This study aimed to classify peri-implant bone defects (PIBDs) on the basis of their radiographic appearance
in a cohort of patients with lower implant-supported overdentures.
Materials and methods
with lower implant-supported overdentures were recruited to participate in the study, which was approved by the ethics committee
of Ignatius Teaching Hospital. Details about the patients' smoking habits were recorded. The participants had a total of 224
implants involving 3214 implant sites. The mean observation time of the subjects was 10.7 years. Panoramic radiographs of
ll sites were evaluated in duplicate (first evaluation [t1], second evaluation [t2]) during 2 weeks by one experienced observer.
PIBDs were classified into the following types: saucer-shaped, wedge-shaped, flat, undercut, and slit-like bone defects. Intra-examiner
agreement was tested using crosstabs and Cohen's kappa coefficient. The association of PIBD type with gender, time after implant
placement, smoking, and treatment strategy was investigated using multivariate test of independence on the basis of spatial
Intra-observer reliability was moderate (κ = 0.51). Saucer-shaped defects were the most frequent
(42.8% [t1] and 44.6% [t2]), followed by wedge-shaped (26.0% [t1] and 27.4% [t2]), flat (10.7% [t2] and 17.7% [t1]), undercut
(8.8% [t1] and 11.9% [t2]), and finally slit-like defects (4.7% [t1] and 5.4% [t2]). Peri-implant bone defects morphology
was significantly associated with gender, smoking, and treatment strategy.
The morphology of PIBDs
can be classified into five meaningful classes, as opposed to the two described in the literature.