Self-designed surgical guides for accurate socket shield preparation: An in vitro evaluation supported by a clinical report.

Abstract

To achieve accurate socket shield preparation with newly proposed guides that are based on guiding rails and to investigate the effect of rail format (unilateral or bilateral) and rail height on the accuracy and efficiency of the guides. Two surgical guides based on grooved rails to guide the rotary instruments were produced. The first guide was used to cut the root into a labial shield with a pre-designed form and a lingual one, while the second guide was used to reduce the socket shield to the alveolar bone crest. The CBCT and intraoral scan data were first obtained and superimposed using the software. After isolating the root which would be used as a socket shield, grooved rails were designed on two separate guide templates according to the chosen rotary instruments to obtain a labial shield with a pre-designed form. An in vitro study was then conducted based on four cases in each group to determine the accuracy, efficiency, and optimal parameters of the guides, which was then verified with a clinical report. Comparisons between groups were performed with a one-way analysis of variance (ANOVA, for comparison between multiple groups) and the Student-Newman-Keuls test (for comparison between two groups). With these two guides, the root can be divided into two pieces, including a palatal one and a labial one with a pre-designed form within a short time. Guide templates with bilateral rails more than 7mm in height and those with unilateral rails 9mm in height significantly increased the surgery accuracy, showing accurate shield preparation and decreased bone injury. Moreover, the guides with bilateral rails of more than 5mm significantly decreased the surgery time for shield preparation. The presented case further verified the accuracy and efficiency of the guides. The newly proposed guides can help to accurately prepare the socket shield, resulting in long-term stability of peri-implant tissues. Moreover, bilateral guiding rails with a height of 7-9mm are recommended in such a guided socket shield surgery.