Why do we need an oral health care policy in Canada?

Although health care is a right of citizenship, severe inequities in oral health and access to care persist. This paper provides information on the financing, organization and delivery of oral health services in Canada. It concludes that dental care has largely fallen out of consideration as health care. The increasing costs of dental insurance and disparities in oral health and access to care threaten the system"s sustainability. The legislation that allows the insured to receive tax-free care and requires all taxpayers to subsidize that expenditure is socially unjust. Unless an alternative direction is taken, dentistry will lose its relevance as a profession working for the public good and this will be followed by further erosion of public support for dental education and research. However, never before have we had the opportunity presented by high levels of oral health, the extensive resources already allocated to oral health care, plus the support of other organizations to allow us to consider what else we might do. One of the first steps would be to establish new models for the delivery of preventive measures and care that reach out to those who do not now enjoy access.     

Identification of a C-shaped canal system in mandibular second molars-part II: the effect of bone image superimposition and intraradicular contrast medium on radiograph interpretation

The purpose of this study was to investigate the effect of image superimposition from surrounding alveolar bone and intraradicular contrast medium on radiographic interpretation of a C-shaped canal system in mandibular second molars. Thirty mandibular second molars with fused roots were collected and stored in 10% formalin solution. After being scanned by microcomputed tomography and reconstructed, the buccal-lingual radiographs of each tooth were taken with or without intraradicular contrast medium and mandibular bony plates. The number of mesial and distal canals in the coronal-to-middle canal portion and the canal number in the apical 4-mm area were recorded. The buccal-lingual and three-dimensional view of reconstructed canal images were used to evaluate the accuracy of radiograph reading. The results were subjected to the Friedman and chi-square test. The results showed that without intraradicular contrast medium, the bone superimposition could decrease the accuracy of canal recognition significantly (p < 0.001), especially in the apical area. When contrast medium was in canals, the canal reading seemed not to be affected by the bone superimposition (p > 0.05). Based on these findings, the intraradicular contrast medium could increase the accuracy of canal recognition of a C-shaped canal system in mandibular second molars despite the bone image superimposition, especially in the detection of continuous C-shaped canals and the canals in the apical area.     

The inhibitory effect of MI paste, fluoride and a combination of both on the progression of artificial caries-like lesions in enamel

This in-vitro study evaluated the inhibition of demineralization in enamel sections produced by MI paste, fluoride and a combination of both, compared to artificial saliva and NaF 5000 ppm in a caries progression pH-cycling model. Twenty-one teeth were demineralized to create subsurface enamel lesions (approximately 200 microns in depth). The teeth were sectioned and characterized using polarized-light-microscopy (PLM). A single section from each lesion was assigned to a treatment group: Artificial saliva, NaF 5000 ppm (Prevident, Colgate), MI paste (Recaldent, GC America Inc), NaF 1100 ppm (Crest, Procter & Gamble) and NaF 1100 ppm plus MI paste. The sections were covered with varnish except for an exposed window on the external surface of the lesion and placed in a six-day pH-cycling model with two daily treatment applications of two minutes each. The sections were characterized by PLM, and the lesion areas were measured using a digital image analysis system. Based on a paired-sample t-test, significant differences (p < .05) in percentage of change in lesion size were found between the high fluoride group and all the other groups. No significant difference was found between the artificial saliva and MI paste group, neither was there any significant difference between the NaF 1100 ppm, the combined application group or the MI paste group alone. In conclusion, the higher concentration of NaF (5000 ppm) reduced lesion progression to the greatest extent. The MI paste group did not show any effect on the inhibition of lesion progression. Further studies on the preventive effect and longer treatment applications are recommended.     

Comparison of remifentanil with fentanyl for deep sedation in oral surgery.

PURPOSE: The aim of this study was to compare recovery for oral surgery patients given a deep sedation regimen of midazolam, propofol, and remifentanil with a standard control of fentanyl in place of remifentanil. MATERIALS AND METHODS: This investigation was designed as a randomized, prospective, single-blinded controlled study. Group 1, the control, received midazolam 0.03 mg/kg, fentanyl 1 microg/kg, and propofol initially at 140 microg/kg/min. Group 2 received midazolam 0.03 mg/kg, remifentanil: propofol (1:500) given at an initial propofol infusion rate of 40 microg/kg/min. Outcome measures included time to response to verbal command, Aldrete score = 9, Postanesthesia Discharge Scoring System = 7, and assessment by the Digit Symbol Substitution Test. RESULTS: Forty-seven subjects were entered in the study. Baseline findings were homogenous between the 2 groups. Subjects in group 2 recovered earlier (P < .005) and required less propofol for both the induction (0.8 +/- 0.4 versus 1.2 +/- 0.6 mg/kg; mean +/- SD, P < .01) and maintenance of deep sedation (46 +/- 9 versus 131 +/- 17 microg/kg/min; P < .005). There were minor differences in vital signs. CONCLUSIONS: This study demonstrated that this remifentanil regimen provided significantly more rapid recovery and used significantly less propofol compared with the fentanyl regimen.     

Static and cyclic loading of fiber-reinforced dental resin.

OBJECTIVE: The aim of this study was to evaluate the flexure strength of unidirectional fiber-reinforced resins under static and cyclic loading with and without thermal cycling. METHODS: The fiber-reinforced resin materials chosen for this project were commercially available endodontic posts and commercially procured bar samples. For all materials, controls for flexure strength were tested in air and in water using three-point loading. Specimens were thermal cycled between 7 and 63 degrees C for 6000 cycles. A staircase approach was used to determine the flexure fatigue limit and scanning microscopy was used to examine the microstructure. RESULTS: The carbon/graphite fiber-reinforced resin posts and the glass FiberKor posts were significantly stronger than the ceramic (zirconia) and the other glass-reinforced resin materials. Thermal cycling caused a significant lowering (11-24%) of the flexure strength for each resin based post system. The ceramic post system decreased only by 2%. Further, for standard size glass fiber-reinforced resin bars, no significant differences between testing in air and water was observed, but a significant difference between static and cyclic loading was noted. SIGNIFICANCE: The decreases in the strength property due to thermal cycling and the cyclic loading of these materials indicates that their utilization in the oral environment enhances their degradation, and potentially shortens their clinical life.     

In vitro antimicrobial activity of various medication preparations on E. faecalis in root canal dentin

The purpose of this study was to evaluate the antimicrobial activity of several medication preparations in root canal dentin infected with Enterococcus faecalis. Roots of extracted bovine incisors were prepared to standardized cylindrical test specimens, 5 mm in height. The smear layer was removed and the samples were autoclaved and then incubated at 37 degrees C/5% CO2 for 24 h in brain-heart infusion (BHI) broth containing 7.0 x 10(4) colony forming units per ml of E. faecalis. The samples were washed in phosphate buffered saline and mounted to individual culture wells with sticky wax. Test medications were applied to fill the canal lumina; medication groups were: (a) sterile H2O (positive control); (b) a 10% mixture of 1.0 g Ca(OH)2 USP in 10 ml sterile H2O; (c) 10% Ca(OH)2 in 0.12% chlorhexidine gluconate (Peridex); (d) Peridex; and (e) uninoculated BHI (negative control). The samples were incubated at 37 degrees C/5% CO2 for 24 h. Dentin samples for quantitative microbiology were then obtained with consecutive sterile burs (ISO 029, 035, 042). All three experimental groups demonstrated significantly greater antimicrobial activity than the positive control (p < 0.001). Group 2 demonstrated significantly greater antimicrobial activity than Group 3 or Group 4 at all dentin depths (p < 0.05). These results suggest that 10% Ca(OH)2 may be more effective than Peridex or 10% Ca(OH)2 in Peridex for the elimination of E. faecalis from dentin tubules.     

Evaluation and management of TMDs, Part 1. History, epidemiology, classification, anatomy, and patient evaluation

The study of temporomandibular disorders has undergone many changes throughout its history. Focus on the structure and function of the TMJ continues to improve our understanding of these complex disorders. A more standardized classification system allows practitioners and researchers to discuss findings in a common language. With improved patient evaluation techniques, the clinician can establish a proper working differential diagnosis and begin focusing attention on treatment planning.     

Antibiotic prophylaxis in intraoral orthognathic surgery

A prospective randomized double-blind study was conducted to evaluate two prophylactic antibiotic regimens in a population of 40 patients undergoing intraoral orthognathic surgery. All patients received one intramuscular dose of 600,000 units procaine penicillin G and 400,000 units aqueous penicillin G preoperatively. Two million units aqueous penicillin G were administered intravenously every three hours intraoperatively and postoperatively three hours after the last intraoperative dose. One group of 20 patients then received 2 million units aqueous penicillin G intravenously every four hours for a total of 12 doses (two days) postoperatively. The second group of 20 patients received a placebo intravenously every four hours for a total of 12 doses (two days) postoperatively. Three infections occurred in the group of patients receiving the placebo postoperatively and none in the group of patients receiving the antibiotics postoperatively.     

Capacity for training in clinical research: status and opportunities

The ability to base patient care on scientific evidence depends in part on the results of translational and applied research. The shortage of trained clinical researchers identified by several sources limits the availability of clinical research studies upon which to base evidence-based therapeutics. This premise suggests that the dental profession needs to train more clinical researchers and faculty to conduct clinical research and to teach its applications to practice. Increasing opportunities for clinical research training in a variety of settings should eventually increase the numbers of clinical researchers, raise faculty involvement in clinical research, and promote science transfer. This paper reports on the current status of clinical research in dental schools, specifies the diverse groups involved in the clinical research enterprise, and identifies underutilized opportunities and partnerships for clinical research training. Data on federal and nonfederal funding of clinical research and training programs are presented. Existing and novel mechanisms for expanding clinical research training throughout and across traditional as well as unconventional environments are explored.