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941.
STATEMENT OF PROBLEM: Noncarious cervical lesions are described as having a multifactorial cause, with occlusal trauma and toothbrush abrasion frequently mentioned as major factors. Finite element modeling studies have demonstrated a relocalization of occlusal stresses to the cervical area due to flexure of the crown. This may cause microcracking, especially under tensile stresses, that will lead to a loss of enamel and dentin in the cervical region. Clinical confirmation of an occlusal cause for noncarious cervical lesions has been difficult to obtain. PURPOSE: This study investigated whether occlusal wear was correlated with an increase in the size of noncarious cervical lesions. MATERIAL AND METHODS: Loss of contour at occlusal and cervical sites on 3 teeth of a single individual was measured using digital and visualization techniques at 3 time intervals over a 14-year time span. The 1983 baseline casts and 1991, 1994, and 1997 clinical impressions of a single adult patient with existing noncarious cervical lesions were replicated in epoxy. Surfaces of all replicas were digitized with a contact digitizing system. Sequential digitized surfaces were fit together and analyzed using AnSur-NT surface analysis software. Clinical losses of surface contour by volume and depth of the left mandibular first molar and first and second premolars were recorded. RESULTS: Nine measurements of cervical volume loss (range 0.9 to 11.5 mm(3)) and 9 corresponding measurements of occlusal volume loss (range 0.39 to 7.79 mm(3)) were made. The correlation between occlusal and cervical volume loss was strong (r(2)=0.98) and significant (P<.0001). CONCLUSION: For the single adult patient in this study, there was a direct correlation between occlusal wear and the growth of noncarious cervical lesions.  相似文献   
942.
The purpose of this study was to investigate the effect of smear layer and direction of dentinal tubules on osteoblast adhesion to human dentin tissue in vitro. Dentin disks were made from human premolars extracted for orthodontic reasons. Dentin disks were cut either perpendicularly to the long axis of the tooth or at 45 degrees to the long axis of tooth. The smear layer was removed by 34% phosphoric acid gel from half of the dentin disk surface. Human osteoblast-like Saos-2 cells were grown in RPMI medium with 10% fetal bovine serum and 1% antibiotic/antimycotic cocktail under standard cell culture conditions. Cells were seeded into Nunc four-well culture plates at 1.5 x 10(5) cells per well with dentin disks in the bottom of each well. After 1 day in culture the dentin disks along with cells grown on their surface were examined with a scanning electron microscopy. Osteoblasts attached and spread on the dentin surface and formed a monolayer in the presence and absence of a smear layer. Cells spread over the dentinal tubules despite their direction. These results suggest that cell adhesion and spreading of osteoblasts is not influenced either by the existence of a smear layer or the direction of the dentinal tubules on the dentin surface.  相似文献   
943.
The purpose of this study was to survey the views of Australian dentists on toothbrush wear, toothbrush renewal periods and recommendations to patients and to investigate the relationship between dentists' views on patients' toothbrush renewal intervals and dentists' own renewal habits. Questionnaires were mailed to 5,596 Australian general dental practitioners and replies received from 3,406 (61 per cent response rate). The majority of respondents (85.7 per cent) felt patients should renew their toothbrushes more often. However, only 45.3 per cent usually made a recommendation to their patients as to when they should renew their toothbrush and only 41.7 per cent thought patients actually followed such recommendations. Most respondents (56.6 per cent) thought the average adult patient should renew a toothbrush every two-three months. A renewal period of one month or earlier was recommended by 23.8 per cent of dentists; four-five months by 8 per cent; and six months or longer by 11.5 per cent. A highly significant correlation was found between the renewal periods recommended for patients and the intervals selected by the dentists for their personal brushes (p < 0.001; chi-square test). Bending and splaying of bristles was the sign identified by the majority of dentists (70 per cent) as indicating the need for a new brush. The findings suggest dentists' recommendations concerning toothbrush renewal intervals may be based on their own toothbrush renewal habits. It is also concluded that dentists think patients comply poorly with their recommendations on toothbrush renewal.  相似文献   
944.
Background: The replacement of a single tooth or several teeth by means of single‐implant restorations is an increasingly used method that needs long‐term validation. Purpose: The goal of this study was to evaluate the outcome of single‐implant restorations by means of fixed restorations and to define the prognosis through marginal bone level estimations. Materials and Methods: From November 1986 to June 1998, 270 Brånemark implants (215 in the upper jaw) were installed in 219 patients (106 males). Both anterior and posterior sites were involved. Of the 263 single restorations, 28 were placed in private dental offices. The patients were followed until June 1999. Results: Twelve implants failed before or at abutment connection or within 6 months afterward. Only four implants failed later. The cumulative success rates were 93% for the implants and 96.5% for the restorations over a period of 11 years. The marginal bone loss during the first 6 months after abutment connection reached 0.71 mm and then dropped to 0.036 mm annually over a period of 10 years. Conclusions: Single‐implant restorations (Brånemark System) are a reliable treatment with a good long‐term prognosis. Failures were concentrated during the healing period and early loading phase.  相似文献   
945.
Effect of gender on acute pain prediction and memory in periodontal surgery   总被引:1,自引:0,他引:1  
Pain is a complex experience that is affected by factors such as gender, stress, anxiety and cognitions. The purpose of this study was to investigate the inter-relationship between gender and acute pain prediction and memory under periodontal surgery treatment. The study was conducted on 15 male and 22 female dental patients (mean age 34 yr, mean education level 14.7 yr), who were scheduled for periodontal surgery. Patients were evaluated during four consecutive appointments: at initial check-up, immediately pre-operatively, 1 wk post-operatively, and at 4 wk post-operative follow-up. Patients were requested to complete questionnaires concerning their anxiety at each appointment and to indicate their subjective evaluations concerning pain (on a visual analogue scale). Evaluations concerning expectation to experience pain during the planned surgery (pain prediction) were made at the first two appointments and evaluations of the experienced pain as remembered from the surgery (pain memory) were made at the last two appointments. Gender had a significant effect on pain prediction and pain memory. Men expected to experience more pain pre-operatively than women but remembered less pain post-operatively. It was concluded that cognitive pain perception in clinical situations differs between genders.  相似文献   
946.
947.
The purpose of this study was to determine the in vitro susceptibility to cetyltrimethylammonium naproxenate for various aerobic and anaerobic micro-organisms responsible for oral and pharyngeal diseases by assessing the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) or minimum fungicidal concentrations (MFCs) and by determining kill-times. The MICs of cetyltrimethylammonium naproxenate for 46 tested strains (25 reference strains and 21 clinical isolates) ranged from 8 to 500 micrograms/ml. The MIC was found to be 31.25 micrograms/ml for 36% of the reference strains. Even lower MIC values (15.63 micrograms/ml) were observed for some anaerobic strains, for Haemophilus influenzae and for Candida tropicalis. MIC and MBC values corresponded for the majority of strains tested while the MFC for C. tropicalis and C. albicans was much higher. Only 9.5% of the clinical isolates gave a MIC value of 31.25 micrograms/ml. Enterococcus faecalis, Streptococcus pyogenes and Staphylococcus aureus showed MIC at 62.5 micrograms/ml. The MIC and MBC values among the isolates were comparable, while the MFC value for the yeasts was greater. A concentration of 125 micrograms/ml of cetyltrimethylammonium naproxenate inhibited the growth of all bacteria, except Enterobacteriaceae and Pseudomonaceae, and yeasts. Cetyltrimethylammonium naproxenate shows very rapid kill-time for S. sanguis (0"), and rapid (15") for S. pyogenes, S. dysgalactiae and S. mutans and for Moraxella catarrhalis, while a longer kill-time was necessary for the other microbes tested.  相似文献   
948.
The recent introduction of intraosseous injection devices has renewed interest in the modality of local anesthesia. Three devices currently available are the Stabident System, the Hypo Brand Intraosseous Needle, and the Cyberjet System. The Stabident System is the most popular and the only one for which published research is available. Primary intraosseous anesthesia is 45 percent to 93 percent effective but of short duration. Supplemental intraosseous anesthesia is 80 percent to 90 percent effective and provides profound anesthesia of long duration (60 minutes or longer). It is used when a prior conventional infiltration or nerve block is inadequate. During use of an anesthetic solution with a vasoconstrictor for intraosseous anesthesia, 46 percent to 100 percent of patients reported an increase in heart rate. There was a 2 percent to 27 percent incidence of moderate and sometimes severe pain during the intraosseous procedure. Postoperative complications occurred in 2 percent to 15 percent of patients and lasted one to 14 days.  相似文献   
949.
Haemophilia A, the most common of bleeding disorders is characterzed by bruishing and spontaneous bleeding into the joints but may remain undiagnosed if present in the mild form. A case is discussed where episodes of bruising and joint sweelling as a child were misdiagnosed as rheumatic fever and the bleeding disorder was diagnosed following recurrent episodes of bleeding after extraction of an upper molar tooth.  相似文献   
950.
BACKGROUND: The significance of serum concentrations of various antibodies and cytokines in the pathogenesis of early-onset periodontitis (EOP) is not well understood. Recent reports suggest differences between young blacks and whites in certain humoral responses, regardless of periodontal status. This study was undertaken to compare the serum concentrations of IgG, IgA, IgM, and IL-1beta in EOP subjects with that of healthy controls, and to study the effect of race on these levels. MATERIAL AND METHODS: This case-control study included 228 individuals, 19-25 years old who were selected from a larger population examined in the National Survey of Oral Health of United States Children in 1986/1987. The subjects were classified by their EOP status and they included 166 subjects with EOP and 62 healthy controls. Blood samples were used to assess the serum concentrations of IgG, IgM, IgA, IgG subclass, and IL-1beta. RESULTS: The serum concentrations of IgG, IgG subclasses, IgA, and IgM in blacks were not significantly different in the generalized, localized and incidental EOP groups as compared to the healthy controls. The serum IL-1beta concentration was slightly and uniformly lower in the EOP groups than in the control group, although not statistically significant. Blacks had significantly higher serum concentrations of total IgG, and of IgG1, IgG2 and IgG3 than whites and Hispanics. Hispanics had significantly higher serum concentrations of IgM and IgG4 than whites and blacks. Hispanics also had a significantly higher serum concentration of IL-1beta than blacks. CONCLUSIONS: Total antibody response in blacks is not associated with EOP classification. Race has a significant effect on serum antibody concentrations irrespective of disease classification, with blacks having significantly higher serum concentrations of IgG1, IgG2 and IgG3 than whites and Hispanics.  相似文献   
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