A 5‐year prospective clinical and radiographic study of non‐submerged dental implants

Abstract

Osseointegrated implants as anchors for various prosthetic reconstructions have become a predictable treatment alternative. It was expected that implants required submucosal placement during the healing period for successful tissue integration. However, it has been demonstrated that healing and long-term health of implants could be achieved with equal predictability in a 1-stage, non-submerged approach. This prospective 5-year study not only calculates implant success by life table analysis, but also evaluates the correlation between observed bone level changes with clinical parameters as measured by suppuration, plaque indices, bleeding indices, probing depth, attachment level and mobility. A total of 112 ITI dental implants were inserted in different areas of the jaws. Clinical and radiographic parameters were evaluated annually for 5 years, whereas a portion of the study group for which 6-year evaluations were available were included in the life-table analysis. The overall success rate after 5 years in service was 99.1%, while after 6 years it was reduced to 95.5% due to the fracture of 3 implants in 1 patient. The mean crestal bone loss experienced during the first year was 0.6 mm followed by an annual yearly loss of approximately 0.05 mm. No significant differences could be found between the amount of bone loss measured at each of the yearly follow-up visits. This suggests that statistically the followed implants did not show any radiographically measurable bone loss following the initial period of bone loss associated with implant placement and osseointegration. Low levels of correlation between the individual and cumulative clinical parameters with radiographically measured bone loss suggests that these parameters are of limited clinical value in assessing and predicting future peri-implant bone loss.

X-ray evaluation at 5–6 years of Straumann implants (part 2)

“…Published data described a mean marginal bone loss of 0.4-0.5 mm during the first year post-implantation and 0.05-0.1 mm annually thereafter [7,14]. Similar observations were noted later by other research groups [16,21,22], who defined the following measurements for the one stage ITI implants: 0.75 mm after the first year and less than 0.1 mm the following years. Another study determined that a mean crestal bone loss ranging from 0.9-1.6 mm in the first year after functional loading was acceptable [17].…”

“…This measurement was carried out on both mesial and distal implant sides [15][16][17], on the 5-year postoperative radiographs. When unclear, the most apical bone-to-implant contact, corresponding to the worst case scenario was taken into account.…”

“…In their 5-year prospective study using standardized radiographs, Weber et al [16] showed that the mean crestal bone loss for Straumann implants during the first year was approximately 0.6 mm, followed by a yearly loss of 0.05 mm. This study considered bone levels on the day of surgery as the baseline, which is uncommon in the dental implant literature to date.…”

“…Several longitudinal studies consider that radiographic monitoring of bone level changes provides valuable insight into the longevity of oral implants [13][14][15][16][17] (Fig. 3).…”

How do peri‐implant biologic parameters correspond with implant survival and peri‐implantitis? A critical review

“…A few studies have looked for correlations between bone loss and clinical parameters among them probing. They concluded that probing depths are of limited value in predicting future peri‐implant bone loss (Dierens et al., 2012; Giannopoulou, Bernard, Buser, Carrel & Belser, 2003; Weber, Crohin & Fiorellini, 2000). Long‐term clinical studies have clearly shown that the probing depth of healthy peri‐implant mucosa is not always smaller than 4 mm but very often up to 6 mm (Dierens et al., 2012; Karoussis et al., 2004; Lekholm et al., 1986).…”