Effects of the Er,Cr:YSGG laser on bone and soft tissue in a rat model

ATR-FTIR spectroscopy imaging of bone repair in mandibular laser-osteotomy

The aim of this study was to verify the effectiveness of attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy in the characterization of bone repair in mandibular osteotomy using erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser and multilaminate drill on each side. Two mandible bone fragments were removed from 30 rabbits, and the process of bone repair was studied immediately, 3, 7, 15, 21, and 28 days after the surgery. The histological analysis allowed detecting differences in the early stages of tissue repair after bone cutting performed with the Er,Cr:YSGG laser or multilaminate drill. The ATR-FTIR spectroscopy technique was sensitive to changes in the organic content of bone tissue repair process.

Effect of erbium, chromium-doped: yttrium, scandium, gallium, and garnet laser-assisted periodontal therapy using radial firing tip during early healing period: a randomized controlled split-mouth clinical trial

BACKGROUND

This study aimed to demonstrate the efficacy of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser-assisted nonsurgical periodontal therapy in periodontitis patients during 8 weeks of healing.

METHODS

A split-mouth, single-blinded, randomized controlled clinical trial was conducted on 12 patients diagnosed with stage III/IV periodontitis and had a minimum of two teeth with probing pocket depth (PPD) > 5 mm in at least two quadrants. Upon randomization, each quadrant was assigned for conventional scaling and root planing (SRP) procedure or laser-assisted therapy (SRP + laser) using radial firing tip (RFPT 5, Biolase). Clinical measurements and gingival crevicular fluid collection were performed for statistical analysis.

RESULTS

In the initial statistical analysis on the whole subject teeth, modified gingival index (MGI) reduction was greater in test group at 1(P = 0.0153), 4 (P = 0.0318), and 8 weeks (P = 0.0047) compared to the control in the same period. PPD reduction at 4 weeks in test group was -1.67 ± 0.59 showing significant difference compared to the control (-1.37 ± 0.63, P = 0.0253). When teeth with mean PPD ≥5 mm were sorted, MGI decrease was significantly greater in test group at 1 (P=0.003) and 8 week (P=0.0102) follow-ups. PPD reduction was also significantly greater in test group at 4 week period (-1.98 ± 0.55 vs -1.58 ± 0.56, test vs control, P=0.0224).

CONCLUSIONS

Er,Cr:YSGG-assisted periodontal therapy is beneficial in MGI and PPD reductions during early healing period.

Evaluation of the effect of Er,Cr:YSGG laser application on peri-implant crevicular fluid receptor activator of nuclear factor-kappa B ligand and osteoprotegerin levels in the non-surgical treatment of peri-implantitis: A randomized clinical trial

BACKGROUND

This study aimed to investigate the effect of erbium, chromium doped:yttrium,scandium,gallium,garnet (Er,Cr:YSGG) laser application combined with non-surgical mechanical debridement (MD) on clinical parameters and peri-implant crevicular fluid receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) levels in the treatment of peri-implantitis.

METHODS

A total of 49 patients who underwent non-surgical treatment of peri-implantitis were randomly divided into two groups. The control group (n = 26) received MD alone, while the laser group (n = 23) received MD+Er,Cr:YSGG. The clinical parameters (bleeding on probing [BoP], gingival index [GI], plaque index [PI], probing depth [PD]), marginal bone loss (MBL), and biochemical parameters (RANKL and OPG) were measured at baseline (T0) and 6 months after treatment (T1).

RESULTS

There was a statistically significant decrease in all the clinical parameters in both groups at T1 compared to T0 (p < 0.05). The BoP, PD, MBL, and RANKL reductions were significantly higher in the laser group than in the control group (p = 0.046, p = 0.014, p = 0.047, p = 0.045, respectively). The OPG levels significantly increased at T1 in the laser group (p = 0.01). The OPG/RANKL ratio increased significantly in both groups at T1, which favored the laser group (p = 0.034).

CONCLUSIONS

Although both treatment methods were influential in treating peri-implantitis, the laser group (MD+Er,Cr:YSGG) yielded more favorable results by reducing clinical inflammation and improving biochemical parameters. Based on these findings, Er,Cr:YSGG laser may be a beneficial adjunctive treatment in this patient group.

Thermal damage and the prognostic evaluation of laser ablation of bone tissue-a review

In recent years, an increasing number of scientists have focused on conducting experiments on laser ablation of bone tissue. The purpose of this study was to summarize the prognosis of tissue and the extent of thermal damage in past hard tissue ablation experiments, and review the evidence for the feasibility of laser osteotomy in surgery. An electronic search of PubMed, China National Knowledge Infrastructure (CNKI), and Web of Science (WOS) for relevant English-language articles published through June 2023 was conducted. This review includes 48 literature reports on laser ablation of hard tissues from medical and biological perspectives. It summarizes previous studies in which the ideal ablation rate, depth of ablation, and minimal damage to bone tissue and surrounding soft tissues were achieved by changing the laser type, optimizing the laser parameter settings, or adding adjuvant devices. By observing their post-operative healing and inflammatory response, this review aims to provide a better understanding of pulsed laser ablation of hard tissues. Previous studies suggest that laser osteotomy has yielded encouraging results in bone resection procedures. We believe that low or even no thermal damage can be achieved by experimentally selecting a suitable laser type, optimizing laser parameters such as pulse duration and frequency, or adding additional auxiliary cooling devices. However, the lack of clinical studies makes it difficult to conclusively determine whether laser osteotomy is superior in clinical applications.

Comparison of Er,Cr:YSGG laser and diode laser in the treatment of gingival melanin pigmentation: a randomized clinical trial

This investigation has aimed to compare the efficiency of clinical depigmentation and repigmentation rate of erbium chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) and diode lasers during a 1-year follow-up and to evaluate patient satisfaction. Twenty-two participants were divided into Er,Cr:YSGG laser and diode laser groups using computer-aided randomization. Dummett Oral Pigmentation Index (DOPI) and photographic assessment with ImageJ Software version 10.2 were performed at the preoperative period and postoperative 1st month, 6th month, and 12th month. Moreover, the study assessed intra- and postoperative intensities of pain and postoperative patient aesthetic satisfaction using the Visual Analog Scale in both groups. The median values of DOPI did not differ statistically between the groups according to time (p > 0.05). In the Er,Cr:YSGG group, the extension of repigmentation was less as compared to the diode group at 1-year follow-up (p = 0.045). In the Er,Cr:YSGG group, the patients felt less intraoperative pain and discomfort compared to the diode group (p = 0.007). No significant differences were found between the two groups in terms of patient aesthetic satisfaction at the 1st and 12th months. The findings indicate that diode and Er,Cr:YSGG lasers can be used safely in depigmentation treatment, while the Er,Cr:YSGG laser has been shown to have superiorities in pain management and patient comfort parameters. Clinical Trial No.: NCT05304624.

Flapless Er,Cr:YSGG laser versus traditional flap in crown lengthening procedure

Background/purpose

Laser technology and minimally invasive therapy has gained attention in many dentistry fields. Er,Cr:YSGG laser is the latest laser type that can be applied on both soft tissue and hard tissue. This study presents periodontal outcome of Er,Cr:YSGG laser flapless crown lengthening procedure compared with traditional technique.

Materials and methods

Twenty-five participants were divided into two groups: 13 patients were treated with the traditional method of crown lengthening and 12 patients were treated using a flapless Er,Cr:YSGG laser. Their periodontal status were measured and compared at baseline, immediately, one month, and three months after surgery.

Results

The results showed a significant increase in clinical crown length immediately after surgery in both groups. After a three-month follow-up, the gingival margin of the laser group remained at stable height with 0.17 ± 0.31 mm increase after surgery, while the gingival margin of traditional group showed both recession and rebounding by -0.13 ± 0.63 mm (p > 0.05) average.

Conclusion

The flapless Er,Cr:YSGG laser crown lengthening with its minimally invasive approach without flap reflection may be an alternative treatment for providing an adequate height of tooth for restoration.

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.

Clinical Outcomes of Free Gingival Graft Following Recipient Bed Preparation with Er,Cr:YSGG Laser Versus Scalpel: A Split-Mouth Randomized Clinical Trial

Objective: Free gingival graft (FGG) procedure is accompanied with a considerable rate of graft shrinkage. This study was aimed to assess the dimensional changes of FGG after recipient site preparation with Er,Cr:YSGG laser and surgical scalpel. Materials and methods: This split-mouth randomized clinical trial evaluated 11 patients with bilateral lack of keratinized gingiva in mandibular premolars. The test side in each patient was prepared with Er,Cr:YSGG laser (3 W power, 300 mJ energy, 10 Hz frequency, long-pulsed mode), whereas the control side was prepared by surgical scalpel. All FGGs were harvested from the palate with standard dimensions of 14 × 9 mm. The graft width, length, surface area, and shrinkage and color match were measured after 1, 3, and 6 months. Postoperative complications, including pain and bleeding were also evaluated using a questionnaire. Results: In both groups, the surface area and width of graft significantly decreased at all time points compared with baseline but the difference in this respect was not significant between the two groups (p > 0.05). In both groups, maximum shrinkage occurred within the first 3 months. In control group, the surface shrinkage in 3 months was significantly greater than the first month (p = 0.025) without significant difference between groups (p = 0.79). The two groups were not significantly different regarding pain score and bleeding score either. On the day of surgery, the test group had slightly lower pain score and higher bleeding score in comparison to the control group without significant difference. The pain and bleeding scores reduced in both groups with no significant difference (p > 0.05). Conclusions: Er,Cr:YSGG laser has promising results for preparation of FGG recipient site and yields results comparable to those of surgical scalpel.

Removal of osseointegrated dental implants: a systematic review of explantation techniques

OBJECTIVES

This systematic review aims to evaluate current literature regarding available techniques for removal of osseointegrated implants in terms of explantation's success, complications, and bone loss.

MATERIAL AND METHODS

Two reviewers conducted a systematic literature search through electronic databases (PubMed and EMBASE), complimented by manual and grey literature searches. Successful explantation was defined as the primary outcome. Complications and availability of residual bone for immediate implantation were defined as secondary outcomes.

RESULTS

Eighteen articles, comprising 372 implants and 241 patients, were included. Five techniques were identified: reverse torque, trephines, burs, piezosurgery, and laser-assisted explantation. Peri-implantitis was the most common reason for explantation, followed by crestal bone loss, fracture, and malpositioning. The reverse torque was the most frequently reported technique (284 implants) with 87.7% success rate. Burs were used for explantation of 49 implants with a 100% success rate, while trephines were utilized for removal of 35 implants with 94% success. Piezosurgery (11 implants) and Er.Cr:YSGG laser (1 implant) showed 100% success. One study reported perforation of the sinus floor following trephine explantation, while another reported fracture of 3 implants following reverse torque application. Further analysis was hindered by the quality of the available studies and their lack of data.

CONCLUSIONS

Reverse torque seems the most conservative, and in the authors' opinion, should be the first choice for explantation despite its inferior success rate. Additional studies with randomized controlled designs and larger sample sizes are required.

CLINICAL RELEVANCE

Dental implants have become the leading choice to replace missing teeth with gradually increasing numbers of complications and failures. An effective, conservative, and economic explantation technique is necessary to allow a successive implant placement.

Effects of an Er,Cr:YSGG Laser on Bone Regeneration in Critical-Sized Calvarial Defects of Rats Exposed to Inhalation of Cigarette Smoke

Objective: To evaluate the effect of the Er,Cr:YSGG laser on healing of critical-sized calvarial defects (CSDs) in rats submitted to inhalation of cigarette smoke. Background: Smoking has been implicated with the delay in the bone healing after osteotomy procedures, then the use of the Er,Cr:YSGG laser for osteotomy in smokers could be an alternative to the conventional drills. Methods: One hundred animals were randomly allocated into four groups: trephine-the CSDs were made with a trephine drill in healthy rats; Er,Cr:YSGG-the CSDs were made with the Er,Cr:YSGG laser in healthy rats; Trephine-S-the CSDs were made with a trephine drill in rats exposed to cigarette smoke; and Er,Cr:YSGG-S-the CSDs were made with the Er,Cr:YSGG laser in rats exposed to cigarette smoke. The inhalation of cigarette smoke started 7 days before the surgical procedure until euthanasia (immediately, 7, 15, 30, or 60 days after the surgical procedure). A histometric analysis and a histological description were performed to evaluate (1) the residual linear lengths and bone formation in the CSDs; (2) the quality of bone healing. Results: The use of Er,Cr:YSGG laser induces more bone formation compared with the trephine in smokers; however, the closure of the CSD was only superior in the Er,Cr:YSGG-S group compared to the Trephine-S group at the 60-day period. Conclusions: The use of the Er,Cr:YSGG laser stimulated the bone repair process after osteotomy procedures in animals submitted to exposure of inhalation of cigarette smoke.

Evaluation of bone healing following Er:YAG laser ablation in rat calvaria compared with bur drilling

The Er:YAG laser is currently used for bone ablation. However, the effect of Er:YAG laser irradiation on bone healing remains unclear. The aim of this study was to investigate bone healing following ablation by laser irradiation as compared with bur drilling. Rat calvarial bone was ablated using Er:YAG laser or bur with water coolant. Er:YAG laser effectively ablated bone without major thermal changes. In vivo micro-computed tomography analysis revealed that laser irradiation showed significantly higher bone repair ratios than bur drilling. Scanning electron microscope analysis showed more fibrin deposition on laser-ablated bone surfaces. Microarray analysis followed by gene set enrichment analysis revealed that IL6/JAK/STAT3 signaling and inflammatory response gene sets were enriched in bur-drilled bone at 6 hours, whereas the E2F targets gene set was enriched in laser-irradiated bone. Additionally, Hspa1a and Dmp1 expressions were increased and Sost expression was decreased in laser-irradiated bone compared with bur-drilled bone. In granulation tissue formed after laser ablation, Alpl and Gblap expressions increased compared to bur-drilled site. Immunohistochemistry showed that osteocalcin-positive area was increased in the laser-ablated site. These results suggest that Er:YAG laser might accelerate early new bone formation with advantageous surface changes and cellular responses for wound healing, compared with bur-drilling.

Evaluation of temperature rise following the application of diode and ErCr:Ysgg lasers: an ex vivo study

Purpose

Erbium, chromium: yttrium, scandium, gallium, garnet (ErCr:Ysgg) lasers have been frequently used in oral surgical procedures and are almost seen as alternatives to diode lasers. The aim of this comparative study was to analyze in an animal model the thermal elevation induced by ErCr:Ysgg and diode lasers in soft tissue and bone.

Materials and methods

Thirty freshly dissected sheep mandibles containing bone and soft tissue were divided into 120 equal parts. Gallium-aluminum-arsenide (Ga-Al-As) diode laser (λ=940 nm) with 1, 2 and 5 W output powers and ErCr:Ysgg laser (λ=2780 nm) with 2.75, 4.5 and 6 W output powers were used on soft and bone tissues separately for 3 seconds with point application. Mean temperature values before and after application of the lasers were compared in soft tissue and bone.

Results

The minimum mean temperature value was observed with 2.75 W ErCr:Ysgg laser while irradiation with 5 W diode laser created the maximum values (p<0.05).

Conclusion

ErCr:Ysgg laser (λ=2780 nm) with 2.75 W power generates low levels of heat compared to diode lasers and may provide safer surgery in soft and bone tissues without destructive effects of temperature increase.

Laser-Assisted Osteotomy for Implant Site Preparation: A Literature Review

PURPOSE

The aim of this study was to review the scientific evidence about the laser osteotomy in implant bed preparation.

METHODS

An electronic search was performed on relevant English articles up to April 2016 in the PubMed, Scopus, and Google Scholar databases.

RESULTS

Twenty-two articles (1 clinical, 13 animal, and 8 ex vivo studies) were included. Implant sites prepared by erbium family lasers and drill showed comparable results regarding the percentage of bone-to-implant contact, values of biomechanical tests, and healing process. Selection of proper laser wavelength and parameters was of paramount importance to minimize the risk of thermal bone damage. Lack of depth control and long time needed for implant site osteotomy with laser were the most challenging concerns for its clinical applicability. Computer-guided laser osteotomy showed promise for future use of laser osteotomy in clinical settings.

CONCLUSION

Evidence from animal studies shows promising results regarding laser osteotomy in implant site preparation. However, because of the lack of clinical studies, it is not possible to make a conclusive result whether there is superiority of laser osteotomy in clinical practice.

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.

Effects on Bone Repair of Osteotomy With Drills or With Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet Laser: Histomorphometric and Immunohistochemical Study

BACKGROUND

The erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser has been widely used in the dental clinic; however, few studies have demonstrated the advantages of the use of this laser for bone osteotomies. The purpose of this study is to evaluate and compare the bone repair process of defects generated by the Er,Cr:YSGG laser or conventional drills.

METHODS

Ninety-six rats were divided into two groups of 48 animals (drill group and laser group). After surgical exposure of the right tibia, the animals were subjected to a 2-mm-diameter osteotomy created by conventional drills (drill group) or by the Er,Cr:YSGG laser (laser group). The animals were sacrificed 0, 3, 7, 14, 30, and 60 days after the creation of the defect, and histologic sections were obtained and used for histomorphometric and immunohistochemical analyses for the detection of osteocalcin, osteoprotegerin, receptor activator of nuclear factor κ-B ligand, vascular endothelial growth factor, and caspase-3.

RESULTS

The osteotomy with the drill produced well-delimited and smooth walls, whereas the osteotomies in the laser group were irregular and presented an amorphous basophilic line and bone necrosis that was slowly resorbed during the repair process. Despite these characteristics, bone repair was similar between groups at various time points, and, at 60 days, the defects in both groups were completely repaired by newly formed bone.

CONCLUSION

The repair process of osteotomies created by the Er,Cr:YSGG laser, despite producing thermal damage to bone tissue, is comparable to that with conventional drills.

Effect of Er,Cr:YSGG laser application in the treatment of experimental periodontitis

The purpose of this study was to evaluate the influence of an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in the absence or presence of manual scaling and root planning (SRP) for the treatment of induced periodontitis in rats. Ligatures were placed in the subgingival region of the maxillary first molar. After a 7-day period, the ligatures were removed, and 40 rats were randomly divided into four groups (G), as follows: (GI) no treatment, (GII) scaling and root planning (SRP) with curettes, (GIII) Er,Cr:YSGG laser irradiation and (GIV) SRP with curettes followed by Er,Cr:YSGG laser irradiation. Seven and 30 days after the treatment, the animals were sacrificed and histologic, histometric and immunohistochemistry analyses were performed. All groups showed similar histopathological characteristics during the evaluation period. The histometric analysis was confirmed using Bonferroni and paired t tests. At 7 and 30 days, groups II, III and IV exhibited greater bone formation in the furcation area when compared to group I (p < 0.0001; p < 0.05). During the 7-day period, the groups irradiated with the laser (III and IV) showed a statistically larger new bone area than the group treated with SRP (II) (p < 0.01). Immunohistochemistry analysis revealed that the control group exhibited a higher expression of tartrate-resistant acid phosphatase (TRAP) and the receptor activator of nuclear factor κΒ ligand (RANKL) when compared to groups II, III and IV (p < 0.05). All treatments were able to reduce the inflammatory processes, consequently enabling the repair of periodontal tissues. The results achieved with the application of the Er,Cr:YSGG laser suggest that this laser can stimulate greater bone formation, especially over a shorter period of time.