Quintessence International, 05/2007

Classic bonded indirect ceramic or resin composite restorations necessitate at least 2 appointments. The present article describes an updated technique for the first appointment comprising cavity preparation, dentin sealing, impression, and provisionalization. Two clinical cases are presented to illustrate the procedures step by step. Palabras clave: adhesive sealing, esthetics, indirect restorations

Objective: The capability of drinks and foods to resist pH changes brought about by salivary buffering may play an important role in the erosion of dental enamel. The aim of the present study was to measure the initial pH of several types of yogurt and to test the degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite to determine the buffering capacity and related erosive potential of yogurt. Method and Materials: Twenty-five milliliters of 7 types of freshly opened yogurt was titrated with 1 mol/L of sodium hydroxide, added in 0.5 mL increments, until the pH reached 10, to assess the total titratable acidity, a measure of the drink's own buffering capacity. The degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite were also calculated, using a computer program developed for this purpose. For statistical analysis, samples were compared using Kruskal-Wallis test. Results: The buffering capacities can be ordered as follows: fruit yogurt > low-fat yogurt > bioyogurt > butter yogurt > natural yogurt > light fruit yogurt > light yogurt. The results suggest that, in vitro, fruit yogurt has the greatest buffering capacity. Conclusion: It can be stated that it is not possible to induce erosion on enamel with any type of yogurt. Palabras clave: buffering capacity, dental erosion, fluorapatite, hydroxyapatite, yogurt

Objective: To evaluate the effect of the activation mode of adhesive cementation on push-out bond strength of fiber-reinforced resin posts to root canal dentin. Method and Materials: Forty mandibular premolars were endodontically treated and randomly divided into 4 equal groups. In groups G-1, G-2, and G-3, Single Bond (3M Espe) was applied and light polymerized for 20 seconds; in group G-4, Scotchbond Multi-Purpose Plus (3M Espe) was used as an autopolymerized adhesive. The dual-cure resin cement Rely X ARC (3M Espe) was light polymerized in G-2 and G-3 but not in G-1 and G-4. The translucent post Light-Post (Bisco) was used in G-3 and the opaque post Aestheti-Plus (Bisco) in the other groups. The roots were sectioned in 3 parts (cervical, middle, apical); each slice was submitted to the push-out test at a crosshead speed of 0.5 mm/min. Data were analyzed by analysis of variance and Tukey test (a = .05). Results: Light polymerization of both the adhesive and resin cement in G-2 led to significantly higher bond strength than in G-1, where only the adhesive was light polymerized. No difference was found between G-2 (opaque post) and G-3 (translucent post). The autopolymerized adhesive showed the highest bond strength in all root regions. The middle and apical post/root regions had similar bond strength, but it was significantly lower than that in the cervical region (P .001). Conclusion: Bond strength to root dentin varied as a function of the activation mode of post adhesive cementation and post/root regions. Palabras clave: adhesive systems, fiber-reinforced resin post, push-out bond strength

Uncommon developmental abnormalities such as fused or geminated teeth are of interest for the clinical problems associated with them. A rare case of fusion between maxillary primary central and lateral incisors and a supplemental incisor occurring bilaterally is presented. The patient was a 4-year-old Thai boy. Intraoral examination revealed an abscess and fistula in the region of the fused teeth as a result of periapical osteolysis. Access cavities were prepared as acute procedures. Because of the unpromising prognosis, surgical removal of the teeth was inevitable. For functional, esthetic, and phonetic rehabilitation, an acrylic denture was incorporated. Palabras clave: denture, fused tooth, periapical lesions, phonetic rehabilitation, tooth complex anatomy, triplicated teeth

Objective: Monochromatic ceramic blocks used for computer-generated posterior restorations require color modification to achieve acceptable shade matches. However, it is not known whether manipulative variables affect the final color of these restorations. This study aimed to determine the effects of ceramic type, thickness, extrinsic colorants, glazing, and luting agent on the final color of monochromatic computer-generated ceramics. Method and Materials: One hundred forty-five ceramic specimens (12 mm 3 10 mm) with different thicknesses were machined from monochromatic ProCAD ceramics (shades 100, 200, and 300; Ivoclar Vivadent) and Vita ceramics (shades A3.5 and 3M2; Vita). The influence of thickness on color was determined on ProCAD and Vita specimens with thicknesses of 1.0, 1.2, 1.5, 2.0, and 10.0 mm, and the influence of extrinsic colorants, glazing, and luting agent was determined on ProCAD and Vita ceramics of 1.5-mm thickness. Panavia F TC (Kuraray) was used to create a luting-agent backing of 100-µm thickness. CIELAB color coordinates (L*a*b*) were measured using a spectrophotometer, and color differences (DE) between the specimens were calculated. The criterion for color difference was considered to be 1.5 DE units. The data were statistically evaluated with ANOVA and the 2-tailed t test with a level of significance of 5%. Results: All 5 variables demonstrated significant differences for both ProCAD and Vita ceramics (P = .000). The DE values were larger than 1.5 units. Conclusion: Thickness and type of ceramic as well as extrinsic colorants, glazing, and a luting agent affect the color coordinates of monochromatic industrial ceramic. Palabras clave: ceramics, color, computer-generated restorations, manipulative variables

Objective: To determine the prevalence of erythema migrans (EM) in northeast Ohio; to identify demographic, health, and dental characteristics associated with this condition in patients aged 1 to 15 years; and to investigate the possibility that EM is a marker for children with multiple medications and certain systemic conditions. Method and Materials: In this retrospective chart review study, 1,900 charts were reviewed at 2 separate offices. One thousand were analyzed at a hospital dental clinic in Cleveland, Ohio, and 900 at a private pediatric dental office in a Cleveland suburb. Data were collected from each chart by 1 investigator and recorded in a database to be statistically analyzed. Nonparametric measures of association and logistic regression were used to determine differences between the presence of EM and the study variables and odds for EM. Significance level was set at P = .05. Results: Seventy-two subjects (3.8%) were found to have EM. The more medications patients were taking, either prescription or over-the-counter, the greater the likelihood of EM (P .001). Similarly, there was increased likelihood of EM with increasing numbers of medical diagnoses. Gender, oral hygiene, and behavioral status were not found to be statistically significant in the presence of EM. Conclusion: Erythema migrans was found in the records of 3.8% of children in 2 clinical facilities in the Midwest. Also, increased prevalence was found among patients with multiple health conditions in conjunction with multiple medication use. Palabras clave: Erythematous patches, etiology, medication use, diagnoses

Pleomorphic adenomas primarily arise in the major salivary glands, especially in the parotid. The most common area is the lower pole superficial to the plane of the facial nerve. In this report, a pleomorphic adenoma in an atypical location-the region of the temporomandibular joint (TMJ)-is presented. The tumor was solitary, closely attached to the capsule of the TMJ and superior to the parotid gland, with clear demarcation. Clinically, the tumor resembled TMJ pathology, but MRI examination led to diagnosis of a benign tumor attached to the TMJ. This report shows that pleomorphic adenoma can be a possible diagnosis for lesions at the joint capsule. Palabras clave: differential diagnosis, magnetic resonance imaging, pleomorphic adenoma, salivary gland tumor, temporomandibular joint

Objective: To evaluate the effect of manual condensation versus a combination of manual and mechanical, or automatic, condensation on the gingival marginal seal of packable resin composite restorations. Method and Materials: Two packable composites, Pyramid Dentin (Bisco Dental) and Filtek P-60 (3M Espe), were tested. The study consisted of 37 extracted caries-free human molars and premolars. In each tooth, 2 standardized Class 2 cavities were prepared and restored using the incremental technique; the mesial restoration was condensed by hand instrument, and the distal by a combination of the manual and mechanical condenser (KaVo). Restored teeth were subjected to automatic thermal stresses and cycling load stresses. Teeth were immersed in 0.5% basic fuchsin at 37°C for 96 hours. Samples were sectioned mesiodistally in 3 sections. Dye penetration at the gingival margin was examined. Results: Automatic condensation of Filtek P-60 and Pyramid demonstrated better sealing properties, with a median dye penetration of 0 and 1, respectively (on a dye penetration scale of 0 to 3), compared to manual condensation, median of 2 (P = .043) and 3 (P = .079), respectively. Better sealing ability was shown with P-60 than with Pyramid Dentin when manual condensation was used (P = .037). No significant difference was observed between the 2 products when tested with automatic condensation (P = .066). Conclusion: In this in vitro study the combination of manual and automatic condensation resulted in reduced gingival margin microleakage for both packable composites. Palabras clave: condensation, marginal seal, packable composite, resin composite

Objective: To compare, retrospectively, the influence of different types of restorative materials on caries in vivo. Method and Materials: Twenty-three primary teeth restored by a single operator with amalgam and 2 polyacid-modified resin composites, and with a band of tooth structure beyond the floor of the cervical box, were selected for microscopic evaluation. The teeth were sectioned mesiodistally with the aid of a hard tissue microtome, polished, and cleaned. A confocal laser scanning microscope was used to measure caries-related autofluorescence in the tooth tissue adjacent to the restorative material. A band of about 400 µm along the interface between the restoration and the tooth structure was observed. The extent of the fluorescent regions was recorded in relation to the total interface length. The specimens were then categorized according to the restorative material used: group A: amalgam (Spherodon, Silmet, n = 11); group D: polyacid-modified resin composite (Dyract, Dentsply DeTrey, n = 6); and group C: polyacid-modified composite (Compoglass, Ivoclar Vivadent, n = 6. The data were analyzed using a one-way analysis of variance (ANOVA) model (a = .05) and Pearson correlation coefficient. Results: No significant differences were found between the materials (P > .05). Conclusion: Within the limits of this clinical study, the data obtained using a small sample size suggests that the effect of the restorative material in primary molars does not have a predominant influence on secondary or residual caries. Palabras clave: amalgam, caries, confocal laser scanning microscope, in vivo, polyacid-modified resin composite, residual caries, restorative materials, secondary caries

The combination of infraoccluded primary molars and agenesis of the permanent successors is rare. This condition progresses with increased severity since the primary teeth do not usually exfoliate spontaneously. The clinical examination of an 11-year-old girl revealed 4 submerged primary second molars, agenesis of all second premolars, and a peg-shaped maxillary lateral incisor. Treatment in this case was surgical extraction of the submerged teeth and placement of removable appliances to maintain space and vertical dimension. Palabras clave: agenesis, ankylosis, infraocclusion, peg-shaped tooth, primary teeth, removable appliance, surgical treatment

Objective: To assess the 10-year clinical performance of resin composite restorations placed using the acid-etch technique. Method and Materials: Clinical evaluation of 58 resin composite restorations was performed by 9 operators of the Operative Dentistry Clinic of the Dental Hospital, Tokyo Medical and Dental University. Conservative preparations had been made and a total-etch adhesive system used for the resin composite restorations, which were placed in 1992 in the Operative Dentistry Clinic. Restorations were scored using the following scale: Alfa-good; Bravo-clinically acceptable; Charlie-clinically unacceptable; Delta-already replaced. The scores were analyzed using the chi-square test and the expected cell frequency (P = .05). Results: The 58 restorations from 26 patients (13 men and 13 women) were identified in the treatment records and analyzed. Twenty-two restorations (37.9%) presented Alfa scores and 17 restorations (29.3%) were clinically acceptable (Bravo scores), while 3 restorations (5.2%) received Charlie scores and 16 restorations (27.6%) had already been replaced (Delta scores). The descending ranking of longevity by restoration type was Class 5 > Class 3 > Class 2 > Class 1 > Class 4 (P = .05). Conclusions: Of the restorations evaluated, 67.2% were serviceable (combined Alfa and Bravo scores) 10 years after placement. Longevity was significantly influenced by cavity type Palabras clave: acid etching, clinical evaluation, dentin bonding system, longevity, resin composite, retrospective study

Periapical pathology is the most common sequelae of pulpal necrosis due to traumatic injury. For the success of endodontic treatment, healing of periapical pathology is necessary and can be achieved by maintaining a sterile root canal system. Calcium hydroxide has the potential to maintain a sterile root canal by its antibacterial and tissue-dissolving property. Two case reports of periapical pathology that healed within a period of 3 to 6 months after intracanal calcium hydroxide dressing are presented. Palabras clave: calcium hydroxide, mandibular incisors, maxillary incisors, periapical lesion, pulpal necrosis, traumatic injury

Obtaining predictable and optimal coverage of exposed root surfaces and correction of corresponding gingival recessions have become important goals of periodontal plastic surgery. Various surgical techniques have been proposed for coverage of root surfaces. A therapeutic advantage may be gained if periodontal regeneration is obtained in addition to coverage of root with gingiva. In this case report, surgical recession coverage was performed as the bilaterally pedicled lateral sliding flap technique with the adjunctive use of enamel matrix derivative bioactive material (Emdogain). A female patient with gingival recession on maxillary central incisors is presented with 4-year follow-up observation. The surgical procedure used in this clinical pilot case study produced a marked reduction in gingival recession that was maintained for 4 years. Initial gingival recession averaged 4.25 mm with a probing depth of 1.25 mm. The 4-year follow-up demonstrated no significant changes in the degree of postoperative results obtained after 1 year. At the 4-year follow-up, a mean of 3.75 mm of root coverage was observed (93.8% root coverage). Probing depth averaged 0.75 mm, indicating a total of 4.25 mm gain of clinical attachment. Within the limits of this case, the results demonstrated the possibility of treating human buccal recessions by means of enamel matrix protein derivative together with the laterally repositioned flap technique, with a predictable reduction in recession and clinical gain in attachment. Palabras clave: bioengineering, enamel matrix proteins, laterally repositioned flap, long-term follow-up, mucogingival procedures, recession

Objective: To quantify wear processes by measuring the retention force changes and the fitting tolerance at different prefabricated attachment systems to estimate the wear constancy and applicability in clinical practice. Method and Materials: Seven prefabricated attachment systems (Dalbo-Classic, Dalbo-PLUS, Dalbo-Z, Mini-Gerber-PLUS, Stufenexzenter, SphäroLock, and Degussa-Kugelankersystem) with different construction and alloy composition were tested. Twenty samples of each system were subjected to 10,000 insertion-separation cycles in a wear simulator with a periodontium-simulating specimen holder. The simulator was designed to record the force needed to insert and to separate the attachment and the distance moved during the insertion and separation cycles. Results: All types of anchors showed wear that led to a loss or to an increase in retention force at the beginning of the wear simulation. Anchors with a plastic retention insert showed the slightest changes in retention force. The wear does not have an effect on the fitting tolerance. Conclusion: Anchor systems that possess an adjustable matrix should be preferred. They allow decreasing or increasing the retention force of an anchor if this force is changed by wear. There is no risk of a loss of support if forces in occlusal direction are exerted because there is no clinically relevant change in the fitting tolerance. Palabras clave: anchors, fitting tolerance, overdentures, prefabricated attachments, retention force changes, wear

Objective: To examine the influence of compressive and deflective force on the filaments of 7 commercially available powered toothbrushes. Method and Materials: The deformation (collapse under force) of the filaments on individual brush heads was measured at a rate of 4 mm/min using an Instron load testing machine under applied loads of 0.5 to 3.0 N. The load was directed perpendicular to the long axis of the filaments. The peak deflection force (deflecting of the filaments from their normal position) was measured with the head of the powered brush oriented horizontally to the applied load. Measurements were taken while the brush head was stationary and during oscillation. Data for peak deflective force were analyzed using a general linear model with post hoc Tukey tests. Results: All powered toothbrushes showed filament deformation when increasing loads were applied. Deformation of the filaments was greatest at 0.5 N and 1.0 N for the Teledyne and was recorded at 1.70 mm and 3.67 mm, respectively. At 2.0 N, greater deformation (5.50 mm) occurred with the Blend-a-Dent, and at 3.0 N, the Sonicare powered toothbrush exhibited a deformation of 3.95 mm. Over the whole range of applied forces, the Braun D15 showed the lowest deformation effects. The different deformations of the filaments recorded between the heads of all powered toothbrushes tested were significant (general linear model, P .001). Also a decrease in peak deflective force was observed between stationary and oscillating toothbrush heads. Conclusions: The compressive and peak deflective forces vary between different brushes, and the ability to resist deformation depends on the arrangement of the filaments on the head of the powered brush. Palabras clave: compressive deformation, peak deflective force, powered toothbrush

Objective: To investigate qualitatively and quantitatively the bacterial aerosols before, during, and after clinical work sessions in different areas within a multichair dental clinic, an isolation clinic, the sterilization center, and the prosthetic laboratory in the College of Dentistry, King Saud University. In addition, the contributions of aerosols generated by different types of dental procedures were investigated. Method and Materials: Air sampling using blood and heart infusion agar plates at 4 selected areas was performed 3 times per day over a 2-week period before, during, and after clinical sessions. Results: The concentration of total bacterial aerosols was 5 times higher in the multichair clinic, 3.6 times higher in the prosthetic laboratory, and 2 times higher in the sterilization center and isolation clinic during working sessions as compared to before the working sessions. At the end of the working day, aerosols decreased 50% to 70% in all areas. Staphylococcus epidermidis had the highest prevalence (37.1%) of colony composition of bacteria examined. Conclusion: This study demonstrates that aerosols increase during and after work sessions and therefore increase the chance for infectious agent transmission. Preventive measures should be instituted to reduce or disrupt aerosols as a transmission route in the multichair dental clinic, sterilization center, prosthetic laboratory, and isolation clinic. Palabras clave: air sampling, airborne infection, bioaerosols, microbial transmission

Objective: This study evaluated the efficiency of repolishing, sealing with surface sealant, and the joining of both in decreasing the surface roughness of resin-based composites after a toothbrushing process. Method and Materials: Ten specimens of each composite (Alert, Z100, Definite, and Prodigy Condensable), measuring 2 mm in thickness and 4 mm in diameter, were made and submitted to finishing and polishing processes on both sides of the specimens using the Sof-Lex system. The specimens were then subjected to toothbrushing (30,000 cycles), and surface roughness (Ra) was analyzed with a Surfcorder SE 1700 profilometer. The upper surface of each composite was etched with 37% phosphoric acid, and the surface-penetrating sealant Protect-it was applied on 1 surface. The roughness of these surfaces was again measured. On the other side, the surface of the specimen was repolished, and the efficiency of this procedure was measured using the profilometer. The surface roughness resulting from the joining of the 2 methods was verified by applying, in the final stage, the surface-penetrating sealant on the repolished surface. Data were analyzed with analysis of variance and Tukey test (P .05). Results: Results showed that the lowest surface roughness values were obtained for Definite, Z100, and Prodigy Condensable after the repolishing process and after the repolishing plus sealing. For Alert, the joining of repolishing plus sealing promoted the lowest values of surface roughness. Conclusion: Of the resin-based composites, Alert demonstrated the highest values of surface roughness in all the techniques tested. Palabras clave: resin composites, surface-penetrating sealant, surface roughness, toothbrushing

Migration or displacement of dental implants into the anatomical sites is a possible but rare complication. This article describes 2 cases of ectopic dental implants in the maxillary sinus, 1 of which was displaced at the time of surgery and the other which migrated 8 years after placement. Palabras clave: complication, dental implants, maxillary sinus

Objective: Commercial quick-heating phosphate-bonded investments are frequently used to reduce the operating time during the dental casting process. The aim of this study was to evaluate the characteristics of commercial quick-heating phosphate-bonded investments. Method and Materials: Characterization of the 2 investments (Maruvest-Speed [Megadental] and Z4 C&B [Neirynck and Vogt]) focused on the setting expansion, compressive strength, thermal expansion, and surface roughness. Two different heating methods-the quick-heating method (QHM) and conventional heating method (CHM)-were used with the investments. The dimensional accuracy and surface roughness of the nickel-chromium alloy castings obtained from the investments were also examined. Results: The Maruvest-Speed investment had a significantly greater setting expansion (2.2%) than the Z4 investment (1.1%) after a 30-minute setting time. The fired strength of both investments was greater with QHM (21.2 to 27.7 MPa) than with CHM (13.8 to 17.9 MPa). The thermal expansion of the Maruvest-Speed investment and Z4 with QHM was 1.7% and 1.4%, respectively. There was no significant difference in surface roughness of the castings between samples treated with QHM and CHM. The dimensional accuracy of the castings was larger in length and slightly deformed in bend. Conclusion: The characteristics of the 2 commercial quick-heating phosphate-bonded investments for the accelerated casting technique may be acceptable. Palabras clave: accelerated casting technique, compressive strength, phosphate-bonded investment, setting expansion, thermal expansion