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31.
The topographic relationship of the apices of the primary teeth to the permanent tooth germs explains the potential for possible developmental disturbances of the permanent teeth after injuries to their predecessors. The anatomical, histologic and clinical aspects of permanent tooth malformation following trauma to the primary teeth are described. One hundred and fourteen children with originally 255 traumatized primary teeth have been re-examined (with an average period of 5.1 years after the trauma) to assess any developmental disturbances of the corresponding permanent teeth. Twenty-three per cent of partially or completely erupted permanent teeth showed developmental disturbances. The most frequent malformation was enamel hypoplasia including enamel discoloration and/or enamel defects. The highest prevalence of developmental disturbances of permanent teeth was found after intrusive injuries of primary teeth.  相似文献   
32.
OBJECTIVES: Thrombotic thrombocytopenic purpura (TTP) is a rare haematological disease of unknown aetiology. This thrombotic microangiopathy is characterized by microvascular lesions with platelet aggregation. It is found in adults and can be associated with pregnancy, cancer, autoimmune diseases, bone marrow transplantation, drugs and bacterial as well as viral infections. The therapy requires a multi-disciplinary team approach involving dentistry. Even if TTP is immediately treated in an adequate manner, it still shows a mortality of up to 20%. AIM: To define a specific treatment concept for periodontal disease and decayed teeth in patients suffering from TTP based on the experiences gained from two cases. CONCLUSION: The two patient cases revealed a possible association of TTP with dental foci. Because of the severity and mortality of this disease, both prognosis evaluation and treatment standards of periodontologically compromised or decayed teeth have to be strictly followed in patients suffering from TTP. In order to avoid recurrence of TTP, it seems important to remove radically teeth of questionable prognosis.  相似文献   
33.
The present study assessed the progression rate of periodontal disease over 8 years in a group of 52 adult patients with various forms of cleft lip, alveolus, and palate considered at risk for progression of periodontal disease. Of special interest was the evaluation of periodontal disease progression at sites adjacent to cleft regions compared to changes found at control sites not directly affected by such defects. High incidences of generalized plaque accumulation and bleeding on probing were noted at both examinations in 1979 and 1987. A mean apical shift of the clinical attachment level amounting to 0.2 mm had occurred over the 8-year observation period. A slight apical displacement of the mesial and distal mean crestal alveolar bone was also noted. The rate of progression of periodontal disease over the 8 years was not found to be different at statistically significant levels at cleft sites compared to control sites. However, the results of this study documented that the cumulative periodontal destruction at 26 to 28 years of age was statistically significant and more pronounced at cleft sites as revealed by greater probing pocket depth and loss of clinical attachment. The differences between test and control sites amounted to 0.3 and 0.4 mm respectively for probing depth and 0.6 mm for loss of clinical attachment. In addition, the discrepancy between alveolar bone height and the levels of the clinical attachment at cleft sites demonstrated the presence of a long supracrestal connective tissue attachment adjacent to cleft defects. Therefore, the alveolar bone height as visualized in radiographs at such sites was considered an unreliable diagnostic tool for the assessment of the degree of periodontal destruction.  相似文献   
34.
Abstract –  Trauma to the primary dentition present special problems and the management is often different as compared with permanent teeth. An appropriate emergency treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases in which the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this third article out of three, the IADT Guidelines for the management of traumatic injuries in the primary dentition, are presented.  相似文献   
35.
This review comprises a short summary of up-to-date clinical knowledge on systemic osteoporosis in order to focus on the clinical dental studies on osteoporosis of the jaws, which have become available within the last 15 years. Diagnosis of jaw osteoporosis requires assessment of the bone mineral content (BMC)/density (BMD) using specially constructed jaw bone scanners and development of a corresponding gender-related set of normal BMC/BMD values for young adults, as in other sites of the skeleton. If other factors are excluded, jaw osteoporosis may involve the risk of minor accentuation of alveolar bone loss after wearing a full denture, in cases of periodontitis and in peri-implant areas. However, implant-supported overdentures conserve bone because of their positive load-related effect on the jaw. Estimation of BMC/BMD is also advisable for edentulous osteoporotic patients. Systemic treatment involving the bone metabolism affects the jaw BMC/BMD positively or negatively as in other skeletal sites, but the magnitude of this effect is site-specific. Future studies of the effect of bisphosphonates on the jaw BMC and alveolar bone loss, and analyses of the bone quality and jaw BMC/BMD in relation to implant treatment, without or with bone transplantation, are required.  相似文献   
36.
The β1-integrins (VLA family) are cellular adhesion molecules (CAM) that play a major role in cell-cell and cell-matrix interactions. The expression pattern of CAM was studied in 5 clinically normal volunteers with healthy gingiva and in 18 patients with clinically different stages of periodontitis. In healthy human gingiva α2. α3 and α6 integrin chains were found in a characteristic distribution, showing a broad continuous expression on the junctional and sulcular epithelium sites. The expression of these integrins was demonstrated primarily on the basal cell layers and in some cells of the stratum spinosum. Inflammatory stages of periodontitis revealed further upregulation of α2, α3 and α6 integrins into the junctional and sulcular epithelial cells, which correlated with the stage of the periodontitis and the extent of the cellular infiltration. α4 and α6 were found to be the predominant β1 integrin chains on inflammatory cells. The amount of δ4 and ş6 positive infiltrative cells increased with the number of inflammatory cells. VCAM-1. the corresponding cell-cell ligand of VLA-4 (α4) was present on the majority of subepithelial vessels in all stages of gingivitis and periodontitis. The α5 subunit was expressed on both endothelium and gingival connective tissue cells. Samples from advanced periodontitis cases showed a higher number of a5 positive mononuclear cells. In comparison to normal epidermis, a human gingival epithelial cells express higher levels of integrins. This expression is further upregulated in advanced stages of periodontitis, indicating changes of the β1 integrin organization.  相似文献   
37.
BACKGROUND: The authors tested the clinical longevity of disposable diamond burs. They cut a series of five preparations and assessed the leakage after restoring the tooth. METHODS: The authors prepared 10 teeth for Class V restorations, and used a new disposable diamond bur for each tooth. The burs were used to cut preparations in extra teeth before being used to prepare a second series of 10 teeth (third use). The authors then cut preparations in extra teeth before preparing a third set of 10 teeth (fifth use). They removed existing restorations in a second group of 30 teeth and extended the preparations using the same regimen of one, three and five bur uses. All preparations were etched and conditioned, and the teeth were restored with resin-based composite. Using a 20-volt direct-current power source and a stainless-steel counter electrode, the authors measured the leakage electrochemically in 1.0 percent sodium chloride for 30 days. RESULTS: Freshly prepared and restored teeth leaked less than reprepared teeth. Leakage was similar for the first and third uses of the bur, but was far greater for the fifth use (P < .01). The previously restored teeth that were cut with the first- and third-use burs behaved the same, but the third-use bur caused more leakage than the fifth-use bur (P < .01). CONCLUSIONS: Reuse of disposable burs can affect leakage behavior. With new preparations, use of a disposable bur to cut more than three preparations increased leakage. For teeth that were reprepared and restored, greater leakage occurred than it did with new preparations, although repeated use of a bur may reduce leakage. CLINICAL IMPLICATIONS: Disposable diamond burs may cut preparations in up to three teeth before adversely affecting leakage behavior. Restoration removal and repreparation of teeth results in greater leakage than that with freshly prepared teeth.  相似文献   
38.
In a double-blind, controlled, cross-over trial on 10 healthy volunteers, the effects of daily doses of maprotiline (75 mg) and zimelidine (100 mg) over a 14-day period were tested on saliva secretion rate and saliva composition. Based on current knowledge of salivary gland physiology and the difference in specificity between the two drugs, differences in salivary gland response could be expected. Since both drugs have anticholinergic effects which influence saliva secretion rate, the measured component concentrations had to be recalculated with regard to dependencies of secretion rate. Maprotiline, but not zimelidine, caused strong inhibition of secretion rate and accommodation ability. Maprotiline consistently caused around 50% increases in concentrations of the following saliva components: protein, amylase, fucose, hexose, sialic acid and potassium. The effects of zimelidine were less pronounced and resulted in initial increases of most organic components. 14 and 18 h after the intake of the drug these increases had disappeared and some of the components instead showed decreased concentrations. The results are consistent with current theories about facilitated serotoninergic and noradrenergic transmissions during treatment with antidepressants.  相似文献   
39.
Advanced surface modifications and materials were tested on the same implant geometry. Six types of dental implants were tested for osseointegration after 2, 4 and 8 weeks in a sheep pelvis model. Four titanium implant types were treated with newly developed surface modifications, of which two were chemically and two were pharmacologically modified. One implant was made of zirconia. A sandblasted and acid-etched titanium surface was used as reference. The chemically modified implants were plasma-anodized or coated with calcium phosphate. The pharmacological coatings contained either bisphosphonate or collagen type I with chondroitin sulphate. The implants were evaluated using macroscopic, radiographic and histomorphometric methods. All implants were well osseointegrated at the time of death. All titanium implants had similar bone implant contact (BIC) at 2 weeks (57-61%); only zirconia was better (77%). The main BIC increase was between 2 and 4 weeks. The pharmacologically coated implants (78-79%) and the calcium phosphate coating (83%) showed similar results compared with the reference implant (80%) at 8 weeks. There were no significant differences in BIC. Compared with previous studies the results of all implants were comparatively good.  相似文献   
40.

Introduction

Most clinical studies on the outcome of apical surgery concentrate on periapical healing based on radiographic and clinical characteristics (signs and symptoms). This study focuses on long-term changes in periodontal parameters after apical surgery.

Methods

Periodontal parameters (ie, probing depth [PD], level of gingival margin [GM], and calculated clinical attachment level [CAL]) were collected at baseline and at 1 and 5 years after apical surgery. Changes in PD, GM, and CAL were calculated over time and were also evaluated in relation to patient-, tooth-, and treatment-related covariables.

Results

One hundred eighty-six of 242 initially identified teeth could be evaluated. Significant changes in GM and CAL were observed at facial sites during the first year after surgery (mean recession of GM was 0.29 mm, mean CAL loss was 0.20 mm), but none of the periodontal parameters significantly changed between 1 and 5 years after apical surgery. With regard to covariables, the type of incision technique was found to be the major factor affecting changes in GM and CAL between baseline and 1 year after surgery. Age, smoking, and type of periapical healing were the variables influencing the periodontal parameters over the longer observation period of up to 5 years.

Conclusions

Patients should be informed about possible changes in periodontal parameters (gingival recession and loss of attachment) after apical surgery. The surgery itself appears to account for changes observed during the first year, whereas patient- and healing-related factors seem to affect periodontal changes seen thereafter.  相似文献   
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