• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.265-269
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• 2014

Objectives: To evaluate the effect of different ultrasonic tip designs on intraradicular post removal. Materials and Methods: The crowns of forty human canine teeth were removed, and after biomechanical preparation and filling, the roots were embedded in acrylic resin blocks. The post spaces were made, and root canal molding was performed with self-cured acrylic resin. After casting (Cu-Al), the posts were cemented with zinc phosphate cement. The specimens were randomly separated into 4 groups (n = 10), as follows: G1 - no ultrasonic vibration (control); G2 - ultrasonic vibration using an elongated cylindrical-shaped and active rounded tip; G3 - ultrasonic vibration with a flattened convex and linear active tip; G4 - ultrasonic vibration with active semicircular tapered tip. Ultrasonic vibration was applied for 15 seconds on each post surface and tensile test was performed in a Universal Testing Machine (Instron 4444 - 1 mm/min). Results: G4 presented the highest mean values, however, with no statistically significant difference in comparison to G3 (p > 0.05). G2 presented the lowest mean values with statistically significant difference to G3 and G4 (p < 0.05). Conclusions: Ultrasonic vibration with elongated cylindrical-shaped and active rounded tip was most effective in reducing force required for intraradicular post removal.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.809-822
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• 1998

Adequate root preparation in the treatment of periodontal disease often involves mechanical instrumentation to remove plaque, calculus perhaps contaminated cementum. Although meticulous scaling and root planing may remove some cementum, the use of aggressive root planing to remove cementum does not appear warranted. So ultrasonic device and rotary instrument appear to be replacing hand instrument. But it is not clear those instruments make smooth root surface as hand instrument. The roghness of the root surface were evaluate with SEM following instrumentation with Gracey curette, Perio Clean and piezo ultrasonic device(Setlec) with various tip. 20 extracted teeth were used in vitro experiment, and 9 teeth of a patient destined for extraction for periodontal reasons were utilized in vivo experiment. It was demonstrated that hand curette created the smoothest surface, while diamond tip tended to roughen the root surface. But the hand curette, Perio Clean, and piezo ultasonic device with scaler tip tend to remove cementum completely. Piezo ultrasonic device with curette-like tip made the desirable smooth surface with partial removal of cementum.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.429-442
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• 2000

Based on current evidence in the literature, it is known that endotoxin is a weakly adherent surface phenomenon and that power-driven instruments can be used to accomplish definitive root detoxification and maximal wound healing without overinstrumentation of root and without extensive cementum removal. And one of the newly developed curette tips used with low power of piezoelectric ultrasonic scaler, is effective to remove calculus and not to remove the excessive cementum. The purpose of this study is therefore, to assess the influence of ultrasonic power and various working parameters on root substitute removal when instrumentation is performed with the curette tip on piezoelectric ultrasonic scaler. This study assessed defect depth, width and area resulting from instrumentation using a piezoelectric ultrasonic scaler with a curette type tip in vitro to acrylic resin block as a root substitute. The working parameters was standardized by the sledge device which controls lateral force(0.5 N, 1 N, 2 N) and instrumentation time(5 sec, 10 sec, 20 sec) and power setting was adjusted 0,2,4,8 in P mode. Power setting had the greatest influence on defect depth compared to lateral force and instrumentation time(standardized regression parameter estimates${\pm}$standard error, $0.37{\pm}0.02$, $0.19{\pm}0.02$, $0.07{\pm}0.02$). The effects on defect area also greatest for power setting($0.57{\pm}0.03$) compared to lateral force and instrumentation time($0.33{\pm}0.03$, $0.12{\pm}0.03$). The effect of the power setting on the defect width($0.15{\pm}0.01$) is not so great as defect depth or defect area compared to lateral force($0.12{\pm}0.01$) and effect of instrumentation time is minimal($0.02{\pm}0.01$). It could be concluded that the power setting has the greatest influence on the defect depth and area in curette type tip with low power of piezoelectric ultrasonic device. Many parameters can be adjusted in various situation in clinical use of piezoelectric ultrasonic scaler but the power setting is the first parameter to be adjusted.

• Journal of Periodontal and Implant Science
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• v.39 no.2
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• pp.139-148
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• 2009

Purpose: Ultrasonic scalers have been widely used for removing biofilm which is considered as major etiologic factor of periodontal disease. The purpose of this study was to evaluate the effect of working parameters of piezoeletric ultrasonic scaler with scaler tip (No. 1 tip) on casting gold alloy removal. Methods: Type III dental casting gold alloy (Firmilay$^{circledR}$, Jelenko Inc, CA, USA) was used as substitute for tooth substance. Piezoeletric ultrasonic scaler and No.1 scaler tip (P-Max$^{circledR}$, Satelec, France) were selected. The selected working parameters were mode (P mode, S mode), power setting (2, 4, 8) and lateral force (0.5 N, 1.0 N, 2.0 N). The effect of working parameters was evaluated in terms of ablation depth, ablation width and ablation area. Results: Mode influenced ablation depth and ablation area. Power also influenced ablation depth and ablation area. Especially, Power 2 and power 8 showed statistically significant difference. Lateral force had influence on ablation width, and 0.5 N resulted significant increase compared with 1.0 N and 2.0 N. Ablation depth was influenced by mode, power and lateral force and defect width was influenced by lateral force. Ablation area was influenced by mode and power. Conclusions: It can be concluded that the use of piezoelectric ultrasonic scaler with No. 1 scaler tip in S mode and high power may result in significant loss of tooth substance.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.823-828
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• 1998

A primary goal of periodontal therapy is the creation of root surfaces that are free of plaque and calculus. It is not yet to be determined whether it is desirable to have a smooth root surface after treatment. It is also not clear what degree of roughness result from different instruments. In the present study various instruments for root surface debridement were evaluated. 20 extracted teeth were utilized, and the teeth were treated with one of the following instrument: Gracey curette, Perio Clean, and piezo ultrasonic device(Setlec, P Max) with general scaler tip, curette-like tip, and diamond tip. 3 dimensional planimetric device(Accura) was used to evaluate the average surface roughness. It was demonstrated hand and power-driven instruments did not have a significant difference in roughness of the root surface following instrumentation. And ultrasonic scaler tip tended to make a most smooth surface than other instruments. The possible reasons of the result were discussed.

• The korean journal of orthodontics
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• v.44 no.1
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• pp.44-49
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• 2014

Objective: To evaluate the effects of ultrasonic instrumentation with different scaler-tip angulations on the shear bond strength (SBS) and bond failure mode of metallic orthodontic brackets. Methods: Adhesive pre-coated metallic brackets were bonded to 72 extracted human premolars embedded in autopolymerizing acrylic resin. The teeth were randomly divided into 3 groups (n = 24 each) to undergo no treatment (control group) or ultrasonic instrumentation with a scaler-tip angulation of $45^{\circ}$ ($45^{\circ}$-angulation group) or $0^{\circ}$ ($0^{\circ}$-angulation group). SBS was tested in a universal testing machine, and adhesive remnant index (ARI) scores were recorded. The Kruskal-Wallis test and Mann-Whitney U-test were used for statistical analysis. Results: The control group had a significantly higher mean SBS value than the treated groups, which showed no significant differences in their mean SBS values. The ARI scores were not significantly different among the groups. Conclusions: Ultrasonic instrumentation around the bracket base reduces the SBS of metallic orthodontic brackets, emphasizing the need for caution during professional oral hygiene procedures in orthodontic patients. The scaler-tip angulation does not influence the SBS reduction and bond failure mode of such brackets.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.173-177
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• 2014

In this study, a 20,000Hz ultrasonic horn was designed and fabricated using a finite element analysis. The horn's resonate frequency was 19,991Hz, and the harmonic response frequency was 20,000Hz. In order to observe the developed horn's performance, 4,000 pieces of displacement data were obtained using an optical sensor and were analyzed using a fast Fourier transform. Finally, the developed horn's resonate frequency was found to be 19,992Hz. The effect of the tip area of the developed horn on the weldability of a Cu sheet was experimentally investigated. It was found that the welding strengths of specimens welded using a small tip area were generally higherthan those of specimens welded using a large tip area.

• Journal of Korean society of Dental Hygiene
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• v.15 no.4
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• pp.713-718
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• 2015

Objectives: The purpose of the study was to investigate the bacterial morphology attached on ultrasonic scaler tips using no cleansing solution, alcohol cotton, liquid chemical disinfecting agent, and autoclave method. Methods: Scaling tip was applied to the mouth and the ultrasonic scaler tips were assigned to four groups. Group 1 was control group with no cleansing solution. Group 2 was treated with alcohol cotton. Group 3 was treated with 2% green Y-Na solution in liquid chemical disinfecting agent, and Group 4 was sterilized by autoclave method. Live bacteria were observed by phase contrast microscopy. The scanning electron microscopy(SEM) revealed the morphological characteristics of scaler surface. The type of attached bacteria were analyzed using SPSS 21.0 program. The data were analyzed by one-way analysis of variance(ANOVA) and Tukey's post-hoc test. Results: The types of sterilization methods had influences on the bacterial viability. The numbers of cocci, bacilli, spiral form bacteria, and filamentous bacteria was observed in $89.00{\pm}3.60%$, $29.67{\pm}3.51%$, $3.33{\pm}0.57%$ and $1.67{\pm}0.57%$ in control group, $31.67{\pm}3.51%$, $63.33{\pm}4.04%$, $2.00{\pm}1.00%$ and $1.67{\pm}0.57%$ in alcohol cotton group, $69.67{\pm}4.50%$, $12.33{\pm}2.51%$, 0% and 0% in liquid chemical disinfecting agent group, and 0.0%, 0.0%, 0.0% and 0.0% in autoclave method group. The clean surface of ultrasonic scaler tip was shown on SEM by autoclave method. Conclusions: The most effective sterilization method of ultrasonic scaler tip was the autoclave method. Autoclave method is the most effective sterilization method and can reduce the cross-infection in the dental clinic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.404-407
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• 2004

Linear ultrasonic motor by bimorph. Transducer for linear ultrasonic motor with symmetric and anti-symmetric modes was studied. The transducer was composed of two piezoelectric ceramic that cross at right angles with each other at tip. In order to exist length vibration mode two piezoelectric ceramics must have 90-degree phase difference with each other. As a result, tip of transducer moves in elliptical motion. Elliptical trajectory of transducer was analyzed by employing the (mite element method(FEM). From the result, the linear ultrasonic motor was measured for characteristics. In this paper, vibration shape of transducer was simulated and the resonant frequency, stabilization frequency and maximum displacement were calculated using the FEA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.187-190
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• 2004

Transducer for ultrasonic linear motor with the symmetric and anti-symmetric modes was studied. The ultrasonic liner motor consists of two Lngevin type piezoelectric vibrators that cross at right angles with each other in tip. In order to excite symmetric and anti-symmetric mode, the transducer must have a 90 degree phase difference of voltage. Therefore, the tip of transducer moves on an elliptical motion. In this paper, the finite element analysis was used. The ultrasonic motor was fabricated using the simulated result and the driving characteristics were measured.