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

Use of CO2 Laser as an Adjunctive Treatment for Caudal Stomatitis in a Cat

Lasers have become a popular tool in veterinary practice, particularly the carbon dioxide (CO2) laser. In humans, the CO2 laser is used most commonly in oral and maxillofacial soft tissue surgery due to its favorable interactions with oral soft tissues. Other types of lasers are better suited for use on hard tissues such as enamel and dentin. This article reviews the history of laser use, physics of laser-tissue interaction, delivery systems, and laser types used in dentistry and oral surgery. This is followed by a case report describing the use of CO2 laser as an adjunctive treatment for therapy of refractory caudal stomatitis in a cat.

Low-power pulsed Nd:YAG laser irradiation for pre-emptive anaesthesia: A morphological and histological study

BACKGROUND AND AIMS

To determine if tooth structure or dental pulp of normal healthy human premolar teeth to be extracted for orthodontic reasons exhibit morphological or histological changes following dental anaesthesia by pulsed Nd:YAG laser and subsequent cavity preparation (CP). Materials (Subjects) and Methods: 54 bilateral paired of human, healthy premolar teeth identified for inclusion in a clinical trial of Nd:YAG-induced anaesthesia and subsequently extracted for orthodontic reasons, were randomly divided into 4 treatment groups: Group 1 - teeth (n=44) were irradiated with 150 µs pulsed Nd:YAG laser-1064 nm (American Dental Laser, dLase300, Sunrise Technologies Inc., Folsom, CA, USA; Average power: 1.1 ± 0.2 W, power density: 39+ 0.7 W/cm(2), area 0.28 cm(2), 15 Hz; energy density:0. 260+ 0.047 J/cm(2)) +Sham EMLA (cream without active component) followed by cavity preparation (CP); Group 2 - Teeth (n=44) - were treated with EMLA + Sham Laser (1 mW 632.8-nm He:Ne laser aiming beam only) with CP; Group 3 Teeth (n=10) - were irradiated with pulsed Nd:YAG laser as above but minus CP; Group 4 (n=10)- was a Control group with teeth untreated (no Laser, EMLA or CP). Clinical anaesthesia was assessed by electric pulp testing (EPT) and CP. Teeth in each of the 4 groups were processed for examination by i) scanning electron microscopy (SEM); ii) longitudinal undecalcified ground sectioning (LUGS); iii) light microscopy of pulpal tissues or iv) dye penetration.

RESULTS

Both Laser and EMLA groups demonstrated no alteration to mineralized tooth structure and dentinal permeability. Mild superficial pulpal changes were found in both groups (3/18 teeth) and of no statistical difference (p>0.99, the McNemar test). Neither Laser nor the Control groups minus CP, showed pulpal changes.

CONCLUSIONS

Low-power pulsed Nd:YAG laser dose, as used in the clinical trial to induce anaesthesia, does not cause morphological damage to the mineralized tooth structure. Both Laser and EMLA groups showed minor superficial pulpal change following cavity preparation which was not statistically significant. Laser and Control groups minus preparation had no pulpal changes.

Effects of CO2 laser irradiation of the gingiva during tooth movement

Patients often feel pain or discomfort in response to orthodontic force. It was hypothesized that CO(2) laser irradiation may reduce the early responses to nociceptive stimuli during tooth movement. The distribution of Fos-immunoreactive (Fos-IR) neurons in the medullary dorsal horn of rats was evaluated. Two hrs after tooth movement, Fos-IR neurons in the ipsilateral part of the medullary dorsal horn increased significantly. CO(2) laser irradiation to the gingiva just after tooth movement caused a significant decrease of Fos-IR neurons. PGP 9.5- and CGRP-positive nerve fibers were observed in the PDL of all study groups. The maximum temperature below the mucosa during CO(2) laser irradiation was less than 40 degrees C. It was suggested that CO(2) laser irradiation reduced the early responses to nociceptive stimuli during tooth movement and might not have adverse effects on periodontal tissue.

Evaluation of Nd:YAG laser on partial oxygen saturation of pulpal blood in anterior hypersensitive teeth

Dentine hypersensitivity has of long been known to be a common clinical problem in dental practices. Lasers have recently come to play a prominent role in the treatment of this disorder. They might, however, cause dental pulp damage. This study was conducted to evaluate the effect of Nd:yttrium-aluminum-garnet (YAG) laser on partial oxygen saturation of pulpal blood in sensitive anterior teeth. In this clinical trial, 65 hypersensitive teeth were selected and randomly allocated to two groups. The study group involved Nd:YAG laser treatment, while no treatment was employed for the control group. Using a pulse oximetry system, evaluations were preformed of the partial oxygen saturation in the pulpal blood before, immediately after, 1 week after, and 1 month after the treatment. The results were analyzed using the SPSS software and repeated-measures analysis of variance and paired-samples t tests. The mean partial oxygen saturation of the blood was found to be 85.4% in the study group, which was not significantly different from that of the control group. No significant differences were observed in the control group between the means obtained from pretreatment and post-treatment intervals (P > 0.05). The Post-treatment partial oxygen saturation mean rose to 89.3% (P = 0.001) and remained constant throughout the following week after it. However, no significant differences were found between the pretreatment partial oxygen saturation mean and the same measurement 1 month after treatment (P = 0.702). Nd:YAG laser therapy for dentine desensitization of anterior teeth caused no persistent changes in the partial oxygen saturation of pulpal blood. It may, therefore, be concluded that the diffusion of heat induced by the Nd:YAG laser into the pulp within the limit of the desensitization parameters cause no irreversible damages in the dental pulp.

Lasers and soft tissue: 'fixed' soft tissue surgery

Within a general practice setting, there are few benign pathological conditions of the attached or keratinised gingival complex that are not amenable to simple surgical intervention. The majority of surgical procedures are adjunctive to the delivery of restorative dentistry. There is an understandable dogma worldwide towards the management of soft tissues as they interface with restorative procedures. Contemporary teaching, both at undergraduate and postgraduate level, would recognise the need for a period of wound healing and stability, based on scalpel-induced incisional therapy. The use of laser wavelengths, based on predictable evidence-based protocols, has re-defined the surgical management of keratinised mucosa that is bound to the underlying periosteum and bone. This can be seen as being of benefit to the clinician in determining the outcome, and the patient in achieving quality results.

Procurement of Autogenous Bone from the Mandibular Ramus with Simultaneous Third-Molar Removal for Bone Grafting Using the Er, Cr:YSGG Laser: A Preliminary Report

Autogenous bone grafting and third-molar removal are surgical procedures routinely performed in dentistry on a daily basis. The purpose of this preliminary report is to describe our clinical experience with the Er, Cr:YSGG laser in the procurement of bone harvested from the ramus and removal of third molars simultaneously from the mandible.

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.

Lasers in periodontics

Publicity about the use of lasers in dentistry has generated considerable interest in both professional and lay audiences. The purpose of this report is to provide information for members of the dental profession about the current and potential application of laser technology to periodontal practice. This report was prepared by the Research, Science and Therapy Committee of the American Academy of Periodontology.

Feline odontoclastic resorptive lesions an unsolved enigma in veterinary dentistry

This article presents a comprehensive review of the literature on feline odontoclastic resorptive lesions (FORLs), including etiopathogenesis, prevalence and predisposition, classification, histopathologic appearance, diagnosis, and treatment. Approximately one-third of all domestic cats may develop FORLs during their life span, and the risk of developing FORLs increases with age. Sophisticated dental treatments promise neither cure nor permanent improvement of affected teeth. Extraction is the current treatment of choice. Research on the etiology of FORLs has not been rewarding in recent years, and the causative factors contributing to the development of FORLs are still unknown.

Pulsed Nd:YAG laser irradiation of the tooth pulp in the cat: II. Effect of scanning lasing

BACKGROUND AND OBJECTIVE

The purpose of the present study was to assess whether "scan irradiation" with a pulsed Nd:YAG laser could produce changes in intrapulpal nerve activities and pulpal blood flow and to investigate whether it would cause tissue damage in the pulp.

STUDY DESIGN/MATERIALS AND METHODS

The pulsed Nd:YAG laser was used to irradiate, in a scanning manner, the canine tooth pulp in sodium pentobarbitone anesthetized cats. The compound action potentials and spike response in the functional single afferent nerve fibers were recorded while responding to various external stimuli applied to the exposed dentin. Histologic observation was performed to detect lasing-induced tissue changes.

RESULTS

Pulpal compound action potentials evoked by various external stimuli were significantly reduced (P < 0.05) and unit firings were observed in both functional single A delta- and C-fibers during irradiation. Unit responses to external mechanical stimulation of the dentin completely disappeared after "scan irradiation" with the pulsed Nd:YAG laser. Histologic observation revealed that irradiation with the laser produced tissue damage in the pulp.

CONCLUSION

"Scan irradiation" with the pulsed Nd:YAG laser of cat's teeth produced alterations in the intrapulpal nerve activities, as well as caused tissue damage in the pulp.