Predoctoral Fixed Prosthodontics Curriculum Survey

Purpose In 1996, a survey of American dental schools was conducted. The purpose of the survey was to determine the curricular structure, techniques taught, and materials used in predoctoral fixed prosthodontics courses. Materials and Methods The survey was mailed to the course directors of predoctoral fixed prosthodontic programs at 53 American dental schools. Of these, 42 schools returned the completed survey, resulting in a response rate of 79%. The mean, median, and the range of responses were computed where applicable. Results The results from this survey show that the mean student-to-faculty ratio in the preclinical course was 11:1, with a median of 10:1 and a range of 5:1 to 25:1. The mean number of laboratory clock hours was 164, with a median of 148 and a range of 81 to 288. The mean number of lecture hours reported was 42, with a median of 35 and a range of 20 to 80. Fifty-five percent of the schools used the Hanau semiadjustable articulator. The most commonly used provisional technique was the thermoplastic custom external surface form (44%). The finish line of choice for the full metal restoration was the chamfer placed circumferentially (74%). The finish line of choice for the porcelain-fused-to-metal restoration was the shoulder placed facially and the chamfer placed lingually (38%). Conclusions Predoctoral fixed prosthodontics education and technical experience varies from school to school, yet a large percentage of schools agree on certain topics.     

A Critique of Topical Fluoride Methods (Dentifrices, Mouthrinses, Operator-, and Self-applied Gels) in an Era of Decreased Caries and Increased Fluorosis Prevalence

Within the last 20 years there has been a decrease in the caries prevalence of US schoolchildren, a change in the intraoral caries pattern, and a slowing of the progress of lesions. Simultaneously, the prevalence of enamel milder, cosmetically acceptable forms and is more noticeable in fluoride-deficient communities than those with optimal or above-optimal water fluoride concentrations. Circumstantial evidence indicates that a principal contributor to the caries decline is the extensive use of fluoride dentifrices. Conversely, although use of a fluoride dentifrice can add to the total daily amount of ingested fluoride in preschool children, there is little evidence to suggest that dentifrice ingestion is a principal factor causing the fluorosis increase. The value of fluoride methods may be assessed in relative or absolute terms. The relative, or percentage, caries reduction attributed to fluoride mouthrinses and gels appears to be a property intrinsic to the methods themselves and generally is little affected by the caries activity of the population being treated. Conversely, the absolute, or numerical, caries reduction is dependent upon the level of disease in the population. Thus, the reported caries decline reduces the number of surfaces prevented from developing caries, even though the percentage reduction remains substantially unchanged. Although inadvertent ingestion of fluoride can result from the use of mouthrinses and gels, there is little evidence to suggest that they have contributed to the fluorosis increase. When using topical methods, prudence should prevail to avoid ingestion of fluoride. Fluoride dentifrices should continue to be used routinely, and although lower potency dentifrices may be considered, the literature does not provide strong support for their need. Use of fluoride mouthrinses and gels for individual patients should be predicted upon their caries activity or risk. Use of these methods in public health programs is a matter of cost-effectiveness, which will be influenced by the caries prevalence of the target population.     

Reactive oxygen species scavenging activity during periodontal mucoperiosteal healing: an experimental study in dogs

Excessive release of reactive oxygen species (ROS) in wounded tissue due to inflammation and ischaemia is a deleterious and destructive phenomenon for the healing process. Hence, scavenging of ROS is one of the essential steps in normal wound repair. In this study, we presented a profile of free radical scavenging enzyme (FRSE) activity of periodontal mucoperiosteal wounds in order to investigate ROS activity during periodontal wound healing. Mucoperiosteal periodontal flaps were elevated in the mandibular buccal region of seven dogs between the first premolar and first molar teeth, creating acute incisional wounds in the inner side of the flaps and they were replaced 30 min after elevation. Gingival samples taken from certain biopsy regions at baseline (before flap elevation), day 3, 12, 21 and 30 were processed for detection of active amounts of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). All enzyme activities had increased by more than 100% of their baseline levels by day 3. SOD activity decreased gradually from days 3 to 30 and reached a level lower than the baseline value. The increase in CAT activity continued until day 21, and decreased to a level higher than the baseline value by day 30. GPX also decreased from day 3, and reached a level less than its baseline value by day 30. Our results suggest that FRSEs may contribute to the detoxification of ROS during periodontal mucoperiosteal healing. This relationship may be utilized to facilitate soft tissue and/or flap management in periodontal or intra-oral treatments.     

Lower lip sucking habit treated with a lip bumper appliance

The patient was an 11-year-old girl with a lower lip sucking habit with increased overjet, maxillary generalized spacing, and mandibular incisor irregularity. Hyperactivity of the mentalis muscle and deepening of the labiomental sulcus because of the abnormal sucking habit was observed. Orthodontic treatment was started with a lip bumper appliance to break the lower lip sucking habit and continued with fixed orthodontic mechanotherapy. The lip bumper appliance therapy resulted in the elimination of the lower lip sucking habit, musculus mentalis hyperactivity, and labiomental strain in addition to a gain in arch length, improvement of the lower incisor inclinations, and overjet reduction.     

Total proteoglycan and chondroitin-4-sulfate levels in gingiva of patients with various types of periodontitis

BACKGROUND: The aim of the present study was to investigate the total proteoglycan (PG) and chondroitin-4-sulfate (C4S) levels in gingival tissue samples obtained from patients with aggressive periodontitis (AgP) and chronic periodontitis (CP) before therapy (baseline) and 1 month after completion of non-surgical periodontal therapy. METHODS: Gingival tissue samples were obtained from 10 AgP and 10 CP patients before initiation of treatment (baseline) and 1 month after non-surgical periodontal treatment. The control group comprised 10 systemically and periodontally healthy subjects. Total PG and C4S levels were determined by biochemical techniques. PG levels were analyzed using a modified Bitter and Muir method. C4S assay was carried out using chondroitin sulphate lyase AC and chondroitin-6 sulphate sulphohydrolase enzymes. The results were tested statistically using parametric tests. RESULTS: The clinical periodontal parameters demonstrated significant decreases in the periodontitis groups (P<0.05) after treatment, and there was no significant difference between AgP and CP groups at baseline and after treatment (P>0.05). At baseline, total PG and C4S levels in both of the periodontitis groups were significantly lower than that of the control group (P<0.05). One month after the non-surgical periodontal treatment, total PG levels in the periodontitis groups were comparable to the control group (P>0.05), whereas C4S levels in the AgP group were significantly lower than the other study groups (P<0.05). In the CP group, total PG and C4S levels increased significantly (P = 0.001 and P = 0.006, respectively) after non-surgical periodontal treatment, but they did not increase in the AgP group (P>0.05). CONCLUSION: The significant increases observed in total proteoglycan and chondroitin-4-sulfate levels after non-surgical periodontal treatment in the CP group but not in the AgP group may suggest that healing patterns differ between the two periodontitis types in terms of PG and C4S composition of extracellular matrix.     

The effects of water and acetone-based dentin adhesives on apical microleakage

In this study, the aim was to assess the in vitro apical microleakage of a resin-based sealer used with two different adhesives. Thirty nine freshly extracted maxillary incisors were used. The teeth were decoronated at the cemento-enamel junction with a water-cooled fissure bur. Chemo-mechanical debridement of the root canals was accomplished with the step-back technique. The smear layer was removed by 19% ethylenediamine tetra acetic acid (EDTA). The roots were then divided into three experimental groups of thirteen teeth in each. Specimens in group 1 were filled with gutta-percha, AH Plus sealer, and water-based adhesive system (Syntac Single Component). Group 2 specimens were filled with gutta-percha, AH Plus sealer, and acetone-based dentin adhesive (Prime & Bond NT ). Specimens of group 3 were filled with only gutta-percha and AH Plus sealer (no adhesive was applied). The teeth were immersed into 2% methylene blue solution. Apical sealing qualities were assessed by measuring the linear dye penetration with a stereomicroscope. Dentin tubule penetration was observed under scanning electron microscopy (SEM). Results showed no statistically significant difference between the materials used, however, the leakage in group 2 was less than group 1 and 3.     

Effect of primer precuring on the shear bond strength of orthodontic brackets

Two adhesive systems, Transbond APC II (3M Unitek, Monrovia, Calif) and Quick Cure (Reliance Orthodontic Products, Itasca, Ill), were used to determine the efficacy of precuring the liquid resin primer phase of the systems to increase shear bond strength. One hundred sixty bovine incisors were divided into groups of 20 specimens. In 1 group, the primer was cured before placement of the bracket with the filled adhesive material, and, in the other group, the primer was not precured. The shear-peel bond strength was tested with a testing machine at 30 minutes and 24 hours. No statistically significant difference in bond strength was found between the groups that had or had not been precured. More adhesive remained on the teeth with the Transbond when the primer was not precured. There is no advantage or disadvantage in bracket bond strength by precuring the primer before placing the bracket and filled component of the adhesive.     

Clinical evaluation of the plaque-removing ability of three different toothbrushes in a mentally disabled group

The aim of the study was to evaluate the efficacy of plaque removal of three different toothbrushes on mentally disabled children in two different age groups. A manual triple-headed brush (SuperBrush; Dento Co. AS [junior, regular]) compared with a new manual toothbrush (CrossAction; Oral-B [35 compact, 40 regular]) and an electric toothbrush with an oscillating rotating head (Braun Plaque Control 3D [Braun 3D]; Oral-B [D15525]). Fifteen children aged 6-12 (Group A) and 15 children aged 13-18 (Group B) with mild mental disabilities participated in the single-blind clinical study. To obtain a plaque-free condition at baseline, professional tooth-cleaning was performed on each participant. After instructions on how to use the toothbrushes, each group started the experiment. After 1 week of application, the Quikley Hein (QH) plaque index and the approximal plaque index (API) were used to assess the oral hygiene status of each participant. This was followed by a week of recess before each group switched to the next type of toothbrush. The study lasted for 5 weeks. Compared to the two other brushes, the Braun 3D was more effective in removing plaque (means of QHI: 1.54 (Braun 3D), 1.77 (SuperBrush), and 2.15 (CrossAction) in total; means of API 1.37 (Braun 3D), 1.52 (SuperBrush), 1.94 (CrossAction). The study indicated that the electric toothbrush is the most effective for removing dental plaque in mentally disabled children, whereas the SuperBrush is a good alternative.