Assessment of Er:YAG laser for cavity preparation in primary and permanent teeth: a scanning electron microscopy and thermographic study

PURPOSE

Most studies of cavity preparation using Er:YAG lasers have employed permanent teeth. This study's purpose was to compare the cutting efficiency of an Er:YAG laser versus diamond burs in primary and permanent teeth in order to measure thermal effects on the pulp and evaluate lased surfaces using scanning electron microscopy (SEM).

METHODS

A total of 80 primary and permanent teeth were used. Crater depths and mass loss were measured after delivering laser pulses at varying energies onto sound or carious enamel or dentin using the Key-3 laser. Control samples were cut using diamond burs in an air turbine handpiece. Thermal changes were measured using miniature thermocouples placed into the pulp chamber. Lased surfaces were evaluated using SEM.

RESULTS

Laser ablation crater-like defects were deeper in dentin than enamel at the same pulse energy. Greater ablation rates for dentin and enamel and significantly more efficient removal of carious tooth structure by laser was present in primary teeth. Temperature rises in the pulp did not exceed the 5.5 degrees Celsius threshold in any teeth during laser ablation.

CONCLUSIONS

The Er:YAG laser is an efficient device for cavity preparations in primary teeth, with no unacceptable increases in temperature detected in this model.

Polymerization shrinkage of different types of composite resins and microleakage with and without liner in class II cavities

AIM

To determine the volumetric polymerization shrinkage of four different types of composite resin and to evaluate microleakage of these materials in class II (MOD) cavities with and without a resin-modified glass ionomer cement (RMGIC) liner, in vitro.

MATERIALS AND METHODS

One hundred twenty-eight extracted human upper premolar teeth were used. After the teeth were divided into eight groups (n=16), standardized MOD cavities were prepared. Then the teeth were restored with different resin composites (Filtek Supreme XT, Filtek P 60, Filtek Silorane, Filtek Z 250) with and without a RMGIC liner (Vitrebond). The restorations were finished and polished after 24 hours. Following thermocycling, the teeth were immersed in 0.5% basic fuchsin for 24 hours, then midsagitally sectioned in a mesiodistal plane and examined for microleakage using a stereomicroscope. The volumetric polymerization shrinkage of materials was measured using a video imaging device (Acuvol, Bisco, Inc). Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U-tests.

RESULTS

All teeth showed microleakage, but placement of RMGIC liner reduced microleakage. No statistically significant differences were found in microleakage between the teeth restored without RMGIC liner (p>0.05). Filtek Silorane showed significantly less volumetric polymerization shrinkage than the methacrylate-based composite resins (p<0.05).

CONCLUSION

The use of RMGIC liner with both silorane- and methacrylate-based composite resin restorations resulted in reduced microleakage. The volumetric polymerization shrinkage was least with the silorane-based composite.

Long-term evaluation and clinical outcomes of children with dental transplants in Temuco city, Chile

AIM

To assess the clinical and radiographic outcomes of 36 transplanted teeth and the possible factors affecting the results.

MATERIALS AND METHODS

In 26 children, 36 teeth transplants were performed. The main reason for transplantations was the loss of anterior teeth due to trauma; 80.5% of transplanted teeth were immature bicuspids. The transplants were clinically and radiolographycally monitored in respect of pulp vitality, root canal obliteration, periradicular changes and root formation. Fisher Exact Test and Kaplan-Meier analyses were performed to determine the association between the variables and estimation of survival rates, respectively.

RESULTS

Thirty (83.3%) of the transplantations were recorded as successful and six as unsuccessful (16.7%). The survival rate was 97.2% during average time of 47.5 months ± 27.8 SD. Only one tooth had been extracted and 5 had survived in not ideal conditions. The majority of immature transplanted teeth developed pulp canal obliteration.

CONCLUSION

Factors associated to successful outcome were immature root formation of donor tooth and short flexible splinting period. The main factor associated to failure was replacement resorption. The surgical technique did not present statistical significance in the clinical outcome. Tooth transplantation has shown high success and survival rates, and should be considered as a real option in growing patients.

Clinical evaluation of resin-based composites in posterior restorations: a 3-year study

OBJECTIVES

The aim of this study was to evaluate the clinical performance of a nanohybrid and a microhybrid composite in class I and II restorations after 3 years.

SUBJECTS AND METHODS

A total of 82 class I and class II restorations were performed in 31 patients (10 males and 21 females) using Grandio and QuiXfil with self-etch adhesives (Futurabond and Xeno III). The restorations were clinically evaluated by 2 operators 1 week after placement (baseline) and at 6 months and 1, 2, and 3 years using modified United States Public Health Service (USPHS) criteria. At the 3-year follow-up, 62 class I and class II cavities were reevaluated in 23 patients (7 males and 16 females). Statistical analysis was performed using Pearson's χ(2) and Fisher's exact tests (p < 0.05).

RESULTS

At the 6-month follow-up, all restorations received Alfa scores with respect to each evaluation criterion. At the 1-year follow-up, 2 QuiXfil restorations had to be replaced and Grandio restorations started to deteriorate in terms of marginal adaptation. At the end of 2 years, 9 Grandio restorations showed significant deterioration of the surface properties, demonstrating Bravo scores. At the end of 3 years, no significant differences were observed regarding color match, marginal adaptation, secondary caries, marginal discoloration, and anatomic form loss between the evaluated materials in 25 class I and 37 class II restorations. At the 3-year follow-up, Grandio restorations had 21% Bravo scores and showed significant deterioration of the surface properties, which were still clinically acceptable according to USPHS criteria. Three QuiXfil and 1 Grandio restorations were replaced because of secondary caries and loss of retention.

CONCLUSIONS

Both the nanohybrid (Grandio) and the microhybrid (QuiXfil) composites were clinically functional after 3 years.

Efficacy of four lining materials in sandwich technique to reduce microleakage in class II composite resin restorations

OBJECTIVES

The aim of the present study was to evaluate the effect of four different sandwich techniques on gingival microleakage of Class II direct composite resin restorations.

MATERIALS AND METHODS

Fifty sound human premolars were selected and randomly divided into five groups (n=10). Class II box only cavities were prepared in one of the proximal surfaces of each tooth with a gingival margin located approximately 0.5 mm below the cemento-enamel junction. Group A (control) was restored incrementally with composite resin (Tetric Ceram). Groups B, C, D, and E were restored with the sandwich technique using a compomer (Compoglass F), flowable composite resin (Tetric Flow), self-cure composite resin (Degufill SC), or resin modified glass ionomer (Fuji II LC), respectively. After thermal-load cycling, the specimens were immersed in 0.5% basic fuschin for 24 hours. Dye penetration (10(-1) mm) was detected using a sectioning technique. Data were analyzed with repeated measurements and Duncan test at α=0.05.

RESULTS

The least amount of microleakage was detected in the incremental group (1.28 ± 0.98). The sandwich technique using resin modified glass ionomer (7.99 ± 9.57) or compomer (4.36 ± 1.78) resulted in significantly more leakage than did the sandwich technique using flowable (1.50 ± 1.97) or self-cure composite (2.26 ± 1.52).

CONCLUSION

According to the results of this study, none of the four sandwich technique composite resin restorations used in this study could reduce gingival microleakage to a greater degree than the incremental technique.

[Medical exchange between faculty of medicine, university of the Ryukyus and Laos country. Medical support with a cleft lip and palate treatment]

The Faculty of Medicine, University of the Ryukyus, started a "Public Health Project in Lao P.D.R.", which is one of the JICA projects, in 1992, and has been carrying out the "Sethathirath Hospital Improvement Project" since 1999 to improve medical treatment and health care in Lao P.D.R. Marked progress has been made. In addition, the projects of "Medical support for cleft lip and palate patients" performed by both the Oral and Maxillofacial Surgery Department of the University of the Ryukyus Hospital and Okinawa-Laos Cleft Lip and Palate Support Center have continued since 2001. So far, 231 cleft lip and palate patients have benefited from these projects, and favorable effects of medical education and technology transfer for medical staff in Laos have been obtained. Furthermore, during the 3-year period of another JICA project, called "From tooth brushing to oral health--Oral care education for Laos children", the dental caries rate of children in Donkoi Elementary School in Laos reduced from 92.5 to 61.8%, showing a decrease of 30.7%. Based on these encouraging results, in 2012, the JICA started a larger partnership project named 'Cha-ganzyu', which is from the dialect of Okinawa meaning health forever, focusing on oral health improvement of school children and local people of Laos.

A unique case of craniopagus twins: considerations and challenges for dental rehabilitation

The purpose of this case report was to describe oral findings and outline challenges and considerations for general anesthetic (GA) and dental management of 4-year-old female craniopagus (cranially conjoined) twins, at high risk for medical comorbidity, who presented for treatment of severe early childhood caries. This hospital-based procedure required good interdisciplinary communication, cooperation, and presurgical planning to address unique challenges and ensure positive postoperative outcomes. Two separate anesthesia teams delivered GA simultaneously to each twin. To minimize anesthetic exposure, two pediatric dental teams completed dental care concurrently. Extensive plaque accumulation and unusual "mirror-image" caries distribution were attributed to frequency and postural pooling during feeding. The rehabilitation objective was to provide definitive dental management, minimizing future need for dental retreatment under GA. Two-month follow-up revealed intact dental restorations, good oral hygiene, and weight gain. For these unique twins however, the challenge of long-term oral health maintenance remains.

Nd:YAG laser in occlusal caries prevention of primary teeth: a randomized clinical trial

Dental caries is still the most prevalent chronic disease affecting human populations. Among the preventive treatments performed, it has been reported that laser irradiation combined with topical fluoride can induce an even greater increase in enamel caries resistance. The aim of this study was to evaluate the Nd:YAG laser, with or without fluoride, in occlusal caries prevention of the primary dentition. A double-blind split-mouth study design was used. Fifty-two children with high caries risk (7.6 ± 1.4 years) were selected and received the following: G1--the first molar was a negative control, and the second received a resin sealant; G2--the first molar was a negative control, and the second received laser irradiation (50 mJ, 10 Hz, 0.5 W); G3--the first molar received only acidulate phosphate fluoride (APF), and the second received APF + laser; G4--fisrt molar received only fluoride varnish, and the second received fluoride varnish + laser. Patients were followed up to 12 months to evaluate the presence of white-spot lesions and/or caries cavities by three calibrated observers. Thirty-five patients completed the study. Significant differences were found between the treatment and control groups (p < 0.05). The laser-alone and resin sealant resulted in statistically lower caries formation than the negative control group (p < 0.05). Nd:YAG laser irradiation in primary teeth effectively prevented occlusal caries in pits and fissures when used alone with lower energy over a 1-year period.

[Rare infection--prolonged A. naeslundii bacteremia caused by severe caries]

Actinomyces is an anaerobic, gram positive, rod shape bacteria that doesn't create spores. Actinomyces is part of the mouth, intestines, vagina and upper respiratory system flora. The infection appears mostly on the face, neck, abdomen and pelvis in cases of mucosa injury and most common in immunosuppressed patients. The spread of Actinomyces through the blood system is rare. In this article we present a 9 year old male patient with no history of diseases who was diagnosed with prolonged bacteremia of A. naeslundii without specific infection excluding severe caries. Characterization of bacteria from the blood culture was performed by molecular biology and the patient was treated with Ampicillin and tooth extraction that led to the disappearance of the bacteremia.

Heat generation caused by ablation of dental hard tissues with an ultrashort pulse laser (USPL) system

Heat generation during the removal of dental hard tissues may lead to a temperature increase and cause painful sensations or damage dental tissues. The aim of this study was to assess heat generation in dental hard tissues following laser ablation using an ultrashort pulse laser (USPL) system. A total of 85 specimens of dental hard tissues were used, comprising 45 specimens of human dentine evaluating a thickness of 1, 2, and 3 mm (15 samples each) and 40 specimens of human enamel with a thickness of 1 and 2 mm (20 samples each). Ablation was performed with an Nd:YVO4 laser at 1,064 nm, a pulse duration of 9 ps, and a repetition rate of 500 kHz with an average output power of 6 W. Specimens were irradiated for 0.8 s. Employing a scanner system, rectangular cavities of 1-mm edge length were generated. A temperature sensor was placed at the back of the specimens, recording the temperature during the ablation process. All measurements were made employing a heat-conductive paste without any additional cooling or spray. Heat generation during laser ablation depended on the dental hard tissue (enamel or dentine) and the thickness of the respective tissue (p < 0.05). Highest temperature increase could be observed in the 1-mm thickness group for enamel. Evaluating the 1-mm group for dentine, a significantly lower temperature increase could be measured (p < 0.05) with lowest values in the 3-mm group (p < 0.05). A time delay for temperature increase during the ablation process depending on the material thickness was observed for both hard tissues (p < 0.05). Employing the USPL system to remove dental hard tissues, heat generation has to be considered. Especially during laser ablation next to pulpal tissues, painful sensations and potential thermal injury of pulp tissue might occur.

Treatment under dental general anesthesia among children younger than 6 years in Lithuania

BACKGROUND AND OBJECTIVE

Dental general anesthesia (DGA) is an efficient treatment modality for young pediatric dental patients. The aim of this study was to identify the reasons for DGA, characteristics of patients receiving treatment under DGA, and treatment performed under DGA for children under school age in Kaunas, Lithuania.

MATERIAL AND METHODS

The study population comprised all patients younger than 6 years treated under GA for dental reasons (n=144) at the University Hospital during a 3-year period from 2010 to 2012. The data were collected by means of clinical dental examinations, a survey of the parents, and the patients' dental records and included personal background, reasons for DGA, dental status, and treatment provided.

RESULTS

More than half (54%) of the children were younger than 4 years; 40% of them resided in cities. The dental caries experience was high: the mean dmft and d were 12.9 (SD, 3.5) and 12.1 (SD 3.9), respectively. The majority (81%) of the children had multiple reasons for DGA, with the need for excessive treatment (93%), followed by dental fear and uncooperativeness (66%), being the most common. The extent of treatment increased with age and was greater among patients from rural areas. Of the 1975 primary teeth treated under GA, 50% were restored, 32% extracted, and 18% targeted with preventive procedures.

CONCLUSIONS

Young children with very high levels of untreated tooth decay are treated under DGA at the Lithuanian University of Health Sciences Hospital. The need for complex treatment as well as dental fear and uncooperativeness are the major reasons for DGA. Multiple caries treatments and extractions are performed for these patients. This study highlights a great need to develop the healthcare system with regard to the appropriate management of caries among young children and postoperative DGA care.

Reasons for extraction of permanent teeth in general dental practices in Tehran, Iran

OBJECTIVES

The aim of this survey was to investigate the primary reason for extraction of permanent teeth, its correlations with age, gender and education level, as well as identify the important predictors for dental caries in general dental centers in Tehran, Iran.

SUBJECTS AND METHODS

The study was conducted over a period of 6 months; its population consisted of 1,382 patients, aged 9-95 years, who underwent tooth extraction. There were 673 (47.8%) male and 709 (51.3%) female patients. The frequency distribution was calculated using the χ(2) test, ANOVA and t test for differences in mean number of extracted teeth and the logistic regression model to evaluate the variables associated with reasons for tooth extraction.

RESULTS

A total of 2,620 teeth were extracted from the 1,382 patients. The highest rate (36.9%) of extraction occurred for those 41-60 years old. Males comprised 48.7% of patients but had more teeth (1,470, 55.3%) extracted than females (1,150, 43.9%). Nine hundred and thirty-six (67.7%) patients had incomplete secondary education or less. Tooth loss due to caries was 51%; periodontal disease was 14.4%; supernumerary and tooth impaction 13.9%. There was a significant association between patient characteristics (age, gender and education level) and number of teeth extracted.

CONCLUSION

Dental caries and periodontal disease were the main reasons for tooth extraction in Tehran, Iran.

Treatment with local hemostatic agents and primary closure after tooth extraction in warfarin treated patients

The aim of this retrospective study was to assess the frequency of postoperative bleeding in patients on warfarin after tooth removal followed by a complete soft tissue closure of the surgical site. A total of 124 consecutive patients, 69 males and 55 females with a mean age of 71 years (range 28-95 years) were included in this study. Inclusion criteria were patients on warfarin with an INR <or=3.5 who were referred for tooth removal (single or multiple) during 2004-2009. After tooth extraction all sockets were packed with an absorbable haemostatic gelatin sponge or a collagen fleece and subsequently the sockets was primary closed with sutures. 5/124 (4%) patients returned with postoperative bleedings. All patients with a postoperative bleeding had received a surgical extraction in the posterior part of the maxilla. Consequently no patient had a postoperative bleeding in the mandible. None of the 124 patients returned to the clinic with a dry socket or postoperative pain. 3/124 (2%) patients returned with postoperative infection that required antibiotic treatment. All patients who bled were managed conservatively and none was admitted to hospital.

CONCLUSION

According to the protocol of this study (local hemostatic, primary closure, sutures and tranexamic acid) the risk of postoperative bleeding after tooth removal in patients on continued warfarin medication is low.

Odontogenic osteomyelitis or bisphosphonate-related osteonecrosis of mandible of patient with autoimmune disease: clinical dilemma

The key to appropriate treatment of odontogenic osteomyelitis or bisphosphonate-related osteonecrosis of the mandible in patients with autoimmune diseases lies in making the correct diagnosis based on meticulous review of signs and symptoms. As this complex case involving a patient with multiple comorbidities illustrates, diagnosis can be difficult, because these conditions may overlap or be mistaken for other conditions. However, prompt treatment is essential to limit the progression, which can be devastating for these medically complex patients. It is, therefore, important to understand local and systemic conditions that can weaken the immune system and predispose patients to chronic bone infection, meticulously go through signs and symptoms, and have a complete medical history, including patient medications.

Causes of tooth extraction at a tertiary care centre in Pakistan

OBJECTIVE

To evaluate the frequency of common causes of permanent tooth extraction and severity of dental condition at the time of tooth extraction.

METHODS

The cross-sectional study was conducted at the Department of Oral and Maxillofacial Surgery, Punjab Dental Hospital, Lahore, Pakistan, from February to June 2010, and involved 1026 patients who were referred for the extraction of permanent teeth. The inclusion criteria comprised caries, periodontitis, restoration failure, trauma, and local pathologies, while 3rd Molar impactions, supernumerary tooth extraction and extractions done as part of orthodontic or prosthodontic treatment were excluded. Oral hygiene was recorded using the Simplified Oral Hygiene Index. SPSS version 17 was used for statistical analysis.

RESULTS

The mean age of the study population was 46.60 +/- 11.321 years, and there were 611 (59.6%) males. A total of 1178 teeth were extracted. Advanced dental caries was the leading cause of tooth extraction (n = 743; 63.1%), followed by periodontitis (n = 309; 26.2%) restoration failure (n = 54; 4.6%), trauma (n = 38; 3.2%) and miscellaneous local pathologies (n = 34; 2.9%). More than half of the patients (n = 540; 52.6%) had poor oral hygiene.

CONCLUSION

Advanced dental caries is the most common cause behind tooth extraction.

What has been the United Kingdom's experience with retention of third molars?

BACKGROUND

In 2000, the first National Institute of Clinical Excellence (NICE) guidelines related to third molar (M3) surgery, a commonly performed operation in the United Kingdom, were published. This followed research publications and professional guidelines in the 1990 s that advised against prophylactic surgery and provided specific therapeutic indications for M3 surgery. The aim of the present report was to summarize the available evidence on the effects of guidelines on M3 surgery within the United Kingdom.

MATERIALS AND METHODS

Data from primary care dental services and hospital admissions in England and Wales during a 20-year period (Hospital Episode Statistics 1989/1990 to 2009/2010), and from private medical insurance companies were analyzed. The volume and, where possible, the nature of the M3 surgery activity over time were assessed together, as were the collateral effects of the guidelines, including patient age at surgery and the indications for surgery.

RESULTS

The volume of M3 removal decreased in all sectors during the 1990 s before the introduction of the NICE guidelines. During the 20-year period, the proportion of impacted M3 surgery decreased from 80% to 50% of admitted hospital cases. Furthermore, an increase occurred in the mean age for surgical admissions from 25.5 to 31.8 years. The change in age correlated with a change in the indications for M3 surgery during that period, with a reduction in "impaction," but an increase in "caries" and "pericoronitis" as etiologic factors, in accordance with the NICE guidelines.

CONCLUSION

The significant decrease in M3 surgery activity occurred before the NICE guidelines. Thus, M3 surgery has been performed at a later age, with indications for surgery increasingly in accordance with the NICE guidelines. The importance of clinical monitoring of the retained M3s is discussed.

Minimally invasive surgical approach in a large mandibular solitary cyst: case report and review of the literature

Solitary bone cyst (SBC) is an intraosseus radiolucent lesions that defers from real cysts for the fact that peripheral epithelial lining is totally absent. It could be classified as a psudocyst and occurs most frequently in young patients. In most cases SBC doesn't cause symptoms and it is often diagnosed accidentally during routine radiographic examination. A right diagnosis of this disease is also complicated because there are no pathognomonic radiographic signs and symptoms: so this form of pseudocyst is often misdiagnosed as a common odontogenic cyst. Despite numerous studies, the pathogenesis of the SBC is not yet established: the most widely accepted theory is that it could be the result of an intramedullary necrosis determined by a trauma. In this article we report a case of SBC in child treated with a minimal surgical approach. This new kind of treatment is much more conservative than the traditional one, it can be performed as outpatients, under local anesthesia and with few postoperative discomfort: For these reasons this minimal invasive technique appears to be particulary suitable for pediatric patients.

Bell's palsy following primary tooth extraction. A case report

Bell's palsy is characterized by acute peripheral facial nerve paralysis. Unilateral paralysis of CN 7 is reported in 20 to 30 people out of 100,000 in the general population. It affects individuals of all ages. Most cases are idiopathic, while a few are identified as resulting from infectious or non-infectious causes. The association between herpes simplex virus-1 (HSV-1) and Bell's palsy has been considered since the 1970s. Few cases have been reported after tooth extraction.

Periodontal response to subgingival restorations in dogs with periodontitis

The aim of this study was to evaluate the periodontal response to subgingival restorations in dogs with naturally occurring periodontitis. At the baseline, the experimental teeth from three dogs (2nd and 3rd upper premolars and 2nd, 3rd and 4th lower premolars) were randomly assigned to Resin-modified Glass Ionomer Cement (RMGIC) and Amalgam (AM) restorations or controls (CT) at the buccal sites with (SUPRA+) or without mechanical supragingival plaque control (SUPRA) and maintained for 90 days. Clinical [Periodontal Probing Depth (PPD), Clinical Attachment Loss (CAL), and Gingival Margin Recession (GMR)], histological (connective tissue inflammatory and epithelium condition) and histometric evaluation (distance between the apical border of the cavity and the bone level and between the apical extension of the epithelium and the bone level) were performed by a calibrated blinded examiner. Better clinical (especially regarding CAL) and histological results (unaltered epithelium and less severe inflammatory connective tissue) were observed associated with RMGIC sites. Histometric evaluation showed less bone loss associated to RMGIC. Overall, SUPRA+ sites presented less inflammatory response. It could be concluded that in dogs with periodontitis, subgingival RMGIC restorations, especially in the presence of supragingival plaque control, elicited better periodontal response than AM restorations.

Decision-making and treatment with respect to surgical intervention in the context of a European Core Curriculum in Cariology

This paper is part of a series of papers towards a European Core Curriculum in Cariology for undergraduate dental students. The European Core Curriculum in Cariology is the outcome of a process starting in 2006 and culminating in a joint workshop of the European Organisation for Caries Research (ORCA) together with the Association for Dental Education in Europe (ADEE) which was held in Berlin from 27 to 30 June 2010. The present paper covers decision-making and treatment with respect to surgical intervention. In particular, it will provide some background information on this part of the European Core Curriculum. Undergraduate dental education should enable the student to become a competent, skilful and caring dentist who is able, upon graduation, to take professional responsibility for diagnosis, as well as effective safe, and long-lasting care in the best interests of the patient. With respect to decision-making around surgical intervention for dental caries, several factors have to be considered. These include, patient needs, preventive strategies, tooth preservation, caries management success and failure rates, as well as short-term and long-term treatment costs. With respect to surgical intervention, manual skills at a high level are required. This is of crucial importance for the graduating dentist allowed to practise dentistry in many EU countries.

High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

CO(2) lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO(2) laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO(2) lasers with minimal peripheral thermal and mechanical damage and without excessive heat accumulation.