ABSTRACT
Background: The fetal amniotic membrane is a biological graft with unique qualities which all lead to wound protection, reducing discomfort, and achieving adequate epithelialization. Materials and Methods: In this animal study, the second and third premolars of the mandible of 4 dogs were extracted. After 4 weeks, 20 mm of mandibular premolar site area were resected on both sides. The created defects on both sides were filled with xenograft. On one side, an amniotic membrane was placed over the graft particles and the reflected flap was sutured. The amount of bone formation in the defects was measured after 4 weeks for two of the dogs and after 8 weeks for the other two, using a caliper. Three histopathological samples from both sides were taken. The collected data were subjected to statistical analysis (Wilcoxon signed-rank and paired sample t-test) using SPSS software at a significant P = 0.05. Results: In the test group, the quantity of bone was 56.81, whereas in the control group bone quantity was 37.38 with statistically significant differences (P = 0.025). In the amniotic membrane group, the inflammation intensity after the graft procedure was moderate (50%) in comparison to the control group where the inflammation was severe (62.5%) (P = 0.041). Conclusion: The amniotic membrane can induce positive osteoinduction effects and be helpful in repairmen of bone defects such as the natural periosteum.
ABSTRACT
BACKGROUND: Plasma rich in growth factors (PRGF) and freeze-dried bone allograft (FDBA) are shown to promote bone healing. This study was aimed to histologically and histomorphometrically investigate the effect of combined use of PRGF and FDBA on bone formation, and compare it to FDBA alone and control group. MATERIALS AND METHODS: The distal roots of the lower premolars were extracted bilaterally in four female dogs. Sockets were randomly divided into FDBA + PRGF, FDBA, and control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 4 weeks. Sockets were assessed histologically and histomorphometrically. Data were analyzed by Kruskal-Wallis test followed by Mann-Whitney U-tests utilizing the SPSS software version 20. P < 0.05 was considered statistically significant. RESULTS: While the difference in density of fibrous tissue in three groups was not statistically significant (P = 0.343), the bone density in grafted groups was significantly higher than the control group (P = 0.021). The least decrease in all socket dimensions was observed in the FDBA group. However, these differences were only significant in coronal portion at week 4. Regarding socket dimensions and bone density, the difference between FDBA and FDBA+PRGF groups was not significant in middle and apical portions. CONCLUSION: The superiority of PRGF+FDBA overFDBA in socket preservation cannot be concluded from this experiment.
ABSTRACT
BACKGROUND: Using local anesthetic is common to control the pain through blocking the nerve reversibly in dental procedures. Gow-Gates (GG) technique has a high success rate but less common. This study aimed to compare the onset time and success rate in GG and standard technique of inferior alveolar nerve block (IANB). STUDY DESIGN: This descriptive, single blind study was consisted of 136 patients (59 males and 77 females) who were randomly received GG or IANB for extraction of mandibular molar teeth. Comparisons between the successes of two anesthetic injection techniques were analyzed with Chi-square test. Incidence of pulpal anesthesia and soft tissue anesthesia were analyzed with Kaplan-Meier method. Mean onset times of pulpal anesthesia, soft tissue and lip numbness were analyzed with Log-Rank test. Comparisons were considered significant at P≤0.05 by using SPSS software ver.15. RESULTS: The incidence of pulpal anesthesia in the IANB group (canine 49.3%, premolar 60.3%) were not significantly different from the GG group (canine 41.3%, premolar 74.6%) (P=0.200 and P=0.723). The success rate in the IANB group (80.82%) was not significantly different from the GG group (92.02%) (P=0.123). Furthermore, onset time of lip and buccal soft tissue numbness in GG group (3.25, 4.96 minutes) was quite similar to IANB group (3.22, 4.89 minutes) (all P values >0.05). CONCLUSIONS: Although this study demonstrated higher clinical success rate for GG than IANB technique, no significant differences in success rates and onset time were observed between two techniques.
