• 제목/요약/키워드: laser cleaning

검색결과 103건 처리시간 0.029초

Effect of different provisional cement remnant cleaning procedures including Er:YAG laser on shear bond strength of ceramics

  • Zortuk, Mustafa;Gumus, Hasan Onder;Kilinc, Halil Ibrahim;Tuncdemir, Ali Riza
    • The Journal of Advanced Prosthodontics
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    • 제4권4호
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    • pp.192-196
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    • 2012
  • PURPOSE. The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS. In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (${\alpha}$=0.05). RESULTS. The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION. The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces.

Laser surface cleaning of simulated radioactive contaminants in various technological environments

  • Maxim Cheban;Serafima Filatova;Yaroslav Kravchenko;Konstantin Scherbakov;Dmitry Mamonov;Sergey Klimentov;Maxim Savinov;Maxim Chichkov
    • Nuclear Engineering and Technology
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    • 제56권7호
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    • pp.2775-2780
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    • 2024
  • Special methods for cleaning surfaces of stainless steel with a coating simulating radioactive contamination have been developed and studied. The removal of simulated surface contamination was performed using lasers in the micron spectral range with pulse durations of 8 ns and 270 fs. Optimal cleaning modes were determined for gas and liquid environments, achieving surface cleaning coefficient of over 90% in a single pass. A correlation between the degree of cleaning in liquids and the viscosity of the environment was discovered.

레이저 복합기의 재제조공정을 위한 전자부품 세정시스템의 개발 (Development of Cleaning System of Electronic Components for the Remanufacturing of Laser Copy Machine)

  • 배재흠;장윤상
    • 청정기술
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    • 제18권3호
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    • pp.287-294
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    • 2012
  • 본 연구에서는 중고 레이저 복합기의 재제조 과정에서 복합기의 성능에 큰 영향을 미치는 인쇄회로기판(printed circuit board, PCB) 등 전자부품에 대하여 세정공정의 도입 적용 가능성을 분석하고 세정장치 및 최적의 운전조건을 설계하였다. 1단계로 물에 의한 부식의 염려가 없는 건식세정방식으로 플라즈마세정에 의한 세정성을 분석하였다. 플라즈마세정 의한 PCB세정에서는 세정이 어느 정도 이루어졌으나 플라즈마가 전도 될 수 있는 피세정물의 금속 부분 주위에서 피 세정물의 손상을 확인할 수 있었으며 레이저 복합기의 재제조용으로는 생산성 및 경제성이 부족하였다. 2단계에서는 경제성이 있는 초음파세정방식을 위하여 현재 현장에서 사용되고 있는 세정제를 포함하여 세정효율이 우수한 4종의 대체 세정제를 선정하여, 세정제의 물성을 측정하였고 세정성을 평가하였다. 준수계 세정제와 비수계 세정제보다 수계 세정제의 세정력이 우수 하였으며, 초음파 주파수가 작을수록 세정력이 우수하였다. 수계세정제 A를 사용하여 28 kHz의 초음파 세기에서 세정을 한다면 30초~1분 내에 빠른 세정이 가능할 것으로 판단되었다. 3단계에서는 선정된 세정제로 초음파 세정시스템을 구축하고, 실제 부품들을 초음파 세정하여 현장에서 사용이 적합한 최적의 세정조건을 구하였다. PCB 보드 및 대전기에 대하여 최적 세정 조건을 구한 결과, 40 kHz, $50^{\circ}C$에서 1분 30초 및 2분에 세정을 끝낼 수 있었다. 수작업에 의존하거나 외부처리를 하고 있는 중소 재제조 업체들은 본 세정시스템의 도입으로 전자부품 기능의 신뢰성이 확보되며 전체적인 재제조 공정의 생산성 및 경제성 향상에 큰 효과를 볼 수 있을 것으로 기대된다.

Influence of access cavity design on calcium hydroxide removal using different cleaning protocols: a confocal laser scanning microscopy study

  • Seda Falakaloglu;Merve Yeniceri Ozata;Betul Gunes;Emmanuel Joao Nogueira Leal Silva;Mustafa Gundogar;Burcu Gucyetmez Topal
    • Restorative Dentistry and Endodontics
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    • 제48권3호
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    • pp.25.1-25.13
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    • 2023
  • Objectives: The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods: Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC. Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results: The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions: The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.