The effects of CO2, Nd:YAG and Er:YAG lasers with and without surface coolant on tooth root surfaces. An in vitro study

In vitro studies the influence of Nd: YAG laser on dental enamels

The present work aimed at assessing chemical, topographical, and morphological changes induced by Nd : YAG laser treatment of dental enamels by means of energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Fifteen human enamel specimens were obtained, three of samples were kept untreated as a control while the others twelve samples were equally divided into four groups where each group have a three samples according to treating approach as: G1:(untreated);G2: (treated with Nd:YAG laser, 100 mJ/pulse,10 Hz/1064nm); G3(treated with Nd:YAG laser, 500 mJ/pulse, 10 Hz/1064nm); G4(treated with Nd:YAG laser 1000 mJ/pulse, 10 Hz/1064nm), and finally G5(treated with Nd:YAG laser, 1000 mJ/pulse, 10 Hz/532nm) respectively. Beside many craters and cracks, the AFM results showed fractures with depths of 19.23 nm, 174.7 nm, 216.9 nm, 207.4 nm and 156.5 nm and width of 559.2 nm, 833.4 nm, 1115 nm, 695.0 nm, and 5142 nm for all Groups respectively. The highest surface roughness was found in G5 with 111.4 nm while the lowest surface roughness was found in G1 to be 14.3 nm. The inside surface of the fissures was also rough. The SEM micrographs revealed modifications to the morphology. EDS was used to measure the phosphorous (P), calcium (Ca), oxygen (O), and carbon (C) percentages presented in crater areas and their surroundings, Ca, P, O, and C levels were observed to vary significantly at the crater and its rim, a lower percentage of C wt% were realized corresponding to laser treatment of 1000 mJ/Pulse laser energy. However, it was not feasible to recognize a specific chemical arrangement in the craters. It is also concluded that the higher depth and particular edge of ablated part when teeth were irradiated by laser with 1000 mJ/10Hz/1064nm.

Effect of Twinlight Laser on the Attachment of Human Gingival Fibroblasts to the Root Surface In Vitro

Background

This study aimed to compare the effectiveness of subgingival scaling and root planing with the Twinlight laser, Er: YAG laser, and hand instrumentation on the removal of endotoxin and attachment of human gingival fibroblasts (HGFs) to cementum surfaces in vitro.

Material/Methods

Single-rooted teeth extracted for periodontal disease were collected and divided into 3 groups: group A, root planing with Gracey curet no. 5/6; group B, irradiation with Er: YAG laser; group C, irradiation with Er: YAG laser and Nd: YAG laser. Endotoxins were determined by the limulus amebocyte lysate test. Cell attachment and proliferation of HGFs on root specimens were evaluated by cell counting kit-8 assay. The root surface and cell morphology were observed by scanning electron microscope.

Results

A flat root surface with scratches was found in group A, Group B had a homogeneous rough morphology without carbonization, and group C had a non-homogeneous rough morphology with ablation. The endotoxin concentration was highest in group A (P<0.05) and lowest in group C (P>0.05). HGFs cultured in group B showed significantly increased adhesion and proliferation compared with groups A and C (P<0.05). HGFs in group B were well attached, covered densely by pseudopodia. HGFs in group A were round with poor extension and short pseudopodia, while the cells in the group C were in narrow, triangular, or polygonal shapes.

Conclusions

Twinlight laser-assisted periodontal treatment effectively improved the biocompatibility of root surface and promoted the attachment and proliferation of fibroblasts by removing calculus and reducing the concentration of endotoxins.

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.

Comparative assessment between bio-adhesive material and silk suture in regard to healing, clinical attachment level and width of keratinized gingiva in gingival recession defects cases

The objective of this study was to compare the silk suture with a cyanoacrylate adhesive to stabilize the free gingival graft in conjunction with Er: YAG laser-assisted recipient site preparation to augment the keratinized tissue in gingival recession cases. This randomized trial comprised of 300 recession defects patients. All the included patients were diagnosed using Miller class I and II gingival recession defects classification. Group I sites were treated with a free gingival graft (FGG) harvested using an Er: YAG laser and further sutured with silk. Group II sites were stabilized with isoamyl 2 cyanoacrylate bio-adhesive material. Clinical parameters, such as gingival recession depth, clinical attachment level, gain in gingival tissue thickness, and width of keratinized gingiva were recorded at baseline, and at third month, sixth month, and 12th month postoperatively. The mean changes in gingival recession from months 3 to 6 and months and 6 to 12 were significant (p < 0.05) in both groups. However, the improvement in recession depth was better in group II than in group I. The mean change in clinical attachment level did not differ significantly between the groups at the different time intervals. However, values tended to be higher in group II than in group I. The width of the keratinized gingiva tended to be higher from baseline to 3 months, baseline to 6 months, baseline to 12 months, 3 to 6 months, and from 6 to 12 months in group II as compared with group I (p > 0.05). Cyanoacrylate could be used as a substitute to silk sutures to stabilize FGGs. Cyanoacrylate was easy to apply, consumed less operating time, and was considered equally efficacious for stabilizing FGGs.

Laser Analgesia Associated with Restorative Dental Care: A Systematic Review of the Rationale, Techniques, and Energy Dose Considerations

It is a common experience amongst laser dentists and patients that mid-IR wavelength application in cavity preparation may be achieved without causing any associated pain. The erbium family of lasers (Er,Cr:YSGG 2780 nm and Er:YAG 2940 nm) are frequently used without employing injectable local anesthesia as an adjunct: the phenomenon arising from the application of these devices is known as laser analgesia. This review seeks to apply a systematic approach to the examination of appropriate published studies but also to highlight the need for much more structured clinical investigations that consolidate photonic dose and methodology. A search of published data using PRISMA criteria was carried out to examine clinical trials into laser analgesia in conjunction with restorative dentistry, applying inclusion and exclusion criteria. From this, 10 published articles were selected for analysis. Suitability assessment was carried out, using a modified Cochrane risk of bias methodology. In 8/10 of the included studies, laser-induced analgesia is claimed to be better and effective, while in 2/10 of the studies, no difference was exhibited compared to the control group. Statistical analysis of three split mouth studies concluded that only one of these investigations reviewed demonstrated a significant analgesic effect for laser treatment while the other two did not support this observation. From this data, it is inconclusive to assess the predictability of laser analgesia in cavity preparation. A possible rationale and laser operating parametry has been discussed. Successful implementation of this treatment modality remains technique sensitive and subject to further investigation.

Effect of different laser types on bonding strength of CAD/CAM-customized zirconia post to root canal dentin: an experimental study

In clinical dentistry, the strength of bonding zirconia posts to root canal dentinal walls currently needs enhancement, and laser application can be an important contribution owing to its features that accommodate adjustable modifications on dental materials. Herein, the effect of different laser treatments applied to dentin surfaces on the strength of bonding zirconia posts to root canal dentinal walls is evaluated by using the pull-out bond strength test in a laboratory setting. A total of 40 single-rooted permanent mandibular premolar teeth that were freshly extracted were used here. The root canal preparation steps were performed using the crown-down technique. Custom-made zirconia posts were produced using CAD/CAM technology. Prior to the application of resin cement, the internal surfaces of the root canals were irradiated using Nd:YAG, Er:YAG, and KTP lasers. Pull-out tests were performed on each specimen by using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were used to compare the pull-out bond strength data. The bond strengths of the laser-treated specimens were greater than those of the untreated controls (p < 0.05). While the value of the pull-out bond strength after Nd:YAG laser treatment was significantly higher than the values obtained after the applications of the Er:YAG and KTP lasers (p < 0.05), the pull-out bond strength after Er:YAG laser treatment was considerably greater than that after KTP laser treatment (p < 0.05). The bond strength between the root canal dentin and the CAD/CAM custom-made zirconia post was improved upon using all the laser modalities in current laboratory settings, among which, application of the Nd:YAG laser was the most successful.

Photonic Therapy in Periodontal Diseases an Overview with Appraisal of the Literature and Reasoned Treatment Recommendations

Recent reviews and meta-analyses of the literature over the past quarter-century have failed to provide enough evidence to prove or disprove the actual utility of photonic therapy in periodontitis, alone or adjunctive to conventional approaches. This apparent paradox has been explained by the many physical, molecular, biological, anatomical, and technical variables of photonic treatments, which can differ in light-emitting devices (laser or LED), wavelengths, irradiation power and modes, clinical objectives, follow-up times, disease grading, and assessment methods. This multi-faceted, controversial scenario has led practitioners to underestimate the actual potential of photonic therapy in periodontal diseases. In this critical appraisal of the literature, we have briefly summarized the main photonic therapies and instruments used in Periodontology, highlighting their main characteristics and limitations. Then, we have tried to identify and discuss the key methodological issues which can have an impact on the outcome of photonic therapies. Our main goal was to identify the best parameters, settings, and methodologies to perform effective periodontal photonic treatments and to extrapolate some recommendations for clinical use. Should these recommendations find a consensus among periodontologists and be adopted in future clinical studies, they will hopefully contribute to dissipate the present confusion and uncertainty on this complex matter.

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.

Behavior of human periodontal ligament cells on dentin surfaces ablated with an ultra-short pulsed laser

This study aimed to evaluate the effects of an ultrashort pulsed laser (USPL) (1064 nm, 20 ps, 100 kHz) with different laser fluences (F, 4, 6, 8 J/cm²) and pulse overlaps (PO, 0, 50%) on human periodontal ligament cells (hPDLs) behavior. Dentin samples were ablated with USPL with different combinations of fluences and pulse overlaps; some samples were ablated with an Er:YAG laser (2940 nm, 150 µs, 100 mJ/pulse, 5 J/cm²) and some samples were ground with a carbide bur. Then hPDLs were grown on the samples after different treatments. Dentin morphology and cell adhesion were observed with SEM and gene expressions were measured by RT-PCR. The results showed dentin surfaces ablated with USPL when F = 4 J/cm², PO = 0, and F = 6 J/cm², PO = 0 were partially intact with obvious ridges and valleys and cells on these surfaces grew mostly along the valleys. USPL ablated surfaces in other groups were entirely ablated and cell cluster formation was observed. The RT-PCR results showed an upregulation of osteocalcin of cells grown on the dentin after some laser treatment. It can be concluded that USPL could improve the attachment and differentiation of hPDLs and thus potentially promote periodontal tissue regeneration.

Comparison of Er:YAG Laser and Hand Instrumentation on the Attachment of Cultured Human Gingival Fibroblasts to Periodontally Involved Root Surfaces

Introduction: The present study compared the effects of erbium-doped yttrium aluminium garnet (Er:YAG) laser and hand instrumentation on the attachment of human gingival fibroblast (HGF) cells to periodontally involved root surfaces. Methods: A total of 40 tooth specimens were collected and treated in four distinct groups: scaled and root planed with hand instruments, scaled with Er:YAG laser, treated with a combination of hand instruments and Er:YAG laser and non-treated control group. The attachment and proliferation rate of HGF were assessed using MTT assay and scanning electron microscope (SEM) examination was used for cell morphological evaluation. Results: The MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide) assay showed significant decrease in HGF cell viability in both hand instruments only and combination treated teeth specimens compared to control specimens (P<0.05), 24 hours after cell seeding. However, at time 48, the cell viability of attached cells in these 2 treated groups was almost similar to control. In contrast, at 24 and 48 hours after cell seeding, viability of attached cells was higher than control in Er:YAG laser treated only specimens (P<0.05). According to SEM study, the laser treated specimens showed more surface roughness. Conclusion: Er:YAG laser increased attachment and proliferation of HGF cells in comparison to the hand instruments method.

Comparing fibroblast attachment in root surface scaling with Er, Cr:YSGG laser versus ultrasonic scaler: A SEM study

BACKGROUND AND OBJECTIVES

The regeneration of periodontal support is the main concern in periodontal therapy. The aim of this in vitro study was to investigate the fibroblasts attachment on root surfaces after scaling with Er, Cr:YSGG laser and ultrasonic instruments using scanning electron microscopy (SEM).

METHODS

72 root plates of ∼6 × 4 × 1 mm³ in dimension were prepared from 27 single-rooted human mature teeth and were then divided into four groups. One group irradiated with a G6 tip of Er, Cr:YSGG laser (2.78 µm, 0.75 W, pulse duration of 140 µs, repetition rate of 20 Hz) for 5 to 7 s, and the other groups were scaled with ultrasonic alone or laser-ultrasonic. The control group was subjected to neither laser nor ultrasonic scaling. Subsequently, Viability and proliferation rates were done using MTT assay on days 3 and 5. Finally the cell attachment was observed using SEM.

RESULTS

The data derived from MTT and cell-attachment analysis indicated that laser-ultrasonic scaling tended to increase cell-viability by the lapse of time (within 3-5 days), with significantly better cell-attachment compared with other groups on days 3 and 5 (p < .05). The comparison of the difference in fibroblast cell attachment rate on both the third and the fifth day with independent T-Test indicated a significant rise on the fifth day compared to the third day of study (p < .05).

CONCLUSION

Indeed, both Er, Cr:YSGG laser and ultrasonic scaling may promote fibroblast attachment on dentinal root surfaces more than laser or ultrasonic scaling alone.

Removal of Dental Implants Using the Erbium,Chromium:Yttrium-Scandium-Gallium-Garnet Laser and the Conventional Trephine Bur: An in Vitro Comparative Study

OBJECTIVE

The purpose of this study was to compare the conventional trephine bur and the Erbium,chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in removing implants in terms of the volume of removed bone, duration of the procedure, and morphological changes on the bone surface.

MATERIALS AND METHODS

Three human mandibles were utilized, and four implants were inserted in each mandible using a drilling handpiece and burs. The implants were divided into two groups (n = 6) in which two implants from each mandible were removed using a trephine bur running at 1200 rounds per minute (rpm) with water irrigation. The remaining implants (n = 6) were removed with Er,Cr:YSGG laser (power 6 W, frequency 20 Hz, pulse duration 50 μs, water 60, air 30). The volume of bone loss was calculated by filling the holes with mercury and measuring its volume. The preparation time was measured with a digital stopwatch and the postoperative bone surfaces were examined under a scanning electron microscope (SEM).

RESULTS

The laser group exhibited a smaller amount of bone loss than the trephine bur group, whereas the latter required a shorter time of preparation. SEM revealed empty trabecular spaces with no signs of carbonization and well-defined edges in the laser group, whereas the trephine group displayed a surface covered with a smear layer and microcracks.

CONCLUSIONS

The Er,Cr:YSGG laser provides superior results over the trephine bur in terms of bone preservation, thermal damage, and cutting efficiency.

Periodontal and peri-implant wound healing following laser therapy

Laser irradiation has numerous favorable characteristics, such as ablation or vaporization, hemostasis, biostimulation (photobiomodulation) and microbial inhibition and destruction, which induce various beneficial therapeutic effects and biological responses. Therefore, the use of lasers is considered effective and suitable for treating a variety of inflammatory and infectious oral conditions. The CO2 , neodymium-doped yttrium-aluminium-garnet (Nd:YAG) and diode lasers have mainly been used for periodontal soft-tissue management. With development of the erbium-doped yttrium-aluminium-garnet (Er:YAG) and erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, which can be applied not only on soft tissues but also on dental hard tissues, the application of lasers dramatically expanded from periodontal soft-tissue management to hard-tissue treatment. Currently, various periodontal tissues (such as gingiva, tooth roots and bone tissue), as well as titanium implant surfaces, can be treated with lasers, and a variety of dental laser systems are being employed for the management of periodontal and peri-implant diseases. In periodontics, mechanical therapy has conventionally been the mainstream of treatment; however, complete bacterial eradication and/or optimal wound healing may not be necessarily achieved with conventional mechanical therapy alone. Consequently, in addition to chemotherapy consisting of antibiotics and anti-inflammatory agents, phototherapy using lasers and light-emitting diodes has been gradually integrated with mechanical therapy to enhance subsequent wound healing by achieving thorough debridement, decontamination and tissue stimulation. With increasing evidence of benefits, therapies with low- and high-level lasers play an important role in wound healing/tissue regeneration in the treatment of periodontal and peri-implant diseases. This article discusses the outcomes of laser therapy in soft-tissue management, periodontal nonsurgical and surgical treatment, osseous surgery and peri-implant treatment, focusing on postoperative wound healing of periodontal and peri-implant tissues, based on scientific evidence from currently available basic and clinical studies, as well as on case reports.

Evaluation of Push out Bond Strength of Fiber Post after Treating the Intra Radicular Post Space with Different Post Space Treatment Techniques: A Randomized Controlled In vitro Trial

Objective

The aim of this study was to evaluate the push out bond strength after treating the post space with different irrigation procedures.

Study Design

The study sample comprised of 60 recently extracted premolars. These teeth were placed in 5.25% sodium hypochlorite solution for 5 min and then washed under tap water. De-coronated samples were biomechanically prepared until F3 ProTaper and obturated using AH-Plus and 30# (6%) gutta-percha. The specimens were allowed to set for 24 h and then post space was prepared. The teeth were randomly assigned into three experimental groups based on the treatment technique: Group A - control, Group B - sodium hypochlorite and ethylene diamine tetra acetic acid (EDTA) and Group C - diode laser and EDTA. The samples were sectioned horizontally and push out bond strength was evaluated. The stereomicroscopic examination was done for evaluating the failure mode. One-way ANOVA variance followed by Tukey's post-hoc test was used for statistical analysis using SPSS software.

Results

Use of diode laser does not enhance the bond strength of fiber post.

Conclusion

Diode laser at a very low pulse can be used as an irrigant adjuvant to vaporize the cement residues. Using diode laser does not enhance the bond strength. EDTA as final irrigant increases the bond strength of fiber post.

Influence of Different Proportions of External Irrigation During the Er,Cr:YSGG Laser Irradiation on Wear and Roughness of Root Surface

INTRODUCTION

The aim of this study was to evaluate the influence of different levels of external irrigation during irradiation with an erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on the roughness and wear of dental tissue during scaling procedures.

METHODS

Twenty-Five uniradicular bovine teeth had the proximal surfaces planed and divided into 3 regions: upper, middle and lower. The upper region was treated with hand instruments, the middle region was not treated and served as a control, and the lower region was treated by the Er,Cr:YSGG laser. The teeth were randomly divided into five groups according to the different proportions of external irrigation used during the laser irradiation: G1: 10%; G2: 20%; G3: 30%; G4: 40% and G5: 50%. The samples were analyzed for roughness and wear on the root surface irradiated with the laser.

RESULTS

There were no differences in the surface roughness and wear parameters between the groups irradiated with the laser, but the laser irradiation produced a rougher surface of the dentin than treatment with hand scaling.

CONCLUSION

Changes in the external irrigation level did not influence the wear and roughness of root surfaces treated with an Er,Cr:YSGG laser.

Effect of Er: YAG or Nd:YAG Laser Exposure on Fluorosed and Non-Fluorosed Root Surfaces: An In Vitro Study

BACKGROUND AND AIMS

Fluorosis affects tooth mineralization. The therapeutic benefit provided by lasers on fluorosed and non fluorosed cementum requires studying and comparing. The aim of this study was to evaluate and compare the root surface changes following Er:YAG or Nd:YAG laser irradiation on periodontally healthy fluorosed versus non-fluorosed teeth by scanning electron microscopy (SEM).

MATERIALS AND METHODS

A total of 76 periodontally healthy fluorosed (FH) and non-fluorosed (NFH) teeth specimens were included in this study. In one group, the experimental root specimens were irradiated using Er:YAG or with Nd:YAG laser in the other. A SEM evaluation was performed to assess the laser induced ultra structural changes in the root surface followed by statistical analysis using Fisher's exact test.

RESULTS

It was observed that both FH and NFH groups were similarly affected by Nd:YAG or Er:YAG laser. However, the former caused more surface changes than the latter on melting of surface (p=0.12 for FH and p=0.08 for NFH), and Er:YAG laser caused more smear layer formation (p=0.51 for FH and p=0.16 for NFH).

CONCLUSION

RESULTS suggest that undesirable morphological changes were observed almost similarly in FH and NFH groups using Er:YAG or Nd:YAG laser. Hence further in-vitro studies at lower energy settings followed by clinical trials are required in this aspect.

Root surface modifiers and subepithelial connective tissue graft for treatment of gingival recessions: a systematic review

BACKGROUND AND OBJECTIVE

Many techniques and flap designs have been used to treat gingival recession by root coverage, but subepithelial connective tissue graft (SCTG) seems to be the gold standard procedure. In an attempt to improve the healing process and increase the success rate of root coverage, some authors have used root modifiers, including different root conditioners, lasers, EMD, recombinant human growth factors and platelet-rich plasma (PRP). The aim of this systematic review was to evaluate the effects of root biomodification in clinical outcomes of gingival recessions treated with SCTG.

MATERIAL AND METHODS

Studies reporting SCTG associated with any form of root surface biomodification for root coverage of gingival recessions (Miller Class I and Class II) were considered as eligible for inclusion. Studies needed to have data of clinical outcomes in a follow up of at least 6 months. Screening of the articles, data extraction and quality assessment were conducted independently and in duplicate.

RESULTS

None of the products evaluated (citric acid, EDTA, PRP, lasers and EMD) showed evident benefits in clinical outcomes. Test and control groups presented similar outcomes related to root coverage and periodontal parameters, with no statistical differences between them. The exception was root biomodification with the neodymium-doped yttrium aluminium garnet (Nd:YAG) laser, which impaired root coverage and had a detrimental effect on clinical outcomes.

CONCLUSION

Based on the present clinical data, the use of root surface modifiers to improve clinical outcomes in gingival recessions treated with SCTG is not justified. More in vivo studies, and randomized clinical trials with larger sample sizes and extended follow up, are necessary.

Modulatory effects by neodymium-doped yttrium aluminum garnet laser on fibroblast attachment to single rooted tooth surfaces following ultrasonic scaling and root planning: An in vitro study

Context:

One of the most important goals of periodontal therapy is connective tissue reattachment to previously diseased root surfaces. In the recent years, laser therapy has been considered as an important tool in improving the treatment of periodontal disease.

Aims:

To evaluate the neodymium-doped yttrium aluminum garnet (Nd: YAG) lasers effects on root surfaces affected by periodontal disease and compare this treatment with scaling and root planning (SRP) in terms of fibroblast attachment.

Materials and Methods:

A sample of 30 single-rooted human teeth extracted because of advanced periodontal disease was used in this study. Sixty specimens obtained by longitudinal sectioning were randomly divided in three groups. Group A control (untreated); Group B SRP; Group C laser (Nd: YAG) and ultrasonic scaling. All specimens were incubated with fibroblast suspension and then fixed and observed under scanning electron microscope.

Results:

With a median of 8, the control group (Group A) exhibited the least number of total fibroblasts among all the three groups. The laser and scaling - treated group (Group C) showed the highest number of fibroblasts (median = 49, mean ± standard deviation [SD] = 48.28 ± 17.18), followed by SRP only (Group B, median = 22, mean ± SD = 22.24 ± 8.67).

Conclusions:

Nd: YAG laser irradiation at specific energy densities can be used as a useful tool to condition the root surfaces, enhancing fibroblast attachment. Hence aiding in re-establishment of the connective tissue attachment to the root surfaces of previously diseased teeth.

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.

Histological and SEM analysis of root cementum following irradiation with Er:YAG and CO2 lasers

Recently, the Er:YAG and CO(2) lasers have been applied in periodontal therapy. However, the characteristics of laser-irradiated root cementum have not been fully analyzed. The aim of this study was to precisely analyze the alterations of root cementum treated with the Er:YAG and the CO(2) lasers, using non-decalcified thin histological sections. Eleven cementum plates were prepared from extracted human teeth. Pulsed Er:YAG laser contact irradiation was performed in a line at 40 mJ/pulse (14.2 J/cm(2)/pulse) and 25 Hz (1.0 W) under water spray. Continuous CO(2) laser irradiation was performed in non-contact mode at 1.0 W, and ultrasonic instrumentation was performed as a control. The treated samples were subjected to stereomicroscopy, scanning electron microscopy (SEM), light microscopy and SEM energy dispersive X-ray spectroscopy (SEM-EDS). The Er:YAG laser-treated cementum showed minimal alteration with a whitish, slightly ablated surface, whereas CO(2) laser treatment resulted in distinct carbonization. SEM analysis revealed characteristic micro-irregularities of the Er:YAG-lased surface and the melted, resolidified appearance surrounded by major and microcracks of the CO(2)-lased surface. Histological analysis revealed minimal thermal alteration and structural degradation of the Er:YAG laser-irradiated cementum with an affected layer of approximately 20-μm thickness, which partially consisted of two distinct affected layers. The CO(2)-lased cementum revealed multiple affected layers showing different structures/staining with approximately 140 μm thickness. Er:YAG laser irradiation used with water cooling resulted in minimal cementum ablation and thermal changes with a characteristic microstructure of the superficial layer. In contrast, CO(2) laser irradiation produced severely affected distinct multiple layers accompanied by melting and carbonization.

Effects of dentin surface modifications treated with Er:YAG and Nd:YAG laser irradiation on fibroblast cell adhesion

OBJECTIVE

The purpose of this in vitro study was to evaluate the effect of surface modifications induced by erbium (Er):YAG and neodymium (Nd):YAG laser irradiation on cell adhesion by comparing it to that of conventional methods for surface preparation after root-end resection.

BACKGROUND DATA

Many studies have been seeking a favorable method to produce a resected root end with optimal conditions for cell response. However, little improvement has been achieved. This study evaluated the biocompatibilities of resected root surfaces after Er:YAG or Nd:YAG laser irradiation on initial cell adhesion.

MATERIALS AND METHODS

Dentin disks were divided into three groups. Group A was left untreated, Group B was treated with Er:YAG laser irradiation (60 mJ/pulse, 10 pps, 60 sec), and Group C with Nd:YAG laser irradiation (60 mJ/pulse, 10 pps, 60 sec). After laser irradiation, the dentin disks were incubated with NIH/3T3 fibroblasts cultured in Dulbecco's modified Eagle's medium. A morphological analysis of the dentin surface and cell adhesion was observed under a scanning electron microscope. Surface roughness was measured using a confocal laser scanning microscope. The statistical analysis was undertaken using ANOVA at a level of significance of 5% (p<0.05).

RESULTS

Morphological analysis and roughness measurement showed that dentin surfaces treated with Er:YAG laser irradiation were rougher than those in Groups A and C. Group B (Er:YAG) exhibited the greatest number of attached cells among all groups after 12 and 24 h.

CONCLUSIONS

Morphological alteration induced by Er:YAG laser irradiation showed a favorable effect on the attachment of fibroblasts to dentin surfaces.

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.

Micromorphology of resin-dentin interfaces using one-bottle etch&rinse and self-etching adhesive systems on laser-treated dentin surfaces: a confocal laser scanning microscope analysis

BACKGROUND AND OBJECTIVES

This study evaluated the hybrid layer (HL) morphology created by three adhesive systems (AS) on dentin surfaces treated with Er:YAG laser using two irradiation parameters.

STUDY DESIGN

Occlusal flat dentin surfaces of 36 human third molars were assigned into nine groups (n = 4) according to the following ASs: one bottle etch&rinse Single Bond Plus (3M ESPE), two-step Clearfil Protect Bond (Kuraray), and all-in-one S(3) Bond (Kuraray) self-etching, which were labeled with rhodamine B or fluorescein isothiocyanate-dextran and were applied to dentin surfaces that were irradiated with Er:YAG laser at either 120 (38.7 J/cm(2)) or 200 mJ/pulse (64.5 J/cm(2)), or were applied to untreated dentin surfaces (control group). The ASs were light-activated following MI and the bonded surfaces were restored with resin composite Z250 (3M ESPE). After 24 hours of storage in vegetable oil, the restored teeth were vertically, serially sectioned into 1-mm thick slabs, which had the adhesive interfaces analyzed with confocal laser microscope (CLSM-LSM 510 Meta). CLSM images were recorded in the fluorescent mode from three different regions along each bonded interface.

RESULTS

Non-uniform HL was created on laser-irradiated dentin surfaces regardless of laser irradiation protocol for all AS, while regular and uniform HL was observed in the control groups. "Stretch mark"-like red lines were found within the HL as a result of resin infiltration into dentin microfissures, which were predominantly observed in 200 mJ/pulse groups regardless of AS. Poor resin infiltration into peritubular dentin was observed in most regions of adhesive interfaces created by all ASs on laser-irradiated dentin, resulting in thin resin tags with neither funnel-shaped morphology nor lateral resin projections.

CONCLUSION

Laser irradiation of dentin surfaces at 120 or 200 mJ/pulse resulted in morphological changes in HL and resin tags for all ASs evaluated in the study.

A short-term evaluation of Nd:YAG laser as an adjunct to scaling and root planing in the treatment of periodontal inflammation

BACKGROUND

This split-mouth, single-masked, randomized, controlled clinical trial compares the short-term outcomes of a combined treatment with scaling and root planing (SRP) and neodymium-doped:yttrium, aluminum, and garnet (Nd:YAG)-laser irradiation with treatment with SRP alone.

METHODS

Thirty patients were recruited. The mandibular left or right side was randomly assigned as the test side (SRP with laser treatment) or control side (SRP alone). The water-cooled Nd:YAG laser was used at 4 W, 80 mJ/pulse, 50 Hz, and with a pulse width of 350 micros. At baseline, gingival crevicular fluid (GCF) samples were taken from the test and control sides, and levels of matrix metalloproteinase (MMP)-8 and interleukin (IL)-1beta, -4, -6, and -8 were measured using standard techniques. The plaque index (PI), gingival index (GI), and probing depth (PD) were measured by calibrated examiners.

RESULTS

At the 1-week follow-up, PD (P <0.001), PI (P <0.05), and GCF volume (P <0.001) showed significant improvement on test sides compared to control sides. At the 3-month follow-up, PD (P <0.01), PI (P <0.01), GI (P <0.01), and GCF volume (P <0.05) also showed significant improvement on test sides compared to control sides. At the 1-week follow up, IL-1beta and MMP-8 levels were significantly reduced on test sides compared to control sides. The 3-month follow-up confirmed that the improvements on test sites had been sustained compared to the treatment outcomes of control sites.

CONCLUSION

In the short-term, SRP in combination with a single application of a water-cooled Nd:YAG laser significantly improves clinical signs associated with periodontal inflammation compared to treatment with SRP alone.

Root surface biomodification with an Er:YAG laser for the treatment of gingival recession with subepithelial connective tissue grafts

BACKGROUND/AIM

Root surface biomodification has been used to treat gingival recession and periodontitis. The principle for this procedure is that removing the smear layer from the root surfaces exposes collagen fibers, which leads to improved healing. Clinical studies generally have failed to find any improvement in clinical parameters when using such agents. The aim of this study was to evaluate and compare the outcome of gingival recession therapy using the subepithelial connective tissue graft (SCTG) with or without Er:YAG laser application for root surface biomodification.

MATERIALS AND METHODS

Twenty-four teeth in 12 patients with Miller class I and II recession were treated with SCTG with (test group) or without (control group) the application of an Er:YAG laser (2 Hz, 60 mJ/pulse, 40 s, with air spray). Clinical attachment level (CAL), recession depth (RD), recession width (RW), and probing depth (PD) were measured at baseline and 6 months postsurgery.

RESULTS

There were no significant differences between test and control groups (p > 0.05). Postoperatively, significant root coverage, gains in CAL, and highly significant increases in the RW were observed in both groups. For test and control groups, the average root coverage was 80% and 86%, respectively (p > 0.05), and complete root coverage was 75% and 67%, respectively.

CONCLUSIONS

The present study showed that root surface conditioning with an Er:YAG laser does not enhance the results achieved when SCTG was performed alone.

Scanning electron microscopy study of cavity preparation in deciduous teeth using the Er:YAG laser with different powers

Using scanning electron microscopy (SEM) we evaluated the morphology of cavity surfaces in deciduous teeth prepared in vitro with the Er:YAG laser with different power parameters. Eight extracted cavity-free deciduous teeth with an intact crown were prepared using a traditional handpiece or an Er:YAG laser with different parameters (10 Hz/200 mJ, 10 Hz/300 mJ and 10 Hz/400 mJ). Samples were then processed and cavity surface morphology was evaluated by SEM to detect open dentinal tubules, or melting or cracking of the dentin. SEM showed that laser cavity preparation in deciduous teeth using different parameters left no smear layer and the dentinal tubules were clear. Dentin melting was not seen after cavity preparation at 200 mJ or 300 mJ, while visible dentin melting and cracks were detected at 400 mJ. The use of the laser at 10 Hz/200 mJ and 10 Hz/300 mJ for cavity preparation in deciduous teeth is safe and effective, but higher powers may damage the dentin.

Root surface biomodification with Nd:YAG laser for the treatment of gingival recession with subepithelial connective tissue grafts

BACKGROUND/AIM

Root surface biomodification has been used to treat gingival recession and periodontitis. The principle for this procedure is that removing the smear layer from the root surfaces exposes collagen fibers, which leads to improved healing. Clinical studies generally have failed to find any improvement in clinical parameters when using such procedures, however. The aim of this study was to evaluate and compare the outcome of gingival recession therapy using the subepithelial connective tissue graft (SCTG) with or without Nd:YAG laser application for root surface biomodification.

MATERIALS AND METHODS

Thirty-four teeth in 17 patients with Miller Class 1 and 2 recession were treated with SCTG with (test group) or without (control group) the application of Nd:YAG laser (1 W, 10 Hz, 100 mj, 60 s, 1064 nm). Clinical attachment level (CAL), recession depth (RD), recession width (RW), and probing depth (PD) were measured at baseline and six months postsurgery.

RESULTS

Both treatments yielded significant improvements in terms of RD and RW decrease and CAL gain compared to baseline values. For test and control groups, the average root coverage was 33% and 77%, respectively (p < 0.05), and the complete root coverage was 18% and 65%, respectively (p < 0.05). The control group showed a greater reduction in RD and RW compared with the test group (p < 0.05).

CONCLUSIONS

The use of Nd:YAG laser as a root surface biomodifier negatively affected the outcome of root coverage with the SCTG.

Lack of adjunctive benefit of Er:YAG laser in non-surgical periodontal treatment: a randomized split-mouth clinical trial

AIM

This split-mouth, randomized, clinical trial aimed to evaluate the efficacy of erbium-doped:yttrium-aluminium-garnet (Er:YAG) laser application in non-surgical periodontal treatment.

MATERIALS AND METHODS

A total of 27 patients underwent four modalities of non-surgical therapy: supragingival debridement; scaling and root planing (SRP)+Er:YAG laser; Er:YAG laser; and SRP. Each strategy was randomly assigned and performed in one of the four quadrants. Clinical outcomes were evaluated at 3 and 6 months. Subjective benefits of patients have been evaluated by means of questionnaires.

RESULTS

Six months after therapy, Er:YAG laser showed no statistical difference in clinical attachment gain with respect to supragingival scaling [0.15 mm (95% CI -0.16; 0.46)], while SRP showed a greater attachment gain than the supragingival scaling [0.37 mm (95% CI 0.05; 0.68)]. No difference resulted between Er:YAG laser+SRP and SRP alone [0.05 mm (95% CI -0.25; 0.36)].

CONCLUSIONS

The adjunctive use of Er:YAG laser to conventional SRP did not reveal a more effective result than SRP alone. Furthermore, the sites treated with Er:YAG laser showed similar results of the sites treated with supragingival scaling.

Clinical and microbiologic follow-up evaluations after non-surgical periodontal treatment with erbium:YAG laser and scaling and root planing

BACKGROUND

This study compared erbium-doped: yttrium, aluminum, and garnet (Er:YAG) laser irradiation (100 mJ/pulse; 10 Hz; 12.9 J/cm(2)) with or without conventional scaling and root planing (SRP) to SRP only for treatment of periodontal pockets.

METHODS

Nineteen patients with pockets from 5 to 9 mm were included. In a split-mouth design, each site was allocated to a treatment group: 1) SRPL, SRP and laser; 2) L, laser; 3) SRP, SRP only; and 4) C, no treatment. Clinical parameters of probing depth (PD), gingival recession, and clinical attachment level (CAL) were evaluated at baseline and 1, 3, 6, and 12 months after treatment. Visible plaque index, gingival bleeding index (GI), bleeding on probing (BOP), and subgingival plaque samples were also measured 12 days postoperatively, in addition to the above mentioned months. Intergroup and intragroup statistical analyses were performed (P <0.05).

RESULTS

GI decreased for SRPL and increased for L, SRP, and C (P <0.05) 12 days postoperatively and decreased for SRPL and SRP (P <0.05) 3, 6, and 12 months after baseline; BOP and PD decreased for all treated groups (P <0.01) 3, 6, and 12 months after treatment. CAL gain was significant for SRPL, L, and SRP (P <0.05) 3, 6, and 12 months postoperatively. SRPL and L presented a significant reduction in the percentage of sites with bacteria 6 and 12 months after treatment (P <0.05).

CONCLUSION

Non-surgical periodontal treatment with Er:YAG laser may be an alternative treatment for reduction and control of the proliferation of microorganisms in persistent periodontitis.

[Er:YAG laser in periodontics and implication in the orthodontic treatment plan]

The Er:YAG laser is used in periodontal surgery to remove excess tissue formations and to clean periodontal pockets. Combined with ultrasonic procedures lasers have significantly advanced the parameters of periodontal surgery. The goal of this article is to review the working mechanisms of the Er:YAG laser in the wide variety of its applications in complex treatment situations in both periodontics and orthodontics.