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991.
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.  相似文献   
992.
Patients are referred to hospital for dento-alveolar surgical procedures requiring supplemental corticosteroid administration. However, it has been reported that medically compromised patients who require routine dental treatment are being referred unnecessarily. This article reports a retrospective study undertaken at a Regional Maxillofacial Unit over a 24-month period, which reveals the referral pattern and management of patients specifically referred for outpatient dental treatment with corticosteroid supplementation. The paper highlights the dilemma confronting practitioners when reviewing the literature on corticosteroid supplementation and the confusion that still exists in both the primary and secondary care settings as to which patients should be prescribed supplemental corticosteroids. A simplified guide is proposed for the clinical management of these patients.  相似文献   
993.
PURPOSE: The objectives of the present study were to determine the prevalence of residual extrusion, pulpal necrosis, and resorption for extruded permanent teeth and to establish the effect of presentation and treatment factors. METHODS: Seventy-two traumatically extruded permanent incisors were studied at the Departments of Paediatric Dentistry in Belfast, Newcastle upon Tyne, and Glasgow. The mean age of the patients was 10.1 years (range=6 to 18 years). Clinical and radiographic outcomes were analyzed and related to presenting and treatment factors. RESULTS: The initial degree of extrusion was moderate for 46 teeth (64%), and the median delay prior to repositioning was 3 hours (range=1 to 168 hours). Pulp necrosis occurred in 31 teeth (43%), residual extrusion was present in 16 teeth (23%), and inflammatory resorption occurred in 11 teeth (15%). Residual extrusion was significantly associated with a delay in repositioning the tooth, pulpal necrosis was significantly more common in teeth with closed apices and in severely extruded teeth, and inflammatory resorption was more common after pulpal necrosis. CONCLUSIONS: Residual extrusion could be minimized by earlier presentation and repositioning. The risk of pulpal necrosis is greatest for severely extruded teeth and for those with closed apices.  相似文献   
994.
995.
BACKGROUND: This study investigated the influence of implant surface on osseointegration around titanium implants inserted in the tibiae of rabbits administered with nicotine. METHODS: Thirty-two (32) New Zealand rabbits were included in the study. After anesthesia, the tibia surface was exposed and 2 screw-shaped commercially available pure titanium implants 7.0 mm in length and 3.75 mm in diameter were placed bilaterally. A total of 128 implants were inserted: 64 blasted with Al2O3 particles (Group 1) and 64 with a machined surface finish (Group 2). The animals were randomly assigned to 1 of 4 treatment subgroups, and daily subcutaneous injections of nicotine were administered: A) saline solution; B) 0.37 mg/kg; C) 0.57 mg/kg; and D) 0.93 mg/kg. In order to label regenerated bone, a 2% calcein green solution was administered by intramuscular injection at 0, 7, and 15 days after implant insertion. After 42 days, the animals were sacrificed and undecalcified sections were prepared. The degree of bone contact with the implant surface, the bone area, and the intensity of bone labeling were measured into the limits of the implant threads. RESULTS: Statistical analysis (2-way ANOVA) revealed no significant difference regarding the effect of nicotine on bone healing around the implants (P>0.05). However, a significant influence of the implant surface on the degree of bone-to-implant contact was detected in groups C (30.13 +/- 4.97 and 37.85 +/- 8.85, for machined and Al2O3-blasted surfaces, respectively) and D (27.79 +/- 3.93 and 33.13 +/- 8.87, for machined and Al2O3-blasted surfaces, respectively) (P<0.05). CONCLUSIONS: Although nicotine administration may not statistically influence bone healing around titanium implants, implant surface design may enhance osseointegration after nicotine administration.  相似文献   
996.
Ninety-one Icelandic practicing dentists (51% response rate) provided information related to the reasons for placement and replacement of 8,395 restorations and 741 sealants in 5,997 patients. Information included the patient's gender and age, the clinician's gender and experience in years since graduation, the defined criteria for replacement of restorations, the estimated past use of material in five-year increments and the records of 100 consecutively placed restorations. The materials used include composite (52.7%), amalgam (29.2%), glass ionomer (9.5%), resin-modified glass ionomer (7.1%) and other materials (1.4%). Although material selection was independent of the clinician's gender, female patients received more composite and fewer amalgam restorations than their male counterparts. Reasons for placing restorations comprised replacement of failed restorations (47.2%), primary caries (45.3%) and non-carious defects (7.5%). Secondary caries was the main reason for replacement for all types of restorations. Chi square analysis related to the dependence between the reasons for replacement and clinician's experience showed that more experienced clinicians recorded a lower frequency of secondary caries than less experienced ones (p<0.0001), while the diagnoses of discoloration and fracture of restorations increased with the clinicians' experience (p<0.0001).  相似文献   
997.
AIM: The purpose of the present study was to compare 2 indices, i.e., the Eastman interdental bleeding (EIB) index and the bleeding on marginal probing (BOMP) index. The comparison was made (a) in terms of the degree of bleeding provoked and the relationship with plaque in natural gingivitis and (b) for the ability of these 2 methods to detect differences between the development of experimental gingivitis in a control group and a group in which the development of gingival inflammation was suppressed by treatment. For the present studies, subjects were selected without interdental recession of the gingival tissues. METHODS EXPERIMENT 1: In this experiment, 43 subjects having established moderate gingivitis were assessed using a random splitmouth design (1st and 3rd/2nd and 4th quadrant). Plaque was scored on all approximal sites after which the BOMP index was assessed in one half of the mouth and the EIB index in the other. RESULTS EXPERIMENT 1: The BOMP index showed a bleeding score of 84% and the EIB index of 87%. The significant correlation between plaque and gingival bleeding for the BOMP index (0.55) was higher than for the EIB index (0.44). METHODS EXPERIMENT 2: For this experiment, 25 subjects participated in an experimental gingivitis trial of the lower jaw. At baseline, first the BOMP index and immediately thereafter the EIB index were assessed at all approximal sites. Experimental gingivitis (EG) was carried out in one randomly assigned quadrant and as a treatment modality only floss was used in the other (FL). RESULTS EXPERIMENT 2: In the EG quadrant, the BOMP index increased to 69% and the EIB index to 73%. Both indices showed a significant correlation with plaque; 0.60 and 0.64 respectively. In the FL quadrant, the BOMP index increased to 38% and the EIB index to 30%. No significant correlation between both gingivitis indices and the amount of plaque was present in the FL quadrant. CONCLUSION: The ability of the BOMP index and the EIB index to assess the level gingival inflammation appears to be comparable.  相似文献   
998.
Abstract: This study investigated the change over time in the area of the posterior mandibular residual ridge in patients wearing either i) mandibular overdentures stabilised by two implants (Brånemark System; Nobel Biocare, Göteborg, Sweden) connected by a bar, or ii) mandibular fixed cantilever prostheses stabilised on five or six implants. Proportional measurements were made in order to compare the area of the residual ridge with an area of bone uninfluenced by resorption. Measurements were made by digitising tracings of panoramic radiographs that were taken shortly after implant insertion and up to seven years later. With the use of overdentures, the posterior bone area index reduced by a mean of 1.1% per annum, while a mean bone area index increase of 1.6% per annum was demonstrated in association with fixed prostheses. A multiple linear regression model was fitted to predict the change in posterior area from type of prosthesis, gender, age, years of edentulism and initial height of the mandible. The model was only significant for initial height of mandible (P = 0.04) and type of prosthesis (P = 0.0001). In conclusion, patients rehabilitated with implant‐stabilised mandibular overdentures demonstrated low rates of posterior mandibular residual ridge resorption, while patients rehabilitated with implant‐stabilised mandibular fixed cantilever prostheses demonstrated bone apposition in the same area.  相似文献   
999.
1000.
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