Laser Use in Dentistry

LaserUse in Dentistry


LaserUse in Dentistry

Thetitle of the journal is BioMedResearch Institution,which is the property of Hindawi Publishing Corporation. Its volumenumber is 2016 published in April 2016 on the pages 1 to 7 that runsfor 7 pages.

Thetitle of this article is Evaluation of Qualitative Changes inSimulated Periodontal Ligament and Alveolar Bone Using a NoncontactElectromagnetic Vibration Device with a Laser Displacement Sensor.

Thearticle authors are HiroshiKobayashi, Masaru Yamaoka, Haruna Ibi, Takuya Yasukawa, Bunnai Ogiso,and Makoto Hayashi. The authors took their time on their experimentand delivered it to Hindawi Publishing Corporation on December 5 2015(Kobayashi etal.,2016). On April 19 2016, this article underwent approval and formallypublished by BioMedResearch Institutionjournal.

HiroshiKobayashi, Haruna Ibi, and Takuya Yasukawa are all affiliated withonly the Department of Endodontics, Nihon University School ofDentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan(Kobayashi etal.,2016). Bunnai Ogiso and Makoto Hayashi have a relationship with theDivision of Advanced Dental Treatment, Dental Research Center, NihonUniversity School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku,Tokyo 101-8310, Japan and Department of Endodontics, Nihon UniversitySchool of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo101-8310, Japan. Lastly, Masaru Yamaoka associates with theDepartment of Physics, Nihon University School of Dentistry, 1-8-13Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan and Division ofApplied Oral Sciences,Nihon University Graduate School of Dentistry,1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan. Since theDental Research Center, Nihon University School of Dentistrysupported this experiment, this article was biased to some extentbecause all the authors relate with the university. They did notinvite an author from a neutral research center to join them andprovide a different viewpoint on the issue.

Theprimary objective of this study is to investigate whether the use ofa laser displacement sensor (LDS) in collaboration with a NEVD(Noncontact Electromagnetic Vibration Device) can effectivelyidentify qualitative modifications in simulated teeth utilizingmechanical frameworks. These teeth models were generated fromalveolar bone and periodontal ligament simulations that consisted ofdifferent qualities of either polyurethane or polyurethane foam.

Theauthors employed three detection methodologies to evaluate thesimulated teeth vibration in the NEVD system. They include Group A,Group B, and Group C. Group A used an accelerometer connected to asimulated tooth, which is a traditional tooth vibration measurement(Kobayashi etal.,2016). Group B measured tooth vibration using both an accelerometerlinked with a simulated tooth and LDS, while Group C employed LDSonly to calculate tooth vibration. The scholars placed the LDS at 50mm apart from a simulated tooth attaching an aluminum foil laterallyabove it to establish a maximum laser reflection. The simulated toothvibration underwent identification via the LDS with a red laserdiode. Then the output signal was recorded in the FFT (fast Fouriertransformation) analyzer through the controller linked to the LDS.Eventually, the FFT analyzer calculated the research tooth model’sfrequency response components utilizing 5 kHz frequency ranges(Kobayashi etal.,2016). Later, calculations followed regarding the mechanicalparameters after analyzing 5 experimental tooth frameworks for everycondition. Additionally, the Steel-Dwass tests and Krustkal-Wallistests assessed the mechanical parameter distinctions among thevarious periodontal ligament circumstances or multiple detectionmethodologies. The Mann-Whitney Utest also pointed out the dissimilarities between the qualities ofthe two forms of bone simulations.

Theresults of these article authors depended on three mechanicalcomponents that included elastic modulus, coefficient of viscosity,and resonant frequency. The elastic modulus in all groups reduced ina curvilinear form as the simulated periodontal ligament’s liquidvolume increased in both polyurethane foam and polyurethane systems.Substantial statistic differentiations occurred in the liquid volumesof 3 mL respectively. The values are 1.21 and 0.79 in 3 mL of GroupA, 1.19 and 0.83 in Group B, and 2.02 and 1.36 in Group C ofPolyurethane and Polyurethane foam respectively (Kobayashi etal.,2016). The 4 mL values include 0.59 and 0.44 in Group A, 0.61 and0.38 in Group B, and 0.88 and 0.53 in Group C in the Polyurethane andPolyurethane foam procedures accordingly. The 5 mL values were 0.30and 0.24 in Group A, 0.29 and 0.24 in Group B, and 0.48 and 0.38 inGroup C of the respective Polyurethane and Polyurethane foamexperiments. However, the polyurethane foam framework’s elasticmodulus was significantly lower when compared to polyurethane’s inevery simulated periodontal condition.

Similarly,the resonant frequency decreased in a curve manner with elevatedsimulated periodontal ligament liquid volumes in the two models. Theauthored observed vital dissimilarities among the 3 mL, 4 mL, and 5mLliquid volumes. Further, this mechanical parameter appeared higher inthe polyurethane system compared to the other system across theboard. On the other hand, the coefficient of viscosity loweredlinearly as the simulated periodontal ligament liquid volume rose inboth of the experimental models. The three liquid volumes yieldedcritical distinct statistics as the polyurethane model showed highresults as opposed to the polyurethane foam setup throughout everysimulated periodontal ligament situation. The values included 4.94and 4.12, 5.06 and 4.00, 7.38 and 4.44 in Group A, B and C in the 3mL volume, 4.13 and 3.56, 3.87 and 3.54, and 6.36 and 4.11 in the 4mL of Group A, B and C, in polyurethane and polyurethane foam(Kobayashi etal.,2016). The 5 mL results included 3.25 and 2.87, 3.18 and 2.87, and3.93 and 2.90 in the Group A, B and C of polyurethane andpolyurethane foam.

Thethree mechanical measurements produced no notable differences in bothGroup A and Group B across the multiple experimental conditions. TheLDS detection mechanism has similar qualities as those witnessed inan accelerometer detection method. Howbeit, Group C’s values of themechanical parameters were notable elevated compared to those in theother groups with an exception of the 4 mL volume in the elasticmodulus and the 5 mL coefficient of viscosity concentration in thepolyurethane foam procedures. The mechanical parameters in this groupalso differed plainly in the many periodontal tissue condition makingthem easily identifiable opposed to those in Group A and Group B.

Theauthors concluded that considering the disadvantages of an in vitroexperiment, using LDS in collaboration with the NEVD procedurepointed out the contrariety between diverse simulated alveolar boneand periodontal ligament status in empirical tooth representations.LDS managed to attain more accurate and apparent mechanicalparameters in comparison with the traditional accelerometer making itmore effectual alongside NEVD in examining periodontal tissueconditions.

Myperception is that this article had a degree of biasness especiallybecause all the authors were linked to a single university, which infact supported the research. That means they relied on informationbased on one institution that increases the chance of inclination.The article’s experiments also used tooth models instead of thereal human tooth making it difficult to ascertain the results basedon the actual periodontal tissue. However, it used secondary researchmaterials from different sources to substantiate their experiment.Therefore, it can be true to say that using the LDS alongside NEVD issufficient when detecting issues with the periodontal tissues.


Kobayashi,H., Hayashi, M., Yamaoka, M., Yasukawa, T., Ibi, H., &amp Ogiso, B.(2016). Evaluation of Qualitative Changes in Simulated PeriodontalLigament and Alveolar Bone Using a Noncontact ElectromagneticVibration Device with a Laser Displacement Sensor. BiomedResearch International,20161-7