Dimensional changes of keratinized mucosa after accordion versus conventional free gingival graft around dental implants: A randomized two-arm parallel clinical trial.

OBJECTIVES: Free gingival graft (FGG) is the most effective way to increase the apico-coronal width of the keratinized mucosa. In case of limited donor tissue, the accordion technique can be used. This study compared FGG for dimensional and clinical changes using accordion and conventional methods. MATERIALS AND METHODS: Ninety-four implants with keratinized tissue deficiency (<2 mm) were randomly assigned to treatment with accordion (49 implants) and conventional (45 implants) FGG. Endpoints including apico-coronal keratinized tissue width, vertical shrinkage, vestibular depth, probing depth, bleeding on probing, and plaque index were measured. The graft harvesting and recipient bed preparation method were similar in the two groups, and the only difference was the graft length. FGG was harvested with a length 40% shorter than the mesiodistal length of the recipient area in the accordion method and as much as the recipient area in the conventional method. RESULTS: vertical graft shrinkage 1, 3, and 6 months following conventional graft placement was 12.04 ± 14.99, 17.12 ± 20.40, and 23.29 ± 24.63 percent, respectively. In the accordion graft group, the shrinkage was significantly greater with 30.10 ± 16.12, 36.99 ± 15.51, and 43.75 ± 18.78 percent at 1, 3, and 6 months, respectively (p-value < .001). Other factors did not show a clinically significant difference between the two groups. CONCLUSIONS: Comparison of vertical shrinkage changes shows that the shrinkage rate in the accordion group is significantly higher than the conventional group. REGISTRATION NUMBER: IRCT20190721044296N1 (Evaluation of dimensional changes of peri-implant attached mucosa following the treatment of free gingival graft by conventional and accordion methods; randomized clinical trial two-arm parallel).

Effect of microthread design on the preservation of marginal bone around immediately placed implants: a 5-years prospective cohort study.

BACKGROUND: This study aimed to evaluate the effect of the microthread design at the implant neck on the preservation of marginal bone around immediately-placed implants in a 5-year follow up. METHODS: Thirty patients received 41 immediately placed implants which were randomly assigned to treatment groups with microthreaded implants (test group, n = 22) or threaded implants (control group, n = 19). Clinical and radiographic analyses were carried out after 1 and5 years. Plaque index, bleeding on probing, suppuration, probing depth and marginal bone loss were subject to evaluations. The results were analyzed with the T-test, Fisher's exact test and Mann-Whitney U test. RESULTS: No implants failed; thirty-five implants (in 27 patients); 21 microthreaded and 14 threaded implants; completed the 5 year follow up. The mean values of the marginal bone loss in microthreaded and threaded groups were 1.12 ± 0.95 mm and 0.87 ± 0.78 mm, respectively during an observation period of 70.9 ± 10.4 months; the differences in marginal bone loss and other pre-implant parameters were not significant between groups (P > 0.05). CONCLUSION: Both implant designs showed acceptable results in terms of the clinical parameters and marginal bone level. Within the limitation of this study, the results did not demonstrate any superiority of the microthread design compared to threaded one in marginal bone preservation around immediately placed implants over 5 years of loading.

The influence of harvesting free gingival graft on self-reported pain perception: A randomized two-arm parallel clinical trial.

BACKGROUND/PURPOSE: Free gingival graft (FGG) is used as an effective method to increase the width of keratinized tissue. However, it can cause pain at the donor site. Techniques accompanied by lesser tissue harvesting can reduce pain after surgery. The purpose of this study was to evaluate the self-reported pain perception following harvesting FGG using conventional and accordion methods. MATERIALS AND METHODS: In this randomized clinical trial study, 31 patients with a deficiency of keratinized tissue around implant were investigated. Sixteen subjects in the accordion group and 15 subjects in the control group received conventional FGG. In the accordion group, FGG was harvested with a length of 60% of the mesiodistal length of the recipient area and with the same length as the mesiodistal length of the recipient area in the conventional group. The patients were asked to record their daily pain using a numerical rating scale. RESULTS: The severity of the pain after reaching to the peak on the second day was reduced and reached zero at day 14 in both groups. Pain severity showed no significant difference between the treatment groups. The highest level of pain was reported in the conventional group in those subjects under 50 years old, and the lowest one was in the conventional group's subjects above 50 years old. There was no difference between men and women in the reported pain between the treatment groups. CONCLUSION: Harvesting graft with a smaller size in the accordion group has no effect on reducing pain. REGISTRATION NUMBER: IRCT20190721044296N1.