Accuracy of four intraoral radiographic techniques on the misfit detection at implant-abutment joint
Name: Pollyana Darós
Type: MSc dissertation
Publication date: 17/03/2017
Advisor:
Name |
Role |
|---|---|
| Sergio Lins de Azevedo Vaz | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Daniela Nascimento Silva | Internal Examiner * |
| Sergio Lins de Azevedo Vaz | Advisor * |
| Vitor Guarçoni de Paula | External Examiner * |
Summary: Misfit at implant-abutment joints (IAJ) may compromise the perimplant tissues health. Periapical radiograph is a complementary method to misfit detection and an orthogonal relation between the central beam, the implant, and the radiographic film is indicated. The aim of this study evaluated the accuracy of 4 intraoral radiographic techniques on the detection of gaps at IAJ. Twenty implants were placed in prototyped jaws and UCLA-type abutments with metal collar were installed. Different gaps were simulated by placing one or three 50-μm-thickness polyester strips at the IAJ, and the absence of the strip represented the control group (no gap). Periapical radiographs with different film-holders were taken for each technique: bisecting, interproximal, parallel-cone and modified-parallel-cone (with a custom-made paralleling index). A total of 240 digital radiographs were evaluated by 4 specialists in dental implants. The ROC curves (Az) and Fishers Exact comparison tests were performed at a significance level of 5%. Diagnostic values (sensitivity, specificity, accuracy, positive, and negative predictive values) were also obtained. The Kappa test was used to assess intra- and inter-evaluator reproducibility, which ranged from substantial to almost perfect, and moderate to substantial, respectively. All diagnostic values were lower for the bisecting technique for both 50- and 150-μm gaps. Az values for the bisecting technique were significantly lower than those obtained for the other 3 techniques (p<.05), which did not differ from each other. The 150-μm gaps were more easily detected than 50-μm gaps only for the bisecting technique (p˂.05). The interproximal, parallel-cone and, modified-parallel-cone techniques were the most accurate to detect misfits at IAJ. The bisecting technique should not be clinically used for this purpose.
