Bone apposition around two different sandblasted, large-grit and acid-etched implant surfaces at sites with coronal circumferential defects: an experimental study in dogs.
OBJECTIVE
The study was designed to evaluate bone apposition around SLA (sandblasted, large-grit and acid-etched) implants compared with modified SLA (modSLA) ones at sites with different sizes of circumferential gaps.


METHODS
All mandibular premolars and first molars of six beagle dogs were extracted. After a healing period of 3 months, three 10-mm-long implants were inserted in each side of the mandible. One implant was inserted with a 0.5-mm and one with a 1-mm gap between the implants and bone around the coronal 5 mm of the implants. The third implant was inserted without a gap as a control. The dogs were sacrificed respectively at weeks 2, 4 and 8 after implant placement for histological and histomorphometric analyses.


RESULTS
The histomorphometric results showed similar pattern of bone apposition for the two surfaces. At 2 and 4 weeks of healing, the percentage of newly formed bone-to-implant contact (BIC%), new bone fill (NBF%) and the distance between the most coronal position of BIC and the defect bottom (B-D) were significantly higher for modSLA (P<0.05). At 8 weeks of healing, this difference was not significant (P>0.05). With regard to the defect size, the histological analyses showed no significant differences between the two defect sizes at all time points (P>0.05).


CONCLUSIONS
Significantly more bone apposition was found for the modSLA surface than for the SLA surface at early stage of healing, indicating that modSLA surface may enhance bone apposition in coronal circumferential defects at non-submerged implants. Gap size within 1 mm may not need any kind of regenerative procedures.
Lai
Hong-Chang
HC
Department of Oral and Maxillofacial Implantology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University, Shanghai, China. lhc9@hotmail.com
Zhuang
Long-Fei
LF
Zhang
Zhi-Yong
ZY
Wieland
Macro
M
Liu
Xin
X
D000539:Alveolar Process / Q000502:physiology / Q000601:surgery; D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D045662:Dental Etching; D003758:Dental Implantation, Endosseous / Q000295:instrumentation* / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D008297:Male; D008334:Mandible; D016348:Osseointegration / Q000502:physiology*; D010027:Osteotomy / Q000379:methods; D013499:Surface Properties
D015921:Dental Implants