Abstract:

Objectives

To observe the different outcomes of wound dehiscence which was treated by non-surgical methods after implant placement simultaneously guided bone regeneration（GBR） surgery using acellular dermal matrix （ADM） as barrier membrane and its impact on the soft and hard tissues in the implant sites.

Methods

128 patients with inadequate vestibulolingual bone volume at alveolar ridge to accommodate the dental implant were selected to perform implant placement with simultaneously in this clinical study. Non-surgical interventions on the treated area were carried out immediately for 1 to 3 weeks with early wound dehiscence over the ADM. Clinical data on wound healing at 2 weeks post-surgery， during the 3 weeks of non-surgical treatment and at the time of second-stage surgery was recorded， respectively. Standardized periapical radiographs of the operated site on the day after surgery and before the second stage surgery were taken， to evaluate the effects of different outcomes on osseointegrationand crestal bone loss， respectively.

Results

The total rate for wound dehiscence in 128 patients was as high as at 52.34% within 2 weeks post-surgery. In 3 patients，3 implants were failed to achieve osseointegration because of infection， and excluded from the subsequent study. The remaining 125 patients were divided into 3 groups according to the wound healing， Group A （53 cases）：wound dehiscence with early ADM exposure. Group B （12 cases）：ADM perforation accompanied by early cover screw exposure. Group C （60 cases）：normal wound healing without dehiscence. With the aid of the non-surgical therapy， the exposed membranes were gradually covered with gingival tissue in all the patients with premature membrane exposure. Within group A，there was marginal bone loss （MBL） in 12 patients， the mean mesial （M） and distal （D） marginal bone were （0.48±0.19） mm and （0.52±0.19） mm； MBL occurred in 11 patients， the mean M and D MBL were （1.00±0.39） mm and （0.80±0.40） mm， respectively； MBL occurred in only 2 patients of group C.The results of t test showed：No significant differences of the mesial and distal MBL were found within A and B groups （P＞0.05）； while there were remarkable differences between group A and group B for mesial and distal MBL （P＜0.05）. However， differences of mesial and distal MBL between Group A and Group C were not statistically significant （P＞0.05）.

Conclusions

The timely non-surgical intervention to early barrier membrane exposure after GBR surgery could maintain the surface of the wound clean，prevent infection， delay the degradation of the membrane， promote epithelialization， and reduce the adverse effects on bone healing； so it was an effective strategy to obtain delayed soft tissue healing.

Key words: Alveolar ridge augmentation, Membrane premature exposure, Guided bone regeneration, Acellular dermal matrix, Wound dehiscence