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Objective: The aim of this study was to perform a systematic and multifaceted comparison of thermal effects during soft tissue ablation with various lasers and an electroscalpel (ES). Materials and methods: Er:YAG, Er,Cr:YSGG, CO 2 , Diode, Nd:YAG lasers (1 W, pulsed or continuous wave), an ES, and a scalpel (Sc; control), were employed for porcine gingival tissue ablation. Temperature changes during ablation were measured by using an infrared thermal imaging camera and a thermocouple. After ablations, the wounds were observed using stereomicroscopy and scanning electron microscopy (SEM), and histological sections were analyzed. Compositional analysis was also performed on ablated sites by SEM wavelength dispersive X-ray spectroscopy. Results: The surface temperature during irradiation was highest with CO 2 (over 500°C), followed by Diode (267°C) and Nd:YAG (258°C), Er:YAG (164°C), ES (135°C), and Er,Cr:YSGG (85°C). Carbonization was negligible (Er:YAG), slight (Er,Cr:YSGG), moderate (Nd:YAG and ES), and severe (CO 2 and Diode). Under SEM observation, Er:YAG and Er,Cr:YSGG showed smooth surfaces but other devices resulted in rough appearances. Histologically, the coagulated and thermally affected layer was extremely minimal (38 μm in thickness) and free from epithelial collapse for Er:YAG. Compared with other devices, less compositional surface change was detected with Er:YAG and Er,Cr:YSGG; additionally, the use of water spray further minimized thermal influence. Conclusions: Among various power devices, Er:YAG laser showed the most efficient and refined gingival ablation with minimal thermal influence on the surrounding tissues. Er:YAG and Er,Cr:YSGG lasers with water spray could be considered as minimally invasive power devices for soft tissue surgery.

Objective: To compare the 6-month clinical efficacy of Er:YAG laser and standard scalpel technique in treating gingival hyperpigmentation., Method and Materials: Patients requesting treatment for moderate to severe gingival hyperpigmentation in the maxilla were enrolled in this split-mouth study. The contralateral maxillary sides were randomly assigned to receive either Er:YAG laser (continuous wavelength of 2,940 nm) with a noncontact tip or the standard scalpel technique. Dummett oral pigmentation index (DOPI) and Hedin melanin index (HMI) were compared at the baseline and at 1 and 2 weeks, and 1, 3, and 6 months following the treatment. Bleeding Index, total treatment time, patient preference, pain perception at the first 3 days, wound healing, and level of satisfaction were also compared. Mann-Whitney test, Kruskal-Wallis test, and chi-square test were used to test the significance between variables. A P value of less than or equal to .05 was considered statistically significant., Results: Of the 22 patients enrolled, 20 completed this study. After assessing DOPI and HMI at 1 and 2 weeks, and at 1-, 3-, and 6-month follow-up appointments, both Er:YAG laser and scalpel were significantly effective in treating gingival hyperpigmentation when compared to baseline (P < .001) but with no statistically significant difference between the two treatment methods (P > .05). More patients preferred the scalpel technique as it was associated with slightly shorter treatment time and less postoperative pain when compared to Er:YAG laser, but with no statistical significance (P > .05). Er:YAG laser sites showed minimal bleeding and more rapid wound healing (P < .001)., Conclusion: Both Er:YAG laser and scalpel technique achieved similar outcomes regarding the efficacy of gingival depigmentation, postoperative pain perception, and the time required for the treatment. Laser therapy requires more advanced technology and is associated with higher financial costs. Therefore, the scalpel technique is still considered the gold standard treatment for gingival depigmentation.

Background: Oral pigmentation, especially in the gingiva poses esthetic problems. Laser therapy has been widely used for cosmetic therapy in dentistry. The aim of the present study was to systematically review the efficacy of surgical laser therapy (SLT) in the management of oral pigmented lesions (OPL)., Materials and Methods: The addressed focused question was "Is SLT effective in the management of OPL?" Databases (MEDLINE via PubMed; EMBASE; Cochrane Central Register of Controlled Trials and Cochrane Oral Health Group Trials Register databases) were searched from 1970 up to and including February 2017., Results: Ten studies were included. The reported number of OPL ranged between 8 and 140. Oral pigmented sites included, gingiva, buccal and labial mucosa, alveolar mucosa and lips. Lasers used in the studies included Q-switched alexandrite, Neodymium-doped yttrium aluminium garnet, diode, Erbium: yttrium aluminium garnet and carbon dioxide laser. Laser wavelength, power output and number of irradiations were 635-10,600nm, 1-10W and 1 to 9 times, respectively. The follow up period ranged from 6 to 24months. All studies reported SLT to be effective in the treatment of OPL. In five studies, recurrence of OPL occurred which ranged from 21.4% to 45%., Conclusions: Lasers are effective in the management of OPL including physiologic gingival pigmentation, smokers' melanosis and pigmentation in Laugier-Hunziker syndrome. Different laser types (CO 2, Er:YAG and Diode) showed comparable outcomes in the treatment of OPL., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Though the Er:YAG laser (ErL) has been used in periodontal therapy, the irradiated tip damage has not been studied in detail. In this study, the change in the energy output, surface morphology, and temperature of quartz tips was evaluated following contact irradiation. Soft tissue, calculus on extracted human teeth, and porcine bone were irradiated by ErL for 60 min at 14.2 or 28.3 J/cm(2)/pulse and 20 Hz with or without water spray. The energy output ratio declined the most in the calculus group, followed by the bone and soft tissue groups with and/or without water spray. Carbon contamination was detected in all groups, and contamination by P, Ca, and/or other inorganic elements was observed in the calculus and bone groups. The rate of energy output reduction and the degree of surface alteration/contamination is variously influenced by the targeting tissue, temperature elevation of the tip and water spray.

The erbium-doped yttrium aluminum garnet (Er:YAG) laser is currently used for periodontal soft tissue management with favorable outcomes. However, the process of wound healing after Er:YAG laser (ErL) treatment has not been fully elucidated yet. The aim of this study was to investigate the gingival tissue healing after ErL ablation in comparison with that after electrosurgery (ElS). Gingival defects were created in 28 rats by ablation with ErL irradiation or ElS. The chronological changes in wound healing were evaluated using histological, histometrical, and immunohistochemical analyses. The ErL-ablated gingival tissue revealed much less thermal damage, compared to the ElS. In the ElS sites, the postoperative tissue destruction continued due to thermal damage, while in the ErL sites, tissue degradation was limited and the defects were re-epithelialized early. Heat shock protein (Hsp) 72/73 expression was detected abundantly remote from the wound in the ElS, whereas it was slightly observed in close proximity to the wound in the ErL sites. Hsp47 expression was observed in the entire connective tissue early in the wound healing and was found limited in the wound area later. This phenomenon proceeded faster in the ErL sites than in the ElS sites. Expression of proliferating cell nuclear antigen (PCNA) persisted in the epithelial tissue for a longer period in the ElS than that in the ErL. The ErL results in faster and more favorable gingival wound healing compared to the ElS, suggesting that the ErL is a safe and suitable tool for periodontal soft tissue management.

Esthetics is an important factor for patients seeking orthodontic treatment, and not always is the orthodontist able to make adjustments on the gingival contour, and this aspect is neglected. Many orthodontists are familiar with the name laser. However, there is a lack of information regarding their application on the orthodontic practice. There are several options for the use of CO(2) lasers on surgical procedures of interest to orthodontists, especially on soft tissues. There is no evidence that the use of the CO(2) laser has any side effect or contraindication on surgical procedures. This paper reports a series of surgical procedures carried out on orthodontic patients. It is concluded that the carbon dioxide laser not only allows surgeons to enhance current surgical options for treatment but also have contributed to the evolution of a variety of new procedures that are now commonplace in oral surgery, and its use shows several benefits for the orthodontic patient.

Background: Previous scanning electron microscopy (SEM) studies using extracted teeth have shown the potential of infrared Er:YAG laser radiation to remove subgingival calculus without causing severe thermal changes, e.g., charring or fusion, to the irradiated root surface. The purpose of the present study was to examine the morphologic changes on root surfaces following Er:YAG laser irradiation in situ using histological observation., Methods: The periodontal pockets of 6 premolars, canines, and incisors that remained in situ in the jaws of human corpses were irradiated with Er:YAG laser radiation at 60 mJ, 100 mJ, or 180 mJ. The pockets were treated in a similar manner to normal clinical circumstances with a total amount of either 50 or 100 laser pulses. Following laser treatment, the entire tooth, marginal gingiva, and underlying alveolar bone were removed from the jaw. The sections were embedded in methyl-methacrylate, serially cross-sectioned, stained with hematoxylin and eosin or gallamine blue, and examined under a light microscope. Additionally, the extension of the thermally changed tissue areas was determined using digital images and histometry., Results: The histological examination revealed two kinds of thermal changes within the laser-treated root surface. Firstly, a thin superficial layer 5 to 10 microm in width was observed. The surface of this layer showed ultrastructural irregularities. Secondly, a semicircular more deeply stained area close to the apical end of the scaling track beneath the irradiated cementum was observed. The depth of this area ranged from 255 microm to 611 microm and appeared to be independent of the radiation energy., Conclusion: In contrast to previous SEM studies, the histological examination indicated thermal changes within the hard tissue bordering the periodontal pocket following Er:YAG laser irradiation.

Objective: The aim of this study is to evaluate gingival collagen for the effect of treatment with the Erbium:YAG Kesler handpiece. The handpiece is designed for gingival resurfacing in cases of hypertrophic gingiva and gingival pigmentation., Background Data: Lasers represent recent technological advances that afford new options for the treatment of periodontal diseases. However, lasers used for esthetic gingival soft tissue resurfacing require careful histopathological evaluation of the effects on tissue. In particular, it is important to determine the effect of laser irradiation on connective tissue, especially the collagen fibers. To date, no stage-wise clinical or histological studies have been performed addressing this issue., Methods: Ten patients underwent irradiation with the following parameters: energy per pulse, 500 mJ; repetition rate, 10 pps; spot size, 3 mm. Gingival biopsy specimens were derived from 6 patients with hypertrophic gingiva and 4 with gingival pigmentation. The patients were examined before laser treatment and at 7 and 14 days after laser treatment. The tissues were fixed in tymph node revealing solution (LNRS), embedded in paraffin, sectioned at 5 microm, and stained with hematoxylin & eosin. The status of collagen in the treatment site was examined under polarized light after picrosirius red (PSR) staining. PSR is a collagen stain that differentiates collagen fiber density or size by means of a spectrum of color changes under polarized light. The major colors are red, orange, yellow, and green., Results: We found a significant difference in the properties of collagen fibers at the first week and at 14 days post-treatment. In the normal gingiva, the predominant polarization colors were in the red-orange range, signifying tightly packed, mature collagen. During the first postoperative week, collagen fibers exhibited polarization colors in the green to green-yellow range, implying loosely packed collagen fibers. After 2 weeks, collagen fibers reacquired their preoperative PSR characteristics., Conclusions: We conclude that sequential series of changes accompany photothermal treatment of the gingiva. The occurrence of this sequence in all successful outcome cases may suggest the importance of these temporally sequenced changes in collagen during gum healing. In any event, the status of PSR staining of gum collagen provides a useful adjunct in the assessment of gingival health.

Fifty-eight extraction patients had one of two gingival flap incisions lased with a 1.4 mw helium-neon (670 nm) diode laser for 30 seconds (fluence = 0.34 J/cm2). Healing rates were evaluated clinically and photographically. Sixty-nine percent of the irradiated incisions healed faster than the control incisions. No significant difference in healing was noted when patients were compared by age, gender, race, and anatomic location of the incision. This study concludes that helium-neon diode lasers, at the previously mentioned energy level, increase the rate of gingival wound healing in 69 percent of patients, without any side effects. For the last 30 years, low-power lasers in dentistry have appeared to stimulate healing rates and increase the rate of repair of injured tissue. Helium-neon and similar lasers emit light in the red (600-700 nm) spectrums and produce energy densities (fluences) below 20 Joules/cm2. They have been studied in a variety of animal tissue culture and human evaluations to determine their ability to increase the rates of wound healing by biostimulation. Over the last three decades, researchers have found that ruby and gas helium-neon (low-power laser radiation) have a biostimulatory effect on living tissue. Studies show that under specific conditions, red spectrum laser light speeds the healing of wounds. Photons from the red light lasers, which include ruby lasers (694 nm), helium-neon gas lasers (632 nm), and helium-neon diode lasers (650-670 nm), appear to stimulate rapid epithelialization and fibroblast (collagen) proliferation in animal and human tissue cultures. Low-power lasers have been reported to reduce post-extraction pain and swelling and to increase rates of wound healing (including scar formation, phagocytosis) in cell culture, animal, and human clinical studies. The new, compact, and inexpensive (under $50) helium-neon diode lasers have produced similar effects. These FDA Class IIIa lasers have no hazards associated with them, although one should avoid direct exposure to the eye for a prolonged period of time. In the past, many biostimulation studies using red spectrum lasers produced confusing data and conflicting results. Some studies reported that the biostimulation effect did not occur in all cases of laser irradiation, while other research reported that it did. Results seem to depend on the delivery of appropriate energy fluence levels (between 1 and 20 J/cm2) and the type of laser (wavelength) used. Several of these studies never described the levels of laser energy used to promote the described biostimulatory results. This caused controversy when determining whether or not helium-neon lasers influence wound healing. Studies suggest that low-power laser exposure can significantly increase the healing rate during the first few days of the healing process; however, studies do not show appreciable net benefit as compared to controls toward the end of a two-week wound repair cycle. The increased healing effect appears to be centered around the early, most sensitive stages of the healing process. Several studies showed optimum tissue healing rates at helium-neon laser exposure levels between 1 J/cm2 and 20 J/cm2. Laser-enhanced biostimulation has been reported to produce metabolic changes within the cells. This results in faster cell division, rapid matrix production (increased collagen, myofibroblasts, etc.), and cell movement. There have been few controlled studies using adequate numbers of human subjects in identifying the beneficial effects of helium-neon laser biostimulation. Ethical concerns, bulky equipment, and problems with biased study designs have frustrated a practical evaluation of laser biostimulation for general dental practice. A recently published "preliminary" study involving 52 patients was designed to reduce these issues. The purpose of this study is to complement the above research and to evaluate whether helium-neon diode laser radiation at average fluences of 0.34 J/c

Fifty-two extraction patients had one of two gingival flap incisions lased with a helium-neon (He-Ne) diode laser at a fluence (energy density) of 1.2 J/cm. The rate of relative healing was evaluated clinically and photographically. Seventy-nine percent of the lased incisions healed more quickly than did the control incisions. No significant difference in healing was noted when patients were compared by age, gender, race, or anatomic location of the incision. This study suggests that He-Ne diode lasers, at the above energy level, appear to increase the rate of gingival wound healing in humans, without negative side effects.

The effect of low level energy infra-red laser irradiation on gingival inflammation was studied. Gingivitis was induced in ten female dental students by refraining from all oral hygiene measures for 28 days. On days 21 and 24 the marginal gingiva, buccal to one of the lateral mandibular incisors, was exposed to 4 minutes of laser irradiation (total dose = 1J). Serving as a control site the gingiva of the contralateral incisors was exposed to ordinary light. There was no statistical difference between the laser exposed sites and the control sites related to either plaque formation or gingival bleeding. The gingivitis reaction was evaluated with the aid of a stereophotographic method by calculating changes in the number of gingival vessels. It was found that the number of vessels identified increased over time for both laser exposed and control sites. The difference between sites at day 28 was not statistically significant (t = 0.82, P > 0.05). These results suggest that low energy laser irradiation (LLLT) does not influence the inflammatory reaction of the gingiva.

A clinical study was conducted on a group of 20 patients who presented with epulis fissuratum caused by denture wearing. CO 2 laser surgery was used to treat these patients and the cases were followed up over a two-year period. The advantage of CO 2 laser surgery on oral tissues was evident by the good response to healing four weeks postoperatively and beyond. No sutures or packing of any kind were used and the wound was allowed to granulate. Re-epithelialization occurred in all patients within 14 days and was complete after about 4 weeks. The lack of wound contraction, scarring, and good re-epithelialization combined with precise tissue destruction make CO 2 laser surgery ideal for this procedure when compared with conventional surgical techniques. The advantage of using CO 2 laser surgery has been demonstrated clinically in the patients treated in this study.

Medical and surgical laser-therapy is becoming more and more important in various branches of Medicine, however independently from clinical results still very little is known about physical-biological interaction between laser beam and living matter. The aim of this study is of finding tissutal and cellular effects of stimulation with soft and mid laser. The study started from an original work carried out at the Institute of Biology of the 1st Faculty of Medicine and Surgery of Naples University from which appears the possibility of visualizing the stage of nuclear active synthesis of the cell, simply by Maloory tricromic colouring. By this method the cellular nucleuses take, usually, a red colour, however in presence of an increase of the RNA nuclear synthesis the nucleuses take a typical blue colour. The importance of the study induced us to research the presence in the oral mucose of the rat after radiation as an effect of biostimulation. The results of this study showed and increase of the epithelial cheratine and a variation of the disposition and of the number of the precheratine grains in treated site. The blue nucleuses have been found at the basal level without any difference between treated and control site. On the other hand their presence is the normal consequence of the epithelial evolution which starts from the basal level which is the most active in the stage of nuclear synthesis.

A CO2 laser (Coherent Medical Model 400) was used to irradiate the gingival tissue of a cynomolgous monkey to determine laser effects on the epithelium and underlying connective tissue. A focal length of 400 mm and a 10-watt power setting at 0.2- and 0.5-second exposure was used. Biopsy results indicated that a 0.2-second duration of CO2 laser irradiation was inadequate to completely de-epithelialize the gingival tissue. A 0.5-second exposure exhibited complete epithelial destruction with little or no disturbance of the underlying connective tissue layer and viable connective tissue 1.0 mm below the impact site.