Highly crystalline MP-1 hydroxylapatite coating. Part II: In vivo performance on endosseous root implants in dogs

Area of Science:

• Biomaterials Science
• Dental Implantology
• Orthopedic Research

Background:

• Oral endosseous implants often utilize plasma-sprayed hydroxylapatite (HA) coatings to enhance osseointegration.
• Variations in HA crystallinity may influence implant integration and bone apposition.
• The MP-1 process is a post-plasma-spray treatment designed to increase HA crystallinity.

Purpose of the Study:

• To compare the in vivo integration strength and bone apposition of standard HA coatings versus MP-1 treated HA coatings on oral endosseous implants.
• To evaluate the effect of increased HA crystallinity on implant osseointegration.
• To determine if extensive dissolution of HA is necessary for bone apposition.

Main Methods:

• Comparison of two plasma-sprayed HA coatings (75% vs. 95% crystalline HA) in a canine mandibular model.
• Assessment of implant integration using pullout strength measurements and histological analysis at 3 and 15 weeks.
• Quantification of bone apposition using two distinct methods at 15 weeks.

Main Results:

• No significant differences in pullout strength or bone apposition were observed between the standard and MP-1 treated HA coatings.
• Histological analysis confirmed that the MP-1 process did not negatively impact the osseointegration rate.
• Qualitative histology suggested potentially greater stability of the MP-1 treated coating, particularly with soft tissue attachment.

Conclusions:

• The MP-1 post-treatment process, while increasing HA crystallinity, does not significantly alter the osseointegration or bone apposition of plasma-sprayed HA-coated oral implants.
• Direct bone apposition to HA-coated implants can occur without substantial dissolution of the coating's calcium phosphate components.
• The findings support the efficacy of both standard and MP-1 treated HA coatings for dental implant applications.