Effects of Er: YAG, 980 nm and 810 nm Diode Lasers Irradiation on Biocompatibility of SLA Titanium Disks Using SaOs2 Cells Morphology

Objectives The use of lasers for the treatment of periimplant hard and soft tissues is now refmore than ever before. Achieving bone integrity. The aim of this study is to evaluate the effects of Er:YAG, 980 nm and 810 nm diode lasers irradiation on biocompatibility of SLA titanium disks by SaOs2 cells morphology.Methods In this in-vitro study sixty sterile titanium disks with SLA surface were divided into four equal subgroups. One subgroup was used as a control group and the remaining three groups were irradiated with Er:YAG laser 980nm and 810nm Doide lasers, separately. After laser irradiation, all discs were autoclaved at 121° C and placed in 24 appropriate plates. The SaOs2 cells were, then, added to the plates at a density of 2×104. The cells were incubated in DMEM, CO2, and penicillin-streptomycin medium at 37 ° C for 3 days. Then, the samples were extracted from the culture medium for scanning electron microscopy. Finally, the photograph was taken by SEM at magnifications of 750, 1000, 3000, and 5000. The analyses were performed through Kruskal-Wallis and Mann-Whitney tests.Results All three groups, irradiated by laser, and the control group have shown spreading cells with plentiful phylopodia, which means the morphology of a mature bone cell. The numbers were 20.7% (Er:YAG), 52.7% (980nm Diode), 48.8% (810nm Diode) and 38.7% (Control) groups, respectively, which were not statistically significant.Conclusion Er:YAG, 980nm and 810nm diode laser irradiations with the parameters mentioned in this study do not have any negative effects on osteoblast cells attachment and their maturity on titanium implants

Evaluation of Effectiveness of Photodynamic Therapy With Low-level Diode Laser in Nonsurgical Treatment of Peri-implantitis

Introduction: Side effects related to antibiotic therapy for peri-implantitis are rare in laser therapy (LT); therefore, the aim of this study was to evaluate the effectiveness of LT and photodynamic therapy (PDT) on patients with primary peri-implantitis.Methods: In this randomized clinical trial, 40 implants presenting primary peri-implantitis in 20 patients with a mean age of 52.6 years old were included using the simple sampling technique. Periodontal treatment comprising scaling and root planing (SRP) was accomplished for the whole mouth while mechanical debridement with titanium curettes and air polishing with sodium bicarbonate powder was accomplished around the implants. The implants were randomly divided into two groups and treated with LT (control) and PDT (test). The clinical indices were measured at baseline, 6 weeks and 3 months after treatment. Real-time polymerase chain reaction (PCR) was used for analysis of microbial samples at baseline and 3-month follow-up. Data were analyzed with SPSS 20, using repeated-measures analysis of variance (ANOVA) and Friedman’s and Mann-Whitney tests (α = 0.05).Results: Both groups showed statistically significant improvements in terms of bleeding on probing (P < 0.001), probing pocket depth (PPD) (P = 0.006) and modified plaque index (P < 0.001), with no significant differences between the 2 groups (P > 0.05). The number of Aggregatibacter actinomycetemcomitans (P = 0.022), Tannerella forsythia (P = 0.038) and Porphyromonas gingivalis (P = 0.05) in the test group and Porphyromonas gingivalis (P = 0.015) in the control group significantly decreased.Conclusion: The results suggested that LT and PDT have significant short-term benefits in the treatment of primary peri-implantitis

Removal of Smear Layer by Two Endodontic Irrigation Solutions and Erbium: Yttrium, Aluminum, Garnet (Er:YAG)Laser. A Scanning Electron Microscope (SEM) Study

INTRODUCTION: The purpose of the present study was to determine the effect of 17% Ethylene,di-amine, tetra-acetic acid (EDTA), 6% phosphoric acid and Erbium: Yttrium, Aluminum, Garnet (Er:YAG) Laser in removing the smear layer by scanning electron microscopy.METHODS: In this study, 80 single-rooted human teeth were selected. Instrumentation was done by use of hand files and step-back technique up to file #40 at apical and file #80 at coronal area. During instrumentation, 1ml of 5.25% sodium hypochlorite (NaOCl) was used as irrigation between each file. The teeth were randomly divided into four groups with different methods of smear removal.17% Ethylene, di-amine, tetra-acetic acid was used in group 1, 6% Phosphoric acid in group 2, Erbium: Yttrium, Aluminum, Garnet laser in group 3, and no intervention in group 4 (as control). Roots were then longitudinally sectioned and prepared for scanning electron micrograph in cervical, middle and apical areas. Data were analyzed by Kruskal-Walis, Mann-Whitney, Friedman and Wilcoxson tests (P<0.05).RESULTS: The results showed a significant difference in smear layer removal between three methods in favor of the EDTA (P<0.001) and Phosphoric groups (P<0.001) with no significant difference between them (P=0.49). Although Er:YAG laser showed some limited ability to remove the smear layer, the effectiveness was not significantly different from the control group (P=0.157).CONCLUSION: Based on the findings of this study, EDTA and Phosphoric acid were effective methods to remove smear layer from the root canal walls but Er:YAG laser showed less efficacy compared to the other experimental groups

The Effects of Diode Laser (980 nm Wavelength) and Chlorhexidin Gel in the Treatment of Chronic Periodontitis

INTRODUCTION: The aim of the present study was to investigate the effects of SRP assisted by the two clinical treatment methods of diode laser or Chlorhexidine Gel applications in comparison with SRP alone.METHODS: Eight patients with moderate to severe chronic periodontitis, each with at least three pockets 4–7 mm deep, were selected for this study. Over 66 pockets were selected and randomly treated by either scaling and root planning (SRP) alone, or by SRP + diode laser (1.5 W,980 nm,30sec, continuous wave)(laser group),or by SRP + chlorhexidine gel-xanthan based (gel group). The clinical indices (probing pocket depth [PPD], clinical attachment level [CAL], and papillary bleeding index [PBI] mean score) and microbiological index (total bacterial count [TBC]) before, 1 month and three months after treatment were measured and evaluated.RESULTS: The results showed that SRP assisted by chlorhexidine gel and diode laser therapies exhibits better results than SRP alone in reducing PPD, improving clinical CAL, and reducing PBI mean score and TBC (p < 0.05) both at one month and three months follow ups. Comparison of clinical indices between the laser group and the gel group showed no significant differences at neither of the follow up stages, but in 3 months follow up interval, the TBC reduction in the laser group was significantly more than the gel group (P < 0.05).CONCLUSION: Treatment with diode laser or chlorhexidine gel as an adjunct to SRP may improve periodontal and microbiological indices compared to SRP alone. Diode laser showed better bactericidal effects in long term

Evaluation of the Effects of 660-nm and 810-nm Low-Level Diode Lasers on the Treatment of Dentin Hypersensitivity

Introduction: Dentin hypersensitivity is a common oral problem that occurs as a short and sharp pain. There are many techniques to treat this condition, the latest of which is laser treatment. The aim of this study was to evaluate the effect of two type of low-power diode lasers (660 nm and 810 nm) on dentin hypersensitivity in order to achieve an acceptable clinical application by adjusting the effective parameters.Materials and methods: In this randomized, double-blind clinical trial, sensitive teeth of 7 patients were divided into three groups with randomized matching method: group I, treated with 660-nm diode laser irradiation; group II, treated with diode laser 810-nm and group III, the control group. Irradiation parameters for 660-nm and 810-nm diode lasers were a power of 30 mW and 100 mW, respectively, in contact and continuous mode, perpendicular to tooth surface with a sweeping motion. Treatments were carried out in four sessions, at weekly intervals. Data obtained were analyzed with SPSS 22, using one-way ANOVA, repeated measures ANOVA and LSD (least significant difference) test. Significance level was considered as a=0.05.Results: There were no significant differences in VAS score changes between the two laser groups after the intervention in the first, second and third weeks compared to baseline (P>0.05). These changes in the fourth week were significantly higher in the 810-nm laser group compared to the 660-nm laser group (P=0.04) and in the 660-nm laser group were more than the control group (P=0.02). Mean VAS scores at 1-week, 1-month and 2-month postoperative intervals were significantly lower in 810-nm laser group than 660-nm laser group and in the 660-nm laser group they were less than the control group (P<0.001).Conclusion: The use of 660-nm and 810-nm diode lasers with a power of 30 and 100 mW, respectively, for 120 seconds was effective in reducing pain in patients with dentin hypersensitivity. However, the effect of 810-nm laser was more long lasting in reducing the dentin hypersensitivity than that of the 660-nm laser.

Effect of Nd:YAG Laser Irradiation on the Number of Open Dentinal Tubules and Their Diameter with and without Smear of Graphite: An in Vitro Study

Introduction: Dentin hypersensitivity (DH) is characterized by tooth pain arising from exposure of dental roots. In this study the efficiency of neodymium yttrium-aluminum-garnet (Nd:YAG) laser in association with graphite on dentinal surface changes as the alternative to the treatment of DH was evaluated.Methods: Sixteen noncarious human third molars were collected and sectioned into 5 parts from cementoenamel junction (CEJ) to the furcation area. The prepared samples were randomly assigned into five groups (Gs) of each 16: Control (G1), treated by Nd:YAG laser at 0.5 W (G2), irradiation of Nd:YAG with a 0.25 W output power(G3), smeared with graphite and then using Nd:YAG laser at output powers of 0.5 W (G4) and 0.25 W (G5). For all groups the parameters were 15 Hz, 60 s, at two stages and with a right angle irradiation. The number and diameter of dentinal tubules (DT) were compared and analyzed by SPSS software, One way ANOVA and Post hoc LSD tests.Results: The number of open dentinal tubules varied significantly between all groups except among G1 with G3 and G2 with G5. Multiple comparison tests also exhibited significant differences regarding the diameter of tubules between the groups two by two except among G2 with G5.Conclusion: Nd:YAG laser used at 0.25 W and 0.5 W with application of graphite smear was able to reduce the number and diameter of dentinal tubules

Graphite Application and Different Powers of Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) Laser on Dentin Surface Changes: A Scanning Electron Microscopy Study

INTRODUCTION: Various methods have been used for the treatment of dentine hypersensitivity such as dentifrices, sealants and different types of lasers. The aim of this study was to evaluate the effect of Neodimium:Yttrium-Aluminium-Garnet (Nd:YAG) laser in association with graphite on the dentin morphologic changes.METHODS: In this experimental in vitro study, 16 freshly extracted third molars were selected. 5 specimens with the dimensions of 2×2×1 mm from root trunk were prepared. Specimens were randomly divided into five groups: group 1 (control, no laser irradiation). Group 2, 3 irradiated by Nd:YAG laser 0.5 and 1W, output power respectively. Group 4, 5 smeared with graphite and then irradiated by Nd: YAG laser 0.5 and 1W output power. Samples were prepared for scanning electron microscopy. Number and diameter of dentinal tubules were determined in different groups and analyzed with the Kruskal-wallis and Mann-Whitney tests (SPSS 16).RESULTS: The number of tubules had significant difference between all groups (P<0.001), except group 1 in comparison with group 2 (P> 0.05), and group 3 in comparison with group 4 (P> 0.05). Micro-cracks and rupture of melted dentin materials were seen in group 4 and 5.CONCLUSION: According to the findings of this study, smearing with graphite on dentin surface increase the absorption of Nd:YAG laser energy and reduced the diameter and number of open dentinal tubules

Smear Layer Removal in the Apical Third of Root Canals by Two Chelating Agents and Laser: A Comparative in vitro Study

Introduction: Smear layer (SL) is produced as a result of mechanical instrumentation of the canal(s). Despite the controversies regarding its removal, the evidence-based trend has shifted towards removing and eliminating the SL. Different methods have been used to remove the SL and the aim of this in vitro study was to evaluate the ability of 17% ethylenediaminetetraacetic acid (EDTA), 18% etidronate and Er: YAG on effective removal of the SL. Methods and Materials: Fifty straight single-rooted teeth were divided into three experimental groups (n=15) and one control group of five. The canals were instrumented with HERO 642 rotary files up to 30/0.06. In group 1, canals were irradiated with Er: YAG laser; in groups 2 and 3, canals were irrigated with 17% EDTA and 18% etidronate, respectively. In group 4 (control) distilled water was used for canal irrigation. The amount of remaining SL was quantified according to Hulsmann’s method with scanning electron microscopy (SEM). Data was analyzed by the Kruskal-Wallis and Mann-Whitney U tests (P<0.05). Results: The results showed statistically significant differences in terms of SL removal among the groups (P<0.05). The amount of removed SL by EDTA was significantly greater followed by Er: YAG laser and 18% etidronate. Conclusion: Within the limitations of this study, EDTA was more effective in removing SL compared to Er: YAG and etidronate

Effect of Nonsurgical Periodontal Treatment Combined With Diode Laser or Photodynamic Therapy on Chronic Periodontitis: A Randomized Controlled Split-Mouth Clinical Trial

Introduction: The optimum removal of bacteria and their toxins from periodontal pockets is not always obtained by conventional mechanical debridement. Adjunctive therapies may improve tissue healing through detoxification and bactericidal effects. The purpose of the present study was to evaluate the impact of adjunctive laser therapy (LT) and photodynamic therapy (PDT) on patients with chronic periodontitis.Methods: Twenty patients with at least three quadrants involved and each of them presenting pockets 4-8 mm deep were included in the study. Periodontal treatment comprising scaling and root planning (SRP) was accomplished for the whole mouth. Applying a split-mouth design, each quadrant was randomly treated with SRP alone (group A), SRP with LT (group B), and SRP with PDT (group C). The clinical indices were measured at baseline 6 weeks and 3 months after treatment. Microbiological samples were taken and evaluated at baseline and 3-month follow-up. Results: All groups showed statistically significant improvements in terms of clinical attachment level (CAL) gain, periodontal pocket depth (PPD) reduction, papilla bleeding index and microbial count compared to baseline (P < .05). The results showed more significant improvement in the 6-week evaluation in terms of CAL in groups B and C than in group A (P < .05). Group B also revealed a greater reduction in PPD than the other treatment modalities (P < .05).Conclusion: The obtained data suggested that adjunctive LT and PDT have significant short-term benefits in the treatment of chronic periodontitis. Furthermore, LT showed minimal additional advantages compared to PDT

The Effect of Er:YAG Laser on Entroccocus faecalis Bacterium in the Pulpectomy of Anterior Primary Teeth

Introduction: Successful root canal therapy depends on the complete elimination of micro-organisms such as Entroccocus faecalis, which is impossible to achieve with the traditional methods. Lasers are recently introduced as a new method to solve the problem. The present study is planned and performed to examining the antibacterial effect of Er: YAG laser.Methods: Sixty extracted anterior primary teeth were prepared and sterilized. E. faecalis bacterium was cultured in canals. Samples were randomly divided into two groups. The first group was disinfected by NaOCl 5/25% and Er: YAG laser and the second group just by NaOCl 5/25%. Samples of canal contents were cultured and colony counts were calculated. The results were analyzed statistically by SPSS software and Mann Whitney test.Results: There was no significant difference between colony counts in both groups (P = 0.142). But the number of colonies in the first group was lower than in the second group.Conclusion: Although, Er: YAG laser cannot completely eliminate E. faecalis bacterium, its simultaneous use with NaOCl decreases E. faecalis