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Background: The placement of implants using a minimally invasive flapless approach has the potential to reduce operative bleeding and postoperative discomfort and minimize crestal bone loss. This article presents follow-up data on a prospective clinical study of implants placed using a flapless procedure. Methods: The original study reported on 57 patients (33 female patients with an age range of 24 to 86 years; 24 male patients with an age range of 27 to 81 years) recruited from three clinical centers (Tucson, Arizona; Gothenburg, Sweden; and Tel Aviv, Israel) who received 79 implants. After an average of 3 years and 8 months, the patients were contacted and invited to return to their respective clinics for reexamination. Thirty-seven patients with 52 implants returned for a follow-up examination; the remaining 20 patients (27 implants) were not available for reexamination and were considered study drop-outs. Results: The cumulative survival rate at the 3- to 4-year follow-up examination remains at 98.7%, reflecting the loss of one implant. The mean probing depth at abutment connection was 2.2 mm, as reported in the initial study (examination 2 at ~2 years postplacement); it was 2.4 mm at the 3- to 4-year second follow-up examination. This change was not clinically or statistically significant. Bleeding score changes also were not significant between the two intervals. The average crestal bone level was -0.7 mm at examination 2 and -0.8 mm at examination 3, a change that approached significance (P <0.06). Conclusions: Minimally invasive flapless surgery offers patients the possibility of high implant predictability with clinically insignificant crestal bone loss for up to 4 years. Proper diagnosis and treatment planning are key factors in achieving predictable outcomes. [ABSTRACT FROM AUTHOR]

Background: Flapless surgery requires penetration of the alveolar mucosa and bone without reflection of mucoperiosteal flaps. Do these techniques force gingival tissue or foreign materials into osteotomies? If so, do such tissues or materials interfere with osseointegration? A proof-of-principle study using a canine model attempted to answer these questions. Methods: Five young adult Hound Labrador mongrel dogs received implants with a moderately roughened surface by anodic oxidation using flapless or conventional one-stage (control) surgery in contralateral jaw quadrants. The implants were placed into the osteotomies, and the international stability quotient (ISQ) was recorded using resonance frequency analysis. These measurements were repeated following a 3-month healing interval when the animals were euthanized, and implants and surrounding tissues were retrieved and processed for histologic analysis. Results: The implants were stable upon insertion and demonstrated increased stability at 3 months without significant differences between surgical protocols. The histologic evaluation showed high bone-implant contact (flapless surgery: 54.7% ± 8.4%; control: 52.2% ± 13.0%; P>0.05) without evidence of gingival tissue or foreign body inclusions. There were no significant differences in marginal bone levels between the surgical protocols. Post-insertion and at 3 months, ISQ values depended on the amount of torque delivered. Immediately post-insertion, for every I unit increase in torque value, the ISQ increased by 0.3 (95% confidence interval: 0.1 to 0.4; P = 0.0043). Three months postoperatively, for every one-unit increase in torque the ISQ value decreased 0.2 (95% confidence interval: -0.4 to -0.1: P=0.0012). The effect of torque on ISQ values was independent of treatment effects and remained significant after adjustment for treatment. Conclusions: The results suggest that implants placed without flap reflection remain stable and exhibit clinically relevant osseointegration similar to when implants are placed with flapped procedures. Greater torque at implant placement resulted in less implant stability at 3 months. [ABSTRACT FROM AUTHOR]

Background: A genetic test for a composite interleukin-1 (IL-1) genotype is being marketed to predict risk for progression of periodontal disease. The objective of this study was to determine the clinical scenario required to produce cost-effective results with the use of IL-1 testing to identify high-risk patients. Methods: A disease simulation model was developed using decision-analytic techniques and a 30-year time frame. Results: Using different modeling scenarios, the genetic test produced results ranging from cost savings of $830,140 and 52.8 fewer cases of severe periodontitis to increased costs of $300,430 and 3.6 additional cases of severe periodontitis (per 1,000 patients). Three parameters in the analysis were highly influential: 1) the compliance rate for maintenance therapy in test positive versus non-tested patients; 2) the effectiveness of non-surgical therapy; and 3) the relative risk of disease progression for test positive patients. Conclusion: The model produced a wide range of outcomes reflecting our incomplete understanding of the biology, optimal treatment, and genetic susceptibility of periodontal diseases. However, the model demonstrates that three clinical parameters are highly influential in determining if IL-1 testing can be implemented in a primary care setting in a cost-effective manner. [ABSTRACT FROM AUTHOR]

A response by Philippe P. Hujoel and colleagues to a letter to the editor about their article "Perspective on Clinical Significance," published in a 2000 issue is presented.