Background: It is believed that during the osseointegration phase of submer
ged dental implants, complete mucosal coverage and isolation of the implant
from the oral cavity avoids trauma and infection and establishes favorable
conditions for osseointegration. Spontaneous early exposure is one of the
complications that could adversely affect osseointegration of implants.
Methods: This study clinically classifies spontaneous early exposure and de
scribes and analyzes this complication in a group of 148 patients treated w
ith 372 submerged implants: 216 (58%) in the mandible and 156 (42%) in the
maxilla. Edentulous sites were exposed by mid-crestal incisions and full th
ickness gingival flaps. Incisions were closed in an attempt to achieve comp
lete closure and healing by primary intention. Measurements were taken to a
void mechanical trauma to the mucosa over the implants. Patients were follo
wed up weekly and examined to identify early exposures. Perforations were c
lassified according to the degree of exposure from 0 (no perforations) to 4
(complete exposure).
Results: Of the implants 51 (13.7%) presented spontaneous early exposure,(2
8) (13%) in the mandible and 23 (14.7%) in the maxilla. Class 2 perforation
was the most frequent, followed by Class 3, Class I and Class 4. Inflammat
ion at the mucosal orifices of the perforations was minimal, but no objecti
ve index (bleeding, probing) was taken in order to avoid morphological chan
ges of the lesions that were biopsied for histological examination.
Conclusions: Early perforation and partial exposure of the implant's coveri
ng device are a focus for plaque accumulation which, if left untreated, may
result in inflammation, damage to the peri-implant mucosa, and possible pe
ri-implant loss.