Quintessence International, 01/2012

Functional and esthetic results can improve significantly when a combined prosthodonticorthodontic treatment approach is employed in cases requiring extensive oral rehabilitation. The patient presented in this case report was treated in his late teens with dental implants as a replacement for his maxillary incisors. Ten years later, the entire maxillary anterior segment was in infraocclusion compared to the rest of the dentition and lip line. Since prosthodontic follow-up treatment alone could not achieve an optimal functional and esthetic outcome, the patient was treated orthodontically prior to renewing the restoration. A fixed appliance was used to intrude the mandibular anterior teeth as well as vertically align the infrapositioned maxillary lateral incisors. Keywords: complication, growth, implant, infraocclusion, orthodontics

Root canal anatomy may present clinicians with a complex clinical challenge that requires diagnostic approaches, access modification, and clinical skills to successfully localize, negotiate, disinfect, and seal the root canal system. This article discusses the clinical implications of endodontic therapy on permanent mandibular first molars. The number of roots on the mandibular first molar is directly related to ethnicity. Canal morphology has a significant effect on treatment protocol: Mesial roots present two canals on a regular basis, adopting 2-2 and 2-1 as the most common configurations. A third canal is present in 2.6% of the population. The most common configuration in the distal root is type I (62.7%), followed by type II (14.5%) and type IV (12.4%). Diagnosis and treatment of complex root canal systems often require specialized training that may be beyond the scope of the average general practitioner. Access modifications are required to find extra roots and/or canals. The instrumentation of the third root requires a different access and small, flexible instruments, given the curvature that is usually present buccally in the apical third. The incidence of isthmuses is 55% in the mesial root and 20% in the distal root. This anatomical configuration should be taken into consideration during endodontic treatment as well as during periapical surgery. Keywords: clinical recommendations, mandibular first molar, root canal anatomy, root canal morphology

Full-arch and partial reconstruction is demanding for the clinician and a challenge for the patient. Traditionally, teeth are extracted, and implants are placed; the patient wears a provisional removable prosthesis during implant osseointegration. The patient is left to deal with a difficult transition from a fixed dentition to a removable one, albeit temporarily. This drastic alteration can generate functional, emotional, and esthetic changes for the patient, thereby making a difficult time even more challenging. Reconstructing the dentition through a staged approach has been documented and involves strategic extractions along with the placement of several implants, but leaves select abutment teeth for a fixed provisional prosthesis. This allows for the provisional prosthesis to be tooth-supported during implant integration and later converted to an implant-supported prosthesis. In this manner, the patient will benefit from a fixed provisional prosthesis throughout the treatment process. A staged approach is contingent upon a thorough periodontal and prosthetic evaluation and work-up. Success requires proper communication between the periodontist, surgeon, restorative dentist, laboratory, and patient. A team approach is necessary for success. The protocol, advantages, and disadvantages for a staged approach to a full-arch implant-supported reconstruction are discussed. The authors also present a case to show how the staged approach can be used for sextant or quadrant rehabilitation. Keywords: provisional prosthesis, serial extractions, staging, transitional abutments

Objective: To clarify the mode of root fracture in 32 endodontically treated teeth that resulted in vertical root fracture (VRF) despite the provision of a crown for fracture prevention. Method and Materials: The teeth included in the study underwent root canal treatment and were restored with crowns without the use of an intracanal post. All teeth underwent photo documentation. Clinical signs and symptoms as well as the patients' ages were recorded. The diameters of the roots and the root canal fillings were measured on radiographs. Fractured roots were investigated using a scanning electron microscope (SEM). Results: The mean patient age was 60.2 years. The VRFs in the group occurred most frequently in the mesial roots of the mandibular first molars. The fracture was predominantly buccolingual. The mean ratio measured between the diameters of the root canal obturations and the outer root surfaces in the radiographs was 33.2%. SEM evaluation showed that most fractures ran from the inner to the outer root surface, and the cracks predominantly ran apical to coronal. Conclusion: Endodontically treated and crowned teeth without root canal posts can develop VRFs. The cracks start at the root canal wall in the apical part of the root and extend toward the outer root surface and coronally. Further investigation is necessary to determine the possible causes and evidence of fracture development. Keywords: apical preparation, apical sclerosis, crack development, root canal treatment, vertical root fracture

Transmigration is the pre-eruptive intrabony migration of a tooth across the midline. This rare phenomenon, the etiology of which is unknown, is usually seen in canines. Two cases of transmigration in the mandibular canines are reported; one shows the transposition of a maxillary canine and premolar. Familial occurence of this phenomenon and a 5-year follow-up showing a change in the inclination of the impacted tooth are outlined. Keywords: familial, impaction, mandibular canine, transmigration

Objective: Recent advances in techniques for detecting oral premalignant lesions and oral squamous cell carcinoma have improved the chances of early diagnosis. Adjuncts for detection of lesions include toluidine blue staining and cytologic examination. The primary objective of this study was to assess the efficacy of 1% toluidine blue (modified Mashberg technique) and cytology in detection of oral premalignant lesions and oral squamous cell carcinoma. Method and Materials: The study included 86 participants suspected of having oral premalignant lesions or oral squamous cell carcinoma. One percent toluidine blue was applied to the lesions, followed by cytology. A biopsy was then performed on the tissue. Histopathologically proven oral premalignant lesions/oral squamous cell carcinoma lesions were analyzed for sensitivity, specificity, postive predictive value, and negative predictive value of both screening techniques. The association of screening techniques and histopathologic diagnosis among the oral premalignant lesions, oral squamous cell carcinoma, and benign groups were analyzed using the Fisher exact test. P < .05 was considered significant. Results: The specificity and sensitivity for oral squamous cell carcinoma and oral premalignant lesions detection of 1% toluidine blue was 81.35% and 66.67%, respectively, while cytology attained 77.97% and 70.37%, respectively. Negative predictive value and positive predictive value were 84.21% and 62.06% for 1% toluidine blue and 85.18% and 59.37% for cytologic examination, respectively. Comparison of 1% toluidine blue and cytology with histopathologic diagnosis shows a significant difference between carcinoma/epithelial dysplasia and no dysplasia and carcinoma/epithelial dysplasia and benign lesions (all, P < .05). Conclusion: The results of this study suggest that 1% toluidine blue and cytology have high sensitivity, specificity, and accuracy in detecting oral premalignant lesions and oral squamous cell carcinoma and can be used as an adjunct for early detection of such lesions. Keywords: cytology, oral cancer, premalignant, screening, toluidine blue

Objectives: Orthodontic thermoelastic archwires produce lighter and more biologic forces than superelastic archwires and could therefore offer the possibility of reducing initial orthodontic pain. Nevertheless, evidence concerning this issue is scarce. The aim of this study was to compare pain perception following first archwire placement in patients with thermal heat-activated (HANT) and superelastic (SE) nickel-titanium archwires. Method and Materials: Thirty subjects (11 males, 19 females; range, 11 to 26 years of age) were recruited. Metal brackets were bonded in the maxillary or mandibular arch. Round 0.016- inch HANT or 0.016-inch SE archwires were randomly placed and tied with elastic ligatures. Each patient was invited to score tooth pain for 7 days at different time points (8:00, 12:00, 16:00, 20:00, and 24:00) using the visual analog scale (VAS). Results: In both groups, pain was highest at day 2 and lowest at day 7. Patients with HANT archwires had significantly lower VAS scores (P < .005) at days 2, 3, and 4 than subjects with SE archwires. This was also the case after adjusting for analgesic consumption, sports practicing, overlapping pain of different origin, and the concomitance of stressful events. The frequency of analgesic consumption was higher in the SE than in HANT group at day 3 (P < .05). No differences in pain perception were found between time points, nor was any correlation found between dental crowding and pain. No difference in pain perception was found between the maxillary and mandibular dental arches. Conclusion: Initial orthodontic pain is reduced when using HANT orthodontic archwires. Keywords: orthodontic pain, superelastic archwire, thermoelastic archwire

Objective: Nowadays, necrotizing periodontal diseases have a low prevalence; however, a better understanding of the etiopathogenesis of these diseases is necessary for determining more adequate preventive and therapeutic strategies. Method and Materials: From a pool of 1,232 HIV-infected patients, 15 presented with necrotizing periodontal diseases, which were evaluated by full-mouth periodontal clinical measurements. Subgingival biofilm samples were collected from necrotizing lesions of six of these individuals. The presence and levels of 47 bacterial species were determined by checkerboard DNA-DNA hybridization. Results: All 15 patients (10 had severe immunodeficiency) had been infected sexually. Thirteen patients were taking antiretroviral medication (66.7% undergoing highly active antiretroviral therapy). Regarding necrotizing periodontal diseases, necrotizing ulcerative gingivitis (60%) was more prevalent than necrotizing ulcerative periodontitis (40%). The frequency of supragingival biofilm and bleeding on probing ranged from 11.5% to 59.2% and 3.0% to 54.0%, respectively, whereas the mean probing depth and clinical attachment level were between 1.48 and 2.61 mm and 1.30 and 2.62 mm, respectively. Species detected in high prevalence and/or counts in necrotizing lesions included Treponema denticola, Eikenella corrodens, Dialister pneumosintes, Enterococcus faecalis, Streptococcus intermedius, Aggregatibacter actinomycetemcomitans, and Campylobacter rectus. In contrast, Parvimonas micra, Prevotella melaninogenica, Fusobacterium nucleatum, Eubacterium nodatum, and Helicobacter pylori were observed in the lowest mean prevalence and/or counts. Conclusion: Necrotizing periodontal disease lesions in HIV-infected patients present a microbiota with high prevalence and/or counts of classical periodontal pathogens, in particular T denticola, as well as species not commonly considered as periodontal pathogens, such as E faecalis and D pneumosintes. In addition, these individuals with necrotizing periodontal disease frequently display severe immunodeficiency and AIDS-defining diseases such as tuberculosis. Keywords: HIV, microbiology, necrotizing ulcerative gingivitis, periodontitis

Objective: To investigate the effects of different acids and etching times on the bond strength of glass fiber-reinforced composite (FRC) posts to composite core material. Method and Materials: Twenty-six FRC posts (FRC Postec Plus) were randomly divided into 13 groups (each n = 2). One group received no surface treatment (control). The posts in the other groups were acid etched with 35% phosphoric acid and 5% and 9.6% hydrofluoric acid gel for four different etching times (30, 60, 120, and 180 seconds). A cylindric polytetrafluoroethylene mold was placed around the treated posts and filled with dual-cure composite core material (MultiCore Flow). All samples were light cured for 60 seconds. After 24 hours of water storage, the specimens were sectioned perpendicularly to the bonded interface under water cooling to obtain 2-mm post-and-core specimens. Eight specimens were made from each group. Push-out tests were performed at a crosshead speed of 0.5 mm/min using a universal testing machine. Data were analyzed by one-way ANOVA followed by the Tukey honestly significant difference test (α = .05). Results: The lowest bond strength was observed in the control group (12.51 megapascal [MPa]). No statistical significant difference was observed among group H5-120 (20.31 MPa), group H9-120 (20.55 MPa), or group P-180 (20.57 MPa) (P > .05). These groups demonstrated the highest bond strength values (P < .05). Conclusion: For the FRC posts, all acid-etching procedures tested showed significantly increased bond strength when compared with the control group. Acid-etching with 5% hydrofluoric acid and 9.6% hydrofluoric acid for 2 minutes and with 35% phosphoric acid for 3 minutes (groups H5-120, H9-120, and P-180, respectively) demonstrated the highest bond strength values between the FRC post and composite core material. Although the bond strength was increased by prolonged acid etching, the microstructure of the FRC posts might have been damaged. Keywords: acid etching, bond strength, composite core material, etching time, FRC post, hydrofluoric acid, phosphoric acid

Objective: This systematic review addressed what the ideal limit is for removing carious tissue to address a caries lesion. Method and Materials: The Medline, Cochrane, and PubMed databases were searched for abstracts of English-language articles published between 2000 and 2010 as well as randomized clinical trials about the total, partial, and/or nonmechanical removal of carious tissue in primary teeth. The analysis of the abstracts was performed individually by two reviewers. The full text of potentially relevant studies was obtained, analyzed based on criteria for quality assessment of a randomized clinical trial, and placed in an evidence-based table. Results: After reading the abstracts, 151 articles were excluded. Six references met the inclusion criteria and were selected for full reading. After the reviewers consulted with one another, three papers were considered potentially relevant to this review. Conclusion: This analysis suggests that minimally invasive procedures for dental tissue are viable choices for stopping caries lesions. Partial or nonmechanical removal of carious tissue favors the arrest of dental caries lesions. Keywords: dental caries, dentin, primary teeth