Accuracy of full-guided vs. pilot-guided implant insertion - A prospective laboratory study in fifth-year dental students.

BACKGROUND: Education of undergraduates in implant dentistry has been extended. In order to assess the correct implant position, the accuracy of implant insertion using templates for pilot-drill guided and full-guided implant insertion was examined in a laboratory set-up in a cohort of undergraduates. METHODS: After three-dimensional planning of the implant position in partially edentulous mandibular models, individual templates for the pilot-drill guided or full-guided implant insertion in the region of the first premolar were produced. A total of 108 dental implants were inserted. The results of the radiographic evaluation of the three-dimensional accuracy were statistically analyzed. Furthermore, the participants completed a questionnaire. RESULTS: The deviation of the three-dimensional angle of the implants inserted fully guided was 2.74 ± 1.49 degrees compared to 4.59 ± 2.70 degrees for pilot-drill guided. The difference was statistically significant (p < 0.01). The returned questionnaires revealed a high interest in oral implantology and a positive evaluation of the hands-on course. CONCLUSIONS: In this study, the undergraduates benefited from applying full-guided implant insertion considering the accuracy in this laboratory examination. However, the clinical effects are not clear as the differences are within a small range. Based on the returned questionnaires, the implementation of practical courses in the undergraduate curriculum should be encouraged.

Harmonization of the Volume of Interest Delineation among All Eleven Radiotherapy Centers in the North of France.

BACKGROUND: Inter-observer delineation variation has been detailed for many years in almost every tumor location. Inadequate delineation can impair the chance of cure and/or increase toxicity. The aim of our original work was to prospectively improve the homogeneity of delineation among all of the senior radiation oncologists in the Nord-Pas de Calais region, irrespective of the conditions of practice. METHODS: All 11 centers were involved. The first studied cancer was prostate cancer. Three clinical cases were studied: a low-risk prostate cancer case (case 1), a high-risk prostate cancer case (pelvic nodes, case 2) and a case of post-operative biochemical elevated PSA (case 3). All of the involved physicians delineated characteristically the clinical target volume (CTV) and organs at risk. The volumes were compared using validated indexes: the volume ratio (VR), common and additional volumes (CV and AV), volume overlap (VO) and Dice similarity coefficient (DSC). A second delineation of the same three cases was performed after discussion of the slice results and the choice of shared guidelines to evaluate homogenization. A comparative analysis of the indexes before and after discussion was conducted using the Wilcoxon test for paired samples. A p-value less than 0.05 was considered to indicate statistical significance. RESULTS: The indexes were not improved in case 1, for which the inter-observer agreement was considered good after the first comparison (DSC = 0.83 ± 0.06). In case 2, the second comparison showed homogenization of the CTV delineation with a significant improvement in CV (81.4 ± 11.7 vs. 88.6 ± 10.26, respectively, p = 0.048), VO (0.41 ± 0.09 vs. 0.47 ± 0.07, respectively; p = 0.009) and DSC (0.58 ± 0.09 vs. 0.63 ± 0.07, respectively; p = 0.0098). In case 3, VR and AV were significantly improved: VR: 1.71(± 0.6) vs. 1.34(± 0.46), respectively, p = 0.0034; AV: 46.58(± 14.50) vs. 38.08(± 15.10), respectively, p = 0.0024. DSC was not improved, but it was already superior to 0.6 in the first comparison. CONCLUSION: Our prospective work showed that a collaborative discussion about clinical cases and the choice of shared guidelines within an established framework improved the homogeneity of CTV delineation among the senior radiation oncologists in our region.