Periodontal tissue, especially the alveolar bone, are closely associated with the progress and efficacy of orthodontic treatment. Prior to and during orthodontic treatment, dentists should fully evaluate the status of periodontal hard tissues to prevent clinical problems. This article aims to discuss bone issues associated with orthodontic treatment, including gingival papilla absence, alveolar bone insufficiency, excessive cortical resistance, and altered passive eruption, etc. The mechanism and prevention methods of these problems are also described.
Gingiva ; Periodontium

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, synthetic bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of synthetic bone (Biogran(R)) and xenogenic bone (BBP(R)) grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, Biogran(R) with PRP was inserted for 25 infrabony pockets as first test group, and BBP(R) with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. 6 months after surgery, each difference of average probing pocket depth was 2.61+/-0.23 for control, 3.40+/-0.33 for 1st test, and 3.45+/-0.37 for 2nd test group. 2. 6 months after surgery, each difference of clinical probing attachment level was 1.39+/-0.12 for control, 2.88+/-0.24 for 1st, and 2.86+/-0.27 for 2nd test group. 3. 6 months after surgery, each difference of Maximal probing attachment level was 1.11+/-0.16 for control, 3.28+/-0.30 for 1st, and 3.27+/-0.35 for 2nd test group. 4. There were significant differences for clinical change of each three group which were between average probing pocket depth and clinical attachment level of 3, 6 months and minimal and maximal attachment level after 6 months 5. There were significant differences for average probing pocket depth which were only at control group and 2nd test group between 1 and 6months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6month of surgery. 6. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minimal and maximal probing attachment level. As the result, PRP with bone graft is very effective for regeneration of periodontium and there is no difference between xenogenic bone and synthetic bone.
Periodontium ; Regeneration* ; Tooth ; Transplants*

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.
Periodontal Diseases ; Periodontium ; Tooth Preparation

STATE MENT of PROBLEMS: Although some clinicians report long-term success with fixed partial denture (FPD) that contain cantilever pontic, the use of cantilever FPDs may be hazardous because of unfavorable leverages during mastication. PURPOSE of STUDY: This study aims to compare the stress induced in the periodontium with normal and reduced bone support, and to analyze the stress distribution patterns of anterior cantilevered FPDs using the finite element method. RESULTS: Cantilever bridge with a reduced bone level generated the highest peak stresses in the periodontium. In the models of reduced bone support, a cantilever bridge exhibited the greatest mobility and a 3-unit fixed restorations induced the smallest mobility of canine. The highest peak stress level of a 3-unit bridge in the periodontium is similar to the unrestored situation. But stress distribution in the bone is modified. CONCLUSION: In reduced bone support, a cantilever bridge exhibited the greatest mobility and stress.
Denture, Partial, Fixed ; Mastication ; Periodontium

Humans ; Orthodontics ; Periodontitis ; therapy ; Periodontium

Humans ; Orthodontics ; methods ; Periodontium ; injuries

A fundamental principle in clasp selection for a specific abutment is the reduction of the transmission of excessive forces to the abutment tooth. Those forces include tilting, tipping, and stress on the abutment tooth. The flexibility of a clasp was believed to directly affect the reduction of such forces. Opinions have been expressed concerning the proper type of clasp to be used to prevent stress on periodontium. In order to evaluate and compare the various designs of a clasp system, it is necessary to measure these force. This study compared the average measurements of forces required to dislodge three kinds of circumferential clasps having different amount of undercuts : the first with a round retentive arm, the second with a half round retentive arm, the third with a wrought wire retentive arm under tensile load. Three commonly used undercuts( 0.01, 0.02, 0.03 inch) were created on nine cast crowns, premolars and molars. The test was run six times for a same clasp. The means of tensile load required to dislodge each of the different clasps were compared statistically using the ANOVA test and multiple range test (Duncan test) The results were as follows. 1. The amount of tensile load of the wrought wire clasp was significa-ntly different from the cast round or half round clasp(P<0.05) 2. The more amount of the undercut, the more tensile load was need-ed to dislodge the clasp. There were significant difference among them(P<0.05) 3. The molar showed higher tensile load than the premolar, and there was significant difference(P<0.05) 4. The means of tensile load according to clasp types showed signific-ant differences at the molar between wrought wire clasp and cast clasp (P<0.05), but did not at the premolar
Arm ; Bicuspid ; Crowns ; Molar ; Periodontium ; Pliability ; Tooth

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, autogenous bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of autogenous bone and xenogenic bone (BBP(R)) grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, autogenous bone with PRP was inserted for 25 infrabony pockets as first test group, and BBP(R) with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. There were significant differences between average probing pocket depth and clinical attachment level of 3, 6 months and minimal and maximal attachment level after 6 months each other. 2. There were significant differences in average probing pocket depth of control group and 2nd experimental group between 1 and 6 months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6 month of surgery. 3. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minimal and maximal probing attachment level. As the result, PRP with bone graft could be very effective for regeneration of periodontium and there was no difference between xenogenic bone and autogenous bone.
Periodontium ; Platelet-Rich Plasma ; Regeneration* ; Tooth ; Transplants*

Adult ; Humans ; Orthodontics, Corrective ; methods ; Periodontium

Periodontitis is a chronic inflammatory disease of periodontal tissues initiated by oral biofilm. Cellular autophagy is an effective weapon against bacterial infection. Recent studies have shown that autophagy not only promotes the removal of bacteria and toxins from infected cells, but also helps to suppress the inflammatory response to maintain the homeostasis of intracellular environment, which is closely related to the development of periodontitis. Here, we reviewed the relationship between autophagy and periodontitis from three aspects: the interactions between autophagy and periodontal pathogen infection, the regulation of autophagy and immune inflammatory responses, and the relationship between autophagy and alveolar bone metabolism. We aim to provide ideas for further study on the mechanisms of autophagy and periodontitis, and ultimately contribute to a better prevention and treatment of periodontitis.
Autophagy ; Bacteria ; Biofilms ; Humans ; Periodontitis ; Periodontium