Influence of three membrane types on healing of bone defects.
OBJECTIVE
To determine and compare osseous regeneration associated with three guided tissue regeneration membrane types (expanded polytetrafluoroethylene, dense polytetrafluoroethylene, and an absorbable polylactic acid/citric acid ester base) and removal forces required for expanded and dense polytetrafluoroethylene membranes.


METHODS
Bilateral osseous defects were created in 30 adult rat calvaria; one defect was covered with a test membrane and the other received no membrane (control). After 2 or 4 weeks, forces required for membrane removal from the tissues were electronically determined, and the calvaria removed and decalcified. Sections through the defects were stained and evaluated electronically and microscopically. Data were analyzed statistically.


RESULTS
Microscopic evaluation with Mann-Whitney U test revealed that dense polytetrafluoroethylene was associated with significantly greater bone formation than expanded polytetrafluoroethylene (p = 0.02) at 2 weeks and absorbable polylactic acid/citric acid ester base (p = 0.004) at 4 weeks. Electronic evaluation of the linear degree of fill with one way ANOVA and Tukey's test found no significant difference (p > 0.05) among the experimental or the control groups. In addition, the Mann-Whitney U test indicated that removal forces required for dense polytetrafluoroethylene were significantly less than for expanded polytetrafluoroethylene (p = 0.003).


CONCLUSIONS
The use of dense polytetrafluoroethylene as a membrane barrier deserves further investigation as it allows osseous regeneration, it is easier to remove from healing soft tissues, and it is inexpensive. A study with larger sample sizes should be conducted.
Department of Periodontics, Baylor College of Dentistry, Dallas, Tex., USA.
T B
TB
Crump
F
F
Rivera-Hidalgo
J W
JW
Harrison
F E
FE
Williams
I Y
IY
Guo
D000704:Analysis of Variance; D000818:Animals; D001673:Biodegradation, Environmental; D001861:Bone Regeneration; D019343:Citric Acid; D048091:Guided Tissue Regeneration / Q000379:methods*; D019344:Lactic Acid; D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers; D011138:Polytetrafluoroethylene / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric
D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers; D019343:Citric Acid; D019344:Lactic Acid; C033616:poly(lactide); D011138:Polytetrafluoroethylene