The edentulous ridge expansion (ERE) technique an experimental study in the dog

Abstract

Objective: To compare the healing and bony crest resorption at implants installed conventionally or applying an edentulous ridge expansion (ERE) technique in the maxilla.

Material and methods: In six Labrador dogs, the first and second maxillary incisors were extracted bilaterally. In the left side of the maxilla (Test), the flaps were elevated and the buccal plate of the alveoli and septa was removed. After 3 months of healing, partial-thickness (split) flaps were dissected and the residual alveolar bone was exposed. In the right side of the maxilla, an implant was installed conventionally (Type IV; Control) while, in the left side, the ERE technique was adopted. Hence, an expansion of the buccal bony crest was obtained, and the implant was subsequently installed (Test). After 3 months of healing, biopsies were obtained and ground sections were prepared for histological analyses.

Results: A buccal vertical resorption of the bony crest of 2.2 ± 1.2 mm and 1.6 ± 0.7 mm was found at the test and control sites, respectively. The difference, however, did not reach statistical significance. The coronal level of osseointegration at the buccal aspect was located at 3.1 ± 1.0 mm and 2.2 ± 0.7 mm from the implant shoulder at the test and control sites, respectively, the difference being statistically significant. The mean values of the mineralized bone-to-implant contact (MBIC%) ranged from 43% to 48% at the buccal and lingual sites. No differences reached statistical significance.

Conclusions: Implants installed by applying an ERE technique may osseointegrate similarly to conventional implant installation. However, vertical and horizontal resorption of the displaced buccal bony wall occurred as well.

Keywords: animal study; bone augmentation; bone healing; dental implants; histology; implant dentistry; ridge expansion; split crest.