Drilling dimension effects in early stages of osseointegration and implant stability in a canine model

Abstract

BackgroundThis study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols.Material and MethodsForty dental implants (4.1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrilling-group) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent.ResultsThe insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs (p<0.001). No significant differences were detected between implant designs for each drilling technique (p>0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique (p<0.03) only, but not for those placed in the 3.75 mm drilling sites (p>0.32).ConclusionsDespite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevailed. Key words: Histomorphometry, biomechanical, in vivo, initial stability, insertion torque, osseointegration.

Influence of Implant Surfaces on Osseointegration: A Histomorphometric and Implant Stability Study in Rabbits

“…It is recognized that drilling protocol (oversized, intermediate or undersized) result in different biological responses with higher BIC and BAFO values for intermediate drilling (22). This fact seems to be related to the blood's clot ability to fill the space between the bone wall and the implant threads which facilitates intramembranous like bone formation at bone interface (20).…”

Biomaterial and biomechanical considerations to prevent risks in implant therapy

“…The hybrid healing osseointegration pathway has been utilized in an attempt to obtain devices that are atemporally stable and is a combination of features presented in the interfacial remodeling and healing chambers osseointegration pathways. Screw‐type implants with large thread pitch and outer to inner thread diameter differences have been designed to allow surgical instrumentation sufficiently large for the formation of healing chambers between threads, implant inner diameter, and bone instrumented walls . For such an implant design configuration, primary stability is obtained by the interaction between the outer regions of the threads that engage bone and such initial stability is proportional to the thread design and the amount of mismatch between implant outer thread and osteotomy diameters.…”

“…Hence, this osseointegration pathway simultaneously presents bone remodeling where engagement between implant and bone occurred, resulting in stability loss that is supposedly compensated by the rapid woven bone formation in the healing chambers formed between threads. Unlike screw‐type implant systems that result in interfacial remodeling osseointegration and plateau root form implants that osseointegrate through healing chambers, implant systems deliberately designed for this purpose are relatively new in the market . Thus, long‐term human retrieved samples are not yet available for adequate assessment of the effect of this healing pathway on long‐term bone morphologic evolution.…”

Osseoincorporation of Porous Tantalum Trabecular-Structured Metal: A Histologic and Histomorphometric Study in Humans

“…[7][8][9][10] PTTM and other methods have been applied to orthopedic titanium hip, knee, and spine implants since 1997, [11][12][13] and more recently to titanium dental implants. [14][15][16] For instance, implants that allow healing chamber formation (defined as void spaces between the surgical instrumentation outer diameter and the implant bulk component, where a blood clot will be present immediately after implantation) after placement have been known for rapid bone formation [17][18][19][20] and the development of haversian-like structures [21][22][23][24] over the implantation time. Under the same prerogative, the PTTM trabecular structure and crystallographic surface texture created by the CVD process have been reported by the manufacturer to increase the percentage of surface area of PTTM dental implants by 52.7% to 81.8%, depending on implant diameter.…”