PURPOSE: This study was aimed to evaluate the effect of implant drilling speed on the composition of particle size of collected bone debris. METHODS: Branemark System (R)drills were used to collect bone debris from 10 drilling holes (1 unit) at 1,500 rpm (Group A) and 800 rpm (Group B) in bovine mandible. After separating particles by size into > 500 microm, between 250 microm and 500 microm, and < 250 microm fractions, particle wet volume, dry volume, and weight were measured and the proportion of 3 fractions of bone debris to total wet volume, dry volume and weight was calculated as wet volume % , dry volume % and weight %. RESULTS: No significant differences were found between Group A and B in wet volume, dry volume, and weight. However, of > 500 microm fractions, Group B had significantly higher wet volume % (P = 0.0059) and dry volume % (P = 0.0272) than in Group A. CONCLUSIONS: The drilling speed influenced the composition of particle size in collected drilling bone debris. The drilling in 800 rpm produced the more percentage of large particles than in 1,500 rpm. However, the drilling speed didn't effect on total volume of and weight of bone debris.
Dental High-Speed Technique ; Dental Implantation ; Mandible ; Mandrillus ; Particle Size

OBJECTIVETo examine the effect of nickel-titanium rotary instruments in reducing post-operative pain.

METHODS95 molars with pulpal and/or periapical involvement were randomly assigned to two groups for root canal preparation. One group was treated with ProFile nickel-titanium rotary instruments; the other was treated by using stainless steel hand files-FlexoFile. The incidence and degree of post-operative pain after root canal preparation in the two groups were recorded.

RESULTSIn ProFile group, the incidence of post-operative pain was 27.7%, while 62.5% of the teeth developed post-operative pain after hand preparation. The difference between two groups was statistically significant (P < 0.01).

CONCLUSIONRoot canal preparation on molars with stainless steel hand files resulted in relatively high incidence of post-operative pain. Mechanical preparation using ProFile nickel-titanium instruments generated less post-operative pain and discomfort.

Adult ; Aged ; Dental High-Speed Technique ; instrumentation ; Dental Instruments ; Female ; Humans ; Male ; Middle Aged ; Nickel ; Pain, Postoperative ; prevention & control ; Retrospective Studies ; Root Canal Preparation ; instrumentation ; Titanium