Application of fiber bragg grating sensing to thermal variation during dental implant site preparation: an in vitro study

BACKGROUND: The objective of this study is to overcome the limitations associated with conventional temperature sensors in assessing the temperature distribution of a surgical implant operation. It achieves this objective by utilizing fiber Bragg grating (FBG) temperature sensors to perform measurements. The performance of these FBG sensors is evaluated by comparison with results reported in previous studies. METHODS: An experimental in vitro model was developed employing bovine rib bones, selected for their physical characteristics analogous to those of human mandibular bone, as test specimens. FBG sensors were placed adjacent to the implant site to monitor temperature fluctuations occurring throughout the surgical procedure. The influence of various factors on temperature variations was measured over seven groups: irrigation and sequential operations (Groups 1-4), drill speed (Group 5), drill diameter (Group 6), and maximum drilling depth (Group 7). Sensor data were analyzed to evaluate the platform's performance, and statistical analyses were conducted to assess the influence of these factors. RESULTS: Fiber Bragg grating sensors can independently and accurately record temperature variations in both cancellous and cortical bone simultaneously. Statistical analysis indicated that irrigation and intermittent drilling effectively mitigate the risk of temperature exceeding the upper limit of human tissue tolerance, with irrigation playing a predominant role in reducing temperature elevation in our study (p < 0.05). Furthermore, larger drill diameters and increased drilling depths significantly increased the maximum temperature changes (p < 0.05). These findings are largely consistent with those reported in previous studies. Moreover, the use of FBG sensors provided novel insights: increased drilling speed causes higher heat generation in cortical bone (p < 0.05), while temperature changes in cancellous bone remain insignificant. Conversely, deeper drilling causes elevated heat production in cancellous bone (p < 0.05), with minimal effects observed in cortical bone. CONCLUSION: The advantages of the sensor include high independence and accuracy, low systematic errors due to its small size, biosafety, and cost-effectiveness resulting from multi-point testing within a single optical fiber. These many advantages make the designed FBG temperature sensor a dependable option for real-time temperature monitoring in future in vivo research and clinical surgical procedures.