Morphological changes of bovine mandibular bone irradiated by Er,Cr:YSGG laser: an in vitro study

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.

Efficacy of Er,Cr Laser incision Corticotomy in Rapid Maxillary Canine Retraction: A Split-Mouth Randomized Clinical Trial

Introduction: This study sought to evaluate the efficacy of lasercision corticotomy for the acceleration of canine movement. Our secondary objectives were assessing the canine rotation, the rate of anchorage control, the level of pain, and the gingival index (GI). Methods: Twelve orthodontic patients (9 females and 3 males) referring to the School of Dentistry and one dental clinic from May 2019 to September 2019 participated in this split-mouth randomized clinical trial. The allocation of the test and control sides was performed by flipping a coin. The mean age of patients was 18.91±3.87 years (range 15-30 years). The treatment plan included maxillary first premolar extraction. Following the initial leveling and alignment phase, an initial impression was made. Corticotomy was carried out with the erbium, chromium-doped yttrium scandium gallium garnet (Er, Cr: YSGG) laser (3.5 W, 30 Hz, 40% air, 80% water) in one maxillary quadrant (the laser side). Canine retraction was immediately initiated following surgery using nickel-titanium closed-coil springs with 150 g force. The impression was repeated 1 month after the onset of retraction. The casts were scanned, and the distance between the canine cusp tip and the rugae line was measured to quantify the amount of anteroposterior canine movement. The molar anchorage control was also evaluated by measuring the distance between the mesial contact of the permanent first molar and the rugae line. Gingival health was evaluated using the GI. The modified McGill pain questionnaire was used to assess the level of patients' pain. Results: Lasercision corticotomy accelerated canine retraction with no adverse effect on gingival health. Anchorage loss in the posterior teeth and pain scores were not significantly different between the control and laser sides. Conclusion: Laser corticotomy can effectively accelerate canine retraction with no complications or discomfort for the patients.

Treatment outcomes of laser therapy in oral submucous fibrosis-a systematic review

Background

The mainstay of oral submucous fibrosis (OSF) management is to increase the mouth opening; thereby improving oral functionalities. In modernized dentistry, laser therapy (LT) could play a major role for trismus relief in OSF patients. The present review was performed to systematically analyze the published literature on LT for OSF management.

Methods

PubMed, Scopus, Web of Science and CINAHL databases were searched until June 2019 using suitable key words and the information was extracted according to the PRISMA guidelines. All full text papers that assessed efficacy of LT for OSF management without limitations on age, gender, ethnicity, or socioeconomic status of the participants were considered eligible. Participants were allocated to the LT alone or in adjunct to oral physiotherapy and medicinal treatment. Outcome parameters included the reduction in trismus. Review articles, case reports, editorial, conference abstracts and in vitro studies were excluded. No restriction was applied on date and language of the publications.

Results

Out of 97 published papers, 7 studies met the inclusion criteria and were included for the analysis. All the studies were clinical and mainly included stage II and III OSF patients. Although different laser types and other parameters were used, all the studies reported improvement in mouth opening in the range of 6.84 mm and 23.7 mm. Additionally, two studies noticed reduced burning sensation and increased tongue protrusion and cheek flexibility. Conclusion: The LT can provide a promising and better means for relieving trismus and probably OSF-related other symptoms in moderate stages of the disease.

Clinical comparison of the use of ER,CR:YSGG and diode lasers in second stage implants surgery

OBJECTIVES

To compare the effects of diode and erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers in second-stage implant surgery applications.

METHODS

This is a cross-sectional study that was carried out on patients who received implant treatment at the Departments of Oral and Maxillofacial Surgery and Periodontology, Van Yuzuncu Yil University, Van, Turkey between January 2017 and January 2018. Implants of the patients in the first group (n=20) were exposed with 940 nm Ga-Al-As diode laser while the implants of the second group (n=20) were uncovered with 2780 nm Er,Cr:YSGG laser in the second-stage surgery. Visual analogue scale (VAS) values during day 0 and following the operation on days 1, 2, 3 intraoperative bleeding grades, number of analgesics used in the postoperative period, operation time per implant, and postoperative complications were recorded.

RESULTS

When gender, smoking, the presence of systemic disease, toothbrushing frequency, analgesic use, bleeding and complications observed at the control session were analyzed, no statistically significant relationship was found between the 2 groups. It was observed that males had statistically significant higher VAS values than females (p less than 0.05).

CONCLUSION

Since diode lasers are more economical, smaller, and can meet the clinical needs of clinicians, it is likely that these lasers may be the preferred choice of the clinicians in surgical procedures.

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.

Comparison of the Effects of Er, Cr: YSGG Laser and Super-Saturated Citric Acid on the Debridement of Contaminated Implant Surfaces

Introduction: Several techniques such as using citric acid, plastic curettes, ultrasonic devices, and lasers have been suggested for debridement of contaminated implant surfaces. This comparative investigation aimed to assess and compare the effects of Er, Cr: YSGG laser and super-saturated citric acid on the debridement of contaminated dental implant surfaces. Methods: In this in-vitro study, 12 contaminated failed implants were collected and randomly divided into 2 groups (6 in group A, and 6 in group B). Also, one implant was considered as the control. The implants were horizontally sectioned into coronal and apical portions and subsequently irradiated by Er, Cr: YSGG laser in coronal and citric acid in apical in group A and the opposite in group B. In order to evaluate the effect of water spray on the laser section, half the laser portion of the implants was irradiated using water, while the other half was irradiated without water with an irradiation time of 1 minute. Results: Results revealed that calculus and plaque removal was greater in the laser part of both groups (with and without water) compared to citric acid parts and the correlation between calculus removal and surface roughness were statistically significant. Furthermore, the surface roughness in the citric acid parts was significantly higher than in laser parts. Water spray during irradiation had a very small influence on understudy factors. Conclusion: Based on the results of this study, the Er, Cr: YSGG laser was more effective in calculus removal and caused less surface roughness compared with citric acid application.

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.

Ablation of porcine bone tissue with an ultrashort pulsed laser (USPL) system

Ultrashort pulsed lasers (USPLs) represent a new generation of laser systems in the field of biophotonical applications. In terms of a pilot project, the study was carried out to evaluate the ablation parameters of bone tissue regarding the medical use of such a laser technology in dentistry. Specimens from ribs of freshly slaughtered pigs were assembled and irradiated with an USP Nd:YVO4 laser (pulse duration 8 ps at 1,064 nm with repetition rates between 50 and 500 kHz) using eligible average output powers in the range of 3.5-9 W and fluences between 1 and 2.5 J/cm(2). Square-shaped cavities of 1-mm edge length in the bone compacta were created employing a scanner system. Cavities were analyzed with an optical profilometer to determine the ablated volume. Ablation rate was calculated by the ablated volume and the recorded irradiation time by the scanner software. Additionally, samples were examined histologically to investigate side effects of the surrounding tissue. Formed cavities showed a precise and sharp-edged appearance in bone compacta. Optimized ablation rate of 5.2 mm(3)/min without any accompanying side effects was obtained with an average output power of 9 W, a pulse repetition rate of 500 kHz, and an applied fluence of 2.5 J/cm(2). Provided that the used laser system will be advanced and adjusted for clinical applications, the outcome of this study shows auspicious possibilities for the use of USPL systems in the preparation of bone tissue.

The Efficacy of ErCr:YSGG Laser Fibrotomy in Management of Moderate Oral Submucous Fibrosis: A Preliminary Study

INTRODUCTION

Oral submucous fibrosis (OSMF) is a chronic insidious disease mainly associated with fibroelastic change of the oral mucous membrane, leading to progressive trismus and oral burning sensation. The management of OSMF is empirical, depends on staging of the condition and is combination of conservative/medical/surgical interventions. Management of moderate OSMF is more challenging as conservative and medical treatments are not effective while surgical techniques involving fibrotomy and reconstruction of resultant defect are excessive. Lasers can provide an alternative and better means for surgical fibrotomy in moderate OSMF as they are minimally invasive and have the advantage of short operating time, less hemorrhage, faster healing, less morbidity, less surgical-site scarring and relapse. Laser fibrotomy in moderate OSMF have been done under general anesthesia.

MATERIALS AND METHODS

A case series of 16 cases of moderate OSMF treated with Erbium Chromium Yttrium Scandium Gallium Garnet (ErCr:YSGG) laser fibrotomy under local anesthesia in combination with cessation of habits, topical steroids, lycopene and oral physiotherapy is presented.

RESULTS

The mean increase in mouth opening achieved at 1 year was 17.5 mm. The mean difference in the preoperative and 1 year mouth opening was found to be statistically significant. The mean difference in the preoperative and six-month Visual Analogue Scale scores for oral burning sensation and Oral Health Impact Profile-14 scores for assessment of oral health-related quality of life was statistically significant implying improvement.

CONCLUSIONS

ErCr:YSGG laser fibrotomy under local anesthesia is a minimally invasive, cost effective, chair-side procedure and an useful adjunct in management of moderate OSMF.

Soft and hard tissue management using lasers in esthetic restoration

Laser technology has become preeminent in the evolution of appearance enhancements. Dentistry has seen a huge breakthrough with the introduction of a combination hard-soft tissue erbium wavelength. The conservative nature of this technique has created a firm footing in the antiaging trend that is spanning the globe. Among the many benefits of this technique are less invasive care and quicker healing responses. In this article, conservative laser and cosmetic modalities are discussed that allows a clinician to be more comfortable in buying a soft/hard tissue laser and also to more quickly become adept with implementing these techniques.

Immediate Implant Placement Into Infected Sites: Bacterial Studies of the Hydroacoustic Effects of the YSGG Laser

This article describes the use of an erbium laser to use photoacoustics to reduce the bacteria in osteotomy sites that were infected by apical pathology. The author shows reduced bacterial counts by performing bacterial cultures following laser treatment. Swabs were taken after the extraction of the tooth and then after the laser was placed into the osteotomy site. The results showed a noticeable reduction of bacteria and no traces of virulent bacteria.

Platelet Derived Growth Factor Secretion and Bone Healing After Er:YAG Laser Bone Irradiation

Er:YAG laser irradiation has been reported to enhance wound healing. However, no studies have evaluated the synthesis of growth factors after laser irradiation. The present study investigated the effects of laser irradiation on the amount of secretion of platelet derived growth factor (PDGF) in the wound, clarifying the effects of the Er:YAG laser on the bone healing. Osteotomies were prepared in the tibiae of 28 rats using an Er:YAG laser (test group). Maximum power of 8 watts, energy per pulse of 700 mJ, and frequency up to 50 Hz were used. The laser was used with external water irrigation, a spot size of 2 mm, energy per pulse of 500 to 1000 mJ/pulse, and energy density of 32 J/cm2. Twenty eight additional rats served as a control group and their osteotomies were prepared with a drill 1.3 mm in diameter at 1000 rpm, with simultaneous saline irrigation. Two rats from the tested group and 2 from the control group were sacrificed on each day following surgery (1–14 days), and the tissue specimens were prepared for histologic evaluation. Immunohistochemical staining with anti-PDGF was performed after histologic examination. The difference between the PDGF staining intensities of the 2 treatment groups was analyzed using a multivariate logistic regression test. A significant rise in PDGF staining occurred in both groups 2–3 days following surgery. However, while high PDGF counts remained for the 2-week experimental period in the laser group, PDGF levels in the control group returned to baseline levels 8 days post surgery. The 2 groups (laser and control) were found to be different throughout the experiment, and the rat type was found to be a significant predictor (P  =  .000011). The present study demonstrated that Er:YAG laser irradiation seems to stimulate the secretion of PDGF in osteotomy sites in a rat model. It is possible that the high levels of PDGF are part of the mechanism that Er:YAG irradiation enhances and improves the healing of osteotomy sites.

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

PURPOSE

The aim of this study was to investigate a comparison of implant bone bed preparation with Er,Cr:YSGG laser and conventional drills on the relationship between implant stability quotient (ISQ) values and implant insertion variables.

MATERIALS AND METHODS

Forty implants were inserted into two different types of pig rib bone. One group was prepared with conventional drills and a total of 20 implants were inserted into type I and type II bone. The other group was prepared with a Er,Cr:YSGG laser and a total of 20 implants were inserted into type I and type II bone. ISQ, maximum insertion torque, angular momentum, and insertion torque energy values were measured.

RESULTS

The mean values for variables were significantly higher in type I bone than in type II bone (P < .01). In type I bone, the ISQ values in the drill group were significantly higher than in the laser group (P < .05). In type II bone, the ISQ values in the laser group were significantly higher than in the drill group (P < .01). In both type I and type II bone, the maximum insertion torque, total energy, and total angular momentum values between the drill and laser groups did not differ significantly (P ≥ .05). The ISQ values were correlated with maximum insertion torque (P < .01, r = .731), total energy (P < .01, r = .696), and angular momentum (P < .01, r = .696).

CONCLUSION

Within the limitations of this study, the effects of bone bed preparation with Er,Cr:YSGG laser on the relationship between implant stability quotient (ISQ) values and implant insertion variables were comparable to those of drilling.

Different air-water spray regulations affect the healing of Er,Cr:YSGG laser incisions

Surgeries performed with high-intensity laser devices may be improved with accurate protocols, including the air-water spray regulation. Thus, this study sought to investigate the healing process of wounds made on the dorsum of rat tongues using an Er,Cr:YSGG laser device with different air-water spray regulations. The incisions were made on the dorsum of Wistar rat tongues using an Er,Cr:YSGG laser with three different air-water spray regulations (100/0%, 50/50%, 11/7%). Scalpel incisions functioned as controls. The sacrifices occurred between 0 and 14 days after surgery. Morphological, histological, and immunohistochemical (fibronectin and type III collagen) analysis of the wounds were performed. The air-water spray regulation influenced wound healing and the inflammatory response, especially in the earlier stages. Incisions performed using the 100/0% air/water spray regulation had the worst results, expressing a greater amount of fibronectin and type III collagen. The 50/50% air/water spray regulation brought in a non-clear surgical field and poor laser interaction with the tissue. The 11/7% air/water spray regulation showed the best clinical results and less pronounced histological events. According to the results encountered, the air-water spray should be regulated to improve surgery.

The use of laser technology (Er;Cr:YSGG) and stereolithography to aid in the placement of a subperiosteal implant: case study

The use of laser technology has helped this clinician to provide treatment with less postoperative pain and increased healing. The subperiosteal implant is a modality that has been used for several decades, although its popularity has declined in favor of endosseous dental implants. In some instances, however, it remains the treatment of choice, specifically in the atrophic mandible (where placement of endosseous implants is not possible) or when placement would increase the chances of jaw fracture. This article reports the case of a patient rehabilitated using a simplified surgical protocol involving laser surgery and stereolithography.

Surgical lasers and hard dental tissue

The cutting of dental hard tissue during restorative procedures presents considerable demands on the ability to selectively remove diseased carious tissue, obtain outline and retention form and maintain the integrity of supporting tooth tissue without structural weakening. In addition, the requirement to preserve healthy tissue and prevent further breakdown of the restoration places the choice of instrumentation and clinical technique as prime factors for the dental surgeon. The quest for an alternative treatment modality to the conventional dental turbine has been, essentially, patient-driven and has led to the development of various mechanical and chemical devices. The review of the literature has endorsed the beneficial effects of current laser machines. However utopian, there is additional evidence to support the development of ultra-short (nano- and femto-second) pulsed lasers that are stable in use and commercially viable, to deliver more efficient hard tissue ablation with less risk of collateral thermal damage. This paper explores the interaction of laser energy with dental hard tissues and bone and the integration of current laser wavelengths into restorative and surgical dentistry.

Effect of a Novel Er:YAG Laser in Caries Removal and Cavity Preparation: A Clinical Observation

OBJECTIVE

We evaluated the applicability of a novel Er:YAG laser under clinical conditions.

BACKGROUND DATA

The Er:YAG laser has been demonstrated to be a safe and effective alternative to the conventional turbine bur, but the relatively low cutting speed prevented the wide application of Er:YAG laser in clinical cavity preparation.

METHODS

A Smart 2940 D laser developed by Deka Corporation was used for cavity preparation in 95 teeth of 45 patients. Parameters were as follows: wavelength 2.94 microm, pulse energy 700 mJ, repetition rate 8 Hz. Pain, discomfort, assessment during cavity preparation, prognosis factor, and overall clinical evaluation were assessed during or after treatment.

RESULTS

No adverse reaction was observed in any tooth. No intraoperative pain or only slight intraoperative pain was described in 85 teeth (89.5%). Cavity preparation was completed with the laser system alone in 90 teeth (94.7%). Overall clinical evaluation showed no safety problems, with a very good or good rating in 86 teeth (90.5%). The overall operation time was 49 sec on average.

CONCLUSION

The Smart 2940 D is an efficient, effective, safe, and suitable instrument for caries removal and for cavity preparation. It greatly shortens operation time.

Er:YAG laser osteotomy for removal of impacted teeth: Clinical comparison of two techniques

BACKGROUND AND OBJECTIVES

In contrast to many techniques currently employed for osteotomy, like saws, drills or modulated ultrasound, lasers offer non-contact and low-vibration bone cutting. Therefore, this report examines the benefits to laser osteotomy in oral surgery using two different short-pulsed Er:YAG laser systems.

MATERIALS AND METHODS

Er:YAG lasers, using either a fiber-optic delivery system and an articulated arm delivery system, were used to remove impacted teeth in 30 patients. In 15 patients an Er:YAG laser utilizing a fiber-optic delivery system was applied for cutting bone, with a pulse energy of 500 mJ, a pulse duration of 250 microseconds and frequency of 12 Hz (energy density 177 J/cm(2)). The other 15 patients were treated with an Er:YAG laser utilizing an articulated arm delivery system, with a pulse energy of 1,000 mJ, a pulse duration of 300 microseconds and a frequency of 12 Hz (energy density 157 J/cm(2)).

RESULTS

In all cases the lasers allowed precise bone ablation without any visible, negative, thermal side-effects. Since the laser tip was used in a non-contact mode and could be positioned freely, unrestricted cut geometries were feasible. Adjacent soft tissue structures could be preserved and were not harmed by the laser beam. However, osteotomies were time consuming, especially if teeth had to be separated. The level of water irrigation limited the use of the laser. In 20% of the cases in which the articulated arm delivery laser was used to section teeth, it was necessary to use a conventional dental drill to finish the procedure.

CONCLUSION

This bone ablation technique, using short Er:YAG laser pulses and water spray, produced good clinical results without any impairment to wound healing. However, for now, the lack of depth control and the time required to perform the necessary osteotomy limit routine clinical application.

In vivo study of the healing processes that occur in the jaws of rabbits following perforation by an Er,Cr:YSGG laser

This study investigates the healing process that takes place in the bone and soft tissue of the maxilla and the mandible after perforation by an Er,Cr:YSGG laser device. The jaws of New Zealand white rabbits were irradiated with an Er,Cr:YSGG laser, forming wounds 0.4 mm in diameter. Irradiation parameters were as follows: repetition rate was 20 pulse/s, pulse duration was 140-200 micros, power was 2 W, exposure time was 10 s, energy density was 80 J/cm(2). After sacrifice at 0-56 days post-surgery, gross observations and histological examinations were performed. Effective hemostasis was achieved after Er,Cr:YSGG laser surgery. There was a minimal delay before the healing began. After 56 days all of the bone defects had been completely replaced by new bone. In conclusion, the Er,Cr:YSGG laser allows precise surgical ablation with minimal thermal damage to adjacent tissues in vivo. The overall subsequent healing was favorable. This laser may potentially be used in minor oral surgery.

Erbium lasers in dentistry

Erbium hard tissue lasers have the capability to prepare enamel, dentin, caries, cementum, and bone in addition to cutting soft tissue. The ability of hard tissue lasers to reduce or eliminate vibrations, the audible whine of drills, microfractures, and some of the discomfort that many patients fear and commonly associate with high-speed handpieces is impressive. In addition, these lasers can be used with a reduced amount of local anesthetic for many procedures. Today, these instruments have evolved from their initial use for all classes of cavity preparations to their ability for removing soft tissue, their usefulness in the disinfection of bacteria within endodontic canals, and most recently, as an alternative to the high speed handpiece for the removal of bone in oral and maxillofacial surgery. In addition, recent research has centered on the value of the erbium family of laser wavelengths in periodontics, including the removal of calculus.

Lasers in dentistry

BACKGROUND

During the last two decades, much has been written in both the scientific literature and the popular press about lasers and their use in the dental office. Both soft- and hard-tissue applications have been discussed, including frenectomy, gingival contouring, caries removal and bleaching.

OVERVIEW

Almost one-third of patients surveyed by the American Dental Association in the late 1990s thought it was very important that their dentists have lasers, which could put pressure on dentists to invest in this tool to attract patients. The authors describe the different types of dental lasers and examine the science behind their applications in dentistry.

CONCLUSION AND CLINICAL IMPLICATIONS

Although lasers do have legitimate uses in dentistry, they do not take the place of any of the more conventional tools in the dentist's armamentarium. Before investing in a laser, dentists should fully understand the differences between the various types, including what the scientific literature says about their applications.