A new device for measuring orthodontic compressive bonding force; a novel bracket positioning gauge with a force sensor

Abstract

Objectives: The optimum adhesive thickness present between bracket base and tooth surface plays an important role in achieving ideal treatment outcome in straight wire technique. As thickness of adhesive largely depends on amount of force applied while bonding an orthodontic brackets on the tooth surface. Therefore, it becomes prudent to find direct and accurate method to quantify the bonding force. The aim of this paper was to describe the design and working of novel bracket positioning gauge with force sensor which directly quantifies the amount of bonding force applied by orthodontists. Material and Methods: The present prototype is a bracket positioning gauge where load cell and vertical stopper blade are fixed on base platform. The force sensing blade attached to load cell detects the force applied and transmit to load cell which converts compressive force into an analogue signals. These inputs are then converted into digital signals for further processing. The prototype was tested five times by ten orthodontists for measuring bonding force while orthodontic brackets were bonded on extracted premolars. The same procedure was repeated after seven days to assess the reproducibility and reliability of prototype. Results: The majority of orthodontists participated in present study applied bonding force between the ranges of 50-200 grams with the mean bonding force applied by participant orthodontists was similar in time interval of seven days with 134.67 grams and 132.76 grams respectively. Conclusion: The novel bracket positioning gauge with force sensor was able to measure compressive bonding force accurately and can aid in achieving optimum adhesive thickness for clinically acceptable bond strength. The present innovation needs further refinements to be more useful in clinical settings.