Influence of early cover screw exposure on crestal bone loss around implants: intraindividual comparison of bone level at exposed and non-exposed implants.
BACKGROUND
The objective of this study was to evaluate the influence of early exposure of the cover screw on crestal bone loss around implants.


METHODS
The study population consisted of 19 patients who were treated with dental implants placed using a two-stage surgical protocol and had early exposed and non-exposed implants (20 early exposed and 20 non-exposed implants). The crestal bone loss at exposed and non-exposed implants in each patient was evaluated with a periapical radiograph taken at the first surgery and at suprastructure insertion using a computerized image-analysis system. The bone loss was compared using the Wilcoxon signed-rank test.


RESULTS
The mean crestal bone loss at exposed implants was 0.40 +/- 0.53 mm, and it was 0.18 +/- 0.26 mm at non-exposed implants. The Wilcoxon signed-rank test revealed a statistically significant difference in crestal bone loss between exposed and non-exposed implants in the same patient (P = 0.02).


CONCLUSIONS
The early exposure of the cover screw that results in breakdown of the mucosal seal seems to accelerate early peri-implant crestal bone loss. Periodic follow-up after the first surgery may be critical for minimizing the influence of early exposure.
Kim
Tae-Hyung
TH
Department of Periodontology, Gangnam Severance Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea.
Lee
Dong-Won
DW
Kim
Chong-Kwan
CK
Park
Kwang-Ho
KH
Moon
Ik-Sang
IS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000209:etiology*; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000295:instrumentation* / Q000379:methods; D015921:Dental Implants; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D016300:Radiography, Bitewing; D013529:Surgical Wound Dehiscence / Q000150:complications; D020390:Tooth Socket / Q000601:surgery; D014945:Wound Healing
D015921:Dental Implants