An Instrument for the Optimal Guiding of Osseointegrated Dental Implants
The purpose of this study was to design an instrument for the optimal guiding of osseointegrated implants intraoperatively to achieve parallelism or desired angulations. Seven patients (4 males and 3 females) were enrolled in the investigation. They ranged in age from 44 to 61 years. Using an instrument designed by the senior author that permitted optimal guiding of the osteotomy instruments (33 Osteofix Oy, Oulu, Finland) we placed in these patients, root form, single stage implants. The difference in angulations between the first and the remaining implants was measured using the abutment replicas on the working models. It was found that the mean deviation angle between the first and the adjacent implant replicas was 2.2° (SD = 0.4°). The largest deviation angles were 2.3° (SD = 0.5°) and 3.1° (SD = 0.8°). The study indicated that the instrument had been designed in a functional manner and that all implants in such relationships can be inserted into their desired positions, either parallel to one another or with the desired angle for the planned prostheses.Abstract

Instrument for optimal guiding of dental implants. 1, Supporting axis. 2, 3, Horizontal bars. 4, Horizontal marginal bar with parallel drill guiding bushing (6). 5, Horizontal marginal bar with angled drill guiding bushing (7). 8, Screws. 9, Nuts. 10, Bushing for instrument fixation on the supporting axis (1)

Bars of the instrument are expanded and placed on the alveolar process of the jaw so that bushings 6 and 10 precisely match the positions of the 2 distalmost implants. The optimal angle of the implants is selected by changing the angle of inclination of bushings 6 and 10 in labiolingual and mesiodistal directions. Figure 3. First clinical osteotomy placed for implant insertion is completed with a 2-mm diameter pilot drill placed in bushing 10. Figure 4. Supporting axis 1 is placed rigidly in the prepared 2-mm osteotomy that had been made through bushing 10. Figure 5. Using the guidance of the new surgical instrument, the osteotomies are made one by one from patient right to left

Working model with long fastening screws mounted on a milling machine. (a) Machine's guide pin is set parallel to the first implant's long fastening screw. (b) Inclination of long fastening screw (angle α in labiolingual direction). (c) Inclination of long fastening screw (angle β in mesiodistal direction). The angles are measured in relationship to the first implant's long fastening screw by the milling machine
Contributor Notes
Gintaras Juodzbalys, DMS, PhD, is an associate professor in the Department of Oral and Maxillofacial Surgery, Kaunas University of Medicine, Kaunas, Lithuania. Correspondence should be sent to Prof Juodzbalys at the Department of Oral and Maxillofacial Surgery, Kaunas University of Medicine, Vainiku 12, LT- 3018 Kaunas, Lithuania (lss@kaunas.omnitel.net)
Aune M. Raustia, DDS, PhD, is a professor in the Department of Prosthetic Dentistry and Stomatognathic Physiology, Institute of Dentistry, University of Oulu, and chief dentist in the Oral and Maxillofacial Department, Oulu University Hospital, Oulu, Finland