Journal of Dental Medicine

Postoperative pain following Root Canal Therapy (RCT) is the common problem for patients,dentist and dental staff. Regardless of cause it appears that postoperative pain and discomfort is related to periapical inflammation. The purpose of this study was to investigate histologically the effect of Ibuprofen on acute apical inflammation following RCT. on cat. Fifty-six cuspids teeth of 14 cats were divided into three groups, 6 cats for experimental group, 6 cats for positive control group and 2 cats for negative control group. In first group, to anesthesize the animals each cat received 10 mg/kg Ibuprofen 36 hours before RCT and repeated every 24 hours. In second group RCT was performed in 24 cat teeth without any prescription. In negative control groups 2 cats, no RCT were done.Following vital perfusion, in interval of 6, 12, 24 hours, samples were post fixed in 10% formalin and five micron sections were prepared, and stained with H&E and studied under the Mann Whitney parameter test. Infilteration of inflamatory cells in 6 hours interval in experimental group was significantly less than two control groups. In 12 hours samples, however, inflammation in experimental group reduced, but it was not significant. In 24 hours samples there was no significant difference between experimental groups and controls. The result of this in-vivo study shows prescription of Ibuprofen before root canal therapy can reduce inflammatory reaction.

Statement of Problem: Reduction of orthodontic therapy treatment time is considered an important goal in the management of malocclusion in adult patients. Corticotomy- facilitated orthodontic treatment may be considered an intermediate therapy between orthognatic surgry and conventional orthodontics for reducing treatment time.
Purpose: This study was undertaken to evaluate and compare the rate of tooth movement of upper canine following corticotomy with conventional method.

Materials and Methods: Ten young adult patients, 17-25 years old was selected through sequential sampling procedure in orthodontics department of Shiraz Dental School. The patients exhibited different orthodontic problems and needed extraction of premolars. Following extraction of premolars and initial phase of orthodontic treatment, corticotomy were performed unilaterally on buccual and palatal sides of extraction area as described by Takami. The other imoperated sides were used as control. After subsiding the resultant inflammation, the activated NiTi spring was used and measurement of the amount of tooth movement were assessed by using Rugae as reference point. The panoramic radiographs were super imposed for evaluation of canines tipping. For analyzing the results, Kolmogorou- simirnov and t.tcst were used.
Results: The rate of canine tooth movement was much greater in the corticotomy sides than the unoperated (control) side (P=0.015). This was especially significant at the end of first week of tooth movement (P=0.000). Comparing the two sides, the amount of canine tipping was much lesser in corticotomy group than the control group (P=0.046). There was no significant difference concerning the anchorage loss between the two groups (P=0.410).
Conclusion: Corticotomy procedure had a positive effect on the rate of tooth movement with less tipping of the canines comparing to conventional orthodontic treatment. To get more benefit from this procedure, it is recommended to select those patients who do not need canine alignment after premolars extraction, such as bimaxillary dento alveolar protrusions.

Background and Aim: The role of applying rotary instruments in reducing preparation time and proper root canal preparation have been approved in permanent teeth. The aim of this study was to compare the rotary instruments (Hero642) and K-files in root canal preparation of primary molars. Time and canal transportation were compared.

Materials and Methods: In this experimental, invitro study, 30 human extracted primary molars with 8 mm length were selected and divided into two equal groups. After preparing access cavity, group 1was prepared by K-files and group 2 by Hero642 systems. Before canal preparation, with # 15 K-file and after canal preparation, with master apical file, canal curvature was evaluated by Weine technique using Radiovisiography. Apical transportation was calculated. Time taken for preparation was recorded by chronometer. The results were analyzed with T-test and Mann-Whitney. P<0.05 was considered as the level of significance.

Results: The average canal transportation angle was 3.42 for Hero642 group and 7.33 for K-file group (p<0.04). The mean instrumentation time was 4.28 for Hero642 group and 8.76 minutes for K-file group (p<0.001). There was a significant difference between two groups.

Conclusion: Based on the findings of this study, it is suggested to apply Hero642 rotary instrument for primary molar canal preparation due to less preparation time and less canal transposition.

Background and Aims: Discoloration of resin composites is considered to be the major factor in esthetic restoration failures. The aim of this study was to evaluate the color stability of resin composites after rebonding with two different adhesive materials.

Materials and Methods: Forty five composite disc samples were divided into three groups (n=15). The surface of specimens was finished by polishing disc and rubber. In group 1, any additional phase was not performed. In group 2, composite discs were etched by %37 orthophosphoric acid, then Margin- bond was used for rebonding. In group 3, the etching procedure was in the same manner used for group 2, but Permaseal was used after etching. After the first phase of spectrophotometric measurement, the specimens were dipped in coffee mix for 3 weeks for aging the specimens. Then the second phase of spectrophotometric evaluation was performed. Collected data was analyzed using one-way ANOVA test followed by Tukey test. P<0.05 was considered as the level of significance.

Results: The mean total color difference (∆E) observed in groups 1 to 3 were 1.4±0.34, 5.24±1.51, and 7.44±1.34, respectively. Statistical significant differences were shown between the groups (P<0.001).

Conclusion: Rebonding with adhesive materials used in this study did not increase the color stability of composite restorations.

  Background and Aims: To ensure root canal treatment success, endodontic microbiota should be efficiently reduced. Several irrigation devices have been recently introduced with the main objective of improving root canal disinfection.The purpose of this study was to evaluate the rinsing effect of RinsEndo system in reduction of enterococcus faecalis in comparison with conventional hand syringe in infected root canals.

  Materials and Methods: 60 extracted single canal anterior teeth were infected with enterococcus faecalis and divided into 3 groups: RinsEndo system, conventional hand syringe and control group. The enterococcus faecalis colonies were counted in each group before and after rinsing. Data were analyzed using Variance and Kruskal Wallis test.

  Results: The mean of enterococcus faecalis growth after rinsing was 3.50×10³ in group with conventional syring rinsing, 2.04×10³ in group with RinsEndo washing and 6.11×10³ in control group. Reduction of enterococcus faecalis after rinsing was statistically significant in each group (P<0.001). The amount of reduction in number of colonies with RinsEndo and conventional syringe rinsing was higher in comparison with control group and this difference was significant (P<0.001). RinsEndo rinsing effect was statistically significantly higher in comparison to conventional syringe as well (P<0.001).

  Conclusion: Rinsing with RinsEndo system was significantly more efficient in reduction of enterococcus faecalis from root canal in comparison with hand syringe washing.