A paralleling technique modification to determine the bone crest level around dental implants

The aim of this report is two-fold. First it analyses the precision of a modification of the parallel technique that can be used in those cases with anatomical limitations. Second, it checks the influence of the reference points' definition of objects to be measured by using both the original and the modified radiographic techniques. 2 intraoral radiographs were taken of 28 implants with 2 different methods: a standard paralleling technique and a modified technique that used a smaller film and a silicone spacer to ensure parallelism. Measurements of peri-implant bone levels and implant width were made in triplicate on digitized film radiographs. The results of the peri-implant bone levels were that with the parallel method the mean was 0.44 mm and the precision was 0.43 mm, and with the modified method the mean was 0.73 mm and the precision was 0.66 mm. In addition to the correct localization of the point of reference in this study, the precision with the parallel method was 0.08 mm and with the modified method was 0.13 mm. Although it was greater with the gold standard technique than with the modified technique, precision was very high for both methods and accurate enough for clinical use.