PMID- 10484111
OWN - NLM
STAT- MEDLINE
DCOM- 19990914
LR  - 20190814
IS  - 0278-2391 (Print)
IS  - 0278-2391 (Linking)
VI  - 57
IP  - 9
DP  - 1999 Sep
TI  - Biomechanical and morphometric analysis of hydroxyapatite-coated implants with 
      varying crystallinity.
PG  - 1096-108; discussion 1108-9
AB  - PURPOSE: The level of crystallinity in hydroxyapatite (HA) is thought to be 
      responsible for its degradation in the physiologic milieu. The purpose of this 
      study was to compare the in vivo bony response to HA coatings of varying levels 
      of crystallinity and determine the optimum composition for promoting 
      osseointegration. MATERIALS AND METHODS: Cylindrical implants of sand-blasted CP 
      titanium and HA-coated titanium of 50% (low), 70% (medium), and 90% (high) 
      crystallinity were inserted into the canine femur for 1, 4, 12, and 26 weeks. 
      Morphometric analysis of undecalcified sections determined the percentage of bone 
      contact with the implant surface. A pullout test was used to measure the 
      interfacial attachment strength of the bone-implant interface. Scanning electron 
      microscope (SEM) examination of the implant surface aided in identifying the 
      failure mode. Coating thickness was measured under light microscopy to determine 
      whether degradation occurred. RESULTS: No significant differences could be found 
      in the percentage of bone contact and interfacial attachment strength between the 
      three types of HA-coated implants throughout the four implantation periods. A 
      significantly higher percentage of bone contact on HA-coated implants than on 
      uncoated titanium implants was noted at 4 weeks. (ANOVA, P<.05). HA-coated 
      implants were also found to have significantly higher interfacial attachment 
      strength than titanium implants at 4, 12, and 26 weeks. Coating thickness 
      decreased gradually with time. The most noticeable reduction was found on the 
      low-crystallinity coatings during the first 4 weeks. Failure of the 
      bone-coating-implant complex occurred mostly within the coating or near the 
      coating-implant interface. CONCLUSIONS: HA coatings on metal implants enhance 
      osseointegration in the early stage of bone healing and provide strong 
      bone-bonding capability, although titanium implants had about the same level of 
      bone contact in the later stage of healing. Crystallinity of HA coatings has no 
      significant influence over the bone formation capacity and the bone bonding 
      strength. However, an HA coating of higher crystallinity is more desirable in 
      providing durability and maintaining osteoconductive properties.
FAU - Chang, Y L
AU  - Chang YL
AD  - School of Dentistry, National Yang-Ming University, Taipei, Taiwan.
FAU - Lew, D
AU  - Lew D
FAU - Park, J B
AU  - Park JB
FAU - Keller, J C
AU  - Keller JC
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Oral Maxillofac Surg
JT  - Journal of oral and maxillofacial surgery : official journal of the American 
      Association of Oral and Maxillofacial Surgeons
JID - 8206428
RN  - 0 (Coated Materials, Biocompatible)
RN  - 0 (Dental Implants)
RN  - 91D9GV0Z28 (Durapatite)
RN  - D1JT611TNE (Titanium)
SB  - IM
MH  - Analysis of Variance
MH  - Animals
MH  - Biomechanical Phenomena
MH  - Cell Adhesion
MH  - Coated Materials, Biocompatible/*chemistry
MH  - Crystallization
MH  - Dental Implantation, Endosseous
MH  - Dental Implants
MH  - Dogs
MH  - Durapatite/*chemistry
MH  - Femur
MH  - *Implants, Experimental
MH  - Microscopy, Electron, Scanning
MH  - Microscopy, Fluorescence
MH  - *Osseointegration
MH  - Titanium
EDAT- 1999/09/14 00:00
MHDA- 1999/09/14 00:01
CRDT- 1999/09/14 00:00
PHST- 1999/09/14 00:00 [pubmed]
PHST- 1999/09/14 00:01 [medline]
PHST- 1999/09/14 00:00 [entrez]
AID - S0278239199001202 [pii]
AID - 10.1016/s0278-2391(99)90333-6 [doi]
PST - ppublish
SO  - J Oral Maxillofac Surg. 1999 Sep;57(9):1096-108; discussion 1108-9. doi: 
      10.1016/s0278-2391(99)90333-6.