No abstract available.
Animals ; Dental Cementum* ; Dentin* ; Dogs*

Dental Cementum ; Humans ; Tooth Fractures

No abstract available.
Dental Cementum* ; Dental Enamel* ; Fibroblasts* ; Gene Expression*

Fibro-osseous lesions are composed of connective tissue and varying amount of mineralized substances, which may be bony or cementum-like structures. It is necessary for oral radiologist to differentiate due to the tendency of these fibro-osseous lesions to show similar histopathologic appearances, while the management of each lesion is different. However we often encounter a little difficulty in judgement because there are some overlaps between concept of each lesions. So recently I suggest, we face a need to review basic concept and classification of several fibro-osseous jaw lesions. In this article, several fibro-osseous lesions, such as fibrous dysplasia, cemento-ossifying fibroma and cemento-osseous dysplasia, will be discussed basing on the review of literature. Particular emphasis will be made on the nomenclature revision of WHO's classification in 1992.
Classification ; Connective Tissue ; Dental Cementum ; Fibroma ; Jaw

The purpose of this study was to investigate the root resorption and repair pattern of human teeth under intrusive orthodontic loadings of varying magnitude and duration. 50 gms, 100 gms, 200 gms of force applied to the 96 experimental teeth with duration of 2, 5, 7, 10 weeks, after removing the arch wire and retaining during 2 and 6 weeks, experimental teeth were extracted. Results were as follows: 1. The initial resorption site was visible in the apex within 2 weeks with 50 gms, 100 gms samples. 2. The sites of resorption increased markedly with duration of the force. 3. The 50 grams samples of the all duration reveal the shallow resorption and the 100 gms samples of the all duration except 2 weeks reveal the shallow and deep resorption sites. 4. After 7 weeks with 50 gms and 100 gms, cellular cementum repair accompanied the continuing resorption. 5. 2 and 6 weeks after removing the force with 200 gms, the same cellular cementum repair accompanied with 50 gms, 100 gms samples.
Bicuspid* ; Dental Cementum ; Humans ; Root Resorption* ; Tooth

Inflammatory external root resorption (IERR) refers to the pathological process of dissolving the hard tissue on the outer surface of the tooth root by the body's own immune system under the stimulation of various physical and chemical factors such as infection, stress, trauma and orthodontic treatment. Severe IERR can lead to endodontic and periodontal diseases, and even the loss of teeth. Therefore, understanding the etiology and the pathogenic mechanism of IERR are of importance in its prevention and treatment. This article will review the etiology and the regulation mechanisms of IERR.
Dental Cementum ; Humans ; Root Resorption ; Tooth Root

Based on current evidence in the literature, it is known that endotoxin is a weakly adherent surface phenomenon and that power-driven instruments can be used to accomplish definitive root detoxification and maximal wound healing without overinstrumentation of root and without extensive cementum removal. And one of the newly developed curette tips used with low power of piezoelectric ultrasonic scaler, is effective to remove calculus and not to remove the excessive cementum. The purpose of this study is therefore, to assess the influence of ultrasonic power and various working parameters on root substitute removal when instrumentation is performed with the curette tip on piezoelectric ultrasonic scaler. This study assessed defect depth, width and area resulting from instrumentation using a piezoelectric ultrasonic scaler with a curette type tip in vitro to acrylic resin block as a root substitute. The working parameters was standardized by the sledge device which controls lateral force(0.5 N, 1 N, 2 N) and instrumentation time(5 sec, 10 sec, 20 sec) and power setting was adjusted 0,2,4,8 in P mode. Power setting had the greatest influence on defect depth compared to lateral force and instrumentation time(standardized regression parameter estimates+/-standard error, 0.37+/-0.02, 0.19+/-0.02, 0.07+/-0.02). The effects on defect area also greatest for power setting(0.57+/-0.03) compared to lateral force and instrumentation time(0.33+/-0.03, 0.12+/-0.03). The effect of the power setting on the defect width(0.15+/-0.01) is not so great as defect depth or defect area compared to lateral force(0.12+/-0.01) and effect of instrumentation time is minimal(0.02+/-0.01). It could be concluded that the power setting has the greatest influence on the defect depth and area in curette type tip with low power of piezoelectric ultrasonic device. Many parameters can be adjusted in various situation in clinical use of piezoelectric ultrasonic scaler but the power setting is the first parameter to be adjusted.
Calculi ; Dental Cementum ; Dental Instruments ; Periodontal Diseases ; Ultrasonics* ; Wound Healing

Based on current evidence in the literature, it is known that endotoxin is a weakly adherent surface phenomenon and that power-driven instruments can be used to accomplish definitive root detoxification and maximal wound healing without overinstrumentation of root and without extensive cementum removal. And one of the newly developed curette tips used with low power of piezoelectric ultrasonic scaler, is effective to remove calculus and not to remove the excessive cementum. The purpose of this study is therefore, to assess the influence of ultrasonic power and various working parameters on root substitute removal when instrumentation is performed with the curette tip on piezoelectric ultrasonic scaler. This study assessed defect depth, width and area resulting from instrumentation using a piezoelectric ultrasonic scaler with a curette type tip in vitro to acrylic resin block as a root substitute. The working parameters was standardized by the sledge device which controls lateral force(0.5 N, 1 N, 2 N) and instrumentation time(5 sec, 10 sec, 20 sec) and power setting was adjusted 0,2,4,8 in P mode. Power setting had the greatest influence on defect depth compared to lateral force and instrumentation time(standardized regression parameter estimates+/-standard error, 0.37+/-0.02, 0.19+/-0.02, 0.07+/-0.02). The effects on defect area also greatest for power setting(0.57+/-0.03) compared to lateral force and instrumentation time(0.33+/-0.03, 0.12+/-0.03). The effect of the power setting on the defect width(0.15+/-0.01) is not so great as defect depth or defect area compared to lateral force(0.12+/-0.01) and effect of instrumentation time is minimal(0.02+/-0.01). It could be concluded that the power setting has the greatest influence on the defect depth and area in curette type tip with low power of piezoelectric ultrasonic device. Many parameters can be adjusted in various situation in clinical use of piezoelectric ultrasonic scaler but the power setting is the first parameter to be adjusted.
Calculi ; Dental Cementum ; Dental Instruments ; Periodontal Diseases ; Ultrasonics* ; Wound Healing

One of the fundamental causes of periodontal disease is accumulation of bacterial plaque and calculus and most effective method of removing these plaque and calculus are scaling and root planning using hand curet and ultrasonic scaler. Many studies concerning residual degenerated mineral content after periodontal therapies have been carried out, but some problems about these studies were also known. This research studies mineral concents and distribution of residual root surfaces after perfoming hand curet and ultrasonic scaler on root surfaces of single rooted teeth which were extracted for periodontal reasons. EPMA were used to avoid errors from chemical quantative analysis and in addition SEM observation was also performed. The results were as follows. 1. No differences were found between curet group andultrasonic scaler group in Ca, P, Mg and Na level. 2. Concentration level was decreased in the sequence of Ca, P, Mg and Na. 3. Ca and P level were decreased as going to apical portion at curet group and ultrasonic scaler group. 4. More cementum was removed at cervical portion compared to other portion at curet group and ultrasonic scaler group. 5. Ca, P, Mg level was higher in dentin compared to cememtum. There was no difference in mineral level for Ca, P, Mg and Na between root surfaces treated with hand curet and ultrasonic scaler.
Calculi ; Dental Cementum ; Dentin ; Hand ; Periodontal Diseases ; Tooth ; Ultrasonics*

PURPOSE: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. MATERIALS AND METHODS: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. RESULTS: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. CONCLUSION: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.
Animals ; Chitosan ; Dental Cementum ; Hand ; Membranes ; Rats ; Regeneration ; Transplants