Use of a laser displacement sensor with a non-contact electromagnetic vibration device for assessment of simulated periodontal tissue conditions

Abstract

A non-contact electromagnetic vibration device (NEVD) was previously developed to monitor the condition of periodontal tissues by assessing mechanical parameters. This system requires placement of an accelerometer on the target tooth, to detect vibration. Using experimental tooth models, we evaluated the performance of an NEVD system with a laser displacement sensor (LDS), which does not need an accelerometer. Simulated teeth (polyacetal rods) were submerged at various depths in simulated bone (polyurethane or polyurethane foam) containing simulated periodontal ligament (tissue conditioner). Then, mechanical parameters (resonant frequency, elastic modulus, and viscosity coefficient) were assessed using the NEVD with the following detection methods: Group 1, measurement with an accelerometer; Group 2, measurement with an LDS in the presence of the accelerometer; and Group 3, measurement with an LDS in the absence of the accelerometer. Statistical analyses were performed using nonparametric methods (n = 5) (P < 0.05). The three mechanical parameters significantly increased with increasing depth. In addition, the mechanical parameters significantly differed between the polyurethane and polyurethane foam models. Although Groups 1 and 2 did not significantly differ, most all mechanical parameters in Group 3 were significantly larger and more distinguishable than those in Groups 1 and 2. The LDS was more accurate in measuring mechanical parameters and better able to differentiate periodontal tissue conditions. (J Oral Sci 58, [93][94][95][96][97][98][99] 2016)

Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor

“…The increased mechanical parameter values observed in Group C may be caused by the decrease in mass of the simulated tooth. A recent study [ 16 ] has shown that more accurate mechanical parameters were obtained when using LDS with NEVD compared to using accelerometer with NEVD in the experimental bone destruction models. This report suggested that the actual total mass of the simulated tooth due to the absence of accelerometer could contribute to more accurate mechanical parameters.…”

“…One of the noncontact types is a laser displacement sensor (LDS), which can measure the distance as well as the acceleration of the target object without mechanical contact (cordless) [ 13 – 15 ]. A recent study [ 16 ] revealed that the application of the LDS, instead of the accelerometer, to NEVD can detect the different degrees of simulated bone destruction and qualities using the in vitro experimental tooth models.…”

Objective and subjective interproximal contact between the implant and the natural tooth

“…However, we did not use either material in our study due to their difficult processability; instead, melamine resin was used owing to its ease of handling. Previous studies have also reported the use of simulated periodontal ligaments made using soft lining materials 27,28 or silicone impression materials 22,23,25,26 . However, the former were consid ered inappropriate here as they harden over a period of time; hence, a silicone rubber material was used for the dental impressions owing to its excellent dimensional stability.…”

Tooth Mobility Measurements- Realities and Limitations

“…Using laser displacement sensor with this device could also provide better clinical operability by eliminating the attachment of an accelerometer that is connect to the fast Fourier transformation analyser by the cord. [33] These methods are either tedious, complex and/or exorbitant for routine clinical application. The investigator requires training for the reproducibility of the results.…”