Prosthetic possibilities using endosseal implants as anchorages--an epidemiological study in 65-year-old subjects

Ambiguity in bone tissue characteristics as presented in studies on dental implant planning and placement: a systematic review

OBJECTIVES

To survey definitions of bone tissue characteristics and methods of assessing them in studies of dental implant planning and placement.

MATERIAL AND METHODOLOGY

Three databases were searched using specified indexing terms. Three reviewers selected from the titles and retrieved abstracts in accordance with inclusion and exclusion criteria. Descriptions of bone tissue characteristics (bone quality, density and quantity) used before or during dental implant placement were searched for and categorized.

RESULTS

The search yielded 488 titles. One hundred and fort-nine publications were selected and read in full text. One hundred and eight were considered relevant. There were many different definitions and classification systems for bone tissue characteristics and examination protocols. Approximately two-third of the included publications reported the Lekholm & Zarb classification system for bone quality and quantity. However, only four studies implemented the Lekholm & Zarb system as originally proposed. A few publications described bone quality in accordance with the Misch or Trisi and Rao classifications systems. Assessment methods were often described only briefly (or not at all in one-fifth of the publications). Only one study presented the diagnostic accuracy of the assessment method, while only two presented observer performance.

CONCLUSION

The differing definitions and classification systems applied to dental implant planning and placement make it impossible to compare the results of various studies, particularly with respect to whether bone quality or quantity affect treatment outcomes. A consistent classification system for bone tissue characteristics is needed, as well as an appropriate description of bone tissue assessment methods, their diagnostic accuracy and observer performance.

Factors related to Periotest values in endosseal implants: a 9-year follow-up

Periotest values (PTV) of successful endosseal implants of 2 one-stage implant systems. TPS and ITI, were followed from 3 months to 9 years in order to determine the factors that contribute to the values. 128 TPS screw implants were inserted in the lower jaw of 34 subjects, (mean age 55 years), for retaining overdentures. 108 ITI implants were inserted in the upper and lower jaws in 50 subjects (mean age 42 years), for retaining overdentures, crowns and bridges. PTVs were first measured after the osseointegration period and thereafter annually. First of all there was a difference between the 2 implant systems. Mean PTVs of TPS bicortical screws were significantly lower (P < 0.05) than those of ITI implants (screws, hollow-screws, hollow-cylinders). Factors which significantly contributed to PTVs of ITI implants were jaw (upper/lower), implant length and region of the jaw in which the implant was inserted. PTVs of ITI implants in the lower jaw were lower than in the upper jaw (P < 0.05). The length of implant had no effect on PTVs in the lower jaw, but in the upper jaw, PTVs of ITI 8-10-mm implants were lower than 12-mm implants (P < 0.05). PTVs of implants inserted in the anterior region of the upper jaw were higher than those in the posterior region (P < 0.05). In conclusion, bone quality and implant length had a statistically significant effect on implant mobility in long-term follow-up. PTVs of various implant systems, however, differ, a fact that must be taken into account in evaluating the success of implants.