Er:YAG laser therapy in combination with GLUMA desensitizer reduces dentin hypersensitivity in children with molar-incisor hypomineralization: a randomized clinical trial

This study aimed to investigate the effectiveness of erbium-doped yttrium garnet (Er:YAG) laser and GLUMA desensitizer for dentin hypersensitivity in teeth affected by Molar-Incisor Hypomineralization (MIH). One hundred twenty children were randomly allocated to four groups: the control (Co) group, the desensitizer (De) group, the laser (La) group, and the laser + desensitizer (La + De) group. Outcome measures included Visual Analogue Scale (VAS) and 14-item Oral Health Impact Profile (OHIP-14) evaluation. For mean VAS scores, a significant reduction was found over time in all groups. Co and De groups, Co and La groups, Co and La + De groups, De and La + De groups, and La and La + De groups differed significantly (p < 0.05). For mean scores in all dimensions of OHIP-14 after treatment 6 months, the La + De group was significantly lower (p < 0.001). The La + De groups and the La groups as well as the La + De groups and the De groups differed significantly in total OHIP, functional limitation, physical disability, and psychological disability (p < 0.05). Physical pain between the La + De groups and the La groups and handicap between the La + De groups and De groups differed significantly (p < 0.05). The mean values of each dimension differed significantly between the group Co and the La + De group (p < 0.0001). Combination therapy of Er:YAG laser and GLUMA desensitizer had greater desensitizing effects and oral health-related quality improvement of life, which might be an effective alternative treatment in dentin hypersensitivity in MIH children.

Evaluation of dentinal tubule occlusion and pulp tissue response after using 980-nm diode laser for dentin hypersensitivity treatment

OBJECTIVES

To evaluate the effectiveness of the 980-nm diode laser for dentinal tubule occlusion, measure the intrapulpal temperature, and investigate the dental pulp response.

MATERIALS AND METHODS

The dentinal samples were randomly divided into G1-G7 groups: control; 980-nm laser irradiation (0.5 W, 10 s; 0.5 W, 10 s × 2; 0.8 W, 10 s; 0.8 W, 10 s × 2; 1.0 W, 10 s; 1.0 W, 10 s × 2). The dentin discs were applied for laser irradiation and analyzed by scanning electron microscopy (SEM). The intrapulpal temperature was measured on the 1.0-mm and 2.0-mm thickness samples, and then divided into G2-G7 groups according to laser irradiation. Moreover, forty Sprague Dawley rats were randomly divided into the laser-irradiated group (euthanized at 1, 7, and 14 days after irradiation) and the control group (non-irradiated). qRT-PCR, histomorphology, and immunohistochemistry analysis were employed to evaluate the response of dental pulp.

RESULTS

SEM indicated the occluding ratio of dentinal tubules in the G5 (0.8 W, 10 s × 2) and G7 (1.0 W, 10 s × 2) were significantly higher than the other groups (p < 0.05). The maximum intrapulpal temperature rises in the G5 were lower than the standard line (5.5 ℃). qRT-PCR showed that the mRNA expression level of TNF-α and HSP-70 upregulated significantly at 1 day (p < 0.05). Histomorphology and immunohistochemistry analysis showed that, compared with the control group, the inflammatory reaction was slightly higher at the 1 and 7 days (p < 0.05) and decreased to the normal levels at 14 days (p > 0.05).

CONCLUSIONS

A 980-nm laser at a power of 0.8 W with 10 s × 2 defines the best treatment for dentin hypersensitivity in terms of compromise between the efficacy of the treatment and the safety of the pulp.

CLINICAL RELEVANCE

The 980-nm laser is an effective option for treating dentin sensitivity. However, we need to ensure the safety of the pulp during laser irradiation.

The effect of combination treatment of CO2-laser irradiation and tetracalcium phosphate/dicalcium phosphate anhydrate on dentinal tubules blockage: an in vitro study

The aim of this study was the evaluation of the in vitro efficacy of a carbon dioxide (CO2) laser, a tetracalcium phosphate/dicalcium phosphate anhydrate (TP/DP) desensitizer and the combination of the desensitizer and additional CO2 laser irradiation as a treatment modality for cervical dentin hypersensitivity. A total of 48 dental specimens, prepared from extracted human premolars and molars, were divided into four groups: a control group, a TP/DP desensitizer paste group, a CO2 laser (10.600-nm wavelength) group, and a paste and laser group. The specimens were coated with nail varnish except in the marked area and were then immersed in 2% methylene blue dye for 1 h. The specimens were then washed, dried, and cut longitudinally. Thereafter, photos of 40 dentin specimens were taken and evaluated. The area of penetration was assessed and reported as percentage of the dentin surface area. Additionally eight dental specimens were examined with the aid of a scanning electron microscope and evaluated. Significant differences in the penetration depth were found for all experimental groups compared to the control group. The lowest penetration area was detected in the paste-laser group (16.5%), followed by the laser (23.7%), the paste (48.5%), and the control group (86.2%). The combined treatment of the CO2 laser and a TP/DP desensitizer was efficient in sealing the dentinal surface and could be a treatment option for cervical dentin hypersensitivity.

Treatment outcome for dentin hypersensitivity with laser therapy: Systematic review and meta-analysis

BACKGROUND

Laser protocols for the treatment of dentin hypersensitivity (DH) have not yet been studied systematically.

OBJECTIVES

The present study aimed to review clinical trials on the treatment of DH with laser therapy through a systematic review and meta-analysis.

MATERIAL AND METHODS

The search of electronic databases resulted in 562 publications up to April 2020. The inclusion criteria were studies carried out on humans and reporting on the treatment of DH with laser therapy. Case reports, literature reviews and systematic reviews were excluded. Selected by abstract, potentially eligible papers were read in full (n = 160). Independent examiners performed data extraction and the assessment of the risk of bias.

RESULTS

A total of 34 studies were included in the analysis, and 11 in the quantitative analysis. It was observed that most studies followed up patients for a maximum of 6 months (55%). Through the meta-analysis, we observed statistically significant differences between the average pain before and after 3 months of treatment with highand low-power lasers. However, through indirect comparisons, it was observed that the high-power laser showed a greater tendency to reduce the pain levels after 3 months of treatment as compared to the low-power laser, but without a statistically significant difference.

CONCLUSIONS

It was possible to conclude that regardless of the type of laser used in the treatment of DH, this treatment is an effective option for the control of pain symptoms. However, it was not possible to establish a defined treatment protocol, since the evaluation methods are very different from each other. Text for Rewiew and clinical cases.

Use of infrared photobiomodulation with low-level laser therapy for reduction of bleaching-induced tooth sensitivity after in-office bleaching: a double-blind, randomized controlled trial

The purpose of this study is to evaluate the use of infrared photobiomodulation with low-level laser therapy (PBM) to reduce bleaching-induced tooth sensitivity (TS) after in-office bleaching. Eighty-three participants were randomized in blocks into two groups. In the experimental group, the patients received an application after each session of in-office bleaching (35% hydrogen peroxide, 1 × 50 min; 2 sessions with 1-week interval), while the laser application was simulated in the control group. The PBM system was operated in continuous mode, using 3 J of energy. A dose of 100 J/cm2 was applied for 30 s with 808 nm (100 mW of power) in the middle third of the crown. The risk and intensity of TS were recorded immediately after bleaching, 1 h, 24 h, and 48 h after each bleaching session, with a visual scale analog (0-10) and a five-point numerical scale (0-4). The color was recorded at the beginning, weekly, and 1 month after the end of the bleaching (VITA Classical, VITA Bleachedguide, and digital spectrophotometer). The risk of TS was 98% (95% CI 88 to 99%) for the laser group and 95% (95% CI 83 to 99%) for the control (RR = 1.03; 95% CI 0.94 to 1.12; p = 1.0). Similarly, no difference in the intensity of TS was detected for both pain scales (p > 0.65). Improvement in color change, regardless of the group, was observed (p > 0.15). The application of an PBM did not reduce the risk and intensity of TS when applied after the procedure using the parameters recommended by the manufacturer.Trial registration number and date of registration: RBR-4HCVSG-04/06/2019.

Photobiomodulation therapy and 3% potassium nitrate gel as treatment of cervical dentin hypersensitivity: a randomized clinical trial

Objectives

This randomized controlled trial aimed to evaluate different protocols for dentin hypersensitivity treatment with low-power lasers and desensitizing agents, and the association between low-power lasers and desensitizing agents.

Materials and methods

Fifty-four patients (303 teeth) were randomly allocated to three groups: G1, 3% nitrate potassium gel, UltraEZ (n = 17); G2, photobiomodulation therapy (PBM) with a low-level infrared laser (n = 17), 100 mW, spot size of 0.028 cm², and dose of 1 J per point; and G3, nitrate potassium + PBM (n = 20). Treatments were applied to the buccal cervical region at intervals of 72 h, and all protocols were performed in three sessions. The patients’ response to evaporative stimuli was rated using the visual analog scale (VAS). Re-evaluations were performed immediately after each application and 1 week, 1 month, and 3 months after treatment. A two-way repeated measures test and Tukey’s post hoc test were used for multiple comparisons (α = 5%).

Results

There was a reduction in pain levels at the end of treatment in all groups. There were no significant differences in VAS score changes between the groups immediately after treatment and after the third month, compared to the baseline (p > 0.05).

Conclusion

Under the limitations of this in vivo study, the proposed three-session protocol was effective in reducing dentin hypersensitivity after 3 months, regardless of the desensitization mechanism used. Conservative and long-term protocols are interesting for the control of pain caused by dentin hypersensitivity.

Clinical relevance

The increase in cervical dentin hypersensitivity prevalence warrants easy-to-apply and long-lasting desensitizing protocols for pain control.

The potential of low-power laser for reducing dental sensitivity after in-office bleaching: a case report

Postoperative sensitivity is one of the most common side effects of in-office bleaching with hydrogen peroxide. Laser phototherapy (LPT) has been suggested as an adjunctive treatment to prevent or minimize tooth sensitivity. This case report aimed to verify the efficacy of LPT in the reduction of sensitivity after in-office bleaching. Tooth bleaching was performed with 35% hydrogen peroxide activated with a hybrid LED-laser device. Immediately after the bleaching treatment, the patient reported dental sensitivity, as measured with a visual analog scale (VAS). To reduce sensitivity, LPT was applied with a 780-nm laser using the following parameters: 70 mW, exposure time of 10 seconds per point of irradiation (middle region of the buccal surfaces of each compromised tooth) in contact mode, energy of 1 J per point. Immediately after LPT, the patient reported a substantially lower level of pain on the VAS. Twenty-four hours after bleaching, the score on the VAS indicated that sensitivity levels had rebounded, and the patient received additional LPT. After 48 hours, the patient reported no dental sensitivity. The results in this patient indicated that irradiation with an infrared low-power laser substantially reduced dental pain generated by bleaching, suggesting that LPT should be considered as an auxiliary method to reduce postbleaching tooth sensitivity.

Application of Diode Laser in the Treatment of Dentine Hypersensitivity

INTRODUCTION

Dentine hypersensitivity is characterized by acute, sharp pain arising from the exposed dentine, most commonly in response to thermal, tactile, or chemical stimuli, and which cannot be linked to any other pathological changes in the tooth or the environment. Therapy uses various impregnating agents in the form of solutions or gels and, in more recent times, laser.

AIM

The aim of this research was to examine the effects of treatment of hypersensitive dental cervix with diode laser.

MATERIALS AND METHODS

The study included 18 patients with 82 sensitive teeth. The degree of dentine hypersensitivity was evaluated by visual analogue scale (VAS), and the treatment was carried out by application of low-power diode laser over the span of three visits, which depended on the initial sensitivity.

RESULTS

There is a significant difference in VAS values measured at the onset of treatment (baseline) and immediately after the first laser treatment (t=9.275; p=0.000), after 7 days, after the second laser treatment (14 days) (t=7.085, p=0.000), as well as after 14 days and the third laser treatment (t=5.517, p=0.000), which confirms the effectiveness of this therapeutic procedure. The results showed a reduction of hypersensitivity in response to tactile stimulus with a probe after the third treatment, even with teeth whose value on the VAS was very high at the beginning of treatment (baseline).

CONCLUSION

Within the scope of the conducted study, laser therapy has provided extremely safe and effective results in the treatment of cervical dentine hypersensitivity.

Applications of Light Amplification by Stimulated Emission of Radiation (Lasers) for Restorative Dentistry

Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years. In the field of restorative dentistry, various kinds of lasers have been developed for diagnostic (e.g. caries detection) and operative applications (e.g. tooth ablation, cavity preparation, restorations, bleaching). The main benefits for laser applications are patient comfort, pain relief and better results for specific applications. Major concerns for using dental lasers frequently are high cost, need for specialized training and sensitivity of the technique, thereby compromising its usefulness particularly in developing countries. The main aim of this paper is to evaluate and summarize the applications of lasers in restorative dentistry, including a comparison of the applications of lasers for major restorative dental procedures and conventional clinical approaches. A remarkable increase in the use of lasers for dental application is expected in the near future.

Comparative evaluation of diode laser, stannous fluoride gel, and potassium nitrate gel in the treatment of dentinal hypersensitivity

The aim of the present study was to compare the efficacy of diode laser (DL) with stannous fluoride and potassium nitrate gels in the treatment of dentinal hypersensitivity (DH). Fifty-four subjects, ages 25-45, having 2 adjacent teeth sensitive to air blast stimulation were included. The subjects were divided randomly into 3 groups (n= 18): Group A, subjects treated with DL; Group B, subjects treated with 0.4% stannous fluoride gel; and Group C, subjects treated with 5% potassium nitrate gel. Each group was evaluated at baseline; at weekly intervals for 2 consecutive weeks; and at 1, 3, and 6 months. All 3 groups showed decreases in the DH scores between baseline and 6 months This was more pronounced in Group A at all time intervals. When the 3 groups were compared between baseline and Week 1, there was a statistically significant decrease across all 3 groups between (P = 0.0020). The greatest difference in the DH scores between baseline and Week 1 was in Group A, compared to Groups B and C. The 940 nm DL was not only efficacious, but also brought about improved immediate relief as compared to stannous fluoride and potassium nitrate gels in the reduction of DH.

Comparative assessment of the sealing ability of Nd:YAG laser versus a new desensitizing agent in human dentinal tubules: a pilot study

Dentinal hypersensitivity is a painful condition that occurs following periodontal treatment. Many treatment alternatives have been considered for this problem, including treatments with laser and dentinal adhesives. This study compared the sealing ability of Nd:YAG laser versus a new resin in scanning electron microscopy (SEM) micrographs. Ten human premolars were sectioned yielding 30 specimens of each premolar, which were randomly divided into three groups. The laser group was irradiated by Nd:YAG laser (1 W, 10 Hz, 60 s), the resin group was treated with the new Seal & Protect resin according to the manufacturer's instructions, and the third group served as the control group and did not receive any interventions. After preparation and gold coating of the samples, they were photographed by SEM at two magnifications (1500× and 4000×). The number and diameter (μm) of the dentinal tubules were recorded in selected fields, and analysis of variance (ANOVA) and Tukey tests were used to determine significant differences between groups. The ANOVA results revealed significant differences in both the mean number (P < 0.001) and diameter (P < 0.05) among the three groups. Further statistical analysis showed a significant difference between the laser group and the resin group in both outcome measures (P < 0.05). Thus, both Nd:YAG laser and the new resin reduced the number and diameter of open dentinal tubules, a result that also explains the desensitization mechanism of these interventions. We further conclude that application of the new resin is more effective than Nd:YAG laser in minimizing the number and diameter of exposed dentinal tubules.

Laser phototherapy in the treatment of periodontal disease. A review

Many studies in the literature address the effect of low-power lasers in the management of pathologies related to periodontal tissues. Due to the lack of standardized information and the absence of a consensus, this review presents the current status of laser phototherapy (LPT) in periodontics and discusses its benefits and limits in the treatment of periodontal disease. The literature was searched for reviews and original research articles relating to LPT and periodontal disease. The articles were selected using either electronic search engines or manual tracing of the references cited in key papers. The literature search retrieved references on wound and bone healing, analgesia, hypersensitivity, inflammatory process and antimicrobial photodynamic therapy. Each topic is individually addressed in this review. The current literature suggests that LPT is effective in modulating different periodontal disease aspects in vitro, in animals, and in simple clinical models. Further development of this therapy is now dependent on new clinical trials with more complex study designs.

Laser applications in endodontics: an update review

The search for new devices and technologies for endodontic procedures always has been challenging. Since the development of the ruby laser by Maiman in 1960 and the application of the laser for endodontics by Weichman in 1971, a variety of potential applications for lasers in endodontics have been proposed. With the development of thinner, more flexible and durable laser fibres, laser applications in endodontics have increased. Since laser devices are still relatively costly, access to them is limited. The purpose of this paper is to summarise laser applications in endodontics, including their use in pulp diagnosis, dentinal hypersensitivity, pulp capping and pulpotomy, sterilisation of root canals, root canal shaping and obturation and apicectomy. The effects of lasers on root canal walls and periodontal tissues are also reviewed.

Low level lasers in dentistry

Low level laser therapy (LLLT) uses light energy, in the form of adenosine triphosphate (ATP), to elicit biological responses in the body. The increased cellular energy and changes in the cell membrane permeability result in pain relief, wound healing, muscle relaxation, immune system modulation, and nerve regeneration. This article investigates the clinical effects of LLLT and explains how it can be applied in the dental field.

Surgical laser use in implantology and endodontics

The use of surgical lasers has been advocated to aid in the placement and second stage recovery of dental implants, together with soft tissue contouring. In addition, laser use has been suggested as an aid in decontamination of the implant surface in cases of peri-implantitis. In endodontics, the association of laser energy with dentine hypersensitivity, bacteriocidal action and pulp-capping, has led to a growing number of reports as to its beneficial use, together with claims of morphological changes in the canal wall, to enhance endodontic treatment success.

Microtensile bond strengths of composite to dentin treated with desensitizer products

PURPOSE

This study was designed to analyze the influence of desensitizing procedures on dentin bond strength.

MATERIALS AND METHODS

Forty bovine incisors were used, divided into four groups (n = 10): G1: control; G2: Gluma Desensitizer (Heraeus Kulzer); G3: Oxa-Gel (Art-Dent); G4: low-intensity laser (MMOptics). The buccal surface was wet ground flat with 180-, 400- and 600-grit silicon carbide abrasive paper to expose midcoronal dentin and create a uniform surface. After the application of the desensitizing agents to the exposed dentin, the specimens were etched with 35% phosphoric acid for 30 s, and an adhesive (Single Bond) was applied and light cured. A 4-mm high crown of composite resin (Filtek Z250) was then built up. Specimens were trimmed to an hourglass shape with cross sections of 1 mm2. Each specimen was individually fractured by a microtensile testing machine at a crosshead speed of 0.5 mm/min. The data, recorded in MPa, were analyzed with one-way ANOVA and the Duncan test (p = 0.05).

RESULTS

Specimens treated with dentin desensitizers (except Gluma) yielded significantly lower mean bond strengths than nontreated control specimens. The mean values in MPa (+/- SD) were: G1: 13.4 (6.2); G2: 13.2 (4.8); G3: 7.15 (4.3); G4: 7.21 (4.6).

CONCLUSIONS

Among the desensitizing agents studied, only Gluma Desensitizer did not detrimentally influence the bond strength values. It is a useful material for dentin desensitization.

Tubule-occluding effect of desensitizing laser treatment on prepared dentin surfaces: an environmental SEM study

PURPOSE

The purpose of this in vitro study was to demonstrate the dentinal tubule-occluding effect of desensitizing laser treatment on dentin surfaces using environmental scanning electron microscopy (E-SEM).

MATERIALS AND METHODS

Ground dentin surfaces were divided into 5 areas. Each area received a different mode of laser irradiation (low potency [LP] versus high potency [HP] and short time [ST] versus long time [LT]). Lased dentin surfaces were viewed and graded under E-SEM at x5000 magnification.

RESULTS

The tubule closure rates of 4 different irradiation modes were as follows: LP/LT (74%) > HP/ST (70%) > LP/ST (51%) > HP/LT (46%) > control (6%).

CONCLUSION

It was demonstrated that desensitizing laser application was an efficient treatment option for the occlusion of dentinal tubule apertures.

Lasers in periodontology

Since the development of the ruby laser by Maiman in 1960, lasers have been widely employed in medicine for a number of years. The purpose of this paper is to summarize potential applications for lasers in dentistry, with special regard to periodontology. This article briefly describes clinical applications of lasers and laser safety. Particularly, the use of a diode laser seems to be promising, especially in already compromised transplant patients, who need to be treated with a technique where the operative and post-operative blood loss, post-operative discomfort and the recurrence of drug-induced gingival overgrowth need to be kept to a minimum or eliminated. Therefore, the use of lasers in periodontology may lead to an alteration in present clinical practice and help to establish the best management strategy because, by maintaining periodontal health, the life quality of patients can be improved.

[Dentine hypersensitivity treated with Nd: YAG laser: experience with 262 cases]

OBJECTIVE

To observe the curative effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulse in treating dentine hypersensitivity.

METHOD

A total of 262 teeth with dentine hypersensitivity were divided equally into 2 groups, namely the test group which received treatment with pulse Nd: YAG laser and the control group treated with sodium fluoride.

RESULTS

The instant, 1-month and 6-month effectiveness in the test group was better than that in the control group, showing significant difference between the two groups (P<0.01).

CONCLUSION

Nd: YAG laser is safe and highly effective in treating dentine hypersensitivity.

Laser therapy in the treatment of dentine hypersensitivity

Cervical dentine hypersensitivity is the most frequent complaint among reported odontalgias. Thus, this study evaluated the effectiveness of two types of lasers (660 nm wavelength red, and 830 nm wavelength infrared) as dentine desensitizers, as well as both the immediate and late therapeutic effects in individuals 25 to 45 years of age. A total of 40 teeth with cervical exposure were treated in 4 sessions. They were divided into 2 groups according to treatment. A 660 nm wavelength red diode laser and an 830 nm wavelength infrared diode laser were used. Dentine sensitivity to cold nociceptive stimulus was evaluated by means of a pain numeric scale from zero to 10 before each treatment session, at 15 and 30 min after irradiation, and in a follow-up period of 15, 30 and 60 days after the end of treatment. Significant levels of dentinal desensitization were only found in patients ranging in age from 25 to 35 years. The 660 nm red diode laser was more effective than the 830 nm infrared laser and a higher level of desensitization was observed at the 15 and 30 minute post-irradiation examinations. The immediate and late therapeutic effects of the 660 nm red diode laser were more evident in 25-35-year-old patients compared with those of the 830 nm infrared diode laser, in terms of the different age groups.

Treatment of cervical dentin hypersensitivity using neodymium: Yttrium-aluminum-garnet laser. Clinical evaluation

BACKGROUND AND OBJECTIVE

The incidence of cervical dentinal hypersensitivity is related to the high number of non-carious cervical lesions. This clinical research was developed in order to evaluate the Nd:YAG laser treatment of cervical dentin hypersensitivity after attempting the removal and control of etiologic factor after two different stimuli.

STUDY DESIGN/MATERIALS AND METHODS

Twenty patients participated in this study in a total of 145 teeth, where 104 received the Nd:YAG laser treatment and 41 remained as control.

RESULTS

The results showed that there was statistically significant reduction of hypersensitivity as for the groups that received the treatment with Nd:YAG laser, as for the control teeth. However, the reduction of cervical dentinal hypersensitivity was statistically greater when there was the association of the removal of etiologic factors with the application of Nd:YAG laser.

CONCLUSIONS

We concluded that the laser irradiation was effective in the treatment of cervical dentin hypersensitivity after 6 months.

Effect of the Clinical Application of the GaAlAs Laser in the Treatment of Dentine Hypersensitivity

OBJECTIVE

The aim of this study was to evaluate the effectiveness of the clinical use of the gallium-aluminum-arsenium (GaAlAs) laser at the maximum and minimum energies recommended by the manufacturer for the treatment of dentine hypersensitivity.

BACKGROUND DATA

Dentine hypersensitivity (DH) is a response to a stimulus that would not usually cause pain in a healthy tooth. It is characterized by sharp pain of short duration from the denuded dentin. Its etiology is unknown. The dentin only begins to show sensitivity when exposed to the buccal environment. This exposure can result after removal of the enamel and/or dental cement, or after root denudation. Different treatments are proposed for this disorder.

MATERIALS AND METHODS

In this study, 25 patients, with a total number of 106 cases of DH, were treated with GaAlAs low-level laser therapy (LLLT). 65% of the teeth were premolars; 14% were incisors and molars; 6.6% were canines. The teeth were irradiated with 3 and 5 J/cm2 for up to six sessions, with an interval of 72 h between each application, and they were evaluated initially, after each application, and at 15 and 60 days follow-up post-treatment.

RESULTS

The treatment was effective in 86.53% and 88.88% of the irradiated teeth, respectively, with the minimum and maximum energy recommended by the manufacturer. There was a statistically significant difference between DH and after a follow-up of 60 days for both groups. The difference among the energy maximum and minimum was not significant.

CONCLUSION

The GaAlAs low-level laser was effective in reducing initial DH. A significant difference was found between initial values of hypersensitivity and after 60 days follow-up post-treatment. No significant difference was found between minimum (3 J/cm2) and maximum (5 J/cm2) applied energy.

Treatment of dentin hypersensitivity by Nd:YAG laser

BACKGROUND, AIMS

Promising results using Nd:YAG laser against dentin hypersensitivity have been reported. The aim of this double-blind, controlled, split-mouth designed clinical trial was to assess the effect of a single Nd:YAG laser application on alleviating hypersensitivity.

METHODS/RESULTS

Seventeen subjects participated in the study. Each of them had two teeth treated; one with the laser activated and one with nonactivated (placebo), for 2 min The assessment of pain was performed by a VAS, after an air blast at baseline immediately after treatment, at 1 week, 4 weeks and 16 weeks. Mean values of VAS for test and control teeth were compared by paired t-test (alpha = 0.05). The results showed mean baseline VAS values of 6.59 (+/- 1.65) and 6.14(+/- 1.95) for test and control teeth, respectively. Immediately after treatment, these values decreased to 4.09(+/- 2.28) and 3.89(+/- 2.11), respectively. After 1 week, 4 weeks and 16 weeks the mean values for test and control teeth were 3.85 +/- 2.36, 4.03 +/- 1.95, 3.60 +/- 2.66, and 4.44 +/- 2.56, 3.41 +/- 2.30, 3.42 +/- 2.30, respectively. There were no statistically significant differences between test and control at any time. However, both groups improved significantly (P < 0.05) from baseline to immediately after application, and at 1 week, 4 weeks and 16 weeks, respectively. The changes that occurred between immediately after application and 1 week, 4 weeks and 16 weeks, respectively, were not statistically significant.

CONCLUSION

It is concluded that the effect of treatment of hypersensitive teeth with Nd:YAG laser is not different from placebo. The observed effects seem to last for at least 16 weeks.

Lasers in endodontics

The first application of lasers in dentistry was the surgical treatment of tumors in the oral cavity, and various lasers, including semiconductor diode, carbon dioxide, helium-neon, neodymium:yttrium-aluminum-garnet, argon, erbium, and erbium chromium, have been developed since and applied in dentistry. This article describes the current and possible future clinical indications, laser devices, techniques, assessment methods, and mechanics.

Treatment of dentine hypersensitivity by lasers: a review

BACKGROUND, AIMS

Since the development of the ruby laser by Maiman in 1960, a variety of papers on potential applications for lasers in dentistry have been published. The purpose of this paper is to summarise laser applications for the treatment of dentine hypersensitivity. The effects of laser on pulp tissue and problems on laser treatment are also reviewed. This article reviews the role of lasers for the treatment of dentine hypersensitivity since 1985, summarises many research reports from the last decade, and surmises what the future may hold for lasers in this treatment.

METHOD

To date, 4 kinds of lasers have been used for the treatment of dentine hypersensitivity, and the effectiveness ranged from 5.2 to 100%, which was dependent on the laser type and parameters used. The mechanism involved in laser treatment of dentine hypersensitivity are relatively unknown.

RESULTS

These require clarification to result in safely effective treatment optimization. In general, the efficiency for the treatment of dentine hypersensitivity using lasers is higher than other methods, but in severe cases, it is less effective.

CONCLUSION

It is necessary to consider the severity of dentine hypersensitivity before laser use.

Pulsed Nd:YAG laser irradiation of the tooth pulp in the cat: I. Effect of spot lasing

BACKGROUND AND OBJECTIVE

The purpose of the present study was to evaluate physiologically pulpal nerve responses and to elucidate histopathologically the pulp tissue reactions to "spot irradiation" with a pulsed Nd:YAG laser.

STUDY DESIGN/MATERIALS AND METHODS

Antidromic compound action potentials and the pulpal blood flow (PBF) were recorded from the canine tooth of a sodium pentobarbitone-anesthetized cat. The laser irradiation-induced pulp tissue changes were histologically investigated.

RESULTS

The coronal antidromic compound action potentials disappeared in all the teeth tested during lasing, and the time needed to erase them was significantly shortened with increases in lasing power (P < 0.05). The radicular PBF increased when spot irradiation was performed, and the coronal PBF also temporarily increased with low-powered lasing. Histologic investigation revealed that spot irradiation with the laser produced severe damage in the pulp tissue in a dose-dependent manner.

CONCLUSION

The present study suggests that spot irradiation with a pulsed Nd:YAG laser risks producing nerve injury and irreversible tissue damage in the pulp with lasing for the purpose of desensitizing hypersensitive dentin.

Effect of HeNe and pulsed Nd:YAG laser irradiation on intradental nerve responses to mechanical stimulation of dentine

BACKGROUND AND OBJECTIVE

Our study aimed to determine how lasing affected intradental nerve responses to dentine stimulation. Study Design/Materials and Methods Intradental nerve activity was recorded from canine teeth of anaesthetised ferrets. Dentine exposed at the tip of the tooth was stimulated with a glass probe. After determining baseline responses to mechanical stimulation, dentine was lased using a pulsed Nd:YAG laser at 60-150mJ/pulse and 10-30 pulses/sec (total power = 0.3-3.0 W).

RESULTS

The HeNe aiming beam alone and Nd:YAG laser at 0.3 W (+ HeNe) had no effect on intradental nerve responses to dentine stimulation. Lasing at 0.6-1. 5 W could either enhance or suppress intradental nerve responses. Lasing at more than or equal to 2.0 W or repeated lasing at lower intensities depressed intradental nerve responses. Lasing often induced intradental nerve firing.

CONCLUSION

HeNe lasing had no effect on intradental nerve excitability. The Nd:YAG laser could depress intradental nerve responses to dentine stimulation.

The combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiation on human dentinal tubules

Various methods and materials used in the treatment of dentin hypersensitivity are thought to achieve a therapeutic benefit by tubule occlusion. The aim of the present study was to evaluate the combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiation on human dentinal tubules. Thirty-six dentin specimens with exposed dentinal tubule orifices were used in this study. The samples were randomly divided into four groups. Groups A, B, and C were varnished by sodium fluoride, whereas group D served as a control. Then, group C was lased by 30 mJ of Nd:YAG laser, 10 pulses/s for 2 min by light painting. Three hours later, groups B and C were brushed by an electrical toothbrush for 30 min. Under SEM observation, the control group showed numerous exposed dentinal tubule orifices, and the sodium fluoride varnished specimens showed closure of exposed dentinal tubule orifices. After electrical toothbrushing, most of the sodium fluoride varnish was brushed away, except in the specimens that were irradiated by Nd:YAG laser. Over 90% of the dentinal tubule orifices were occluded by sodium fluoride varnish combined with Nd:YAG laser irradiation.

Effects of CO2 laser in treatment of cervical dentinal hypersensitivity

The effectiveness of CO2 laser therapy in the reduction and elimination of dentinal hypersensitivity in vivo and its thermal effects on tooth surfaces in vitro were investigated. Twenty-three patients with 91 sensitive teeth participated in this study and were followed for 3 months. The parameters used with CO2 laser were 1 W in a continuous wave mode and irradiation time ranging from 5 to 10 s. Hypersensitivity was assessed by thermal stimulus (a blast of air from a dental syringe). Thermal effects were measured by thermography using 10 extracted human teeth. After laser treatment, all patients were immediately free from sensitive pain. Over 3 months, the CO2 laser treatment reduced dentinal hypersensitivity to air stimulus by 50%. All teeth remained vital with no adverse effects. Thermography revealed no temperature increase on irradiated tooth surfaces subjected to water coolant. These results show that the CO2 laser is useful in the treatment of cervical dentinal hypersensitivity without thermal damage to pulp.

Long-term effects of CO2 laser irradiation on treatment of hypersensitive dental necks: results of an in Vivo study

OBJECTIVE

The present in vivo study was performed to examine the long-term effects of combined CO2 laser treatment and fluoridation on hypersensitive dental necks.

SUMMARY BACKGROUND DATA

Attempts have been made to treat dental hypersensitivity by sealing exposed dentinal tubules, primarily using fluoride preparations, strontium chloride, and hydroxyapatite. However, these treatment methods have the disadvantage that the preparation is effective only for a limited period of time and must be applied repeatedly, at short intervals. The CO2 laser has been shown to have an excellent sealing effect on hypersensitive dentinal surfaces.

METHODS

Test subjects suffering from dentinal hypersensitivity were recruited from the patients of the Department of Conservative Dentistry, School of Dentistry of the University of Vienna, Austria and treated with combined laser irradiation and fluoridation with stannous fluoride gel. The patients were followed up for a period of 18 months. In vivo examinations were supplemented by atomic absorption spectroscopy (AAS) of tiny dentin samples obtained from the dental necks 6 weeks and 18 months after laser treatment and by scanning electron microscopy (SEM).

RESULTS

Compared to conventional fluoridation, combined laser irradiation and fluoridation was shown to be effective in the treatment of hypersensitive dental necks. When success was defined as complete freedom from pain, the success rate in the laser group was 96.5%. Furthermore, examinations of irradiated teeth under the scanning electron microscope still revealed complete closure of the dentinal tubules four and six months after laser treatment. AAS showed that tin was present in the samples, which indicates that combined laser treatment and fluoridation result in permanent integration of fluoride in the dentin surface.

CONCLUSIONS

Based on these results, the CO2 laser can be recommended as an ideal tool for desensitization of dental necks.

Sealing depth of Nd:YAG laser on human dentinal tubules

Dentin permeability and hypersensitivity are both reduced when the dentinal tubules are occluded. Previous scanning electron microscopic studies showed that Nd:YAG laser could cause melting of dentin and closure of exposed dentinal tubules without dentin surface cracking. Therefore, the aim of the present study was to evaluate the sealing depth of Nd:YAG laser on human dentinal tubules. Thirty-six dentin specimens with exposed dentinal tubule orifices were used in this study. Samples were randomly divided into three groups. Groups A and B were lased by Nd:YAG laser at energy of 30 mJ with 10 pulses/s for a stroke along the dentin surface. Group C was not lased and served as a control. Subsequently, group B was frozen in liquid nitrogen and split by a sharp chisel. Under SEM observation, nonlased specimens showed numerous exposed dentinal tubule orifices, and lased specimens showed melting of dentin and closure of exposed dentinal tubule orifices. The sealing depth of Nd:YAG laser on human dentinal tubules was approximately 4 microns.

The current status of low level laser therapy in dentistry. Part 2. Hard tissue applications

While most applications of low level laser therapy (LLLT) in dentistry are directed toward soft tissues, in recent years there has been increasing interest in tooth-related or hard tissue applications of LLLT. This report provides an overview of applications of LLLT in the treatment of dentine hypersensitivity and pain arising from the periodontal ligament, and describes the phenomenon of lethal laser photosensitization and its applications in the treatment of dental caries. Technical aspects of LLLT equipment and safety concerns are also discussed.

[Using Nd-YAG laser to desensitize the hypersensitive dentine in preparing the abutment teeth for removable partial dentures prosthesis]

Patients often suffer from sensitivity and pain while preparing the seats of occlusal rests of clasps on abutment teeth with hypersensitive dentine for removable partial dentures prosthesis. Base Nd-YAG laser desensitization effect by making a hard surface layer in the hypersensitive dentine of the abutment teeth, We use this method to treat the teeth before and after occlusal seats of clasps preparation, 20 patients, more than 30 occlusal seats of clasp rests are completed smoothly without any suffering since 1991. All the patients wear their dentures satisfactorily without afterward side effect. After half one year to four years followed observation all the rests adapt to their seats well without marking wear, We believe that the desensitizing effect of Nd-YAG Laser is effective in preparing occlusal seats for removable partial denture prosthesis.

Transient effects of low-energy CO2 laser irradiation on dentinal impedance: implications for treatment of hypersensitive teeth

This study evaluated the effect of CO2 laser irradiation on dentinal impedance by passing known cyclic potentials across dentinal wafers mounted as a window in an electrolytic cell and measuring the resulting electrical impedance. Wafers were equilibrated in 0.1 M of KCl. The wafer specimens were irradiated with a CO2 laser (12 W, 0.1 ms, energy density 1.25 J/cm2). The time for impedance equilibration after irradiation was compared with equilibration after mounting. Mounted samples required 48 h to approach equilibrium in the electrolyte. After laser irradiation, impedance of previously equilibrated samples also required 48 h to equilibrate. This, along with exponential curve fitting, confirmed that laser treatment reintroduced a transient alteration in impedance. Equilibration time after irradiation and the mounting were similar. Dentin desociation apparently caused this transient impedance. Energy dispersive X-ray analysis confirmed the disappearance of K+Cl- after irradiation. Therefore, laser irradiation may cause dentinal desociation, yielding temporary clinical relief of dentinal hypersensitivity until rehydration occurs.

The advantage of CO2-treated dental necks, in comparison with a standard method: results of an in vivo study

Various methods are used for treatment of hypersensitive dental necks. They all aim to seal exposed dentinal tubules, which are open toward the oral cavity and transmit stimuli to the sensitive nerve endings of the tooth pulp. The main sealing materials are fluoride preparations, strontium chloride, and hydroxyapatite. However, these materials must be applied periodically to achieve permanent freedom from pain. Since the introduction of laser technology into dentistry, efforts have been made to treat dentine hypersensitivity with the laser. An in vitro study revealed that CO2 laser irradiation results in almost complete closure of the dentinal tubules in the dental neck region. In the present in vivo study, the efficacy of laser treatment was examined in 72 patients with dentine hypersensitivity and 72 control patients over a period of 12 weeks. When success was defined as complete freedom from pain, the success rate in the laser group was 94.5%; when marked pain relief was included in the definition of treatment success, 98.6% of the patients were treated successfully. Treatment of the control group with conventional dental neck fluoridation resulted in no marked improvement. Laser Doppler measurements of pulpal blood flow immediately before and after treatment revealed no effects of laser irradiation on pulpal blood flow. Dentine samples were obtained from the dental necks 6 weeks after laser treatment and examined with atomic absorption spectroscopy (AAS). Tin was present in the samples, which suggests that the combined laser treatment and fluoridation result in permanent integration of fluoride in the dentine surface.

Low level laser therapy for dentinal tooth hypersensitivity

A comparative double blind study testing low level laser therapy (Gallium/Aluminium/Arsenide laser [GaAlAs]) against placebo was carried out in the management of dentinal tooth hypersensitivity. Subjects demonstrating dentinal hypersensitivity and complying with strict selection criteria were randomly assigned to an active and placebo group. Low level laser therapy was applied for one minute to both the apex and cervical area of the tooth; and reapplied at one week, two-week and eight-week intervals. Dentinal hypersensitivity was rated at each visit. There were 28 subjects in the placebo group and 22 and 21 subjects, respectively, in the tactile sensitivity and thermal sensitivity groups. Comparisons between the groups were conducted using independent groups t-test. In both the tactile and thermal sensitivity groups differences between the active and placebo groups were significant from the first week and increased further in the second and eighth weeks. The mean value of thermal sensitivity decreased 67 per cent (p < 0.001) compared with placebo (17 per cent) and tactile sensitivity decreased 65 per cent (p = .002) compared with placebo (21 per cent) at eight weeks. Results demonstrate that the GaAlAs laser is an effective method for the treatment of both thermal and tactile dentinal hypersensitivity. There were no reported adverse reactions or instances of oral irritation.

[Lasers in dentistry and in oral and maxillofacial surgery]

During the last few years, lasers have begun to appear in dentistry. There are, however, different types of lasers and different therapeutic indications in almost every field of dentistry. This is a review of the current literature on the applications of lasers in oral and maxillofacial surgery.

Clinical applications and basic studies of laser in dentistry and oral surgery

In our clinical use of lasers, mainly CO2 laser for oral surgery, we found that the laser had many advantages over an electrome and the laser improved the local control rate for malignant tumors. Low-power laser has been used to treat hypersensitive dentin, to relieve pain caused by neurotic disease around mouth, and to promote the healing of those diseases. The results obtained from the clinical applications showed that irradiation of the hypersensitive dentin with low-power laser was significantly effective in desensitization. An in vitro study showed no effects of diode or He-Ne laser irradiation on the growth of cells, but showed changes in the initial cell adhesion rate. He-Ne laser irradiation to the wound in the skin of hamsters caused to change the activities of the types I and III collagenase. This fact suggest that laser irradiation acted to promote the healing of wound.

Sealing of human dentinal tubules by XeCl 308-nm excimer laser

Root hypersensitivity occurs as a result of exposed dentinal tubules. Various methods and materials have been tried in an attempt to occlude these tubules. The purpose of this investigation was to study by scanning electron microscope the effects of XeCl excimer laser on exposed dentinal tubules of human extracted teeth. Fifteen 3-mm-thick slices were cut at the cementoenamel junction from 15 extracted human teeth by an electric saw. By using a diamond bur to remove the cementum layer the dentinal tubules were exposed. Each slice was scored by a permanent marker into four equal quadrants. Three of the quadrants were lased for 4 s by XeCl excimer laser with fluences ranging from 0.5 to 7.0 J/cm2 and pulse repetition of 25 Hz. The unlased quadrant served as control. The specimens were mounted on a stub, sputter coated by gold, and examined by scanning electron microscope. Nonlased surfaces showed numerous exposed dentinal tubules. In contrast, all specimens lased at fluences of up to 1 J/cm2 showed the presence of melted dentin which closed the dentinal tubules. At fluences of 4 J/cm2 and higher, rupture of molten materials and exposure of dentinal tubules were noted. The results indicate the application of XeCl excimer laser at specific fluences can cause melting of dentin and closure of exposed dentinal tubules.

The effectiveness of the Nd:YAG laser in the treatment of dental hypersensitivity

Dentin hypersensitivity is one of the most painful and least predictably treated chronic conditions in dentistry. The effectiveness of laser therapy in the reduction of dentin hypersensitivity and its effects on pulpal vitality were studied. Nineteen subjects participated in the randomized, double-blind study, and were followed up for three months. Two sites were treated. One received helium neon (He:Ne) laser treatment and the other received He:Ne plus Nd:YAG (He:Ne+Nd:YAG) laser treatment. Laser treatment consisted of 30 millijoules (mJ) to 100 mJ per pulse, at 10 pulses per second (pps) in increments of 10-40 seconds each over a total treatment time of less than two minutes, without local anesthesia. Hypersensitivity was assessed by mechanical stimulus (using a sharp explorer), and thermal stimulus (using a blast of cold air from a dental syringe). Pulpal vitality was measured using an electrical stimulus. The results indicate that immediately following laser treatment and for three months thereafter, the subjects' perceived level of discomfort decreased. He:Ne treatment reduced dentin hypersensitivity to air by 63 per cent and to mechanical stimulation by 61 per cent over three months. The He:Ne + Nd:YAG treatment reduced dentin sensitivity to air by 58 per cent and to mechanical stimulation by 61 per cent. All teeth remained vital after laser treatment, with no adverse reactions or complications. He:Ne and He:Ne + Nd:YAG laser treatment can be used to reduce dentin hypersensitivity without detrimental pulpal effects.

Nd: YAG pulsed laser: a successful tool to desensitize hypersensitive prepared abutment teeth in fixed prosthodontics

Dentinal hypersensitivity follows several therapeutic dental procedures as well as occurring de novo. Pain being an unpleasant sensation, originates from dentine which has a rich supply of myelinated nerve ending. There are several theories that explain the mechanism of pain of dentinal origin. Thermal, tactile and chemical stimuli when applied to affected teeth might result in brief mild discomfort to prolonged severe pain. There are several theories regarding dentinal hypersensitivity.

The soft laser: therapeutic tool or popular placebo?

Because of the alleged effectiveness of soft laser therapy in the treatment of a wide range of medical and dental conditions, it is becoming increasingly popular with both patients and practitioners. It was the purpose of this study to assess soft laser treatment of hypersensitive dentin, gingivitis, pulp-capped teeth, herpes labialis, and nausea. Clinical trails demonstrated no advantage in augmenting or replacing conventional treatment of these conditions with soft laser therapy, despite its positive effect on patient attitude toward treatment.