBCT scans were taken preoperatively, following access cavity preparation and post instrumentation. 200 µm thick slices were obtained 4mm apical and coronal to the cemento-enamel junction. The peri-cervical dentin thickness was calculated on the facial, lingual, mesial, and distal for all the three obtained scans. RESULTS: The analysis showed that access cavity preparation and instrumentation resulted in a significant loss of tooth structure in Group I on all surfaces, but in Group II, there was a significant loss of tooth structure only in the mesial, lingual, and distal surfaces (P < 0.05). CONCLUSION: Incisal access cavity preparation resulted in lesser loss of dentin in the peri-cervical region.

Comparative evaluation of the efficacy of two modes of delivery of Piroxicam (Dolonex(®)) for the management of postendodontic pain: A randomized control trial.

BACKGROUND: Alleviating pain is of utmost importance when treating patients with endodontic pain. AIM: To compare and evaluate the efficacy of two modes of delivery of pretreatment Piroxicam (Dolonex(®), Pfizer) for the management of postendodontic pain. MATERIALS AND METHODS: Sixty-six patients with symptomatic irreversible pulpitis were randomly divided into three groups of 22 subjects Group I - control group, no pharmacological intervention, Group II - patients received pretreatment oral Piroxicam (40 mg), Group III - patients received pretreatment intraligamentary injections totaling 0.4 mL of Piroxicam. Single visit endodontic therapy was performed by a single endodontist. Visual analogue scale was used to record pain before treatment and 4, 8, 12, 24, and 48 h postoperatively. Mann-Whitney U-test and Kruskal-Wallis tests were used to analyze the data. RESULTS: The patients in Groups II and III perceived less postendodontic pain as compared to Group I (P < 0.05), at all the time intervals. At 12, 24, and 48 h, pain experience in patients of Group III was significantly less. CONCLUSIONS: Intraligamentary mode of delivery of Piroxicam was more efficacious.

Efficacy of Ribbond and a fibre post on the fracture resistance of reattached maxillary central incisors with two fracture patterns: a comparative in vitro study.

AIM: To compare the fracture resistance of maxillary central incisor fragments having two different fracture patterns and re-attached using two different posts - fibre post and Ribbond. MATERIALS AND METHODS: Sixty extracted human maxillary central incisors were randomly divided into two groups of thirty samples each. Group A consisted of samples with 'labio-palatal' fracture pattern and Group B with a 'palato-labial' fracture pattern. The crowns of all the samples were sectioned using safe-sided diamond discs. Following cleaning and shaping and sectional obturation, the samples were randomly subdivided into two subgroups of 15 samples each. Prefabricated fibre post (Reforpost, Angelus, Londrina, PR, Brazil) was placed in all samples of Subgroup I, and Ribbond (Ribbond Inc., Seattle, WA, USA) was placed in all samples of Subgroup II. The fragments were re-attached, fracture resistance was tested using Instron Universal Testing Machine, and the failure modes were assessed using a stereomicroscope. RESULTS: Group A with a labio-palatal fracture pattern exhibited higher fracture resistance as compared to Group B (palato-labial) in both subgroups. The fibre post (Subgroup I) exhibited higher fracture resistance as compared to Ribbond (Subgroup II). The Ribbond group exhibited significantly more number of repairable failures as compared to fibre post group. CONCLUSION: The labio-palatal pattern of fracture is a favourable type of fracture on palatal load application. The fragments re-attached using the fibre post (Reforpost) had a higher resistance to fracture. However, teeth restored with Ribbond posts exhibited 100% repairable failures upon load application. The fracture pattern had no influence on the failure modes.

Comparison of Radicular Peroxide Leakage from four Commonly used Bleaching agents following Intracoronal Bleaching in Endodontically treated teeth - An In Vitro Study.

BACKGROUND: Non vital bleaching is simple, conservative procedure for esthetic correction of discolored endodontically treated teeth. The aim of this study was to determine and compare the amount of peroxide leakage from four different bleaching agents i.e superoxol, sodium perborate, combination of superoxol & sodium perborate and carbamide peroxide during intracoronal bleaching, as the safe and effective bleaching is the need of the hour. MATERIALS & METHODS: 50 extracted maxillary centrals were selected for the study. Following standardized protocol access, cleaning and shaping by step back technique and obturation was done using guttapercha and AH plus sealer. Access was sealed with Cavit G and outer root surface was coated with wax and nail varnish. The teeth were separated into crown and root and the root portion was placed in plastic tube containing distilled water for 7days.After incubation, 3mm of gutta-percha was removed below CEJ and 2mm glass ionomer cement base was placed. Grouped into five categories based on the bleaching agent placed in pulp chamber as -group1 (control)-distilled water, group 2-sodium perborate with distilled water , group 3- 30% hydrogen peroxide ,group 4-mixture of sodium perborate and 30% hydrogen peroxide and group 5-10% carbamide peroxide gel. Peroxide leakage was measured after 24hrs using ferrothiocyanate method and optical density using spectrophotometer. Statistical analysis of the data was conducted using ANOVA and multiple comparisons within the groups was done using BONFERRONI method (Post-Hoc tests). RESULTS: The results showed highest peroxide penetration from 30% hydrogen peroxide followed by mixture of sodium perborate with 30% hydrogen peroxide, mixture of sodium perborate with distilled water and least penetration from 10% carbamide peroxide gel. The results were statistically significant. CONCLUSION: Radicular peroxide leakage in 10% carbamide peroxide was significantly lower than the other tested bleaching agents making it a very safe alternative for intracoronal bleaching. How to cite this article: Madhu KS, Hegde S, Mathew S, Lata DA, Bhandi SH, Shruthi N. Comparison of Radicular Peroxide Leakage from four Commonly used Bleaching agents following Intracoronal Bleaching in Endodontically treated teeth - An In Vitro Study. J Int Oral Health 2013; 5(4):49-55.