Quintessence International, 10/2004

Life is about changes. And if we are lucky, the changes are positive. My life has been blessed because, with the exception of my father's death, my transitions have been largely positive. I have a wonderful wife, Penny, and two wonderful sons, Trey and John. My private practice continues to bring challenge and joy, and I am in the best physical shape of my life. But it is now time for another positive transition. I will soon leave QI and address other projects. I am pleased to be the first to announce to QI readers that Avishai Sadan, who has been on the QI editorial board for several years, has been appointed the new editor-in-chief. Those of us who know Avishai, know him to be intelligent, hard-working, focused, and decisive-all qualities that make him a brilliant choice for the job. For my part, this has been a lovely ride and one that I will never forget. My experience would have been much less positive without the help of many friends. My thanks go to all the great folks Quintessence, including Lori Bateman and Marti Tiedeman, with whom I have worked closely on this journal. You have made a difficult job easy. Also kudos to my great office staff, especially Leigh Ann Artho and Christi Cohen for their ongoing assistance, and to Sol Cohen, my editorial assistant, for making it all possible. My special thanks go to those wonderful colleagues who have given freely of their time to review articles. Many of them have been reviewing for QI since well before my term as editor and deserve great praise for their dedicated efforts on the part of this journal. Others whom I have added to the mix over the years have helped to round out the expertise needed to cover all the varied specialties QI addresses in its pages. I salute you all for your assistance. Without your unheralded efforts, journals such as this would cease to exist, and dentistry would suffer. I now fade happily from the scene. Good-bye. Thomas G. Wilson, DDS Editor-in-Chief

Objective: To measure 2-week postoperative sensitivity in Class II composite restorations placed with a self-etching adhesive (Clearfil SE Bond) or a total-etch adhesive (Prime&Bond NT) with or without a flowable composite as cervical increment. Method and materials: Upon approval by the University of Guarulhos Committee on Human Subjects, 100 restorations were inserted in 46 patients who required Class II restorations in their molars and premolars. Enamel and dentin walls were conditioned with a self-etching primer (for Clearfil SE Bond) or etched with 34% phosphoric acid (for Prime&Bond NT). A 1- to 2-mm-thick increment of a flowable composite (Filtek Flow) was used in the proximal box in 50% of the restorations of each adhesive. Preparations were restored with a packable composite (Surefil). The restorations were evaluated preoperatively and 2 weeks postoperatively for sensitivity to cold, air, and masticatory forces using a visual analog scale. Marginal integrity of the accessible margins was also evaluated. Statistical analysis used a mixed linear model with subject as a random effect. Results: Ninety-eight teeth from 44 subjects were observed at 2 weeks. The type of adhesive and use of flowable composite had no significant effects or interaction for any of the four outcomes of interest, ie, change from baseline to 2 weeks in sensitivity and response time for the cold or air stimulus. For the air stimulus, the overall average change from baseline was not significant for either sensitivity or response time. For the cold stimulus, the overall average change from baseline was significant for both sensitivity and response time. No case of sensitivity to masticatory forces was observed. Conclusion: No differences in postoperative sensitivity were observed between a self-etch adhesive and a total-etch adhesive at 2 weeks. The use of flowable composite did not decrease postoperative sensitivity.

Objective: This study evaluated the effectiveness of proximal contacts in Class II restorations using two types of matrix bands (steel and polyester) with two different restoration techniques (incremental and with prepolymerized particles). Method and materials: Eighty-eight Class II adjacent restorations using Prodigy resin composite were performed: 44 with the incremental technique (22 with steel matrix bands, 22 with polyester matrix bands) and 44 utilizing prepolymerized resin particles (22 steel matrix, 22 polyester matrix). The restorations were clinically evaluated at baseline and at 6, 12, and 18 months. Proximal contacts obtained immediately after restoration procedure in all restorations were satisfactory. Results: No statistically significant alterations were found in 18 months of evaluation. Conclusion: Regardless of the utilized resin composite, there were no differences in the amount of proximal contact variations with respect to tested techniques and matrices.

Objective: The purpose of this study was to evaluate the microleakage of Class V cavity preparations restored with three different types of resin composite and an ormocer. Method and materials: Forty Class V cavities were prepared in buccal and lingual surfaces of 20 recently extracted molar teeth. The occlusal margin of each restoration was on enamel and the gingival margin on dentin. Teeth were randomly assigned to four groups of 5 teeth each and restored as follows: Group I, flowable resin composite (Tetric Flow); Group II, hybrid resin composite (Z100); Group III, packable resin composite (Solitaire 2); Group IV, organically modified ceramics-ormocer (Admira). In all groups, the manufacturers' instructions were strictly followed. All restorative resin composite materials were placed in one increment. All teeth were then immersed in 0.5% basic fuchsin solution for 24 hours after thermocycling (200 cycles; between 4°C to 60°C). The teeth then were longitudinally sectioned and observed under a stereomicroscope. The degree of dye penetration was recorded and analyzed with the Kruskal-Wallis and Mann-Whitney tests. Results: No statistically significant differences in microleakage were observed between groups either on enamel or dentin. Conclusion: All restorative materials demonstrated equal effectiveness in reducing microleakage.

Objectives: To determine the minimum exposure times consistent with optimized surface microhardness numbers (VHN) for the top and bottom surfaces, respectively, of a resin composite (1.5-mm depth) cured using a quartz-halogen activation lamp. Additionally, to determine the conditions appropriate to achieve optimized bottom/top hardness ratios. Method and materials: Disk specimens of a commercial resin composite restorative (Spectrum TPH) were exposed to a quartz-halogen lamp, and VHNs were measured for the top and bottom surfaces at elapsed times of 1 hour and 24 hours. Results: Data were dependent on exposure time, time elapsed after exposure, and the surface involved. Exposure time featured limiting values in excess of which no significant increase in microhardness took place. All microhardness data increased significantly over an elapsed time interval between 1 hour and 24 hours postexposure. Microhardness ratios (bottom/top) were dependent on exposure time only and were not influenced by time elapsed after exposure. Conclusion: Minimum exposure time may be considered as the greater of the times to achieve optimized top hardness and optimized hardness ratio, respectively.

Objective: The aim of this study was to evaluate the influence of Carisolv on the shear bond strength (SBS) of hydrophilic adhesive systems in dentin. Method and materials: Two hundred bovine incisors were polished with 320- to 1,000-grit aluminum oxide paper and randomly divided into 10 groups (n = 20). The adhesive systems were used according to manufacturer's instructions, and a restorative resin composite (Definite) was inserted in a Teflon matrix and cured. The specimens were kept in humid storage for 7 days at 37°C. The SBS tests were performed in an EMIC universal testing machine with a crosshead speed at 0.5 mm/min. The mean values (MPa ± [SD]) were analyzed with analysis of variance and Dunnett and Tukey tests. Results: The results were expressed in decreasing values (MPa): G6 = 18.55 ± 6.95; G3 = 17.55 ± 5.73; G2 = 17.05 ± 5.33; G8 = 16.95 ± 7.13; G7 = 16.94 ± 5.22; G4 = 16.31 ± 3.38; G1 = 15.85 ± 4.45; G9 = 14.21 ± 5.87; G5 = 12.89 ± 3.79; and G10 = 12.31 ± 5.18. Conclusion: Carisolv did not interfere in the adhesion to dentin, but its cleanser technique did interfere.

Cemento-ossifying fibroma is a mesodermal, slow-growing, benign fibro-osseous lesion of the jaws. A case of mandibular molar enlargement that was treated previously by other surgeons and diagnosed as cemento-ossifying fibroma, is presented. Two recurrences occurred 4 and 8 years after surgery due to incomplete surgical removal.

Objective: This study treated patients with temporomandibular disc displacement with reduction (with pain, limited mandibular movement, and clicking sound symptoms) using a combination of analgesics, injection, mandibular exercise, and occlusal splints. Method and materials: Twenty-five patients with temporomandibular joint (TMJ) disorders were evaluated for pretreatment complaints and clinical findings, such as TMJ sounds, mandibular deviation, limited mouth opening, and bilateral magnetic resonance imaging results. Diagnostic treatment was then planned; all patients received occlusal splints, and 10 patients received injections. Results: Evaluations were conducted 1 year after the initial diagnosis and treatment. Complaints (especially of pain) by the patients who received injections had reduced significantly. After 6 months of occlusal splinting, clinical findings of patients with TMJ disc displacement had greatly improved. To manage parafunctional habits of the patients, night plate usage was continued. Therefore, clinical symptom reduction was maintained. Conclusion: The use of mandibular manipulation technique can decrease the anterior disc displacement of the TMJ.

Objective: To determine the prevalence of odontogenic jaw cysts in a Jordanian population and to compare these data with previously published reports from other geographic areas. Method and materials: The files on odontogenic jaw cysts treated between 1989 and 2001 in the Oral and Maxillofacial Pathology Diagnosis Service at the Department of Oral Medicine and Oral Surgery, Faculty of Dentistry, Jordan University of Science and Technology, were reviewed. Clinical and radiographic data were recorded and microscopic slides evaluated according to the most recent World Health Organization classification. Cases were analyzed with regard to age, sex, and anatomic site. Results: A diagnosis of odontogenic jaw cyst was established in 654 patients, with a male-to-female ratio of 1.7:1. Radicular cyst was the most common type of odontogenic cyst found (41.7%), followed by dentigerous cysts (24.8%). The peak age affected was between the third and fifth decades. Both jaws were almost equally affected. The most common anatomic site of incidence was the maxillary incisor/canine region, followed by the mandibular molar region. Conclusion: This study indicates that there are some geographic differences with regard to the relative frequency, sex, and anatomic distributions of odontogenic cysts.

Objectives: The aims of this study were to measure the dimensions of connectors and retainer copings of metal-ceramic fixed partial denture (FPD) frameworks and to explore, by means of a questionnaire, the factors viewed by technicians as important in their planning and provision of such dimensions. Method and materials: Using two calliper devices, measurements were made of 66 consecutive FPDs under production in a dental school-based laboratory. The dimensions of 176 connectors and 124 retainers were analyzed with reference to FPD length and to number of pontics in a span. Questionnaires were completed by all 14 technicians working in the fixed prosthodontics section of the laboratory. Results: The largest mean vertical connector dimensions were in the anterior regions of both arches, while the largest mean horizontal dimensions were in the posterior regions. Dimensions were unrelated to FPD size and length of interabutment span. The minimum thickness of the retainer coping walls was generally below optimal recommendations. Available space was the factor most commonly cited by technicians as dictating the dimensions that they applied. Conclusion: Dimensions were generally smaller than current recommendations, which the questionnaire responses indicate are largely due to space constraints.

Objective: The purpose of this study was to evaluate the effects of some commonly used disinfectants on physical properties of four temporary soft denture-liner materials. Method and materials: Soft-liner materials, including three plasticized acrylic resin-liners (Tempo, Immediate, Flexacryl Soft) and one silicone-based material (Ufi Gel P) were studied. Specimens prepared with the soft-liner materials were tested after the application of disinfectants (5% Deconex and 3.5% Savlex for 10 minutes; 2% sodium hypochlorite and 5.25% sodium hypochlorite for 5 minutes) and were compared with the control group (not disinfected; immersed in distilled water). Five specimens of each material were tested and data collected on days 4, 7, 11, and 15. The hardness values were determined using the Shore A hardness test. Results: Water sorption test results showed that the disinfectants had statistically significant effects on water sorption values (except days 7 and 15 for Flexacryl Soft and days 4, 7, and 11 for Ufi Gel P). Water solubility and hardness test results also showed statistically significant effects on the materials by the disinfectants. Conclusion: Disinfectants significantly affected the physical properties of water sorption, water solubility, and hardness of the soft-liner materials.

Clinical effects of forces applied by dental occlusion on the periodontium have been evaluated for decades. Historically, trauma from occlusion has been considered as a major etiologic factor of inflammatory periodontal diseases, while some researchers have interpreted it to be of less importance or without any detectable importance in periodontics. In this study, five three-dimensional models of a maxillary central incisor were created using ANSYS 5.40. The only difference in each model was the height of the alveolar bone that showed from normal height (13 mm of alveolar bone height) to 8 mm of alveolar bone loss (5 mm of alveolar bone height). Five-point forces of 0.3 N summing up to 1.5 N were applied in a parallel line, 1 mm apical to the incisal edge on the palatal side in a palatolabial direction. The maximum (S1) and minimum (S3) principal stresses in the nodes of the labial side of the periodontal ligament (apical to the alveolar crest) were assessed. Analysis was done using the finite element method. An increase of S1 (up to 16 times in the cervical and 11.25 times in the apical area) and S3 (up to 17.13 times in the cervical and 9.9 times in the apical area) in comparison to the normal model was shown. The highest stress levels were traced in the subcervical area, except for the last model (8 mm of the alveolar bone loss). According to the results of this study, 2.5 mm of alveolar bone loss can be considered as a limit beyond which stress alterations were accelerated. Based on the FEM analysis, alveolar bone loss increases stress (S1 and S3) produced in the PDL, in spite of applying the same force vector.

Objectives: The purpose of this study was to investigate the influence of different in vitro tests on the ranking of four dentin bonding systems (OptiBond FL, Solid bond, OptiBond Solo, Etch 3.0) and to determine operator influence on push-out test results. Method and materials: One-hundred eighty extracted human molars were used in this study. For all bonding systems, bond strengths were determined using the shear, tensile, and push-out tests. In the push-out test, two series of specimens were bonded by two operators. Additionally, margin adaptation in Class V cavities was evaluated using scanning electron microscopy and dye penetration. Results: Both test methods and bonding systems revealed a significant influence on bond strength. Ranking of mean bond strengths was identical in the shear and tensile tests but different in the push-out test. In addition, material ranking in the push-out test was found to be operator dependent. No correlation was observed between bond strength and margin adaptation. A weak correlation was found between the percentage of gap formation and dye penetration in Class V cavities. Conclusion: Comparisons of dentin bonding systems based on the results of different in vitro tests may be misleading. Operator influence on the results of push-out tests require further consideration.