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.

Enhanced access and isolation by simple modifications of dental armamentarium.

A good armamentarium facilitates the efficient working of the dentist which in turn improves the quality of treatment rendered to the patient. The present invention of the unit consisting of the flexible mirror attached to the suction and the dual suction tip aims at improving the clinical efficiency of dental treatments provided. This compact unit is designed to improve the visualization and isolation of the operating field. It is also easy to fabricate and alleviates the very relevant shortcomings of clinical work.

Comparative evaluation of decalcifying agents for dissolution of pulp stones: An in vitro study.

Background: Despite constant advances in science, obscurity remains in the efficient removal of pulp stones to aid in successful root canal treatment. In this context, chemical means of dissolving pulp stones were explored. Aim: The aim of this study is to evaluate and to compare the efficacy of decalcifying agents on the dissolution of pulp stones. Materials and Methods: The study was divided into two groups for pulp stone analysis (21 samples) and dentin analysis (54 samples). Twenty-one pulp stones from patients aged 18-70 who underwent root canal treatment were collected and divided into three subgroups (n = 7) randomly. They were subjected to chemical treatment in a labeled glass container with 5 ml of the respective chemical agents, such as 17% ethylenediaminetetraacetic acid solution (positive control), no treatment (negative control), and newly developed Physiological Simulated Decalcifying Agent (PSDA). At the end of the study period (24 h), the samples were removed, rinsed with deionized water, and subjected to physical analysis, scanning electron microscopy (SEM), and Energy -dispersive X-ray spectroscopy (EDS) analysis. Under dentin analysis, 54 maxillary premolars scheduled for orthodontic extraction without caries or extensive restorations were selected, following which 2-mm thick transverse dentinal sections at the cementoenamel junction level were obtained and randomly divided into two groups for SEM (n = 21) and microhardness analysis (n = 33). The samples were subjected to respective chemical treatment groups similar to pulp stones for 24 h and analyzed using SEM, EDS, and microhardness analysis. Results: Postchemical treatment with the newly developed decalcifying solution, the pulp stones showed the absence of nodular crystallites and surface softening under SEM and a decrease in the calcium level under EDS analysis. Concerning the microhardness of dentin, no significant changes could be observed. Conclusion: The newly explored PSDA was found to be efficacious in the decalcification of pulp stones at a clinically relevant time of 24 h, without significantly affecting the structural integrity and the hardness values of dentin.

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.

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.

Effect of Staining and Bleaching on Color stability and Surface Roughness of Three Resin Composites: An in vitro study.

AIM: This study evaluated the effect of staining and subsequent bleaching on the color stability and surface roughness of three resin composites. MATERIALS AND METHODS: One hundred and eight customized plastic disks from a plastic mold with an outer diameter of 10 mm and thickness of 1.02 mm were fabricated. Samples were divided into three groups of 36 specimens each - Group I (Estelite® α - Supranano), Group II (Filtek™ Z250 XT - Nanohybrid), and Group III (Filtek™ P90-Silorane). Subsequently, baseline surface color and roughness values were tabulated using spectrophotometer and profilometer, respectively. The specimens were then subjected to staining with coffee and turmeric for a period of 3 h/day for 40 days and following this, bleaching of the samples was done using a bleaching agent carbamide peroxide gel 15% for 8 h/day for 14 consecutive days. RESULTS: Estelite® α performed better by maintaining color stability with minimal roughness compared to Filtek™ P90 and Filtek™Z250 XT. Turmeric had a greater potential to stain composites compared to coffee in all the groups.

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.

The effect of 2% chlorhexidine on the bond strength of two different obturating materials.

The bond strength of ActiV GP and gutta-percha/AH Plus after using 2% CHX as final rinse was evaluated in this study. According to the final irrigation regimen forty roots were divided into two groups (n = 20) randomly: Group 1-5 ml of 17% EDTA; Group 2-5 ml of 17% EDTA followed by 5 ml of 2% chlorhexidine gluconate (CHX). Based on the obturation system the two groups were further subdivided into two subgroups (n = 10). The roots were horizontally sectioned from the coronal and midthird sections for measuring the push-out bond strength. CHX/AH Plus (2.795 ± 0.42 MPa) and EDTA/ActiV GP (1.489 ± 0.117 MPa) recorded the highest and lowest mean bond strength values respectively. It was concluded that when 2% CHX was used as a final irrigation rinse the bond strength of both gutta-percha/AH Plus and ActiV GP obturation system improved significantly.

CT evaluation of canal preparation using rotary and hand NI-TI instruments: An in vitro study.

BACKGROUND: Controlled, uniformly tapered radicular preparation is a great challenge in endodontics. Improper preparation can lead to procedural errors like transportation of foramen, uneven dentine thickness, stripping of root canal, formation of ledge, zip, and elbow in curved canals. These procedural errors and their sequel can adversely affect the prognosis of treatment. AIM/OBJECTIVES: The present in vitro study aims to evaluate canal preparation based on the following factors: canal transportation, remaining dentine thickness and comparing centering ability between hand Ni-Ti K files and ProTaper rotary Ni-Ti instruments using computed tomography (CT). MATERIALS AND METHODS: For evaluation, 30 mesiobuccal roots of maxillary molars were selected. Of these, 15 roots were distributed into two groups where Group 1 included hand instrumentation with Ni-Ti K-files; and Group 2 comprised ProTaper NiTi rotary system. Pre instrumentation and post instrumentation three-dimensional CT images were obtained from root cross-sections that were 1 mm thick from apex to the canal orifice; scanned images were then superimposed and compared. RESULT: It was observed that the manual technique using hand Ni-Ti K-file produced lesser canal transportation and maintained greater dentine thickness than the rotary ProTaper technique at middle and coronal third and this difference was statistically significant. No significant difference was seen with regard to canal transportation and remaining root dentine at apical levels. With regard to centering ratio, no significant difference was seen between both the groups at all levels. CONCLUSION: ProTaper should be used judiciously, especially in curved canals, as it causes higher canal transportation and thinning of root dentine at middle and coronal levels. None of the groups showed optimal centering ability.