Effects of different oxidized surfaces of implant on osseointegration; resonance frequency and histomorphometric analysis study in mini-pigs

Removal torque of bicortically stabilized RBM(resorbable blast media) pin implants in rabbit tibia / 대한치과보철학회지

STATEMENT OF PROBLEM: The use of small diameter implants having less than 3 mm in diameter were restricted because of lack of bonding strength to bone. PURPOSE: The purpose of this study was to observe how much resorbable blast media pin implants increase the binding force to the bone compared to machined transitional pin implants by measuring removal torque, and whether they can be used as final implants for replacement of small diameter teeth. MATERIAL AND METHOD: Fifteen rabbits were used in this study. Two kinds of implants (resorbable blast media pin implants and machined transitional pin implants) were inserted in each tibia bicortically. After healing time of 2, 4 and 8 weeks, the removal torque values were recorded and the rabbits were sacrificed for histological analysis. Linear finite element method analyses were conducted to compare bicortical fixation with monocortical fixation. RESULT AND CONCLUSION: Within the limitation of this in vivo study, the following conclusions were drawn: 1) The removal torque value of RBM pin implants showed statistically significant increase compared to machined pin implants at 2, 4, and 8 weeks respectively (p<0.05). 2) The removal torque value of RBM pin implants at 2, 4, and 8 weeks was increased statistically significantly with time (p<0.05). 3) Bicortical fixation showed better stress distribution compared with monocortical fixation in a linear finite element method analysis. 4) RBM pin implants are not recommended as transitional implants because they showed a lot of bone fracture in histologic specimens.

An experimental study of newly designed implant with RBM surface in the rabbit tibia: resonance frequency analysis and removal torque study / 대한치과보철학회지

STATEMENT OF PROBLEM: The importance of fixture design and surface treatment. PURPOSE: The clinical success of dental implants is affected by many factors such like as degree of osseointegration, the effective load dispersion for the prostheses, and a lot of attempts have been made to overcome the difficulties. In this study, efforts were made to find the possibility of clinical acceptance of the dental implants of newly designed surface and resorbable blast media surcace. MATERIALS AND METHODS: In this study, two groups of custom-made, screw-shaped implants were prepared. Tthe first with the consisting of Branemark clone design and the other with the new design. These implants were divided into four groups according to the kinds of surface treatment. Four implants(AVANA., Osstem, Busan, Korea) of each group were installed in twenty rabbits. Group A was consisted of Branemark clone implant left as machined, Group B with Branemark clone implants with RBM(Resorbable blast media) surface, Group C with newly designed implants left as machined and Group D with newly designed implants with RBM surface. One of the twenty rabbits died from inflammation and the observation was made for six weeks. Specimens from four groups were observed using scanning electron microscopy with 40, 100, 1000 magnification power and microsurface structures were measured by white-light scanning interferometry for three dimensional surface roughness measurements(Accura 2000., Intek-Plus, Korea.). Removal torque was measured in 17 rabbits using digital torque gauge(MGT 12R, Mark-10 corp., NY, U.S.A.) immediately after the sacrifice and two rabbits were used for the histologic preparation(EXAKT 310., Heraeus Kulzer, Wehrheim, Germany) of specimens and observed under light microscope. Resonance frequency measurement(Osstell(R)) was taken with the 19 rabbits at the beginning of the implant fixation and immediately after the sacrifice. RESULTS: Following results were taken from the experiment. 1. The surface of the RBM implants as seen with SEM had rough and irregular pattern with reticular formation compared to that of turned specimens showing different surface topographies. 2. The newly designed implant with RBM surface had high removal torque value among four groups with no statistical significance. The average removal torque was 49.95+/-6.70Ncm in Group A, 51.15+/-4.40Ncm in Group B, 50.78+/-9.37Ncm in Group C, 51.09+/-4.69Ncm in Group D. 3. The RFA values were 70.8+/-4.3Hz in Group A, 71.8+/-3.1Hz in Group B, 70.9+/-2.5Hz, 72.7+/-2.5Hz in Group D. Higher values were noted in the groups which had surface treatment compared to the untreated groups with no statistical significance. 4. The results from the histomorphometric evaluation showed a mean percentage of bone-toimplant contact of 45+/-0.5% in Group A, 55+/-3% in Group B, 49.5+/-0.5% in Group C, and 55+/-3% in Group D. Quite amount of newly formed bone were observed at the surface RBM-treated implants in bone marrow space.