Accuracy of a direct drill-guiding system with minimal tolerance of surgical instruments used for implant surgery: a prospective clinical study

PURPOSE: A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses. MATERIALS AND METHODS: For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (α=.05). RESULTS: The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually. CONCLUSION: The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.

Accuracy of the healing abutment and impression coping combined system on implant impression / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the 3 dimensional accuracy of impression taking on the newly developed healing abutment and impression coping combined system comparing conventional pick-up type impression. MATERIALS AND METHODS: For 10 patients who had a single missing tooth on molar area, dental implants (SuperLine; Dentium, Seoul, Korea) were placed and healing abutment (MyHealing; Raphabio Co., Seoul, Korea) abutments were connected. After 3 months, transfer type impression with MyHealing and pick-up type impression with impression coping were performed twice in the same patients, and master models were fabricated. Customized prosthetic abutments (Myplant; Raphabio Co., Seoul, Korea) were milled and connected to the master casts. Through a dental scanner (Scanner S600; Zirkonzahn, South Tyrol, Italy), the master casts were converted into virtual casts. The length and angulation differences between casts were measured using 3 dimentional analysis program (Geomagic Qualify 12; Geomagic, Morrisville, NC, USA). Statistical significance was calculated using Kruskal Wallis test and Mann-Whitney U test (alpha=.05). RESULTS: The length differences between the two systems were 0.032 mm in sagittal plane, and 0.029 in coronal plane, and 0.023 mm in horizontal plane. The angulation differences were 0.755#x00B0; in sagittal plane, and 1.275#x00B0; in coronal plane, and 0.420#x00B0; in horizontal plane. CONCLUSION: The accuracy of newly developed healing abutment system is similar to that of conventional pick-up impression. The new system can reduces chair time by not using separate impression coping.