Quintessence International, 08/2004

A 14-year-old male patient reported with a horizontal fracture of almost the entire crown of a maxillary incisor, extending subgingivally at the palatal side. After root canal therapy and electrosurgery, the tooth fragment was reattached using a total-etch dentin-bonding system and a hybrid composite. Due to enamel cracks and the necessity for more retention, the labial surfaces of the teeth were veneered with a microfilled composite. The clinical situation of the reattached teeth was confirmed successful by radiographic and photographic assessment after 1, 3, 6, and 12 months. The restoration of an anterior tooth with original tooth fragment in young patients has advantages over conventional composite or prosthetic restorations. However, reattached teeth with fracture extending subgingivally, require long-term follow-up.

Objective: The purpose of this study was to investigate the influence of tooth-polishing pastes and sealants on values obtained with a caries diagnostic system based on detection of caries-associated fluorescence (DIAGNOdent, KaVo). Method and materials: Ten tooth-polishing pastes and four dentifrices were measured alone, and it was shown that products containing pumice gave high DIAGNOdent values. The deepest occlusal pits of 20 extracted sound premolars (12 unsealed teeth, 8 sealed teeth) were measured before polishing, after rotating-brush polishing with pumice-containing tooth-polishing paste, and after final rotating-brush polishing with water in this in vitro study. In the clinical phase, the deepest occlusal pits of 21 molars and 2 premolars that clinically required application of sealant were measured before polishing, after rotating-brush polishing with one of two pumice-containing tooth-polishing pastes, and after sealant application. All measurements were done five times, and the average values were obtained. Data were statistically analyzed using analysis of variance subsequent to Fisher's protected, least significant difference. Results: Clinical study showed that the value after polishing with either of the two polishing pastes was significantly higher than the value before polishing. Both in vitro and clinical studies showed that the value was increased by pumice-containing paste polishing and rotating-brush polishing with water after paste polishing could not recover the value to the level before paste polishing. Sealant treatment in the clinical study significantly decreased DIAGNOdent values, and the values after sealant application were lower than the values before polishing. Conclusion: Polishing pastes and sealants used in this study could interfere with DIAGNOdent values.

ntraradicular post systems. Method and materials: Seventy-five bovine roots of similar dimensions were assigned to five groups (n = 15), according to the intraradicular post system used: cast post and core; titanium post; carbon-fiber post; glass-fiber post; and zirconium-oxide post. Following post cementation, the roots were embedded in polystyrene resin composite and submitted to fracture-resistance testing, with a compressive load at an angle of 135 degrees in relation to the long axis of the root at a speed of 0.5 mm/min. All data were statistically analyzed with analysis of variance and Sidak test. Results: The titanium posts presented higher mean values of fracture resistance when compared to glass-fiber posts and zirconium-oxide posts and similar values compared to carbon-fiber posts. Also, roots treated with cast posts and cores presented similar results when compared to roots treated with prefabricated posts. Conclusion: All prefabricated intraradicular post systems evaluated presented similar resistance to fracture when compared to cast posts and cores, and among the prefabricated ones, titanium and carbon-fiber posts could be best indicated.

A 6-year-old girl with Glanzmann thrombasthenia presented with caries and periapical lesions in the primary mandibular second molars and moderate gingivitis of the maxillary and mandibular anterior teeth. Dental extraction was recommended, and before every surgical intervention, the patient underwent platelet-concentrate transfusion to prevent hemorrhage. Epsilon aminocaproic acid was administered 6 hours before, and 48 hours after every dental procedure to prevent bleeding. In this case, treatment was effective in the prevention of hemorrhagic complications, during the required dental procedures.

Objective: The effects of chin cup therapy on the mandible in Class III malocclusions have been investigated extensively via cephalometric analyses. However, the actual sites of mandibular skeletal change are not detectable with conventional cephalometric analysis. It is important to elucidate the association between remodeling of the mandible with the mechanical stress applied with chin cup therapy. Method and materials: In this study, the geometric morphometric changes in the mandible from chin cup force and/or growth were investigated using strain tensor analysis. Results: This geometric morphometric analysis reveals that mandibular deformation arises partly due to a size change and partly due to a shape change. The direction and magnitude of principal vectors of the strain tensors may provide more information about this deformation. Conclusion: Strain tensor analysis may show the degree of transformation within the mandibular geometric configuration due to treatment effects and/or growth changes as seen on lateral cephalometric radiographs.

Objectives: To test the efficacy of an intermittent use, dental unit waterline cleaner, containing 0.12% chlorhexidine, in a proprietary formulation, to reduce bacterial levels in three functioning dental units with independent water reservoir systems. Method and materials: Baseline water samples were first taken from six units. Two ounces of the undiluted test product was run through lines, left overnight, and flushed out the next morning. This was repeated for 6 nights initially, and once a week thereafter for 12 weeks. Three control dental units did not have chemicals added. Weekly samples were collected in bottles containing sodium thiosulphate on the afternoon before overnight treatment, plated on R2A agar, and incubated at room temperature for 7 days. Results: Mean colony-forming units per millimeter (CFU/mL) in treatment units declined from 23,389 (± 20,085) at baseline, to 6 (± 10) in week 4, to 5 (± 2) in week 12. Statistical analysis showed a significant difference between treatment and control units. Conclusion: Intermittent treatment of dental unit waterlines with 0.12% chlorhexidine gluconate (CHX), in a proprietary formulation, resulted in significantly reduced bacterial counts to levels that were consistently below the American Dental Association's goal of 200 CFU/mL for 8 weeks.

Objectives: Staphylococcus aureus and mutans group streptococci can cause, among many other diseases, infective endocarditis and postoperative infections. The reduction of the number of these microorganisms in the oral cavity prior to surgical procedures has been related to a decreased incidence of such occurrences. The aim of this study was to evaluate the effect of a single preprocedural rinse with 0.12% chlorhexidine solution (Periogard) on the salivary counts of S aureus and mutans group streptococci and determine maximal inhibitory dilutions (MID) of this and 0.05% cetylpyridinium chloride solution (Cepacol). Method and materials: Saliva was collected from 60 patients before and after 30-second mouthrinses with chlorhexidine and cultured in appropriate media. The number of microorganisms was calculated based on the colony-forming units (CFUs). For the in vitro MID determination, 25 strains of S aureus were seeded in the media containing one of the sequential dilutions of both antiseptics. Results: S aureus, Streptococcus mutans, and Streptococcus sobrinus were initially isolated from 45%, 63%, and 28% of the patients, respectively. After rinsing with chlorhexidine, the reductions in the CFUs were above 99% for all the studied microorganisms. In the MID determination, all isolates were inhibited with 1/20 and 1/80 dilutions of cetylpyridinium and chlorhexidine, respectively. Dose-response curves were obtained for both antiseptics. Conclusion: Single preprocedural chlorhexidine mouthrinse is effective in reducing salivary microorganisms to levels currently considered safe to perform invasive procedures, and it is still effective in a 1:80 dilution.

An unusually large complex odontoma of the maxilla, occupying the entire maxillary sinus with expansion into the floor of the orbit and left nasal fossa, is reported. Although occurrences of complex odontomas are not considered rare, odontomas attaining extremely large sizes, especially involving the entire maxillary sinus with extension to the orbital floor and nasal fossae, are indeed, rare. In this article, the literature is reviewed to identify the common clinical, radiographic, and histologic characteristics of such lesions, and the outcome of treatment is discussed. Complex odontomas occasionally have significant growth potential, especially in the first two decades of life. Early recognition and consideration for surgical excision are key to successful management of this common odontogenic lesion. When odontomas extend beyond the alveolar process into the fascial planes, nasal fossae, paranasal sinuses, and orbits, computed tomography can readily demonstrate the extent and boundaries of the lesion.

Trigeminal neuralgia, which may involve one or more branches of the trigeminal nerve, is considered to produce one of the most severe types of pain. As it may be associated with other conditions, in some cases, the patient is subjected to unnecessary treatment. A case of nonidiopathic trigeminal neuralgia associated with internal carotid aneurysm, is presented.

Sports dentistry has been considered a prominent area of dentistry because dental health can limit the abilities of athletes, both professional and nonprofessional, in their training and competition. Dental decay is associated with the frequent use of carbohydrates, recommended as an energy source for exercise. Strong indications exist regarding the possibility to use saliva as a performance determinant and for evaluation and prescription of physical activity. This study evaluated the salivary profiles (pH, flow rate, mutans streptococci and Lactobacillus counts) and decayed, missing, and filled teeth of 18 female soccer players (13 to 19 years old) of the Olympic Training and Research Center of São Paulo, before and after a training session. The salivary flow rate presented a significant reduction after training; however, there was no significant alteration in pH. Fifty percent of the players presented 10⁵ to 10⁶ mutans streptococci, and 66% presented 10³ Lactobacillus. Several salivary components protect against microorganisms that cause superior respiratory tract infections (common in athletes), as well as participating in the remineralization mechanism during cariogenic challenges. Thus, due to the salivary flow rate reduction in this population with a high number of cariogenic microorganisms, noncariogenic drink ingestion at regular intervals and maintenance of hydration levels during training, are suggested.

This article describes a new posterior preparation and retainer design for resin-bonded fixed partial dentures to resist eccentric loading, using a noble alloy (a silver-palladium-copper-gold alloy), a recently developed metal adhesive conditioner (Metaltite), and an adhesive resin-luting agent (Super-Bond C&B).

A nasal prosthesis can reestablish esthetic form and anatomic contours for midfacial defects often more effectively than can surgical reconstruction. This case report describes the clinical and laboratory procedures for fabricating a nasal prosthesis.

Objective: Clinical studies show a high failure incidence after years of service of endodontically treated premolars, when restored with post-core crowns, especially those with short posts or deficient ferrules. The reason for this can be a deterioration of the luting cement around the post by fatigue from functional loading. In particular, the anatomy of premolars may frequently be incompatible with the application of long endodontic posts. The aim of this study was to evaluate the influence of fatigue loading on the quality of the cement layer between posts with restricted lengths and the root canal wall in premolars. As the stiffness of posts may affect the outcome, post-and-core systems with varying post stiffness were selected. Method and materials: Four types of post-and-core systems were selected for this study: three prefabricated post systems combined with a resin composite core material and one cast post and core. The three prefabricated posts were titanium posts (Tenax), quartz-fiber posts (Aestheti-Post), and quartz-coated-carbon-fiber posts (Aestheti-Plus). The post-and-core restorations were made on single-rooted, human, maxillary premolars from which the coronal sections were removed at the level of the proximal cementoenamel junction. Following endodontic treatment, a cast post and core (post length 6 mm) was prepared for each tooth individually (direct method) and cemented into the root canal with chemical cure Panavia 21 TC. The prefabricated posts were directly cemented in the root canal and then, after applying a dual-cure adhesive (Clearfil Photobond), built up with a core build-up composite (Clearfil Photocore). For each group (n = 8), half of the specimens were exposed to fatigue loading (10⁶ load cycles) almost perpendicular to the axial axis (85 degrees), while the other half was used as the control. Three parallel, transverse root sections of 1.5-mm thickness, were cut from each specimen. These sections were examined by scanning electron microscopy (SEM) to evaluate the cement integrity, while the retention strength of the cemented post sections was determined with a push-out test. Results: Fatigue loading did not cause separation of the buildups from the roots or affect the push-out strength. On a univariate level, only SEM evaluation showed significant differences between the types of post, fatigue loading, and between the levels of root sections. The cement integrity with the titanium post was significantly less than with the other three systems, which did not differ among themselves. The differences could not be explained by differences in stiffness between the posts. Conclusion: A composite core build-up material bonded to the dentin and supported by quartz-fiber posts or quartz-coated-carbon-fiber posts, cemented with adhesive cement like Panavia 21 TC, may be a viable alternative for the conventional cast core.

Objectives: Laboratory tests confirmed superior physical properties of fiber-reinforced resin composites; however, clinical failures continue to be observed. This in vitro study introduces a new method to measure strain and fracture resistance in glass fiber-reinforced pontics. Method and materials: Thirty standardized pontics in five groups were fabricated. Pontics were reinforced with: glass fiber (group 1); glass-fiber bundle surrounded by glass-fiber mesh (group 2); glass fiber with glass-fiber mesh parallel to the pontic's occlusal surface (group 3); or glass-fiber mesh parallel to glass-fiber bundle (group 4). Unreinforced resin composite pontics served as controls (group 5). A laser interferometer measured inner strains (µm/mm) in sectioned pontics, occlusally loaded with 250 N and 450 N, with a universal testing machine. Inner strains were measured on three levels (1, 2, and 3). Specimens were then loaded to crack onset, and loads were recorded. Comparisons were made using analysis of variance. Kruskal-Wallis and Fisher's exact tests were used, respectively, for nonparametric and categorical data. Results: Group 3 showed significantly lower mean strain values than controls. No significant differences in maximal inner strain values or crack onset loads were recorded. The framework of Group 3 inhibited crack propagation significantly better than that in groups 2 and 5. Conclusion: Within the limitations of this study, speckle interferometry proved to be a promising method for analyzing strains of pontics under load. The tested framework designs in this study had only limited influence on load-to-crack onset. When strategically placed, a glass-fiber mesh prevented crack propagation.