Achieving Dental Analgesia with the Erbium Chromium Yttrium Scandium Gallium Garnet Laser (2780 nm): A Protocol for Painless Conservative Treatment.

OBJECTIVE: The aim of this research is to evaluate those techniques and optimal parameters of Erbium Chromium Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser use in delivering predictable painless (or with very limited discomfort) restorative cavity preparation without the aid of injected local anesthesia. MATERIAL AND METHODS: This study was conducted on 30 patients (26 adults and 4 youth 9-16 years old; average age, 37) treated in a private practice. For each patient, a single cavity was prepared using the Er,Cr:YSGG laser (2780 nm). An Electric Pulp Tester (EPT) was used to monitor the changes in pulp sensibility threshold. The patient experience was tested before and after the treatment using a modified Visual Analogue Scale (VAS) and Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) to evaluate pain and anxiety. RESULTS: Pain analysis indicated that 80% of patients (24 out of 30) felt no pain and no discomfort, or only a very slight sensation. None of the 30 patients requested anesthesia. EPT was found to be unreliable in evaluating pulpal pain threshold levels. A tendency was noted wherein greater discomfort was felt by anxious patients. On average, the older the patient, the less discomfort was felt. The factors that have a greater tendency to promote discomfort were: posterior teeth, greater caries depth, greater use of higher power levels and ablation time. CONCLUSIONS: Using the Er,Cr:YSGG laser, it was possible to avoid local anesthesia during cavity preparation with a bur. The treatment was effective in a high number of cases (80%), leading to reduction in the anxiety frequently associated with dental care.

A three-dimensional evaluation of microleakage of class V cavities prepared by the very short pulse mode of the erbium:yttrium-aluminium-garnet laser.

The aim of this study was to evaluate microleakage along resin restoration in cavities prepared with an erbium:yttrium-aluminium-garnet (Er:YAG) laser, with and without acid etching, and to compare it with that in diamond-drilled cavities. Thirty intact molars were divided into three equal groups. In the teeth in group I, class V cavities were prepared with a diamond drill. Cavities in groups II and III were prepared with an Er:YAG laser (400 mJ/15 Hz for enamel and 250 mJ/10 Hz for dentine). The cavities in groups I and II were acid-etched and adhesive and flowable composite were applied to all cavities. The specimens were first immersed in dye for 24 h and then in 5% nitric acid for 72 h for softening. The fillings were extracted and photographed through a dissecting microscope. The leakage area was measured with specially designed software. The Kruskal-Wallis test showed that the best ranking was group II [mean range (m.r.) = 27.46], followed by group I (m.r. = 33.48) and, lastly, group III (m.r. = 45.15). The differences between groups I and III (P = 0.023) and between groups II and III were statistically significant (P = 0.080). The least microleakage was found in those cavities prepared by Er:YAG laser and subsequently acid-etched, whereas the most leakage was in the lased cavities that had not been etched; the traditional diamond-drilled acid-etched cavities produced medium leakage.

Influence of cavity preparation with Er:YAG Laser on enamel adjacent to restorations submitted to cariogenic challenge in situ: a polarized light microscopic analysis.

BACKGROUND AND OBJECTIVES: Er:YAG laser has been used for caries removal and cavity preparation, using ablative parameters. Its effect on the margins of restorations submitted to cariogenic challenge has not yet been sufficiently investigated. The aim of this study was to assess the enamel adjacent to restored Er:YAG laser-prepared cavities submitted to cariogenic challenge in situ, under polarized light microscopy. STUDY DESIGN/MATERIALS AND METHODS: Ninety-one enamel slabs were randomly assigned to seven groups (n = 13): I, II, III-Er:YAG laser with 250 mJ, 62.5 J/cm2, combined with 2, 3, and 4 Hz, respectively; IV, V, VI-Er:YAG laser with 350 mJ, 87.5 J/cm(2), combined with 2, 3, and 4 Hz, respectively; VII-High-speed handpiece (control). Cavities were restored and the restorations were polished. The slabs were fixed to intra-oral appliances, worn by 13 volunteers for 14 days. Sucrose solution was applied to each slab six times per day. Samples were removed, cleaned, sectioned and ground to polarized light microscopic analysis. Demineralized area and inhibition zone width were quantitatively assessed. Presence or absence of cracks was also analyzed. Scores for demineralization and inhibition zone were determined. RESULTS: No difference was found among the groups with regard to demineralized area, inhibition zone width, presence or absence of cracks, and demineralization score. Inhibition zone score showed difference among the groups. There was a correlation between the quantitative measures and the scores. CONCLUSION: Er:YAG laser was similar to high-speed handpiece, with regard to alterations in enamel adjacent to restorations submitted to cariogenic challenge in situ. The inhibition zone score might suggest less demineralization at the restoration margin of the irradiated substrates. Correlation between the quantitative measures and scores indicates that score was, in this case, a suitable complementary method for assessment of caries lesion around restorations, under polarized light microscopy.

Influence of local anaesthesia on the quality of class II glass ionomer restorations.

OBJECTIVE: To investigate the influence of local anaesthesia on the quality of class II glass ionomer restorations with discomfort as cofactor. MATERIAL AND METHODS: The study population consisted of 6- to 7-year-old schoolchildren in Paramaribo and its environs. To be included, each child needed to have a proximally situated cavity in a primary molar that was accessible to hand instruments and where no pulp exposure was expected. They were randomly divided into four treatment groups: conventional method with and without local anaesthesia and atraumatic restorative treatment method (ART) with and without local anaesthesia. The restoration quality was scored using the evaluation criteria for ART restorations (successful if restoration is correct or has a minor defect and fails if defects are larger than 0.5 mm, if secondary caries is observed, if the restoration is fractured, partly or totally lost or if the pulp is involved) at 6 and 30 months after treatment. The extent of discomfort was registered by assessing the behaviour (modified Venham score) and observing the heart rate during treatment. RESULTS: For this study 153 children were treated with hand instruments (ART) and 146 children with rotary instruments (conventional method). A total of 198 restorations were evaluated during follow-up periods. There were no significant differences in patient discomfort between the ART and the conventional group and between the anaesthesia and the non-anaesthesia group. The conventional restorations demonstrated significantly higher success rates than ART restorations after 6 (P = 0.001) and 30 months (P = 0.032). There were no significant differences in success rate between the anaesthesia and the non-anaesthesia group. CONCLUSION: Local anaesthesia has no influence on discomfort during treatment. Furthermore, discomfort during treatment does not affect the success rate of restorations.

A randomised, controlled and blinded histological and immunohistochemical investigation of Carisolv on pulp tissue.

OBJECTIVES: This investigation was undertaken to test the hypothesis that Carisolv would show the same safety profile as physiologic saline when in direct contact with pulp tissue for 30 min. Furthermore, the sensory nerve fibre reaction in response to the injury was evaluated. METHODS: Incisors and molars in 40 Sprague-Dawley rats were opened and the pulp tissue randomly exposed to either Carisolv or NaCl for 30 min. Observation periods ranged from I day to I week. RESULTS: Light microscopic examination showed an almost identical cellular response in both test teeth and controls, which consisted of a localised inflammation represented predominantly by macrophages. Immunohistochemistry revealed an accumulation of beaded CGRP-immunoreactive fibres in immediate vicinity of the lesion, suggesting that the nerves had emitted small sprouts. Some fibres at this location were SP-positive, but very few, or no nerve fibres, displayed NPY-immunoreactivity. This innervation pattern was seen in both test and controls in similar distribution and at similar intensity. CONCLUSIONS: Results obtained in this study suggests the hypothesis to be valid, i.e. Carisolv does not seem to add appreciable adverse effects over and beyond what is caused by the experimental procedures. Furthermore, Carisolv does not seem to influence the distribution or neuropeptide expression of sensory nerve fibres in the pulp.

The safety and efficacy of treatment with air abrasion technology.

AIMS: To evaluate patient and operator exposure to respirable particulates following the use of air abrasion in tooth preparation, and to compare the microleakage of pit and fissure sealants after conventional, bur and air abrasion preparation of the pits and fissures. METHODS: To examine air abrasion safety, sampling data were collected using a physical model of the upper torso of a patient. Previously extracted bovine incisors were prepared using an air abrasion instrument. Patient and operator exposure samples were collected. The variables examined included the size of the alumina oxide particles, the speed of particle delivery and the method of dust collection. To assess the efficacy of air abrasion, 36 extracted human molars were divided into three groups. The groups were prepared by conventional acid etching, opening the pits and fissures with a round bur, or by air abrasion. To simulate oral conditions, sealed teeth were immersed in artificial saliva and thermocycled. Teeth were immersed in a 1% solution of methylene blue and sectioned to assess the microleakage associated with each sealant. CONCLUSIONS: (1) Dust from the KCP 1000 is insufficient to be a health hazard to patients or operators, (2) chair-side suction can be used as an alternative to the KCP 1000 suction, (3) superior sealants were obtained when tooth surfaces were prepared by a bur, compared to air abrasion and conventionally prepared surfaces, and (4) air abrasion tooth surfaces demonstrated less microleakage than conventionally prepared tooth surfaces.

Clinical evaluation of transcutaneous electronic nerve stimulation for pain control during tooth preparation.

The purpose of this study was to evaluate the effectiveness of a transcutaneous electrical nerve stimulation unit. The effects of electronic dental anesthesia and local anesthesia for deep cavity preparations in primary molars were compared in children aged 7 to 9 years by using the Eland Color Scale. The patients had symmetric teeth requiring Class I cavity preparation. One of the teeth was treated with electronic anesthesia and the other with local anesthesia. The tooth and method were selected randomly. Both restorations were finished at the same visit. There was no statistically significant difference between the groups in the perception of pain. Fifty-six percent of the children preferred transcutaneous electrical nerve stimulation, while 36% of them preferred local anesthesia.

Kinetic cavity preparation: protection of the cavo-surface enamel.

A significant defect of kinetic cavity preparation systems is damage to cavo-surface sound tooth enamel. The purpose of this study is to establish a protective method for cavo-surface sound tooth enamel during air-powder abrasive system cavity preparation, using protective varnish. A total of 39 extracted human primary teeth were used for this experiment. Protective varnish was applied to the tooth surface in single, double and triple coats. The kinetic instrument was used for cavity preparation. Class V cavities were prepared on the border area of varnish coated and intact tooth surface. After removal of varnish with a supersonic washer, specimens were dried and gold plated with ion-spatter, following which cavity margin enamel was observed through a SEM. Tooth surface enamel where coated with varnish appeared intact and the cavo-surface margin remained at a right angle form. However, tooth surface enamel without varnish coating appeared rough, and the cavo-surface margin exhibited a round shape. It seems likely that kinetic energy was absorbed by the soft varnish coating, thereby protecting the enamel. Protective varnish was found to provide a protective effect for cavo-surface sound enamel, and was also found to promote a sharp edge at the cavo-surface margin, during kinetic cavity preparation.

Histopathologic effects of kinetic cavity preparation for the removal of enamel and dentin. An in vivo animal study.

Recent developments in technology, direct placement restorative materials, and cavity preparation design have renewed interest in kinetic cavity preparation, a term to describe the use of air-abrasion for removal of tooth structure. This study compared the pulpal response of 120 teeth in mixed-breed dogs treated with four kinetic cavity preparation combinations of pressure (80 psi and 160 psi) and aluminum oxide particle sizes (27 microns and 50 microns) to those treated with high-speed rotary burs. Class V buccal preparations were made and restored with an interim material. Teeth were collected 72 hours after surgery, decalcified, sectioned, stained with hematoxylin and eosin, and blindly evaluated by two examiners at the minimal dentin thickness. Samples were graded for extent of displacement, disruption, inflammation, and necrosis of pulpal structures. Differences between groups were analyzed with the use of Bonferroni-adjusted multiple Mann-Whitney-Wilcoxon tests with p < 0.05 being significant. Higher pressures and smaller particles yielded significantly fewer pulpal effects than the high-speed treated teeth whereas lower pressures and larger particles were not significantly different for most effects evaluated. No adverse soft tissue effects were noted when kinetic cavity preparation was directed at attached gingiva.

Transcutaneous electrical nerve stimulation (TENS) for pain management during cavity preparations in pediatric patients.

The purpose of this study was to evaluate the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) in pain reduction during cavity preparations in pediatric patients. Twenty patients, ages eight to fourteen years, were treated for Class I amalgam restorations in mandibular first permanent molars using TENS in a double blind protocol. Randomized assignments were made for ten experimental and ten control patients. Using the visual analogue scale, the ANOVA test indicated a significant decrease (p < 0.01) in patient ratings between the TENS experimental and the control group. It can be concluded there was a statistically significant decrease in the pain perceptions of pediatric patients during Class I amalgam cavity preparations in mandibular first permanent molars.

Temperature rise due to finishing of direct restorative materials.

An in vitro study was performed to evaluate the effect of four variables on the temperature rise produced by the finishing of restorations. The four variables were: restorative material, finishing agent, finishing time, and depth of dentin under the restoration. Class V preparations were cut on extracted premolars and restored with amalgam, composite, or glass ionomer cement. Finishing was done with wet pumice and cup, wet pumice and a brush, a grit rubber polishing point, and an aluminum oxide- coated disc. Finishing time was continuous or intermittent for up to 1 minute. Dentin thickness under the restoration was 0.5 mm to 3.0 mm. Amalgam produced the highest temperature rises at the pulp, while composite and glass ionomer were no different than the untreated (virgin) tooth. Aluminum oxide discs produced the largest temperature rise, wet pumice with a brush the least. Temperature rise increased almost linearly with continuous finishing, while intermittent finishing significantly reduced temperature rise in all cases. Thickness of remaining dentin was only significant for the amalgam restoration, and then only at 1.0 and 0.5 mm.

Character and frequency of discomfort immediately following restorative procedures.

Within 24 hours after dental treatment, discomfort was experienced by 78% of the patients questioned. Sensitivity to cold was the most frequent type of discomfort experienced (reported by 50% of the patients). Postoperative discomfort resulting from cold stimulus was most often mild (in 78%), occasionally moderate (in 22%), and never severe. The duration of postoperative discomfort resulting from cold stimulus was most often fleeting (reported by 94%) and seldom prolonged (reported by 6%). The second most frequent type of postoperative discomfort reported was associated with the administration of the local anesthetic. Sensitivity to sweets does not seem to be a source of postoperative discomfort following routine operative dental procedures.