Quintessence International, 05/2006

Dens invaginatus is a dental malformation that may give rise to several complications. Caries of the invagination can severely weaken the whole tooth, making it susceptible to fracture. Subgingival fractures are major complications threatening tooth survival and usually require periodontal/orthodontic/prosthetic treatment if long-term viability is to be ensured. This article describes a case of single-session restoration of a fractured invagi-nated tooth by means of endodontic treatment followed by fragment reattachment. Keywords: dens in dente, dens invaginatus, fracture, reattachment, resin cement

Many clinicians consider the prosthetic restoration of missing posterior teeth by means of a 5-unit fixed partial denture with a pier abutment a non-favorable situation. The present article assesses the validity of the pier abutment by means of a critical review of the literature and mathematical analysis of the forces generated within a fixed partial denture of this design. Few studies are available, and none substantiate the theory that the pier abutment serves as a fulcrum. A mathematical model suggests that debonding may occur in the anterior abutment, but not due to the teetering of the fixed partial denture around the pier abutment. Keywords: fixed partial denture, fulcrum, non-rigid connectors, pier abutment

Ozone has been successfully used in medicine because of its microbiologic properties for more than 100 years. Its bactericide, virucide, and fungicide effects are based on its strong oxidation effect with the formation of free radicals as well as its direct destruction of almost all microorganisms. In addition, ozone has a therapeutic effect that facilitates wound healing and improves the supply of blood. For medical purposes, ozone may be applied as a gas or dissolved in water. Despite the advantages that the therapeutic use of ozone offers, reservations remain in terms of its application in the oral and maxillofacial area. Particularly, the gaseous application of ozone is critically evaluated because of its possible side effects on the respiratory system. The objective of this article is to provide an overview of the current applications of ozone in dentistry and oral surgery. Research was based on peer-reviewed sources found through a Medline/PubMed search and other textbooks, reviews, and journals. Keywords: caries, dentistry, disinfection, germs, microbiologic effect, oxidation, ozone, soft tissue, surgery

Objective: The purpose of this randomized, double-blind, clinical trial was to compare the marginal seal of 2 packable resin composite materials in moderate to large lesions on molars. Method and Materials: Fifty participants in need of a moderate to large Class 2 or complex Class 1 molar restoration were randomly distributed into 4 groups, to receive either Alert (Jeneric/Pentron) or SureFil (Dentsply/Caulk) resin composite with or without a surface sealer. Each participant received one restoration. With the exception that study protocol limited increments to no more than 4 mm, teeth were restored according to the manufacturers' instructions, and surface sealer was applied after finishing in the desig-nated groups. Use of Alert includes routine placement of a flowable composite liner. Clinical performance of the restorations was evaluated in 8 categories at baseline, 6 months, and 12 months. The 2 materials were compared to determine if a difference in marginal seal existed between groups. The number of restorations exhibiting marginal staining was compared using Fischer's exact test at a significance level of 5%. Results: Six participants did not present for the 12-month recall. At 12 months, 19 (90.5%) Alert restorations and 15 (68.2%) SureFil restorations did not exhibit marginal staining. There was no statistically significant difference between the 2 restorative materials for marginal staining. Overall, 3 restorations were rated as failures. Conclusion: At 12 months, materials placed with a flowable liner were not associated with a significant reduction in marginal staining. Keywords: Class 2 posterior restoration, flowable composite liner, marginal seal, marginal staining, packable resin composite, surface sealant

Objective: The purpose of this study was to compare the root canal transportation of the crown-down technique performed with the Ni-Ti rotary ProFile system (Dentsply/Maillefer), with the step-back technique using stainless steel K-Flexofiles (Dentsply/Maillefer). Method and Materials: Thirty simulated root canals in resin blocks were equally divided into 2 groups. The first group was instrumented with the ProFile system in a crown-down technique and the second group with hand K-Flexofiles in a step-back technique. After instrumentation, resin blocks of both groups were scanned by a transparency scanner, and the derived images were superimposed with the scanned image of an uninstrumented block. Transportation was digitally calculated by a computer software, and results were statistically evaluated by Student t test. Results: Statistically significant differences (P .05) were found among the 2 groups at 1, 2, 4, 5, and 6 mm from the apical foramen. No statistically significant difference was detected at 3 mm from the apical foramen. Conclusion: ProFile caused less transportation at 1 and 2 mm from the apex, whereas at 3 mm, both instrumentation techniques caused the same transportation. Standard deviation was less in the ProFile group than in the hand file group, indicating a more standardized preparation. Keywords: crown-down technique, rotary files, shaping ability, simulated root canal, step-back technique, transportation

The increase in patient demands for enhanced esthetics has prompted the development of several all-ceramic restorative systems. Despite their esthetic advantage, unsatisfactory mechanical properties have restricted the clinical indications of all-ceramic restorations. Recently, densely sintered zirconia-based restorations have become available. This material appears to have adequate strength and toughness to allow for the fabrication of anterior and posterior crowns and fixed partial dentures. This clinical report describes the procedures used for the restoration of maxillary incisors with the zirconia-based Lava system. Keywords: all-ceramic fixed partial dentures, ceramic restorations, esthetics, flexural strength, mechanical properties, zirconia

Objective: The purpose was to compare orofacial (temporomandibular) pain with other pain complaints regarding impairment and health care utilization in a sample of 1,011 children and adolescents from a metropolitan area in Germany. Method and Materials: Individuals aged 10 to 18 years were sampled in schools using a 2-stage cluster technique. Orofacial pain in the previous month was assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders. Additionally, participants were questioned about headache, back pain, abdominal pain, pain-related impairment, and health care utilization (visits to doctors, analgesic consumption) in the previous month. Results: Headache was reported by 50% (95% CI: 45% to 56%) of participants, stomach pain by 36% (95% CI: 32% to 41%), back pain by 31% (95% CI: 25% to 36%), and orofacial pain by 15% (95% CI: 12% to 18%). Girls were more affected than boys. The range of "severe" and "very severe" impairment lay between 8% (orofacial pain) and 22% (headache). The range of treatment demand was between 10% and 17% (orofacial pain: 15%), and the range for analgesic consumption between 18% and 24% (orofacial pain: 22%). The more pain experienced, the more impairment, doctor consultations, and analgesic consumption were reported (x2 test: P 0.05). Risk of orofacial pain was 60% higher for subjects with head, back, and/or abdominal pain (odds ratio: 1.6; 95% CI: 1.3 to 1.9). Conclusion: In children and adolescents, orofacial pain occurs about half as often as other pain complaints. However, relative to their prevalence the different pain complaints are similar regarding impairment and health care utilization. Keywords: chi-square distribution, chronic disease, cross-sectional studies, epidemiology, health services needs and demand, orofacial pain, prevalence, quality of life

Objective: The aim of this study was to evaluate and compare the antibacterial effect of chlorhexidine and calcium hydroxide slow-release devices on oral bacteria. Method and Materials: The agar diffusion test was used to evaluate the antibacterial effect of the slow-release devices Activ Point (chlorhexidine; Roeko) and Calcium Hydroxide Plus Point (Roeko) on 8 anaerobic and 2 facultative oral bacterial strains, as well as 2 bacterial cultures randomly sampled from necrotic root canals and incubated in anaerobic and aerobic broth for 48 hours. The efficiency of the medicaments against the various strains was evaluated using a nonparametric test (Friedman type) and a second nonparametric test (Wilcoxon's signed rank test). Results: Activ Point produced significantly larger inhibition zones (P .001) than the calcium hydroxide slow-release device around all tested bacterial strains. Conclusion: The chlorhexidine slow-release device (Activ Point) exhibited significant antibacterial activity in the agar diffusion test and merits study as an intracanal medicament. Keywords: agar diffusion test, calcium hydroxide, chlorhexidine, slow-release device

Objective: The purpose of this study was to evaluate 2 thione primers and 3 resin adhesives for enhancement of bonding strength to a silver-palladium-copper-gold alloy. Method and Materials: Two different sized disk specimens (10- and 8-mm diameter by 2.5-mm thick) were prepared from a silver-palladium-copper-gold alloy (Castwell M.C. 12, GC). The specimens were airborne-particle abraded with 50-µm-grain alumina, conditioned either with a thiouracil primer (Metaltite, Tokuyama Dental) or with a triazine dithione primer (V-Primer, Sun Medical), and then bonded with 1 of 3 acrylic resins: a benzoyl peroxide-amine redox-initiated resin adhesive (Multi-Bond, Tokuyama Dental) or a tri-n-butylborane-initiated resin adhesive (Super-Bond C&B and Super-Bond Quick, Sun Medical). For each adhesive, unprimed specimens were prepared as experimental controls. Shear bond strength was determined after thermocycling (100,000 cycles). Results: Use of primers significantly (P .05) enhanced the bond strength of specimens in all adhesives. Irrespective of the type of primer, the strength of Multi-Bond adhesive was significantly (P .05) lower than that of Super-Bond C&B and Super-Bond Quick adhesives. The strength of the 2 tri-n-butylborane-initiated adhesives did not differ significantly (P > .05). The mean strength of the Super-Bond C&B adhesive was 40.4 MPa with Metaltite and 37.8 MPa with V-Primer; that of Super-Bond Quick adhesive was 40.9 MPa with Metaltite and 36.5 MPa with V-Primer. Conclusion: Use of thione primers effectively enhanced the strength of the bond to the silver-palladium-copper-gold alloy. Furthermore, the combinations of primers and tri-n-butylborane-initiated adhesives were found to be more efficient for bonding. Keywords: initiator system, resin adhesive, shear bond strength, silver-palladium-copper-gold alloy, thermocycling, thione primer

Lupus erythematosus is considered to be a high risk factor for periodontitis. As an auto-immune disease of unknown origin, cutaneous lupus erythematosus (CLE) is subdivided into 3 categories: chronic (CCLE), subacute (SCLE), and acute (ACLE). While the ACLE has a high prevalence of conjunctive periodontal lesions, aggressive periodontitis in patients with CCLE has been rarely reported. This article describes the case of a patient diagnosed with aggressive periodontitis. Three months after the diagnosis of periodontitis, the patient experienced advancing hair loss (alopecia), pale fingers and toes, as well as edema in the legs and around the eyes. Skin biopsy showed follicular hyperkeratosis with perivascular mononuclear cell infiltrate. Colliquation of the basal cells, thickening of the basal lamina, and vacuolar degeneration of basal keratinocytes were also found. A lupus band test was positive, and diagnosis of CCLE was established. Three months following the treatment of lupus with antimalarial agents, the periodontal condition became stable with no further exacerbation or progression of the existing periodontitis. An 11-month postsurgical follow-up revealed stable periodontal and general medical conditions. A patient's medical history should be re-evaluated in the event of recurrence of periodontal lesions refractory to periodontal treatment. The control of systemic conditions like lupus erythematosus is essential for a good prognosis in the treatment of periodontitis as well as for the general health of the patient. Keywords: acute cutaneous lupus erythematosus, aggressive periodontitis, antineutrophil cytoplasmic antibodies, chronic cutaneous lupus erythematosus, cutaneous lupus erythematosus