Resorption beneath silastic mandibular implants. Effects of placement and pressure

Area of Science:

• Biomaterials Science
• Oral and Maxillofacial Surgery
• Veterinary Medicine

Background:

• Silicone rubber (Silastic) implants are used in mandibular reconstruction.
• Bone resorption is a potential complication of such implants.
• Understanding factors influencing resorption is crucial for surgical outcomes.

Purpose of the Study:

• To investigate the impact of silicone rubber mandibular implant pressure and placement on underlying bone resorption.
• To compare supraperiosteal versus subperiosteal implant positioning.
• To assess the effect of varying implant pressures (minimum, moderate, maximum) on mandibular bone.

Main Methods:

• A randomized, controlled animal trial was conducted on ten adult hounds.
• Silastic blocks were implanted supraperiosteally and subperiosteally in each mandible.
• Implant pressure was manipulated using titanium miniplates, and mandibles were examined after 4 months.

Main Results:

• Mandibular bone resorption occurred under all implanted Silastic blocks.
• No statistically significant difference in resorption was observed between supraperiosteal and subperiosteal placements.
• Higher implant pressures were associated with a trend toward reduced bone resorption.

Conclusions:

• Some degree of bone resorption appears unavoidable with Silastic mandibular implants.
• Implant placement (supraperiosteal vs. subperiosteal) is not a significant factor in minimizing resorption.
• Increased implant pressure may paradoxically decrease mandibular bone resorption, challenging existing assumptions.