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To compare the effect of three different surface zirconium oxide treatments on binding strength and fracture patterns between zirconia and veneering ceramics. Methods: A total of 40 zirconia specimens and 10 nickel-chromium alloy were divided into 5 groups (n=10 in each group): a treatment group by zirconium oxide sand-blaste (Group A), a zirconia bonded porcelain group (Group B), a hot-etching solution group (Group C), a non-treatment zirconia (Group D) and a non-treatment nickel-chromium alloy group (Group E). After all treatments, a veneering porcelain (4 mm×4 mm×2 mm) was formed onto the center of all substrate specimens by plastic coating method. Shear bond strength (SBS) test with a universal testing machine was used in each group. Scanning electron microscopy was used to observe the surface morphology of the damaged specimen interface, which was randomly selected from each group. Results: The SBS test showed that there was no significant difference in SBS results between the Group A, the Group B and the Group D (both P>0.05), and both of them were significant less than that in the group E (both P<0.05). The SBS results in the Group C were significantly higher than that in the Group D, the Group A, and the Group B (all P<0.05), but there were no significant difference compared with that in the Group E (P<0.05). Conclusion: Sand-blaste and liner application on zirconia ceramic contribute no effect to binding strength between zirconia and veneering ceramics, but hot-etching solution can increase the binding strength between zirconia and veneering ceramics.
Subject(s)
Ceramics , Dental Bonding , Dental Stress Analysis , Dental Veneers , Materials Testing , Microscopy, Electron, Scanning , Shear Strength , Stress, Mechanical , Surface Properties , ZirconiumABSTRACT
Intellectual property in medical institutions has been getting more attention in research activity.Large general hospitals have made significant achievements in intellectual property,and the management of intellectual property right has also gradually become the norm.This article discussed the possibility to carry out the intellectual property management in the primary health care sector,based on their current status and characteristics,proposed an evaluation system which suitable for the primary health care sector.We described the structure and method of this system,explored a standardized intellectual property management process used in primary health care institutions.
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Objective To investigate the aged-related changes of biochemical mark and bone histomorphology in rats and to explore the effects ofαD3 on aged rats. Methods Sixty male Wistar rats with different age were divided into four groups, including group A (6-week-old male wistar rat), group B (6-month-old male wistar rat), group C (24-month-old male wistar rat) and group D (24-month-old male wistar rat +αD3). Group D was treated with αD3 three times per week for 10 weeks at a does of 0.05μg/(kgrameters. The left femur and mandible were collected for histomorphology. Results Compared with group A, ALP (alkaline phosphatase) and BGP in group B, C and D were decreased with age increased [(87.30 ±12.22)mmol/L VS (257.20 ±92.26) mmol/L, (55.23 ± 18. 18 ) mmol/L VS (257.20 ±92. 26) mmol/L,(46.17 ± 16. 6) mmol/L VS (257. 20 ±92. 26 mmol/L); (4. 37 ± 1.46) ng/L VS (9. 03 ±2. 04) ng/L,(3.80±1.00) ng/L VS (9.03 ±2.04) ng/L, (3.59 ±0.64) ng/L VS( 9.03±2.04) ng/L, P <0. 05]. TRACP5b in group C and D increased more than that in group B [( 15.69 ± 1.62 ) pg/L VS ( 7. 26 ±2.13) pg/L, ( 14.16 ± 1.88 ) pg/L VS ( 7. 26 ± 2. 13 ) pg/L, P < 0. 05]. Testosterone decreased significantly with age increased, but no significant difference was found among four groups. Testosterone was positive related with trabecular area of mandible. Bone gla protein was positive related with alkaline phosphatase and negative related with tartrate - resistant acid phosphatase 5b. Trabecular areas of femur increased in group C and D were greater than that in group B[(220310. 6 ±76360. 50) μm2 VS ( 105093.5 ±73242. 2) μm2, (293085.9 ±68230. 78) μm2 VS ( 105093.5 ±73242. 2) μm2, P <0. 05]. Compared with group B,the trabecular thickness of group C was increased by 53%, while trabecular separation was increased 123%. Trabecular area of group D was increased by 33% compared with group C. Conclusions Theresults showed that bone formation was decreased and absorption was increased with age increased. Testosterone was positive related with trabecular area of mandible. Alfacalcidol had the effects to promote the bone mass of mandible.
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OBJECTIVE: Factors that result in systemic osteoporosis will also affect maxillofacial bones for the latter is a component of skeleton. Present studies are being focused on how is the effect of the drugs that are used to treat systemic osteoporosis on maxillofacial bones. In this article we reviewedclinical and experimental studies about the drugs that acts on maxillomandibular and alveolar bone loss in order to find treatment for maxillofacial bone loss.DATA SOURCES: Medline was searched from January 1999 to October 2001 for English literatures with the searching words of "osteoporosis,mandible, bisphosphonates, herb, estradiol." And Chinese journal database was also searched from January 1995 to December 2004 for Chinese literatures with the searching words of "osteoporosis, mandible, bisphosphonates,herb estradiol"DATA SELECTION: The literatures of therapeutic and controlled studies were chosen, from which the non-random trials and repeated ones were excluded. The full texts of the remaining literatures were found and those of random and controlled trials were included in this review.DATA EXTRACTION: Seventeen literatures that were about random trials on the treatment of maxillofacial bone loss were collected. Thirteen of these 17 were included in this review and 4 of repeated trials were excluded.DATA SYNTHESIS: The subjects in the 17 literatures were all patients with osteoporosis that were in compatible with diagnosis standard. Drugs that act by inhibiting bone resorption, increasing bone mass and ameliorating bone quality were used. The effects of the drugs were compared and analyzed in perspective of the density, mass and strength of bone.CONCLUSION: Medicines for systemic osteoporosis are effective in ameliorating maxillomandibular bone structure, delaying alveolar bone resorption and promoting new bone formation.
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OBJECTIVE: As a part of the whole skeleton,oral maxilloficial bone can also be affected by the risk factors of systemic osteoporosis. This paper reviewed literature on the possible correlation of systemic osteoporosis with oral alveolar bone resorption,periodontal disease,healing of implanted denture and temporomandibular joint disease that result from oral maxillofacial osteoporosis.DATA SOURCES: Literature in English between January 1999 and December 2003 were searched with the computer in Medline Database by the following key words: osteoporosis,alveolar trophy,periodontitis,implanted denture and tempororomandibular joint with; meanwhile literature was also searched in Chinese Periodical Database and Wanfang Database of the same period by the same key words in Chinese.STUDY SELECTION: Literature involving treatment group and control group were screened in the first trial. Then those non-randomized clinical trials were excluded and the others were looked up for full text. Inclusion criteria: randomized controlled clinical trial(RTC) . Exclusion criteria: repeated study.DATA EXTRACTION: A total of 27 articles of randomized or non-randomized studies on the possible association of systemic osteoporosis with oral alveolar bone atrophy, implanted denture and temporomandibular joint disease were collected,and 18 trials met the inclusion criteria.DATA SYNTHESIS: All subjects in the 18 studies were confirmed of having osteoporosis according the diagnostic standards. Changes of oral maxillofacial bone in systemic osteoporosis were explored by observing bone density,residual teeth, the height of alveolar ridge so as to make comparative and correlation analysis.CONCLUSION: In systemic osteoporosis, mandible bone may also have rarefaction changes.