Objectives: This research was carried out to evaluate the effect of different implant collar surfaces (machined and rough collar) on the supporting structures of implant retained mandibular over denture in controlled type II diabetes mellitus.
Materials and methods: It is a cross-over randomized clinical trial where 20 implants were placed in 10 completely edentulous patients. All patients were informed that they would be a part in this study and agreed to share and follow the instructions given to them in the form of signed consent. Each patient received both types of implants. The two implants have the same diameter, length, and surface configuration except for the collar design, one implant has a machined collar while the other has a roughened collar. Patients had controlled type II diabetes mellitus with glycosylated hemoglobin ⪯7. Follow-up CBCT Scans were taken at 0, 6 and 12 months after loading to evaluate marginal bone changes in the two groups over a follow-up period of one year. The acquired data were then tabulated and statistically analysed.
Results: The results of this study showed a statistically significant difference in marginal bone changes. Six months from loading the mean marginal bone loss was 0.706 and 0.476 for group I and group II, respectively. Twelve months from loading the mean marginal bone loss of 1.368 and 0.882 for group I and group II, respectively.
Conclusion: Rough surfaced collar implants showed more favourable results than machined collar implants in maintaining the supporting structures in controlled type II diabetes mellitus patients.