In vitro CO2 9.3-µm short-pulsed laser caries prevention-effects of a newly developed laser irradiation pattern.

Caries prevention with different lasers has been investigated in laboratory studies and clinical pilot trials. Objective of this in vitro study was to assess whether 9.3-µm microsecond short-pulsed CO2 laser irradiation enhances enamel caries resistance without melting, with and without additional fluoride application. Seven groups of enamel, totaling 105 human enamel samples, were irradiated with 2 different carbon dioxide lasers with 2 different energy application systems (original versus spread beam; 9.3 µm wavelength, pulse repetition rate 43 Hz vs 100 Hz, fluence ranges from 1.4 to 3.9 J/cm2, pulse duration 3 µs to 18 µs). The laboratory pH-cycling was performed with or without additional fluoride, followed by cross-sectional microhardness testing. To assess caries inhibition, the mean relative mineral loss delta Z (∆Z) was determined. To evaluate for melting, scanning electron microscopy (SEM) examinations were performed. For the non-laser control groups with additional fluoride use, the relative mineral loss (ΔZ, vol% × µm) ranged between 512 ± 292 and 809 ± 297 (mean ± SD). ΔZ for the laser-irradiated samples with fluoride use ranged between 186 ± 214 and 374 ± 191, averaging a 58% ± 6% mineral loss reduction (ANOVA, P < 0.01 to P < 0.0001). For the non-laser-treated controls without additional fluoride, the mineral loss increased (ΔZ 914 ± 422 to 1224 ± 736). In contrast, the ΔZ for the laser-treated groups without additional fluoride ranged between 463 ± 190 and 594 ± 272 (P < 0.01 to P < 0.001) indicative of 50% ± 2% average reduction in mineral loss. Enhanced caries resistance was achieved by all applied fluences. Using the spread beam resulted in enhanced resistance without enamel melting as seen by SEM. CO2 9.3-µm short-pulsed laser irradiation with both laser beam configurations resulted in highly significant reduction in enamel mineral loss. Modifying the beam to a more homogenous profile will allow enamel caries resistance even without apparent enamel melting.

Bond strength of etch-and-rinse and self-etch adhesive systems to enamel and dentin irradiated with a novel CO2 9.3 µm short-pulsed laser for dental restorative procedures.

The objective of this study was to evaluate the influence of CO2 9.3 µm short-pulsed laser irradiation on the shear bond strength of composite resin to enamel and dentin. Two hundred enamel and 210 dentin samples were irradiated with a 9.3 µm carbon dioxide laser (Solea, Convergent Dental, Inc., Natick, MA) with energies which either enhanced caries resistance or were effective for ablation. OptiBond Solo Plus [OptiBondTE] (Kerr Corporation, Orange, CA) and Peak Universal Bond light-cured adhesive [PeakTE] (Ultradent Products, South Jordan, UT) were used. In addition, Scotchbond Universal [ScotchbondSE] (3M ESPE, St. Paul, MN) and Peak SE self-etching primer with Peak Universal Bond light-cured adhesive [PeakSE] (Ultradent Products) were tested. Clearfil APX (Kuraray, New York, NY) was bonded to the samples. After 24 h, a single plane shear bond test was performed. Using the caries preventive setting on enamel resulted in increased shear bond strength for all bonding agents except for self-etch PeakSE. The highest overall bond strength was seen with PeakTE (41.29 ± 6.04 MPa). Etch-and-rinse systems achieved higher bond strength values to ablated enamel than the self-etch systems did. PeakTE showed the highest shear bond strength with 35.22 ± 4.40 MPa. OptiBondTE reached 93.8% of its control value. The self-etch system PeakSE presented significantly lower bond strength. The shear bond strength to dentin ranged between 19.15 ± 3.49 MPa for OptiBondTE and 43.94 ± 6.47 MPa for PeakSE. Etch-and-rinse systems had consistently higher bond strength to CO2 9.3 µm laser-ablated enamel. Using the maximum recommended energy for dentin ablation, the self-etch system PeakSE reached the highest bond strength (43.9 ± 6.5 MPa).

Influence of irradiation by a novel CO2 9.3-µm short-pulsed laser on sealant bond strength.

The objective of this in vitro study was to evaluate whether irradiation of enamel with a novel CO2 9.3-µm short-pulsed laser using energies that enhance caries resistance influences the shear bond strength of composite resin sealants to the irradiated enamel. Seventy bovine and 240 human enamel samples were irradiated with a 9.3-µm carbon dioxide laser (Solea, Convergent Dental, Inc., Natick, MA) with four different laser energies known to enhance caries resistance or ablate enamel (pulse duration from 3 µs at 1.6 mJ/pulse to 43 µs at 14.9 mJ/pulse with fluences between 3.3 and 30.4 J/cm2, pulse repetition rate between 4.1 and 41.3 Hz, beam diameter of 0.25 mm and 1-mm spiral pattern, and focus distance of 4-15 mm). Irradiation was performed "freehand" or using a computerized, motor-driven stage. Enamel etching was achieved with 37% phosphoric acid (Scotchbond Universal etchant, 3M ESPE, St. Paul, MN). As bonding agent, Adper Single Bond Plus was used followed by placing Z250 Filtek Supreme flowable composite resin (both 3M ESPE). After 24 h water storage, a single-plane shear bond test was performed (UltraTester, Ultradent Products, Inc., South Jordan, UT). All laser-irradiated samples showed equal or higher bond strength than non-laser-treated controls. The highest shear bond strength values were observed with the 3-µs pulse duration/0.25-mm laser pattern (mean ± SD = 31.90 ± 2.50 MPa), representing a significant 27.4% bond strength increase over the controls (25.04 ± 2.80 MPa, P ≤ 0.0001). Two other caries-preventive irradiation (3 µs/1 mm and 7 µs/0.25 mm) and one ablative pattern (23 µs/0.25 mm) achieved significantly increased bond strength compared to the controls. Bovine enamel also showed in all test groups increased shear bond strength over the controls. Computerized motor-driven stage irradiation did not show superior bond strength values over the clinically more relevant freehand irradiation. Enamel that is made caries-resistant with CO2 9.3-µm short-pulsed laser irradiation showed at least equal or significantly higher shear bond strength to pit and fissure sealants than non-laser-irradiated enamel. The risk of a sealant failure due to CO2 9.3-µm short-pulsed laser irradiation appears reduced. If additional laser ablation is required before placing a sealant, the CO2 9.3-µm enamel laser-cut showed equivalent or superior bond strength to a flowable sealant.

Development of gingival esthetics in the terminal dentition patient prior to dental implant placement using a full-arch transitional fixed prosthesis: a case report.

Despite significant advances in dental therapeutics, there are patients for whom no reasonable treatment is available that will reliably restore or maintain their existing dentition. The causes of future edentulism include advanced caries, failing root canal therapy, inadequate numbers of teeth to support a fixed prosthesis, untreatable periodontal disease, or a history of failed previous rehabilitations. For these patients, dental implants may provide a more predictable future than retention of their remaining teeth. It is proposed that transitional fixed prostheses designed specifically for a patient with terminal dentition offer the advantage of maintenance and development of proper gingival esthetics with improved function. Prior to implant placement, the gingival frame is established, enhancing the overall appearance of the final, full-arch implant rehabilitation. The specific prosthodontic and surgical techniques required for successful treatment of these patients are presented.

Development of gingival esthetics in the edentulous patient with immediately loaded, single-stage, implant-supported fixed prostheses: a clinical report.

Many clinicians have reported on the success of immediately loaded implants supporting a bilaterally stabilized provisional fixed prosthesis. This protocol offers several advantages, including increased masticatory function, minimized uncontrolled transmucosal loading through cross-arch stabilization, improvement of psychologic well-being, and reduction in treatment time. However, the development and maintenance of proper dentogingival esthetics in the edentulous maxilla presents substantial challenges for the implant team. This article presents the specific pretreatment diagnostic requirements for immediate loading of single-stage implants and demonstrates a new surgical technique, followed by appropriate prosthodontic management, to develop an optimal gingival profile with interdental papillae surrounding a natural-looking dentition. One hundred fifty-one ITI implants were placed into 22 dental arches and immediately loaded with a 1-piece fixed prosthesis. The results of this technique over the last 5 years are presented.

The treatment dilemma of the furcated molar: root resection versus single-tooth implant restoration. A literature review.

Successful treatment of furcated molar teeth presents the periodontist and prosthodontist with a challenging dilemma. Accepted treatment modalities include chemotherapeutic maintenance, root planning, open flap debridement, modified Widman flap, bone grafting with and without guided tissue regeneration, and osseous resection with and without root removal. Determining the appropriate treatment for an individual patient that is both cost-effective and offers the greatest long-term prognosis can be a daunting task. The literature is replete with studies of different therapeutic alternatives for furcated molar teeth. A relatively new treatment option is complete removal of the tooth combined with ultimate placement of an endosseous implant and restoration with a single crown. A review of the relevant literature with special emphasis on root resection therapy and single molar implant placement is presented. The relative merits of each treatment modality and guidelines for their use are discussed.

Fabrication of treatment restorations using acrylic resin denture teeth.

A technique is disclosed for fabricating esthetic, long-term treatment restorations by using acrylic resin denture teeth facings. The advantages of this method for provisional restoration construction are reduced costs and predictable, satisfying results.