Hard Tissue Laser Research Articles

Evaluation of self-etching primer and erbium-doped yttrium aluminum garnet laser on bracket bond strength: An in-vitro study

Introduction: The purpose of this study was to evaluate and compare the shear bond strength, the adhesive remnant scores and surface characteristics of the teeth prepared for bonding with erbium-doped yttrium aluminum garnet (Er:YAG) hard tissue laser, self-etching primer (SEP) and phosphoric acid etching. Materials and Methods: Seventy-eight human premolars, extracted for orthodontic purposes were randomly divided into three groups, enamel was irradiated with 37% phosphoric acid in Group-1, with SEP in Group-2 and with Er:YAG laser at 1.5-W in Group-3. After surface preparation standard edgewise stainless steel premolar brackets were bonded; one tooth in each group was not bonded and was examined under a scanning electron microscopic. The brackets were debonded 24 h later; shear bond strengths were measured, and adhesive remnant index scores were recorded. Results: Statistically significant differences were found between phosphoric acid etching, SEP, 1.5-W laser irradiation. Adhesive remnant scores were compared with the Chi-square test, and statistically significant differences were found between all groups. Conclusions: The mean shear bond strength obtained with 37% phosphoric acid etching, SEP and Er-YAG laser etching were clinically acceptable. SEP produces a more conservative etch pattern and more shear bond strength than phosphoric acid. More adhesive was left on the SEP treated enamel as compared to enamel treated with acid and laser etching.

Hard tissue lasers: An insight

Origin of light amplification for stimulated emission of radiation (LASER) had its roots way back in 1960 when Maiman invented the first hand held ruby laser. LASER is the common acronym used for LASER. Current scientific review has touched various aspects like the historical landmarks, luminaries behind several landmarks in the invention of lasers in a chronological order, hard tissue lasers along with dental operating microscope and magnification have made practice of restorative and microsurgery facile and due to its versatility have found numerous applications extending to almost all spheres of restorative dentistry and minor oral surgery. Owing to its profound advantages such as reduced anxiety to drill phobic patients, excellent predictability, and uneventful postoperative healing have urged modern dental surgeons to embrace laser technology aggressively. This review addresses hard tissue laser physics, protocols and parameters and clinical applications and tips.Clinical Relevance To Interdisciplinary Dentistry Erbium lasers have increased affinity for basic chromphores like water and hydroxyapatite crystals. This affinity makes these lasers suitable for various restorative clinical procedures involving both hard and soft tissues. They are a valuable adjunct in:Tooth preparation for restorative procedure, etching of enamel, relative analgesia, disinfection of root canal lumen and they can also effectively disinfect enamel up to 300-400 μm Periodontal surgical procedures such as gingivectomy, gingivoplasty, frenotomy, osseous recountouring and removal of subgingival calculusCrown lengthening, tooth preparation, implant osteotomy, recovery of implants, effective disinfection of perimplantitis, creating positive bony architecture etc.

Measurements of erbium laser-ablation efficiency in hard dental tissues under different water cooling conditions

Laser triangulation measurements of Er:YAG and Er,Cr:YSGG laser-ablated volumes in hard dental tissues are made, in order to verify the possible existence of a "hydrokinetic" effect that has been proposed as an alternative to the "subsurface water expansion" mechanism for hard-tissue laser ablation. No evidence of the hydrokinetic effect could be observed under a broad range of tested laser parameters and water cooling conditions. On the contrary, the application of water spray during laser exposure of hard dental material is observed to diminish the laser-ablation efficiency (AE) in comparison with laser exposure under the absence of water spray. Our findings are in agreement with the generally accepted principle of action for erbium laser ablation, which is based on fast subsurface expansion of laser-heated water trapped within the interstitial structure of hard dental tissues. Our measurements also show that the well-known phenomenon of ablation stalling, during a series of consecutive laser pulses, can primarily be attributed to the blocking of laser light by the loosely bound and recondensed desiccated minerals that collect on the tooth surface during and following laser ablation. In addition to the prevention of tooth bulk temperature buildup, a positive function of the water spray that is typically used with erbium dental lasers is to rehydrate these minerals, and thus sustaining the subsurface expansion ablation process. A negative side effect of using a continuous water spray is that the AE gets reduced due to the laser light being partially absorbed in the water-spray particles above the tooth and in the collected water pool on the tooth surface. Finally, no evidence of the influence of the water absorption shift on the hypothesized increase in the AE of the Er,Cr:YSGG wavelength is observed.

Effectiveness of Er,Cr:YSGG Laser in the Excision of different Oral Soft Tissue Lesions

Er,Cr:YSGG laser, a hard tissue laser absorbed well by chromophore water apart from hydroxyl appetite crystals can be used in the excision of soft tissue lesions. Aims and objectives: To assess the effectiveness of Er, Cr: YSGG laser in the excision of four different soft tissue lesions and the objective was to assess pain during and after procedure, bleeding during procedure and wound healing after 1 week. Materials and methods: Four patients with different soft tissue lesions, such as peripheral ossifying fibroma, traumatic fibroma, intraoral lipoma and fibroma of the gingival. Er, Cr: YSGG laser with a wavelength of 2,780 nm (Waterlase, MD, Biolase, USA) with the settings of 1.50 W, air 30% and water 10%, MT, H mode, 25 Hz was used and pain assessed by behavioral pain rating scale, ‘faces’ pain rating scale and visual analog scale, bleeding and wound healing by visual method with photographs. Results: No discomfort to the patient during and after laser procedure, no local anesthesia needed, no suture, no antibiotics were prescribed. Minimal bleeding was dere. No edema and good wound healing was observed. Conclusion: Er, Cr: YSGG laser can be used as an alternative to conventional scalpel excision.

Nd: yag & Er:yag Lasers in Prevention and Conditioning of Enamel by Nabiha Hussain

The Food and Drug Administration (FDA) has approved of a variety of hard and soft tissue lasers for use in the dental treatment of adults and children. Because dental lasers boast unique absorption characteristics, they are used to perform specific dental procedures and improve its characteristics by using some of lasers in prevention and conditioning of enamel as Nd:yag and Er:yag lasers. Lasers have been tested to improve enamel properties in order to enhance its resistance to demineralization. Since the 1960s, when associated with fluoride by special wavelengths of some lasers. This study evaluated the influence of both Er: YAG and Nd: YAG laser irradiation on deciduous enamel demineralization. The Nd: YAG laser wavelength of 1064nm exhibits strong thermal effect in soft dental tissue because of its appropriate absorption characteristics, is also efficient in the increase of the enamel resistance and play an important role in the prevention of dental caries by forming enamel granules of variable sizes. Er:YAG. Its emitted wavelength of 2940nm matches exactly the maximal absorption in water which play main role in conditioning of Hydroxyapatite nanorods of enamel.

Diode Laser and White Lesions: A Clinical Study on Postoperative Recovery, Depth Control and Wound Healing

Laser dentistry has always been a subject of interest. Among hard and soft tissue lasers, the latter finds much more acceptance in terms of clinical applications. Diode lasers have found much acceptance in all the branches of dentistry. Compact size and financially viable-diode laser has become a big practice enchancer tool. The difference in contact and noncontact mode in treating white lesions, in terms of various clinical parameters has been discussed.

American Academy of Periodontology Statement on the Efficacy of Lasers in the Non‐Surgical Treatment of Inflammatory Periodontal Disease

American Academy of Periodontology Statement on the Efficacy of Lasers in the Non‐Surgical Treatment of Inflammatory Periodontal Disease

Restorative Dentistry for Children Using a Hard Tissue Laser

This article will describe how a hard tissue laser is used in various restorative procedures. The erbium family of lasers (Er,Cr:YSGG and Er:YAG) are highly absorbed in water and, to a lesser extent, in tooth mineral. Because a carious lesion contains significantly more water than healthy enamel or dentin, the laser can offer some selectivity in removing the diseased material. Furthermore, these lasers can offer some degree of anesthesia. In these clinical photos, an Er,Cr:YSGG laser (Waterlase or Waterlase MD, 2780-nm; Biolase Technologies, Irvine, CA) was used.

Thulium fiber laser lithotripsy: An in vitro analysis of stone fragmentation using a modulated 110-watt Thulium fiber laser at 1.94 µm

The high-power Thulium fiber laser has previously been shown to rapidly vaporize and coagulate soft urinary tissues (e.g., prostate). This is the first preliminary study of a high-power Thulium fiber laser for fragmentation of urinary stones. A continuous-wave, high-power Thulium fiber laser operating at a wavelength of 1.94 microm, was modulated to operate in pulsed mode with an output pulse energy of 1 J through a 300-microm-core silica fiber at a 20 milliseconds pulse length and repetition rate of 10 Hz. The fragmentation time to reduce uric acid (UA) (n = 13) and calcium oxalate monohydrate (COM) (n = 6) stones into particles < 2 mm was measured. Mean initial mass of the UA and COM stones measured 860+/-211 and 763 +/- 204 mg. Fragmentation rates measured 388 +/- 49 and 25 +/- 2 mg/minute. Average time needed to fragment the UA and COM stones into particles < 2 mm was 2.25 +/- 0.63 and 30.7 +/- 8.4 minutes, respectively. The high-power Thulium fiber laser, when operated in pulsed mode, is capable of fragmenting both soft (UA) and hard (COM) urinary stones. The Thulium fiber laser may be useful as a single laser system for use in multiple soft and hard tissue laser ablation applications in urology.

LASERS AND AIR ABRASION: New Modalities for Tooth Preparation

Hard tissue lasers and air abrasion units have a place in the modern dentist's armamentarium. Speed, comfort, ease of approach, public relations, and patient appeal are some of the advantages. The dentist's own comfort and satisfaction, knowing that he or she is doing the best dentistry without frightening the already fearful patient, should help the dentist decide which one of the modalities to incorporate into his or her practice.

THE FUTURE OF LASERS IN DENTISTRY

In 1998, a laser-related trade journal printed an article on laser dermatology indicating that because of new applications, reduced prices, and instruments becoming more user-friendly, the dermatology laser market was becoming a billion dollar industry. If the same holds true in dentistry--keeping in mind that there are only approximately 7000 dermatologists in the United States--think of the potential for the dental laser market. It is huge, but to reach that potential, several criteria must be met: Market penetration must double in the next 4 to 5 years. Instrument sizes must diminish. Laser prices must decrease to an average of $10,000 for soft tissue lasers and $25,000 for hard tissue lasers over the next 10 years. Meeting these criteria would generate the necessary revenues for increased expenditures for research and development to improve existing delivery systems and develop new fiber types, continue development of a short-pulsed hard tissue laser to replace air turbines, and combine wavelengths into a single package, while looking into new wavelengths. If all of the above-mentioned become a reality in 10 to 15 years, the growth of the dental laser market could be limitless because of the hugeness of the worldwide dental marketplace. The last 20 years have witnessed many new developments in dental technologies, and the next 20 years promise to be even richer in technologic advancements. Lasers will be in the forefront of that growth.

HARD TISSUE LASER PROCEDURES

A more conservative, less invasive treatment of the carious lesion has intrigued researchers and clinicians for decades. With over 170 million restorations placed worldwide each year, many of which could be treated using a laser, there exists an increasing need for understanding hard tissue laser procedures. An historical review of past scientific and clinical hard research, biophysics, and histology are discussed. A complete review of present applications and procedures along with their capabilities and limitations will give the clinician a better understanding. Clinical case studies, along with guidelines for tooth preparation and hard tissue laser applications and technological advances for diagnosis and treatment will give the clinician a look into the future.

Pulpal Temperature Changes During Desensitisation And Other Low‐Power Hard‐Tissue CO2 Laser Procedures

AbstractThermal insult to pulpal tissue is recognised as a major limitation to the use of lasers for dental hard tissue procedures. This study examined thermal changes at the level of the dental pulp in human molar teeth irradiated with a CO2 dental laser using a pulsed mode of operation. Sectioned molar teeth were exposed, in vitro, to CO2 laser radiation. The laser parameters were those used clinically for laser desensitisation and laser‐enhanced fluoride treatment. Fissure regions and root surfaces were irradiated. For settings which might reasonably be used clinically, the temperature rise was not of a magnitude which would be expected to cause pulpal inflammation or necrosis. With regard to thermal properties of tooth structure, times taken to reach the maximum temperature reduced, and times taken to cool to baseline increased with increasing laser exposures.

Hard tissue laser ablation mechanisms

The aim of this work is the experimental and theoretical investigation of the influence of variable laser parameters (wavelength, fluence, pulse repetition rate) and of the optical and thermophysical properties of bone tissue (absorption coefficient, tissue inhomogeneity) as well as of the sample thickness on ablation thresholds and ablation rate. Ablation and perforation experiments were conducted using a semiconductively pre-ionized transverse excitation atmospheric pressure (TEA) carbon dioxide (CO2) laser (10.6Μm and a sliding discharge TEA [hydrogen fluoride (HF)] laser (2.9Μm). The experimental data are discussed with respect to the following ablation mechanisms: thermal melting and vaporization process, pressure oscillation of gases released by the thermal decomposition of collagen and/or apatite, stresses due to the expansion of superheated water.