RESUMO
All contours of the restoration not directly related to occlusion are related to the gingival tissues only. And proper contour of restoration is essential for the health of the periodontal tissues. But there are so many controversies about the contour of the restoration, and there is no uniform agreement in the literature as to which contour of restoration is best for periodontium. In general, the contour of restoration means the supragingival contour only but in the case of the intracrevicular restorative procedure the subgingival contour of restoration must be considered. Because a portion of the restoration is placed in a gingival sulcus which is extremely vulnerable to periodontal disease. In this article the concepts or theories of the supragingival contour, the subgingival contour, and the emergence profile were discussed. The contour of the restoration and the biotype of the periodontium must be considered in intracrevicular restorative procedure. And sufficient tooth preparation is important factor to develop the proper contour of restoration which is kind to periodontium.
Assuntos
Doenças Periodontais , Periodonto , Preparo do DenteRESUMO
The objective of the present study was to investigate the vertical and horizontal location of the molar furcations in korean. The samples used in this study included 132 maxillary molars and 120 mandibular molars. Of them, 47 maxillary molars and 34 mandibular molars had the fused roots. So, 85 maxillary molars(54 1st and 31 2nd molars) and 86 mandibular molars(46 1st and 40 2nd molars) were measured. The vertical and horizontal location of molars were measured with divider and digimatic micrometer and their means and standard deviation calculated. The results were summarized as follows: 1. The ratio of fused roots found in this study was the highest in the maxillary second molars with 59%, followed by mandibular second molars(46%) and maxillary first molars(7%) and none were discovered in the mandibular first molars. 2. In the study of the vertical location of molar furcation, the results were as follows : In the maxillary first molars, the length in descending order were distal(5.06mm), mesial(4.52mm) and buccal(4.01mm) and in the maxillary second molar, distal(4.04mm), mesial(4.02mm) and buccal(3.87mm). In the mandibular first molar, the length was 3.69mm on the lingual side and 2.81mm on the buccal side, and in the mandibular second molar, 3.87mm on the lingual and 3.61mm on the buccal side. 3. The location of the mesial and distal furcations in horizontal dimension measured showed following results : buccal and mesial furcations of the maxillary molars and buccal and lingual furcations of the mandibular molars generally found at the center, but the mesial furcation of the maxillary molars were found approximately two thirds toward the palatal aspect.
RESUMO
Chitosan has been known as a wound healing agent. The purpose of this study was to evaluate the biocompatibility and guided bone regenerative effect of chitosan and chitosan-cellulose membranes. The effects of chitosan and chitosan-cellulose membranes on the growth and survival of human periodontal ligament cells were examined by rapid colorimetric MTT(tetrazolium) assay, and the tissue response and resorption pattern were observed by implanting the membranes into the subcutaneous tissue of the back of rats for 6 weeks. To evaluate the guided bone regenerative potential of membranes, the amount of newly formed bone in the rat calvarial defects(8mm in diameter) was measured by histomorphometry and radiomorphometry 1,2 and 4 weeks after implantation of membranes. Chitosan and chitosan-cellulose membranes showed no adverse effect on the growth and survival of human periodontal ligament cells. When membranes were subcutaneously implanted, inflammatory reaction was observed at 1 week and which gradually subsided 2 weeks after implantation. Membranes remained intact throughout the experimental period of 6 weeks. Radiomorphometric analysis of the craniotomy sites revealed that chitosan and chitosan-cellulose membrane implanted sites showed increased radiopacity over control. Statistically significant differences with control were found in chitosan-cellulose membrane implanted group at 2 and 4 weeks, and chitosan membrane implanted group at 4 weeks(P<0.05). Histomorphometric data indicated a pattern of osseous healing similar to radiomorphometric analysis. There was a statistically significant difference between control and chitosan-cellulose membrane implanted group at 4 weeks(P<0.05). These results implicate that chitosan and chitosan-cellulose membrane might be useful for guided bone regeneration.
Assuntos
Humanos , Ratos , AnimaisRESUMO
There are so many considerations for successful restorative dentistry and the periodontal consideration is one of the most important facors to consider. In modern dentistry intracrevicular margin is popular due to esthetic reason. But the marginal tissue recession after intracrevicular restoration is one of the most troublesome phenomena. The marginal tissue recession may be controlled with understanding the mechamsms. In conclusion (1) the inflammation of periodontium must be controlled before intracrevicular restorative percedure (2) the width and thicknes of keratinized gingiva must be evaluated before intracrevicular restorative procedure (3) tooth preparation must follow the natural scallop of CEJ.