Antimicrobial activity of Er, Cr: YSGG and Ultrasonic on E. faecalisbiofilm in the mesial root canal systems of lower molars / Atividade antimicrobiana de Er, Cr: YSGG e Ultrassônico no biofilme de E. faecalis nos sistemas de canais radiculares mesiais de molares inferiores

The internal topography of the root canal is complex, especially for the permanent molar's mesial root. In response to such issues, improved irrigation techniques have been created, which use laser pulses to agitate fluids and improve microbial deposit removal. Objective: To assess the effectiveness of the Er,Cr:YSGG laser with a wavelength of 2,780 nm via photon-induced photoacoustic streaming (PIPS) protocol which agitated of 2% chlorohexidine (CHX) in removing mature Enterococcus faecalis (E. faecalis) biofilm in root canal systems of lower molars. Material and Methods: The mesial roots of lower first and second molars were separated and inoculated with E. faecalis bacterial suspension for 30 days. The roots were irrigated with CHX, some of them were agitated with a passive ultrasonic device (PUI), while the other roots were agitated by an Er,Cr:YSGG laser in PIPS at 60 µs/pulse, 5 Hz, (0.25, 0.5, 0.75, and 1) W. An atomic force microscope (AFM) was used as a new method to get the results in the isthmus area; the obtained results from each group were compared with each other. Results: Based on the AFM and SEM analyses, laser and ultrasonic activation groups showed higher antimicrobial efficacy than the conventional syringe irrigation group (P<0.05). Conclusion: Based on the investigation's findings, the activation of 2% CHX solution by Er,Cr:YSGG laser in PIPS and PUI offers better mature bacterial biofilm removal in the mesial root of lower human molars than the same irrigant with the SI technique (AU)

A topografia interna do canal radicular é complexa, especialmente para a raiz mesial do molar permanente. Em resposta a esses problemas, foram criadas técnicas aprimoradas de irrigação, que utilizam pulsos de laser para agitar fluidos e melhorar a remoção de depósitos microbianos. Objetivo: Avaliar a eficácia do laser Er,Cr:YSGG com comprimento de onda de 2.780 nm via protocolo de streaming fotoacústico induzido por fótons (PIPS) que agitou clorohexidina a 2% (CHX) na remoção de Enterococcus faecalis maduro (E. faecalis) biofilme em sistemas de canais radiculares de molares inferiores. Material e Métodos: As raízes mesiais de 28 primeiros e segundos molares inferiores foram separadas e inoculadas com suspensão bacteriana de E. faecalis por 30 dias. As raízes foram irrigadas com CHX, sendo algumas delas agitadas com aparelho ultrassônico passivo (PUI), enquanto as demais raízes foram agitadas com laser Er,Cr:YSGG em PIPS a 60 µs/pulso, 5 Hz (0,25, 0,5, 0,75 e 1) W. Um microscópio de força atômica (AFM) foi utilizado como um novo método para obter os resultados na área do istmo; os resultados obtidos de cada grupo foram comparados entre si. Resultados: Com base nas análises de AFM e SEM, os grupos de ativação por laser e ultrassom apresentaram maior eficácia antimicrobiana do que o grupo de irrigação com seringa convencional (P<0.05). Conclusão: Com base nos achados da investigação, a ativação da solução de CHX a 2% pelo laser Er,Cr:YSGG em PIPS a (60 µs/pulso, 5 Hz, 0,75 W) oferece melhor remoção de biofilme (AU)

Histological evaluation of the surgical margins of oral soft tissue incisions using a dual-wavelength diode laser and an Er, Cr:YSGG laser; an ex vivo study

Abstract Oral soft tissue lesions require a precise diagnosis by oral biopsy with the ability to recognize these lesions within histopathological levels, so the instrument used for the incisions should be safe and cause little to no harm to the surrounding tissue. Objective This study compared a dual-wavelength diode laser and an Er, Cr:YSGG laser in oral soft tissue incisions to determine the most effective and safest laser system at the histopathological level. Methodology The (810 and 980 nm) dual-wavelength diode laser was used at 1.5 W and 2.5 W (CW) power settings, and the (2780 nm) Er, Cr:YSGG laser was used at 2.5 W and 3.5 W (PW) power settings. Both laser systems were used to incise the tissues of freshly dissected sheep tongue pieces to obtain the following histopathological criteria: epithelial tissue changes, connective tissue changes, and lateral thermal damage extent by optical microscopy. Results The epithelial and connective tissue damage scores were significantly higher in the dual-wavelength diode laser groups than in the Er, Cr:YSGG laser groups (P<0.001), and there was a significant difference between some groups. The extent of lateral thermal damage was also significantly higher in the diode laser groups than in the Er, Cr: YSGG laser groups (P<0.001), and there was a significant difference between groups. Group 2 (2.5 W) of the diode laser was the highest for all three criteria, while group 3 (2.5 W) of the Er, Cr:YSGG laser was the lowest. Conclusion The Er, Cr:YSGG laser with an output power of 2.5 W is, histologically, the most effective and safest laser for oral soft tissue incision. The dual-wavelength diode laser causes more damage than the Er, Cr:YSGG laser, but it can be used with a low output power and 1 mm safety distance in excisional biopsy.

Erbium laser in the debonding of ceramics: a literature review / Laser de érbio na remoção de cerâmicas: uma revisão de literatura

Background: The debonding of crowns and ceramic veneers with laser is already a reality in the clinic. It presents benefits in comparison to traditional removal with the use of a rotating instrument; however, there is still no consolidated protocol and many professionals use it without the necessary scientific basis. Objective: The aim of this work was to perform a literature review on the debonding of indirect ceramic restorations using the Er:YAG and Er,Cr:YSGG lasers to provide clinical professionals and the scientific community a careful analysis, and also to guiding the use of irradiation at laser for such procedures. Methods: Bibliographic searches were performed in the following databases: Pubmed, Web of Science and Google Scholar. According to the inclusion criteria adopted, twenty-seven clinical and in vitro studies were selected in the period from 2007 to 2021. In the present work, the composition of the crowns and facets, as well as the types of cement and the laser irradiation protocols adopted in the selected studies is detailed. Conclusions: It was concluded that the use of erbium lasers for debonding of indirect ceramic restorations proved to be more selective and conservative when compared to removal with a rotary diamond instrument. Furthermore, it was shown to be in more efficient in debonding different types of ceramics. However, there are great variations in the "debonding" protocols, which emphasizes the need for further studies that seek to standardize the irradiation protocols considering the different clinical situations (AU)

Antecedentes: A remoção de coroas e facetas cerâmicas com laser já é uma realidade clínica e apresenta benefícios em relação à remoção tradicional com uso de instrumento rotatório diamantado; entretanto, ainda não existe um protocolo consolidado e muitos profissionais o utilizam sem o embasamento científico necessário. Objetivos: O objetivo deste trabalho foi realizar uma revisão da literatura sobre a remoção de restaurações cerâmicas indiretas utilizando os lasers Er:YAG e Er,Cr:YSGG para fornecer uma análise cuidadosa aos profissionais clínicos e à comunidade científica, além de orientar o uso da irradiação a laser para tal aplicação. Métodos: As buscas bibliográficas foram realizadas, nas seguintes bases de dados: Pubmed, Web of Science e Google Scholar. De acordo com os critérios de inclusão adotados, foram selecionados vinte e sete estudos clínicos e in vitro no período de 2007 a 2021. No presente trabalho, a composição das coroas e facetas, bem como os tipos de cimento e os protocolos de irradiação laser adotados nos estudos selecionados foram detalhados. Conclusão: Concluiu-se que o uso dos lasers de érbio para remoção de restaurações cerâmicas indiretas mostrou-se mais seletivo e conservador quando comparado à remoção com instrumento rotatório diamantado, além de ser eficiente na remoção de diferentes tipos de cerâmicas. No entanto, existem grandes variações nos protocolos de "debonding", o que enfatiza a necessidade de novos estudos que busquem uma padronização dos protocolos de irradiação considerando as diferentes situações clínicas.(AU)

Application research progress of Er，Cr：YSGG laser in root canal therapy / 口腔疾病防治

@#Erbium，chromium：yttrium scandium gallium garnet（Er，Cr：YSGG）laser is mainly used for root canal treatment，periodontal disease，tooth decay，dentin hypersensitivity，pulp amputation，etc in the field of dentistry.This paper mainly describes the research progress of Er，Cr：YSGG laser in root canal therapy from following four as⁃pects：root canal sealing，sterilization，cavitation effect and the effect on periapical tissue. The experimental results showed that when the operation parameters of Er，Cr：YSGG were 2 ~ 4 w and 20 Hz，it could effectively remove the stained layer of dentin tubules and improve the tightness between materials and dentin. The thermal effect produced by Er，Cr：YSGG energy has a sterilizing effect，while the optical conductivity of the tooth enables the rinse solution to enter deeper tissues，further improving the sterilizing effect. Er，Cr：YSGG also has a cavitation effect，which destroys the surface tension of the deep solution，removing the stain layer and bacteria in the deep layer. However，with the same operation parameters，if Er，Cr：YSGG is not used properly，the thermal effect of Er，Cr：YSGG will cause some damage to the periapical tissues. Therefore，reasonable use time of Er，Cr：YSGG and water cooling conditions are important.

Effect of Surface Treatment of Two Ceramic Materials by Er, Cr:YSGG Laser Irradiation on The Shear Bond Strength to Resin Cement: "a Comparative in-Vitro Study" / Efeito do tratamento de superfície de dois materiais cerâmicos por Irradiação de laser Er, Cr:YSGG na resistência ao cisalhamento a cimento Resinoso: "um estudo comparativo in-Vitro"

Objective: The aim of this study is to assess the effect of Er,Cr:YSGG laser on the shear bond strength (SBS) and surface topography of two CAD/CAM ceramic materials bonded with self adhesive resin cement. Material and methods: sixty ceramic CAD/CAM discs were obtained, 30 lithium disilicate (IPS Emax) (Group LD), and 30 hybrid resin ceramic (Vita Enamic) (Group RC). The Slices were allocated into six groups (n=10) according to ceramic material and surface treatment; Group (LD-C): IPS Emax treated with 9% hydrofluoric acid (HF), Groups (LD-L1) and (LD-L2): IPS Emax treated with Er,Cr:YSGG, Group (RC-C): Vita Enamic treated with 9% hydrofluoric acid (HF), Groups (RC-L1) and (RC-L2): Vita Enamic treated with Er,Cr:YSGG laser. The laser parameters and irradiation protocol was 1.5 W (L1) and 2.5 W (L2). All samples were cemented with self-adhesive resin cement and thermocycled for 5000 cycles. The SBS was measured using a universal testing machine and the mean values (MPa) were analyzed using Two-way (ANOVA) (P ≤ 0.05) and Bonferroni's post-hoc test. Results: RC-C (16.55) showed highest SBS followed by LD-C (13.79), which revealed no statistically significant difference with RCP1 (12.33) and RC-P2 (11.2). The lowest SBS values were found with LD-P1 (2.7) and LDP2 (2.1). SEM analysis revealed Vita Enamic to have the highest surface roughness. Fracture pattern analysis showed adhesive failure with IPS Emax groups and mixed failure with Vita Enamic groups. Conclusion: Er,Cr:YSGG laser irradiation with the parameters used did not increase SBS of IPS Emax and Vita Enamic with composite resin compared to HF acid etching (AU)

Objetivo: O objetivo deste estudo é avaliar o efeito do laser Er,Cr:YSGG na resistência ao cisalhamento (SBS) e na topografia superficial de dois materiais cerâmicos CAD/CAM cimentados com cimento resinoso autoadesivo. Material e métodos: foram obtidos sessenta discos cerâmicos CAD/CAM, 30 de dissilicato de lítio (IPS Emax) (Grupo LD) e 30 de resina híbrida (Vita Enamic)(Grupo RC). Os discos foram alocados em seis grupos (n = 10), de acordo como material cerâmico e o tratamento de superfície; Grupo (LD-C): IPS Emaxtratado com ácido fluorídrico (HF) a 9%, Grupos (LD-L1) e (LD-L2): IPS Emaxtratado com Er,Cr:YSGG, Grupo (RC-C): Vita Enamic tratada com ácido fluorídrico (HF) a 9%, Grupos (RC-L1) e (RC-L2): Vita Enamic tratada com laser Er,Cr:YSGG. Os parâmetros do laser e o protocolo de irradiação foram de 1,5 W (L1) e 2,5 W (L2). Todas as amostras foram cimentadas com cimento resinoso autoadesivo e termocicladas por 5000 ciclos. A SBS foi medida usando uma máquina de ensaios universais e os valores médios (MPa) foram analisados usando (ANOVA) a dois fatores (P ≤ 0,05) e teste post-hoc de Bonferroni. Resultados: RC-C (16,55) apresentou maior SBS seguido por LD-C (13,79), que não revelou diferença estatisticamente significante com RCP1(12,33) e RC-P2 (11,2). Os menores valores de SBS foram encontrados comLD-P1 (2,7) e LD-P2 (2,1). A análise por MEV revelou que a Vita Enamic possui maior rugosidade de superfície. A análise do padrão de fratura mostrou falha adesiva nos grupos IPS Emax e falha mista nos grupos Vita Enamic. Conclusão: A irradiação com laser Er,Cr:YSGG com os parâmetros utilizados não aumentou a SBS de IPS Emax e Vita Enamic ao cimento resinoso em comparação com o condicionamento ácido com HF.(AU)

Short-term clinical efficacy observation of adjunctive Er,Cr:YSGG laser application following subgingival scaling in patients with severe periodontitis / 上海交通大学学报（医学版）

Objective • To observe the short-term clinical efficacy of adjunctive Er,Cr:YSGG laser application following subgingival scaling in patients with severe periodontitis. Methods • In this parallel control design clinical trial, 46 patients with severe periodontitis were selected. Baseline examination was performed 2 weeks after supragingival scaling. Then the patients were randomly divided into the test group and the control group, with 23 cases in each group. After ultrasonic subgingival scaling, sites with probing depth (PD) ≥ 5 mm of patients in two groups received subgingival debridement with Er,Cr:YSGG laser and hand curettes, receptively. The changes in plaque index (PLI), PD, clinical attachment level (CAL), the percentage of bleeding on probing (BOP) positive sites, and the degree of subjective pain during treatment with visual analogue scale(VAS)were compared between two groups at baseline, 6 weeks after treatment, and 3 months after treatment. Results • For sites with PD ≥ 5 mm, PLI, PD, CAL, and the percentage of BOP positive sites significantly reduced for both groups at 6 weeks and 3 months after treatment compared with baseline (all P=0.000). For sites with 5 mm ≤ PD ≤ 6 mm, the CAL of the test group was significantly lower compared with the control group at 6 weeks after treatment (P=0.036). For sites with PD ≥ 7 mm, the PDs of the test group were significantly lower compared with the control group at 6 weeks and 3 months after treatment (P=0.002, P=0.039). The PD reduction between baseline and 6 weeks after treatment was greater in the test group compared with the control group (P=0.015). The CAL of the test group was lower compared with the control group at 6 weeks after treatment (P=0.011). The VAS of the test group was significantly lower than that of the control group (P=0.005). Conclusion • Adjunctive Er,Cr:YSGG laser application following subgingival scaling can achieve similar short-term clinical efficacy compared with traditional hand curettes. Er,Cr:YSGG laser may be beneficial particularly on the reduction of PD and regain of CAL in deep pockets on a short-term basis, which can make the patients more comfortable. Subgingival scaling with adjunctive Er,Cr:YSGG laser application can be an effective way for the non-surgical periodontal therapy.

Short-term clinical efficacy observation of adjunctive Er, Cr:YSGG laser application following subgingival scaling in patients with severe periodontitis / 上海交通大学学报（医学版）

Objective · To observe the short-term clinical efficacy of adjunctive Er, Cr:YSGG laser application following subgingival scaling in patients with severe periodontitis. Methods · In this parallel control design clinical trial, 46 patients with severe periodontitis were selected. Baseline examination was performed 2 weeks after supragingival scaling. Then the patients were randomly divided into the test group and the control group, with 23 cases in each group. After ultrasonic subgingival scaling, sites with probing depth (PD) ≥5 mm of patients in two groups received subgingival debridement with Er, Cr:YSGG laser and hand curettes, receptively. The changes in plaque index (PLI), PD, clinical attachment level (CAL), the percentage of bleeding on probing (BOP) positive sites, and the degree of subjective pain during treatment with visual analogue scale (VAS) were compared between two groups at baseline, 6 weeks after treatment, and 3 months after treatment. Results · For sites with PD≥5 mm, PLI, PD, CAL, and the percentage of BOP positive sites significantly reduced for both groups at 6 weeks and 3 months after treatment compared with baseline (all P=0.000). For sites with 5 mm ≤ PD ≤ 6 mm, the CAL of the test group was significantly lower compared with the control group at 6 weeks after treatment (P=0.036). For sites with PD ≥ 7 mm, the PDs of the test group were significantly lower compared with the control group at 6 weeks and 3 months after treatment (P=0.002, P=0.039). The PD reduction between baseline and 6 weeks after treatment was greater in the test group compared with the control group (P=0.015). The CAL of the test group was lower compared with the control group at 6 weeks after treatment (P=0.011). The VAS of the test group was significantly lower than that of the control group (P=0.005). Conclusion · Adjunctive Er, Cr:YSGG laser application following subgingival scaling can achieve similar short-term clinical efficacy compared with traditional hand curettes. Er, Cr:YSGG laser may be beneficial particularly on the reduction of PD and regain of CAL in deep pockets on a short-term basis, which can make the patients more comfortable. Subgingival scaling with adjunctive Er, Cr:YSGG laser application can be an effective way for the non-surgical periodontal therapy.

Research progress on the bonding strength of primary teeth after Er, Cr: YSGG laser irradiation / 口腔疾病防治

@#With many advantages such as safety, effective cutting of enamel and dentin, Er, Cr: YSGG laser has gained more and more attention in recent years. After irradiation, the morphology, composition, and structure of tooth surface has changed, yet, the effect of these alterations to the bonding strength of the subsequent material is controversial. The paper has made a review from the following four aspects: Mechanism for tooth hard tissue cutting with Er, Cr: YSGG laser; The structure characteristics of primary teeth; The enamel bonding strength of primary teeth after Er, Cr: YSGG laser treatment; Safety, superiority and expectation for the application of Er, Cr: YSGG laser in primary teeth.

Effect of Laser Pre-Drilling on Insertion Torque of Orthodontic Miniscrews: A Preliminary Study

PURPOSE: To evaluate the effect of different-sized drill tips and laser irradiation times on the initial stability of orthodontic miniscrews placed in Er,Cr:YSGG-laser pre-drilled holes in an animal model. MATERIALS AND METHODS: Laser pre-drilled holes were made in dog mandibular bone with an Er,Cr:YSGG laser using irradiation times of 5, 7, 9, 11, and 13 seconds, and tip diameters of 0.4 and 0.6 mm. The maximum diameter and depth of the pre-drilled holes was measured with micro computed tomography. The maximum insertion torque was measured during placement the miniscrew. RESULT: Laser pre-drilled holes were conical shaped. The maximum diameter of pre-drilled holes increased with longer laser irradiation times (P>0.05) and larger tip diameters (P < 0.05). The depth of pre-drilled holes increased with longer laser irradiation times and larger tip diameters (P < 0.05). When the 0.4 mm tip, but not the 0.6 mm tip, was used, the insertion torque decreased significantly with longer laser irradiation times (P < 0.05). CONCLUSION: Tip diameter impacted insertion torque more than irradiation time. It takes at least 9 seconds using a 0.6 mm tip to create a 0.8 mm diameter and 1.0 mm depth hole in thick cortical bone.

The effect of Er, Cr∶YSGG laser irradiation on the acquired acid resistance of enamel and dentin in vitro / 实用口腔医学杂志

Objective:To investigate the acid resistance of tooth hard tissues irradiated by different power outputs of Er,Cr∶YSGG laser.Methods:Samples in laser groups were irradiated using Er,Cr∶ YSGG laser with the power outputs of 2.5,3.5 and 5 W for enamel and 2 W,3 W and 4 W for dentin,respectively.The calcium and phosphate ion dissolved was measured after decalcification in lactate buffer solution for 24 h.The atomic percentage of calcium and phosphate on the surface of samples was examined by X-ray energy dispersive spectroscopy and the morphological changes were investigated by SEM.Results:In all laser groups of enamel samples except 2.5 W group calcium and phosphate ion dissolved less than in control group and block group (P＜0.05).There's no statistic difference between different power groups.Compared with control group and block group,Ca/P ratio increased(P＜0.05).There's no statistic difference of the atomic percentage of Ca and P on the surface of dentin samples between each 2 groups.SEM observation showed that the surface of the laser irradiated samples was rouph,the space among enamel fibers was increased,the dentin around dentinal tuble orifice was protruded and looked like collar flange.Conclusion:Er,Cr∶YSGG laser irradiation with a range of power is effective in increasing acquired acid resistance of dental hard tissue.There was no relationship between laser power outputs and acid resistance.

Occluding effect of two kinds of Er laser on dentinal tubules:An in vitro study / 实用口腔医学杂志

Objective:To evaluate the occluding effect of 2 kinds of Er laser on dentinal tubules.Methods:27 dentine discs were prepared,etched with 0.5 mol/L EDTA and then divided into 3 groups(n =9).The samples in group A without treatment were used as the controls,in group B treated with Er:YAG laser irradiation and in group C treated with Er,Cr:YSGG laser irradiation.The occluding effect was examined by scanning electron microscopy (SEM).Results:Micrographs of SEMshowed obvious occluding effect in group B and C.The dentinal tubule exposure rates of group A,B and C were 33.61 0% ±7.545%,4.1 86% ±0.723% and 3.798% ± 0.843% respectively(among 3 groups,P 0.05).Conclusion:The 2 kinds of Er laser can block dentinal tu-bules.

Microshear bond strength according to dentin cleansing methods before recementation

PURPOSE: The aim of this study was to determine the efficiency of Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet laser in different output powers for removing permanent resin cement residues and therefore its influence on microshear bond strength compared to other cleaning methods. MATERIALS AND METHODS: 90 extracted human molars were sectioned in 1 mm thickness. Resin cement was applied to surface of sliced teeth. After the removal of initial cement, 6 test groups were prepared by various dentin surface treatment methods as follows: no treatment (Group 1), ethylene diamine tetra acetic acid application (Group 2), Endosolv R application (Group 3), 1.25 W Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser irradiation (Group 4), 2 W Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser irradiation (Group 5) and 3.5 W Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser irradiation (Group 6). The topography and morphology of the treated dentin surfaces were investigated by scanning electron microscopy (n=2 for each group). Following the repetitive cementation, microshear bond strength between dentin and cement (n=26 in per group) were measured with universal testing machine and the data were analyzed by Kruskal Wallis H Test with Bonferroni correction (P<.05). Fracture patterns were investigated by light microscope. RESULTS: Mean microshear bond strength +/- SD (MPa) for each group was 34.9 +/- 17.7, 32.1 +/- 15.8, 37.8 +/- 19.3, 31.3 +/- 12.7, 44.4 +/- 13.6, 40.2 +/- 13.2 respectively. Group 5 showed significantly difference from Group 1, Group 2 and Group 4. Also, Group 6 was found statistically different from Group 4. CONCLUSION: 2 W and 3.5 W Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet laser application were found efficient in removing resin residues.

Shear bond strength of resin cement to an acid etched and a laser irradiated ceramic surface

PURPOSE: To evaluate the effects of hydrofluoric acid etching and Er,Cr:YSGG laser irradiation on the shear bond strength of resin cement to lithium disilicate ceramic. MATERIALS AND METHODS: Fifty-five ceramic blocks (5 mm x 5 mm x 2 mm) were fabricated and embedded in acrylic resin. Their surfaces were finished with 1000-grit silicon carbide paper. The blocks were assigned to five groups: 1) 9.5% hydrofluoric-acid etching for 60 s; 2-4), 1.5-, 2.5-, and 6-W Er,Cr:YSGG laser applications for 60 seconds, respectively; and 5) no treatment (control). One specimen from each group was examined using scanning electron microscopy. Ceramic primer (Rely X ceramic primer) and adhesive (Adper Single Bond) were applied to the ceramic surfaces, followed by resin cement to bond the composite cylinders, and light curing. Bonded specimens were stored in distilled water at 37degrees C for 24 hours. Shear bond strengths were determined by a universal testing machine at 1 mm/min crosshead speed. Data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests (alpha=0.05). RESULTS: Adhesion was significantly stronger in Group 2 (3.88 +/- 1.94 MPa) and Group 3 (3.65 +/- 1.87 MPa) than in Control group (1.95 +/- 1.06 MPa), in which bonding values were lowest (P<.01). No significant difference was observed between Group 4 (3.59 +/- 1.19 MPa) and Control group. Shear bond strength was highest in Group 1 (8.42 +/- 1.86 MPa; P<.01). CONCLUSION: Er,Cr:YSGG laser irradiation at 1.5 and 2.5 W increased shear bond strengths between ceramic and resin cement compared with untreated ceramic surfaces. Irradiation at 6 W may not be an efficient ceramic surface treatment technique.

Morphological analysis of irradiated dentin by scanning electron microscope under anhydrous condition / 国际生物医学工程杂志

Objective To observe the surface morphology of dentin irradiated by Er,Cr∶YSGG laser under anhydrous conditions and discuss the possible clinical applications of the laser.Methods 11 freshly extracted specimens (approximately 1.5 mm thick) taken from the first premolars were selected.One was regarded as the control group without any treatment and the remaining ten were divided into 5 groups whose dentin surface was irradiated by Er,Cr∶ YSGG laser with different energy (1,2,3,4,6 W) under anhydrous condition.The specimens were routinely prepared for electron microscopic scanning observation.Results As the output power increased with Er,Cr∶YSGG laser irradiation,the dentin surface was observed of the constriction of tubular lumen,and part of the tubules closed.The dentin surfaces with 3 ～6 W laser irradiation were observed thermal injury alters such as micro crack and carbonization.Conclusion 1 ～2 W anhydrous Er,Cr:YSGG laser irradiation play a more ideal and safe constriction and sealing role to dentinal tubules,and the laser is expected to be used for the treatment of dentin hypersensitivity.

New innovative technology: waterlase in periodontics.

The Waterlase ™ is a revolutionary tool for dentists which is a unique combination of laser energy and water, a process called Hydro Photonics™, to perform many traditional dental procedures with less need of anesthesia. Since the Waterlase laser cuts hard and soft tissue without heat, vibration or pressure, the dentist may be able to perform the procedure without anesthesia. Also, using the Waterlase laser reduces bleeding, post-operative pain and swelling and the need for pain medication in many cases. It is extremely versatile. It can be used for a wide range of hard and soft tissue procedures including decay removal, cavity preparation, root canals, smile design, frenectomy, gingivectomy, gingivoplasty, curettage, vestibuloplasty, operculectomy, crown lengthening, flap surgery, removal of granulation tissue and bone surgical procedures and many others.

A comparison of bone bed preparation with laser and conventional drill on the relationship between implant stability quotient (ISQ) values and implant insertion variables

PURPOSE: The aim of this study was to investigate a comparison of implant bone bed preparation with Er,Cr:YSGG laser and conventional drills on the relationship between implant stability quotient (ISQ) values and implant insertion variables. MATERIALS AND METHODS: Forty implants were inserted into two different types of pig rib bone. One group was prepared with conventional drills and a total of 20 implants were inserted into type I and type II bone. The other group was prepared with a Er,Cr:YSGG laser and a total of 20 implants were inserted into type I and type II bone. ISQ, maximum insertion torque, angular momentum, and insertion torque energy values were measured. RESULTS: The mean values for variables were significantly higher in type I bone than in type II bone (P or = .05). The ISQ values were correlated with maximum insertion torque (P < .01, r = .731), total energy (P < .01, r = .696), and angular momentum (P < .01, r = .696). CONCLUSION: Within the limitations of this study, the effects of bone bed preparation with Er,Cr:YSGG laser on the relationship between implant stability quotient (ISQ) values and implant insertion variables were comparable to those of drilling.

The effect of Er,Cr:YSGG irradiation on microtensile bond strength of composite resin restoration / 대한치과보존학회지

The purpose of this study was to evaluate the effect of Er,Cr:YSGG laser irradiation with hypersensitivity mode on microtensile bond strength of composite resin. Twenty extracted permanent molars were randomly assigned to six groups, according to the irradiation of Er,Cr:YSGG laser, adhesive system (Optibond FL or Clearfil SE bond) and application time of etchant (15 sec or 20 sec). Then composite resin was build up on each conditioned surface. The restored teeth were stored in distilled water at room temperature for 24 h and twelve specimens for each group were prepared. All specimens were subjected to microtensile bond strength and the fracture modes were evaluated. Also, the prepared dentin surface and laser irradiated dentin surface were examined under SEM. The results were as follows: 1. The microtensile bond strength of laser irradiated group was lower than that of no laser irradiated group. 2. Regardless of laser irradiation, the microtensile bond strength of Optibond FL was higher than that of Clearfil SE bond. And the microtensile bond strength of 20 sec etching group was higher than that of 15 sec etching group when using Optibond FL. 3. The SEM image of laser irradiated dentin surface showed prominent peritubular dentin, opened dentinal tubules and no smear layer.

An experimental study on the effect of LASER on soft tissue healing

Effects of the Er,Cr:YSGG laser on bone bed preparation with various laser tips / 대한치과보철학회지

STATEMENT OF PROBLEM: Preparation of implant beds with lasers is considered a safe and reliable method, but the accuracy of this technique has not been examined. PURPOSE: The purpose of this study was to evaluate the accuracy and effectiveness of implant bed preparation using an Er,Cr:YSGG laser. MATERIAL AND METHODS: An Er,Cr:YSGG laser was applied to pig rib bone. The laser was employed at a 5.75 W power setting, 30 Hz/sec pulse repetition, and 70 micro sec pulse duration with 50 % water and 60% air spray. According to laser tips the groups were divided as follows; Group 1: paralleled - shaped sapphire tip (0.6 mm phi), Group 2: paralleled - shaped zirconia tip (0.6 mm phi), Group 3: tapered sapphire tip (0.4 mm phi). The Er,Cr:YSGG laser tip was separated by 1 mm from the bone and applied for 15 seconds in a non-contact mode. After the application, the bone was sectioned for specimens. Histologic measurements were determined by computerized morphometry. The length of the prepared bone surface was measured and the width of the entrance was measured. The results were analyzed with one-way ANOVA (P<0.05). RESULTS: The prepared length of group 3 was longer than that of group 2. The prepared bone width was larger than the width of the laser tip in every group. Additional bone removal was observed adjacent to the prepared area and displayed an irregular surface. CONCLUSION & DISCUSSION: Different cutting effects were observed according to the laser tip, emphasizing the importance of proper tip selection in the clinical setting. This preliminary study supported the existence of hydrokinetic effects.

Scanning electron microscopic study of implant surface after Er,Cr:YSGG laser irradiation