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.

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.

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.

Evaluation of effect of three different dental unit waterline antimicrobials on the shear bond strength to dentin - An ex vivo study.

BACKGROUND: In restorative treatment dental unit water is used while irrigating the cavity and also in the use of composite restorations to flush away the etchant to place bonding agent. These antimicrobials may influence the bond strength of the dentine bonding agent to the dentine. AIM AND OBJECTIVE: To evaluate the effect of three different dental units waterline antimicrobials on the shear bond strength of dentin. MATERIALS AND METHODS: Sixty freshly extracted human teeth were taken and the occlusal surfaces were sectioned to obtain a flat dentin surface. Then the teeth were randomized into 4 groups depending on the antimicrobial used: Group 1(Distilled water), Group 2 (Alpron), Group 3 (CitriSil), and Group 4 (Chlorhexidine). The dentine surface was prepared for bonding and composite resin was placed in two increments of 2 mm each. The specimens were stored in distilled water, thermo cycled after 7 days shear test was performed by using the universal testing machine. RESULT: No significant difference between Group 1 and Group 2 with regard to shear bond strength. There was a significant difference in the SBS of Group 1 and Group 3 and Group 4. The SBS of group 2 was higher than Group 3 and Group 4 and the difference was statistically significant. CONCLUSION: Citrisil and Chlorhexidine groups showed affected bond strength whereas Alpron did not vary with bond strength.