Effect of ER:YAG and diode laser irradiation on the root surface: morphological and thermal analysis

Comparative Analysis of Er:YAG and Er,Cr:YSGG Lasers on Root Debridement and Cell Attachment Versus Conventional Instrumentation Methods: A Scoping Review

Effective subgingival debridement is essential for periodontal therapy. Subgingival debridement techniques induce morphological changes that influence healing. While hand instruments and ultrasonic scalers are the gold standard, erbium lasers offer potential advantages in biocompatibility and healing. This scoping review compares the effectiveness of erbium lasers (Er,Cr:YSGG (erbium, chromium-doped yttrium-scandium-gallium-garnet) and Er:YAG (erbium-doped yttrium-aluminum-garnet)) and conventional debridement methods in calculus removal, root surface topography, and cellular attachment following root debridement, based on in vitro studies. A systematic search was conducted in PubMed and Google Scholar for English-language articles published between 2014 and 2024. Studies evaluating erbium lasers compared to conventional debridement methods were included. A total of 1224 studies were initially identified from two databases: PubMed and Google Scholar. Following the eligibility assessment, 15 in vitro studies were analyzed. All methods effectively achieved subgingival instrumentation; additionally, erbium lasers produced smear layer-free surfaces with increased porosity, which may facilitate fibroblast attachment. However, laser-treated surfaces exhibited greater roughness and crater formation compared to conventional methods, with higher energy levels contributing to thermal damage. While some studies reported residual calculus on laser-treated surfaces, others demonstrated enhanced calculus removal and minimal root substance loss. Cell attachment studies indicated that Er:YAG lasers promoted fibroblast viability and proliferation, whereas high-energy Er,Cr:YSGG applications had variable effects on biocompatibility. Erbium lasers present a promising alternative to conventional debridement methods, improving smear layer removal and cell adhesion. However, variations in laser parameters impact treatment outcomes, emphasizing the need for standardized protocols. Further in vivo and clinical studies are required to validate their long-term effectiveness in periodontal therapy.

Effectiveness of the dual wavelength diode laser as an adjunct to non-surgical treatment in treating periodontal pocket in periodontitis patients: A randomized clinical study

Laser technology has affected the field of Periodontology in many ways. They help to manage periodontal disease. This investigation aimed to compare the clinical results of diode laser in conjunction with scaling and root planing (SRP) and SRP alone in treating periodontal pockets in Periodontitis patients. This randomized controlled clinical research utilized a split-mouth approach. It included 25 patients (11 females and 14 males, aged 20 to 65) presenting a moderate periodontal pocket with depths of 4-7 mm on both the right and left sides of the mouth. Two groups were utilized: the control group (SRP alone) on the right side of the mouth and the experimental group (SRP in conjunction with diode laser) on the left side of the mouth. The intervention comprised a single session of scaling and root planing (SRP) accompanied by 10-second administrations of a dual-wavelength diode laser Working within the wavelength range 810-980 nm on the left side. In contrast, the contralateral side received SRP only. Probing Pocket Depth, clinical attachment loss, Plaque Index, and Bleeding on Probing Index were assessed at baseline, 1.5 months, and 3 months post-treatment. The results indicate that both therapies enhanced periodontal parameters at 1.5 and 3 months compared to the baseline. SRP + diode laser, on the other hand, demonstrated a substantial enhancement in probing depth.(PD;4.92 ± 0.65-3.82 ± 0.87-3.55 ± 0.80 vs. 4.95 ± 0.67-4.14 ± 0.93-3.90 ± 0.93, p < 0.001) and BOP%(100.0%-43.2%-34.80% vs. 100.0%-54.8%-44.0%, P < 0.05) in contrast to SRP alone. No substantial differences were detected in CAL and plaque percentages between treatment groups (P > 0.05) at 1.5 and 3 months post-treatment. Conclusions indicate that within the limit of this study, the integration of scaling and root planing (SRP) with diode laser therapy resulted in a significant reduction in moderate periodontal pocket depth and bleeding on probing over the 3-month trial period in patients with Periodontitis.

Effect of Er: YAG laser therapy in non-surgical periodontal treatment: an umbrella review

AIM

The current umbrella review aimed to summarize the effect of erbium-doped yttrium aluminum garnet (Er: YAG) laser adjunct with the conventional non-surgical periodontal treatment which was evidenced from available systematic reviews.

METHODS

An extensive literature search was piloted by two independent reviewers in the PubMed, Scopus, Science Direct, and Google Scholar databases. The search was limited to the English language from 2011 to 2023 years. The methodological quality of systematic reviews 2 (AMSTAR 2) guideline was followed to evaluate the risk of bias for the selected studies. Cohen's kappa statistic was implemented to evaluate the level of agreement to assess the risk of bias in the selected studies.

RESULTS

A total of 472 studies were initially identified. After removing the duplicates and screening, a total of four studies were selected for the current overview. Based on the quality assessment tool, each study scored as high, moderate, low, and critically low-quality study following AMSTAR 2 tool. Inter-rater reliability by Cohen's Kappa statistics showed near-perfect agreement (0.95) between the two reviewers.

CONCLUSION

Even though weak evidence of effectiveness was observed for Er: YAG laser application in non-surgical periodontal treatment, the clinical benefits are still lacking.

The comparative study of temperature rise, time consuming and cut quality among piezosurgery, conventional rotary instruments and Er: YAG laser in apicectomy

OBJECTIVES

This study aimed to compare the temperature rise, time consuming and cut quality of apicectomy using three different methods.

MATERIALS AND METHODS

Twenty-four single-rooted teeth were collected and divided into four groups operating apicectomy with a NINJA tip of a piezoelectric device (G1), a diamond bur with 300,000 rpm (G2), and Er: YAG laser at 200 mJ/ 30 Hz (G3) as well as 250 mJ/ 30 Hz (G4). The temperature elevation and time were recorded and the cut quality was evaluated via stereomicroscope and scanning electronic microscopy (SEM).

RESULTS

The temperature increases for G1 was significantly higher than for G2. However, there was no significant difference between G1 and G2 with laser groups respectively. The median time for apicectomy was: 100.14s for G1, 22.65s for G2, 33.58s for G3, and 21.80s for G4. G1 is the most time-consuming group and there was no statistically significance in the comparisons with G2, G3 and G4. Cut quality was assessed by crack occurrence, smear layer formation and dentinal tubules exposed. The percentage of cracked teeth in G1 and G2 was 33.33% and for laser groups the percentage was 16.67% each. SEM showed that no smear layer formed and almost all dentinal tubules were exposed on resected surfaces for G3&G4, surfaces from G2 were partly covered by smear layer, and surfaces from G1 were fully covered by smear layer and with no dentinal tubules exposed.

CONCLUSIONS

Er: YAG laser and conventional rotary instruments were safe and efficient for apicectomy and with a better cut quality when compared with piezoelectric equipment. Er: YAG laser could be a promising technique for apicectomy and further studies are necessary, especially larger sample in vivo investigations, to verify the feasibility of Er: YAG laser in endodontic surgery.

In Vitro Evaluation of the Different Supragingival Prophylaxis Tips on Enamel Surfaces

Objective: Periodontal instrumentation during supragingival prophylaxis may increase enamel surface roughness, which may lead to increased dental biofilm accumulation and demineralization of the enamel. The aim of this study was to evaluate the changes of the enamel surface profilometrically after the application of different scaler tips used for the professional supragingival prophylaxis. Materials and methods: Forty-eight enamel block samples obtained from extracted human maxillary premolar teeth were prepared and randomly assigned to four different treatment groups. Each treatment group was instrumented by the same clinician with different tools as Group 1: Er:YAG laser chisel tip, Group 2: scaler, Group 3: new generation universal curette; and Group 4: ultrasonic device. Sample surfaces were evaluated with a profilometer before and after instrumentations and after the polishing process. Results: Baseline roughness of the prepared enamel samples was similar between the groups. After instrumentation and polishing, the Er:YAG laser chisel tip revealed the most irregular surface morphology, whereas the new generation curette induced the smoothest surface. Conclusions: New generation universal curette is a promising tool, which can be used safely for supragingival calculus removal without the need for polishing on enamel surfaces.

LASER in periodontal treatment: is it an effective treatment or science fiction?

There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

Could We Set a Convenient Irradiation Time to Reduce the Possibility of Thermal Pulp Damage During Diode Laser as an Adjunct to Periodontal Treatment? An In Vitro Analysis

Background: To identify the most effective time procedure for irradiation to prevent possible harmful pulp temperature rises during diode laser (DL) as an adjunct to scaling and root planning (SRP) treatment. Methods: One hundred fifty freshly extracted human teeth (30 molars, 30 premolars, 30 canines, 30 upper incisors, and 30 lower incisors) were irradiated using a 940-nm DL with a power output at 0.8 W and exposure time of 10, 20, 30, 40, 50, 60 sec per specimen. The thermocouple was used to measure intrapulpal temperature. As an addition, the impact of dark deposits on the root surface was investigated for the intrapulpal temperature rise. The threshold value of 5.6°C is predetermined to damage the pulp. Temperature variations were measured at every 10 sec for five different types of teeth, and statistical analysis was performed. Results: Despite large differences between tooth types, the observed temperature increases for all tooth types were below the threshold of 5.6°C in 20 sec. Dark deposits on the tooth surface reduced the reliable working time of DLs (p < 0.01). Conclusions: DLs as an adjunct to SRP treatment at 0.8 W in molars, premolars, canine, upper incisors, and lower incisors for 42, 37, 38, 27, and 21 sec, respectively, generate acceptable temperature rises for pulp but should be changed as 39, 21, 26, 23, and 13 sec, respectively, in the presence of dark deposits.

Dentinal tubule occlusion using Er:YAG Laser: an in vitro study

OBJECTIVES

We analyzed the effects of the Er:YAG laser used with different parameters on dentinal tubule (DT) occlusion, intrapulpal temperature and pulp tissue morphology in order to determine the optimal parameters for treating dentin hypersensitivity.

METHODOLOGY

Dentin specimens prepared from 36 extracted human third molars were randomized into six groups according to the treatment method (n=6 each): control (A); Gluma desensitizer (B); and Er:YAG laser treatment at 0.5 W , 167 J/cm2 (50 mJ, 10 Hz) (C), 1 W , 334 J/cm2 (50 mJ, 20 Hz) (D), 2 W , 668 J/cm2 (100 mJ, 20 Hz) (E), and 4 W and 1336 J/cm2 (200 mJ, 20 Hz) (F). Treatment-induced morphological changes of the dentin surfaces were assessed using scanning electron microscopy (SEM) to find parameters showing optimal dentin tubule occluding efficacy. To further verify the safety of these parameters (0.5 W, 167 J/cm2), intrapulpal temperature changes were recorded during laser irradiation, and morphological alterations of the dental pulp tissue were observed with an upright microscope.

RESULTS

Er:YAG laser irradiation at 0.5 W (167 J/cm2) were found to be superior in DT occlusion, with an exposure rate significantly lower than those in the other groups (P<0.05). Intrapulpal temperature changes induced by Er:YAG laser irradiation at 0.5 W (167 J/cm2) with (G) and without (H) water and air cooling were demonstrated to be below the threshold. Also, no significant morphological alterations of the pulp and odontoblasts were observed after irradiation.

CONCLUSION

Therefore, 0.5 W (167 J/cm2) is a suitable parameter for Er:YAG laser to occlude DTs, and it is safe to the pulp tissue.

Can We Determine an Appropriate Timing to Avoid Thermal Pulp Hazard During Gingivectomy Procedure? An In Vitro Study with Diode Laser

Objective: Diode laser (DL) is a frequently preferred tool for soft tissue incision and ablation in oral surgery. The aim of this study was to find the most effective irradiation time protocol to avoid potential harmful temperature rise in pulp during DL-assisted gingivectomy. Materials and methods: Ninety human freshly extracted teeth (30 anterior, 30 premolar, and 30 molar) were irradiated using a 940 nm DL with power output of 1 and 2 W and exposure time of 10, 20, 30, 40, 50, and 60 sec per specimen. Intrapulpal temperature was evaluated with thermocouple. Additionally, the effect of dark deposits on root surface for intrapulpal temperature rise was investigated. Temperature differences with every 10 sec were evaluated for three different teeth types, and statistical analyses were performed. Results: Anterior and premolar teeth exceeded the threshold values earlier than molar teeth for both 1 and 2 W. Despite the significant differences among the types of teeth, at 10 sec, temperature rise recorded for all types of teeth was below the critical value of 5.6°C, which cause pulp damage. Dark deposits on teeth surface boosted thermal effect of DLs (p < 0.01). Conclusions: Gingivectomy with DLs at 1 W on anterior, premolar, and molar teeth for 20, 40, and 60 sec, respectively, generates acceptable temperature rise; however, it should be <10, 20, and 40 sec at 2 W, respectively. Especially in the anterior teeth, DLs should be performed with caution to avoid pulp damage.

Prospects on Nano-Based Platforms for Antimicrobial Photodynamic Therapy Against Oral Biofilms

Objective: This review clusters the growing field of nano-based platforms for antimicrobial photodynamic therapy (aPDT) targeting pathogenic oral biofilms and increase interactions between dental researchers and investigators in many related fields. Background data: Clinically relevant disinfection of dental tissues is difficult to achieve with aPDT alone. It has been found that limited penetrability into soft and hard dental tissues, diffusion of the photosensitizers, and the small light absorption coefficient are contributing factors. As a result, the effectiveness of aPDT is reduced in vivo applications. To overcome limitations, nanotechnology has been implied to enhance the penetration and delivery of photosensitizers to target microorganisms and increase the bactericidal effect. Materials and methods: The current literature was screened for the various platforms composed of photosensitizers functionalized with nanoparticles and their enhanced performance against oral pathogenic biofilms. Results: The evidence-based findings from the up-to-date literature were promising to control the onset and the progression of dental biofilm-triggered diseases such as dental caries, endodontic infections, and periodontal diseases. The antimicrobial effects of aPDT with nano-based platforms on oral bacterial disinfection will help to advance the design of combination strategies that increase the rate of complete and durable clinical response in oral infections. Conclusions: There is enthusiasm about the potential of nano-based platforms to treat currently out of the reach pathogenic oral biofilms. Much of the potential exists because these nano-based platforms use unique mechanisms of action that allow us to overcome the challenging of intra-oral and hard-tissue disinfection.

Effects of Er:YAG Laser on the Attachment of Human Periodontal Ligament Fibroblasts to Denuded Root Surfaces Simulating Delayed Replantation Cases: An In Vitro Study

Objective: To investigate the effects of Er:YAG laser on the attachment of human periodontal ligament fibroblasts (hPDLFs) to denuded root surfaces simulating delayed replantation cases. Background data: Dental avulsion is one of the most severe dental traumas, which is often treated with replantation. In delayed replantation scenarios, poor prognosis, including root resorption, usually occurs due to poor root surface conditioning and nonviable hPDLF attachment. Methods: Thirty-six root fragments (5 × 5 × 2 mm) were obtained from periodontium tissue-free premolar root surfaces. Specimens were randomly and equally assigned to the following: Group A, untreated control; Group B, 25 J/cm² and 10 Hz of Er:YAG laser irradiation; and Group C, 50 J/cm² and 10 Hz of Er:YAG laser irradiation. Some specimens in each group were then prepared for surface topography visualization under SEM, others were subjected to coculture with hPDLF suspension, and cell adhesion was further evaluated by SEM. Results: Group A presented homogenous smooth root surface, with fewer and round-shaped cells attached; Group B and C exhibited rather rough and irregular morphologies, and spindle-shaped fibroblasts were firmly attached by numerous lamellipodia and extensions. After a 3-day coculture, the number of fibroblasts attached in Group A was significantly lower compared with the other two laser-treated groups (p = 0.008 < 0.05). No significant alterations were observed between the two laser groups (p = 0.135 > 0.05). Conclusions: Er:YAG laser-treated root surfaces are compatible for the attachment of PDLFs, which suggests that Er:YAG laser irradiation may be used as a promising strategy for root surface conditioning in delayed replantation cases.

Assessment of antibacterial activity of 2.5% NaOCl, chitosan nano-particles against Enterococcus faecalis contaminating root canals with and without diode laser irradiation: an in vitro study

Objective: This study was done to evaluate the antibacterial effect of chitosan nano-particles (CNPs) root canal irrigant as a new alternative to Sodium hypochlorite (NaOCl) for disinfection of root canals inoculated with Enterococcus faecalis, with and without laser activation.Methodology: Sixty single rooted human premolars were decoronated, prepared and had their apical foramina sealed. E. faecalis were incubated in the root canals for 15 days. The teeth were then randomly divided into two experimental groups (n = 30) according to the disinfection protocol used. In Group I: disinfection was performed using the irrigant solutions only (Saline, 2.5% NaOCl, CNPs). Whereas in Group II, disinfection was done using the same irrigants followed by Diode laser at (980-nm) at 2 W output for 5 × 5 s. Intra-canal bacterial samples were taken before and after canal disinfection to determine the CFU count.Results: In group I, 2.5% NaOCl was as effective as CNP in eradication and significantly more effective than Saline (p = 0.008) in eradication of E. faecalis. In Group II, either 2.5% NaOCl or CNP in combination with diode laser irradiation showed a similarly high effect in bacterial eradication.Conclusions: Within the parameters used in this study, a combination therapy consisting of irrigation followed by diode laser irradiation should be utilized as an effective treatment modality for eliminating E. faecalis from root canal systems.

Clinical Effectiveness of Er: YAG Lasers Adjunct to Scaling and Root Planing in Non-Surgical Treatment of Chronic Periodontitis: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND Er: YAG lasers (ERLs) show suitable characteristics for scaling and root planing, but previous studies have drawn conflicting conclusions. This meta-analysis aimed to systematically appraise the available evidence concerning the effectiveness of ERLs as an adjunct to scaling and root planing (SRP) for non-surgical periodontal treatment. MATERIAL AND METHODS Randomized controlled trials (RCTs) comparing ERLs+SRP with SRP alone for the treatment of chronic periodontitis were searched in 9 electronic biomedical databases up to January 2018. The weighted mean differences (WMDs) and 95% confidence intervals (CIs) were counted for probing depth (PD) reduction, clinical attachment level (CAL) gain, and visual analog scale (VAS) score. Heterogeneity was evaluated with the I² statistic for interstudy comparisons and the χ²-based Q statistic for intra-study comparisons. Sensitivity analysis was conducted by switching to a random or fixed effect model based on the heterogeneity. Publication bias was measured by Begg's test. RESULTS Ten related RCTs met the inclusion criteria. There were statistically significant differences in the assessed clinical parameters at the three-month follow-up: PD reduction (WMD=0.32, 95%CI range from 0.14 to 0.51, p<0.001; p=0.003, I²=69.7%); CAL gain (WMD=0.31, 95%CI range from 0.22 to 0.40, p<0.001; p=0.209, I²=28.8%); and VAS scores (WMD=-1.38, 95%CI range from -2.45 to -0.31, p<0.001; p=0.182, I²=44%). There were no significant differences at the six- and twelve-month follow-ups. Sensitivity analysis revealed that the results were consistent. No evidence of publication bias was detected. CONCLUSIONS This systematic analysis demonstrated that ERLs+SRP provides additional short-term effectiveness and that patients experience less pain compared to SRP. There were no significant differences at the medium-term and long-term follow-ups. Long-term well-designed RCTs are required.

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 microorganisms 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.

Transcanalicular Diode Laser-Assisted Revision Surgery for Failed Dacryocystorhinostomy With or Without Distal or Common Canalicular Obstruction

PURPOSE

To report the outcomes of transcanalicular diode laser-assisted revision surgery for failed dacryocystorhinostomy with/without distal or common canalicular obstruction.

METHODS

The medical records and recorded videos of consecutive transcanalicular diode laser-assisted revision surgeries performed for failed dacryocystorhinostomy between May 2011 and May 2015 were reviewed. Cases of unavailability of video and cases lost to follow up after surgery were excluded from the study. With respect to the level of obstruction, lacrimal drainage systems were divided into Group 1 (obstruction at the level of the ostium) and Group 2 (obstruction at the level of the distal or common canaliculus). Data associated with anatomical and functional success were analyzed.

RESULTS

Revision dacryocystorhinostomy surgeries were performed on 68 patients during the study period. Transcanalicular diode laser-assisted revision surgeries were performed on 48 eyes of 39 patients. Mean follow-up period after revision surgery was 13.3 ± 12.6 months. Overall, anatomical success rate was 83.3% (40/48) and functional success rate was 68.8% (33/48). Anatomical success rates and functional success rates in the 2 groups showed no significant difference (80.0% [24/30] vs. 86.7% [13/15], p = 0.699; 70.0% [21/30] vs. 66.7% [10/15], p = 1.000, respectively).

CONCLUSIONS

Transcanalicular diode laser-assisted revision surgery may be an alternative technique for failed dacryocystorhinostomy. Distal or common canalicular obstruction did not affect the outcomes of revision surgeries.

Analysis of Human Tooth Pulp Chamber Temperature After 670 nm Laser Irradiation: In Vitro Study

OBJECTIVE

One of the limiting factors of employing laser radiation on dental therapies is the potential of causing thermal injuries to pulp tissues. The purpose of this study was to evaluate intra-chamber temperature increase on extracted human teeth exposed to 670 nm wavelength InGaAlP laser diode radiation.

MATERIALS AND METHODS

In vitro intra-chamber temperature measurements of 12 standardized human teeth (incisors, canines, premolars, and molars; n = 3) were taken both before and after laser radiation. A type-K thermocouple fast-response thermocouple wire with a 0.5 mm diameter probe was inserted into the tooth pulp chamber (ICEL-Manaus-brand). The laser device Lasotronic-brand InGaAlP laser diode was used to irradiate tooth enamel, perpendicularly to the external surface for 30 sec, with power of levels of 340, 272, 204, 136, and 68 mW. The measurements were taken at three time points: 0, 30 sec, and 3 min after the laser irradiation. Measurements were repeated 24 h after removal and reinsertion of the probe in the pulp chamber. The temperature gradient (ΔT in °C) was calculated (ΔT = final temperature-initial temperature) for each group. Data of ΔT were statistically analyzed by two-way analysis of variance (ANOVA) at the 95% confidence level and compared by Tukey post hoc test (α = 0.05).

RESULTS

ANOVA showed statistically significant differences to the interaction of factors (p < 0.05). The highest ΔT values obtained were observed to incisors with 340 mW, 272 mW; 204 mW of power (respectively 4.7°C, 4.2°C, and 3.1°C); and canines presented the lowest ΔT (0.8°C-0.3°C) with no influence of power output.

CONCLUSIONS

Since the thermal increase was observed in this study, especially in incisors, attention should be paid to avoid pulpal damage.

Effects of Root Debridement With Hand Curettes and Er:YAG Laser on Chemical Properties and Ultrastructure of Periodontally-Diseased Root Surfaces Using Spectroscopy and Scanning Electron Microscopy

Introduction: The efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser for root debridement in comparison with curettes has been the subject of many recent investigations. Considering the possibility of chemical and ultra-structural changes in root surfaces following laser irradiation, this study sought to assess the effects of scaling and root planing (SRP) with curettes and Er:YAG laser on chemical properties and ultrastructure of root surfaces using spectroscopy and scanning electron microscopy (SEM). Methods: In this in vitro experimental study, extracted sound human single-rooted teeth (n = 50) were randomly scaled using manual curettes alone or in conjunction with Er:YAG laser at 100 and 150 mJ/pulse output energies. The weight percentages of carbon, oxygen, phosphorous and calcium remaining on the root surfaces were calculated using spectroscopy and the surface morphology of specimens was assessed under SEM. Data were analyzed using one-way analysis of variance (ANOVA). Results: No significant differences (P > 0.05) were noted in the mean carbon, oxygen, phosphorous and calcium weight percentages on root surfaces following SRP using manual curettes with and without laser irradiation at both output energies. Laser irradiation after SRP with curettes yielded rougher surfaces compared to the use of curettes alone. Conclusion: Although laser irradiation yielded rougher surfaces, root surfaces were not significantly different in terms of chemical composition following SRP using manual curettes with and without Er:YAG laser irradiation. Er:YAG laser can be safely used as an adjunct to curettes for SRP.

Combined application of Er:YAG and Nd:YAG lasers in treatment of chronic periodontitis. A split-mouth, single-blind, randomized controlled trial

BACKGROUND

The aim of the present study was to compare the effectiveness of combined Er:YAG and Nd:YAG laser therapy to that of scaling and root planing with hand instruments in non-surgical treatment of chronic periodontitis.

MATERIAL AND METHODS

Twenty-five systemically healthy patients with chronic periodontitis were selected for this study. The quadrants were randomly allocated in a split-mouth design to either combined Er:YAG (160 mJ/pulse, 10 Hz) and Nd:YAG laser (100 mJ/pulse, 20 Hz) therapy (test group) or scaling and root planing alone (control group). At baseline, 1 month and 3 months after treatment, plaque index, gingival index, probing depth, clinical attachment level and bleeding on probing (%), were recorded and gingival crevicular fluid and subgingival plaque samples were taken. The gingival crevicular fluid levels of interleukin-1β and tumor necrosis factor-α were analyzed by enzyme-linked immunosorbent assay. Quantitative analysis of red complex bacteria was performed using quantitative real-time polymerase chain reaction.

RESULTS

The clinical parameters had significantly improved for both groups after treatment. There were statistically significant differences in probing depth and clinical attachment level between the test and control groups only for deep pockets (≥7 mm) (P<.05). No significant differences between the two groups were observed for the biochemical and microbiological parameters at any time points (P>.05).

CONCLUSIONS

The present study suggests that a combined course of Er:YAG and Nd:YAG laser therapy may be beneficial particularly in inaccessible areas such as deep pockets on a short-term basis. Further, well-designed studies are required to assess the effectiveness of the combination of these lasers.

Comparison of Er:YAG Laser and Ultrasonic Scaler in the Treatment of Moderate Chronic Periodontitis: A Randomized Clinical Trial

Introduction: Periodontitis is an inflammatory periodontal disease that leads to tooth loss. Recently laser has been introduced as an alternative treatment for periodontitis. The aim of the present study was to compare the effect of Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser with ultrasonic scaler in patients with moderate chronic periodontitis. Methods: In this randomized single-blind clinical trial, 27 patients with moderate chronic periodontitis were selected. One quadrant of the patients was treated by Er:YAG laser and the other one by ultrasonic scaler. Clinical parameters, including periodontal pocket depth (PPD), papillary bleeding index (PBI) and clinical attachment level (CAL) were measured before, as well as 6 and 12 weeks after treatment. Data were analyzed by SPSS 20 software using Friedman test, paired t test, independent t test and Mann-Whitney test. The significance level was set at 0.05. Results: The means of clinical parameters in both groups were significantly improved in the first and second follow-ups (P < 0.001). Although the means of PPD, PBI and CAL were slightly higher in the laser group than in the ultrasonic group, the differences were not statistically significant between these two groups (P > 0.05). Conclusion: Although both ultrasonic scaler and Er:YAG laser could effectively improve clinical periodontal parameters, the results did not reveal the superiority of Er:YAG laser over ultrasonic scaler or vice versa.

In Vitro Study of Temperature Changes in Pulp Chamber During Root Planing Procedure Using Er:YAG Laser

AIM

To assess temperature changes at specified time intervals during Er:YAG laser scaling and root planing of surfaces with dental calculus.

MATERIALS AND METHODS

Fifteen single-rooted teeth with advanced periodontal disease were extracted and fixed in a cylinder thermostat filled with distilled water at constant temperature (35.5°C). A specially designed thermal probe (type K thermocouple) accurate to ±0.1°C over the range from 20°C to 80°C was fitted into the pulp chamber of tooth sample. Scaling and root planing of the mesial and distal root surfaces was performed using an Er:YAG laser (Lite Touch, Syneron Dental, Israel) with a wavelength of 2940 nm, provided with a chisel tip, and at the following settings: output energy 100 mJ and 50 Hz, duration of irradiation - 40 sec, the tip in contact mode oblique to the root surface at an angle of approximately 10-15 degrees and water spray level 5-6. The temperature inside the pulp chamber was measured every 10 sec.

RESULTS

The temperature in the pulp chamber taken every 10 seconds and compared with the temperature of 35.5°C at baseline decreased by 1.6°C, 2.4°C, 2.5°C, and 2.5°C for the first, second, third and fourth measurement, respectively. These changes did not reach statistical significance.

CONCLUSION

The Er:YAG laser does not increase the temperature inside the pulp chamber. The assessed changes do not depend on the duration of irradiation which was kept within 40 seconds. Therefore, this treatment modality causes no thermal damage to the pulp under the above defined conditions and can be considered safe.

Effect of the lasers used in periodontal therapy on the surfaces of restorative materials

The present study aimed to reveal potential damage of the lasers, which are used as an alternative to manual instruments in periodontal therapy, might cause to the surface of restorative materials. Four different restorative materials were used: a glass-ionomer cement (GIC), a flowable composite (FC), a universal composite (UC) and an amalgam. Ten cylindrical samples (8 mm × 2 mm) were prepared for each restorative material. Two laser systems were used in subgingival curettage mode; an 940 nm diode laser (Epic Biolase, Irvine, CA) and an Er,Cr:YSGG laser (Waterlase iPlus, Biolase, Irvine, CA). After laser irradiation, roughness of the sample surfaces was measured using a profilometer. Additionally, atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses were performed to evaluate the morphology and surface deformations of the restorative materials and surfaces. The laser irradiation did not affect the surface roughness of any restorative materials relative to that of the control group (p > 0.05) except for the Er,Cr:YSGG treatment on GIC (p < 0.05). SEM and AFM images verified the results of the surface roughness tests. Within the limitations of the present study, it was demonstrated that Er,Cr:YSGG and diode lasers, aside from the Er;Cr:YSGG treatment on GIC, caused no harmful surface effects on adjacent restorative materials. SCANNING 38:227-233, 2016. © 2015 Wiley Periodicals, Inc.

Intrapulpal temperature changes during root surface irradiation with dual-wavelength laser (2780 and 940 nm): in vitro study

This work reports that the ablation volume and rate of porcine skin changed significantly with the change of skin water content. Under the same laser irradiation conditions (532 nm Nd:YAG laser, pulse width = 11.5 ns, pulse energy = 1.54 J, beam radius = 0.54 mm), the ablation volume dropped by a factor of 4 as the skin water content decreased from 40 wt. % (native) to 19 wt. % with a change in the ablation rate below and above around 25 wt. %. Based on the ablation characteristics observed by in situ shadowgraph images and the calculated tissue temperatures, it is considered that an explosive rupture by rapid volumetric vaporization of water is responsible for the ablation of the high water content of skin, whereas thermal disintegration of directly irradiated surface layer is responsible for the low water content of skin.

Anti-infective therapy with an Er:YAG laser: influence on peri-implant healing

In addition to conventional treatment modalities (mechanical and chemical), the use of lasers has been increasingly proposed for the treatment of periodontal and peri-implant infections (i.e., cleaning and detoxification of implant surfaces). Preliminary results from basic studies have pointed to the high potential of the Erbium-doped: Yttrium, Aluminum and Garnet (Er:YAG) laser. Furthermore, preliminary clinical data indicate that treatment with this kind of laser may positively influence peri-implant healing. The aim of this research update is to evaluate, based on the currently available evidence, the use of an Er:YAG laser for the treatment of peri-implant infections and to indicate its potential as a new treatment modality.

A comparative scanning electron microscopy study between hand instrument, ultrasonic scaling and erbium doped:Yttirum aluminum garnet laser on root surface: A morphological and thermal analysis

BACKGROUND AND OBJECTIVES

Scaling and root planing is one of the most commonly used procedures for the treatment of periodontal diseases. Removal of calculus using conventional hand instruments is incomplete and rather time consuming. In search of more efficient and less difficult instrumentation, investigators have proposed lasers as an alternative or as adjuncts to scaling and root planing. Hence, the purpose of the present study was to evaluate the effectiveness of erbium doped: Yttirum aluminum garnet (Er:YAG) laser scaling and root planing alone or as an adjunct to hand and ultrasonic instrumentation.

SUBJECTS AND METHODS

A total of 75 freshly extracted periodontally involved single rooted teeth were collected. Teeth were randomly divided into five treatment groups having 15 teeth each: Hand scaling only, ultrasonic scaling only, Er:YAG laser scaling only, hand scaling + Er:YAG laser scaling and ultrasonic scaling + Er:YAG laser scaling. Specimens were subjected to scanning electron microscopy and photographs were evaluated by three examiners who were blinded to the study. Parameters included were remaining calculus index, loss of tooth substance index, roughness loss of tooth substance index, presence or absence of smear layer, thermal damage and any other morphological damage.

RESULTS

Er:YAG laser treated specimens showed similar effectiveness in calculus removal to the other test groups whereas tooth substance loss and tooth surface roughness was more on comparison with other groups. Ultrasonic treated specimens showed better results as compared to other groups with different parameters. However, smear layer presence was seen more with hand and ultrasonic groups. Very few laser treated specimens showed thermal damage and morphological change.

INTERPRETATION AND CONCLUSION

In our study, ultrasonic scaling specimen have shown root surface clean and practically unaltered. On the other hand, hand instrument have produced a plane surface, but removed more tooth structure. The laser treated specimens showed rough surfaces without much residual deposit or any other sign of morphological change.

Antimicrobial photodynamic therapy using a diode laser with a potential new photosensitizer, indocyanine green-loaded nanospheres, may be effective for the clearance of Porphyromonas gingivalis

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is a new treatment method for the removal of infectious pathogens using a photosensitizer and light of a specific wavelength, e.g., toluidine blue with a wavelength of about 600 nm. We explored a new photosensitizer and focused on indocyanine green (ICG), which has high absorption at a wavelength of 800-805 nm. We investigated the bactericidal effect of PDT on Porphyromonas gingivalis using a new photosensitizer, ICG-loaded nanospheres with an 805 nm wavelength low-level diode laser irradiation.

METHODS

We designed ICG-loaded nanospheres coated with chitosan (ICG-Nano/c) as a photosensitizer. A solution containing Porphyromonas gingivalis (10(8)  CFU/mL) with or without ICG-Nano/c (or ICG) was prepared and irradiated with a diode laser or without laser irradiation as a negative control. The irradiation settings were 0.5 W with a duty ratio of 10%, for 3-100 ms in repeated pulse (RPT) or continuous wave mode. CFU were counted after 7 d of anaerobic culture.

RESULTS

We observed that ICG-Nano/c could adhere to the surface of P. gingivalis. When ICG-Nano/c was used for aPDT, irradiation with RPT 100 ms mode gave the lowest increase in temperature. Laser irradiation with ICG-Nano/c significantly reduced the number of P. gingivalis (i.e., approximately 2-log10 bacterial killing). The greatest bactericidal effect was found in the RPT 100 ms group. However, laser irradiation (RPT 100 ms) with ICG, as well as without photosensitizer, had no effect on the number of bacteria.

CONCLUSIONS

Within the limits of this study, ICG-Nano/c with low-level diode laser (0.5 W; 805 nm) irradiation showed an aPDT-like effect, which might be useful for a potential photodynamic periodontal therapy.

Evaluation of blood cell attachment on Er: YAG laser applied root surface using scanning electron microscopy

BACKGROUND

Periodontal regeneration is dependent on the uninterrupted adhesion, maturation and absorption of fibrin clots to a periodontally compromised root surface. The modification of the root surface with different agents has been used for better fibrin clot formation and blood cell attachment. It is known that Er:YAG laser application on dentin removes the smear layer succesfully.

AIM

The aim of this study is to observe blood cell attachment and fibrin network formation following ER:YAG laser irradiation on periodontally compromised root surfaces in comparison to chemical root conditioning techniques in vitro.

MATERIALS AND METHODS

40 dentin blocks prepared from freshly extracted periodontally compromised hopeless teeth. Specimens were divided in 5 groups; those applied with PBS, EDTA, Citric acid and Er:YAG. They were further divided into two groups: those which had received these applications, and the control group. The specimens were evaluated with scanning electron microscope and micrographs were taken. Smear layer and blood cell attachment scoring was performed.

RESULTS

In the Er:YAG laser applied group, smear layer were totally removed. In the blood applied specimens, better fibrin clot formation and blood cell attachment were observed in the Er:YAG group. In the group that had been applied with citric acid, the smear layer was also removed. The smear layer could not be fully removed in the EDTA group.

CONCLUSION

Er:YAG laser application on the root dentin seems to form a suitable surface for fibrin clot formation and blood cell attachment. Further clinical studies to support these results are necessitated.

Temperature variation during apicectomy with Er:YAG laser

OBJECTIVE

The purpose of this in vitro study was to evaluate the generated temperature of the Er:YAG laser, with three different pulse durations for apicectomy, compared with tungsten bur and surgical saw.

BACKGROUND DATA

Apicectomy is an endodontic surgery performed to remove the root apex and curette adjacent periapical tissue because of lesions of the apical area that are not healing properly.

METHODS

Sixty single-rooted extracted human teeth were resected by three cutting methods: tungsten bur, surgical saw, and Er:YAG laser irradiation with three different pulse durations; pulse duration 50 μs, pulse duration 100 μs, and pulse duration 300 μs. Teflon-insulated, type K thermocouples were used to measure temperature changes during the apicectomy process. Data were analyzed using the general linear models procedure of the SPSS statistical software program.

RESULTS

Although there was no statistically significant difference for the mean values of temperature changes at 1 mm away to the cutting site of teeth, there was statistically significant difference among groups for the mean values of temperature changes at 3 mm away to the cutting site of teeth. Additionally, there was statistically significant difference among groups for the total time required for apicectomy.

CONCLUSIONS

The laser irradiation with pulse duration 50 μs appears to have the lowest temperature rise and the shortest time required for apicectomy of the three pulse durations. However, Er:YAG laser for apicectomy in all pulse durations could be used safely for resection in endodontics in the presence of sufficient water.

Effects of laser-aided circumferential supracrestal fiberotomy on root surfaces

OBJECTIVE

To evaluate and compare the effects of circumferential supracrestal fiberotomy in vivo (using diode, CO(2), and Er∶YAG lasers) on the morphology and chemical composition of the root surface.

MATERIALS AND METHODS

Forty healthy premolar teeth, intended for extraction for orthodontic reasons, were used in this study. Root surfaces were treated using different laser methods, as follows: (1) control; (2) Er∶YAG laser (2.94 µm, 100 mJ, 10 Hz); (3) diode laser (808 nm, 1.2 W, continuous wave); and (4) CO(2) laser (10.6 µm, 3 W, continuous wave). Subsequently, the teeth were removed and subjected to scanning electron microscopic (SEM) examination and energy dispersive x-ray (EDX) spectrometric analysis.

RESULTS

SEM analysis indicated that no thermal changes, including melting or carbonization, were observed following the lasing procedures. EDX analysis showed that the laser procedures resulted in similar mineral contents (weight % of calcium and phosphate) as compared to those in the control group.

CONCLUSION

Based on these findings, we concluded that laser-aided procedures, when used at appropriate laser settings, preserve the original morphology and chemical composition of cementum.