The influence of smoking on the outcome of surgical periodontal therapy -2-year retrospective study / 대한치주과학회지

The purpose of this study was to examine the effect of smoking on the clinical, radiographic outcome of surgical peridontal therapy. The outcome of periodontal surgery was evaluated in 51 systemically healthy subjects that had received maintenance care. The study subjects consisted of 26 smokers and 25 non-smokers. The average age of smoking patients was 51 years old and non-smoking patients was 48 years old. Changes of probing pocket depth(PPD) and radiographic bone height, and number of missing teeth compared between smokers and non-smokers during maintenance period after surgical therapy. The clinical parameters were less favorable in the smoking group compared with non-smoking group. The number and percentage of missing teeth were greater in smokers(21.6%) than non- smokers(12.4%), especially in molars. The mean presurgery PPD was similar in smokers and non-smokers, molars and premolars, but significantly decreased at least 2 years after surgery. The mean PPD reduction was significantly greater in nonsmokers than smokers. Both in the smoking and non-smoking group, the mean PPD reduction was significantly greater in premolars than molars. The radiographical evaluation was also less favorable in the smoking group than non-smoking group. The radiographic evaluation of bone height in smokers showed bone loss. On the contrary, bone height of nonsmokers showed bone gain during the period of maintenance. But there was no significant difference between molars and premolars. The clinical and radiographic outcomes of the smoking group was less favorable than those of the nonsmoking group. Therefore, smoking seems to influence on the clinical and radiographic outcomes of surgical periodontal therapy.

Study on tooth mortality after periodontal therapy / 대한치주과학회지

The main goal of periodontal treatment is the long-term maintenance of teeth. Periodic maintenance program is need to prevent periodontal disease and maintain healthy periodontium. Hirschfeld and Wasserman(1978) studied 600 treated periodontal patients. This study categorized periodontal patients using well-maintained, downhill, extreme downhill groups. The purpose of our study is to evaluate effect of periodontal treatment and analyse tooth loss after periodontal treatment using this classification. The study population of 59 patients had been treated and maintained for mean 5.8 years. All patients were on a periodic maintenance program at 2-, 3-, 4-, or 6-month intervals. The average age of the patients at the time of original therapy was 49.6 years. To analyse tooth loss, modified classification was used on the basis of response to therapy using by Hirschfeld and Wasserman in 1978. The results were as follows: 1. 59 treated patients were lost mean 1.42 teeth per patient for 5.8 years of maintenance period. 2. Maxillary first molars were most frequently lost but mandibular lateral incisors were lost no tooth during maintenance period. 3. Tooth mortality received surgical treatment had similar to received nonsurgical treatment. 4. Tooth loss was more frequent in maxillary teeth than mandibular teeth, and posterior teeth than anterior teeth, and more frequent tendency in male than female.

Human Periodontal Ligament Fibroblasts Support the Osteoclastogenesis of RAW264.7 Cells / 대한치주과학회지

The fibroblasts are the principal cells in the periodontal ligament of periodontium. As the periodontal ligament fibroblasts (PDLF) show similar phenotype with osteoblasts, the PDLF are thought to play an important role in alveolar bone remodeling. Cell-to-cell contacted signaling is crucial for osteoclast formation. Recently it has been reported that PDLF enhance the bone resorbing activity of osteoclasts differentiated from hematopoietic preosteoclasts. The aims of this study were to clarify the mechanism of PDLF-induced osteoclastogenesis and 2) whether we can use preosteoclast cell line instead of primary hematopoietic preosteoclast cells for studying the mechanism of PDLF-induced osteoclastogenesis. Osteoclastic differentiation of mouse macrophage cell line RAW264.7 was compared with that of mouse bone marrow-derived M-CSF dependent cell (MDBM), a well-known hematopoietic preosteoclast model, by examining, 1) osteoclast-specific gene expression such as calcitonin receptor, M-CSF receptor (c-fms), cathepsin K, receptor activator nuclear factor kappa B (RANK), 2) generation of TRAP(+) multinucleated cells (MNCs), and 3) generation of resorption pit on the OAASTM plate. RAW264.7 cultured in the medium containing of soluble osteoclast differentiation factor (sODF) showed similar phenotype with MDBM-derived osteoclasts, those are mRNA expression pattern of osteoclast-specific genes, TRAP(+) MNCs generation, and bone resorbing activity. Formation of resorption pits by osteoclastic MNCs differentiated from sODF-treated RAW264.7, was completely blocked by the addition of osteoprotegerin (OPG), a soluble decoy receptor for ODF, to the sODF-containing culture medium. The effects of PDLF on differentiation of RAW264.7 into the TRAP(+) multinucleated osteoclast-like cells were examined using coculture system. PDLF were fixed with paraformaldehyde, followed by coculture with RAW264.7, which induced formation of TRAP(+) MNCs in the absence of additional treatment of sODF. When compared with untreated and fixed PDLF (fPDLF), IL-1beta-treated, or lipopolysaccharide- treated and then fixed PDLF showed two-fold increase in the supporting activity of osteoclastogenesis from RAW264.7 coculture system. There were no TRAP(+) MNCs formation in coculture system of RAW264.7 with PDLF of no fixation. These findings suggested that we can replace the primary hematopoietic preosteoclasts for RAW264.7 cell line for studying the mechanism of PDLF-induced osteoclastogenesis, and we hypothesize that PDLF control osteoclastogenesis through ODF expression which might be enhanced by inflammatory signals.

A comparative study of periodontal conditions around mesially tipped molars by a tipping degree / 대한치주과학회지

The aim of this study was to compare periodontal conditions around mesially tipped molars by a tipping degree. Patients who had been consecutively treated at the Department of Periodontology, Chonbuk National University Hospital from October 1999 to August 2001 were assessed with radiographs taken at their molar regions. Of all molars investigated, 142 molars of 116 patients tipped mesially more than 10 degrees to the line perpendicular to an occlusal plane were selected for the study. The tipped molars were divided into 2 groups with a reference to a tipping degree, i.e., 66 slightly tipped(group 1 : or =30degrees). Probing depth(PD), plaque retention index(PRI) at mesial surfaces of tipped molars and tooth mobility(TM) were recorded at the clinical examination. Tipping degree(TD) and alveolar bony defect(ABD) at the mesial surface of the molars were measured in a radiograph. The results showed that no statistical differences were found between groups in all measured variables. In Pearson correlation analysis performed in the same group, a positive relationship was shown between PRI and PD in the group 1 and, in the group 2, between PRI and PD as well as PRI and ABD(p < 0.01). However, no statistically significant relationship was found between TD and all other variables in both groups. Within limitations of this study, it may be concluded that tipping degree did not seem to influence periodontal conditions, i.e., PD, ABD and TM of mesially tipped molars per se, but plaque presence/absence seemed to mainly affect the periodontal conditions of the tipped molars.

The Effect of Various Plaque Control Devices on Roughness and Morphology of Titanium Implant Surface / 대한치주과학회지

The purpose of this study was to compare surface roughness and morphologic changes after use of various plaque control devices to titanium implant surfaces. The study materials were 6 ITI titanium implants(Bonefit(R)) and 5 plaque control devices. 6 implants were divided into 6 different groups and instrumented by each plaque control devices as follows. 1) Group I : untreated control 2) Group II : Titanium curette(Titanium curette(R), 3i) 80 vertical/horizontal strokes 3) Group III : Plastic curette(Implacare(R), Hu-Friedy) 80 vertical/horizontal strokes 4) Group IV : Plastic tip-ultrasonic scaler(Amdent(R), Amdent) 160 seconds 5) Group V : Rotating interdental brush(Identobrush(R), Identoflex) 160 seconds 6) Group VI : Abrasive rubber cup polisher(Zircate(R), Prophy paste, Dentsply) 160 seconds. All specimens were prepared for evaluation by surface roughness tester, optical stereomicroscopy(OM) and scanning electron microscopy(SEM). The Ra and Rt mean values of the tested specimens were 1) Group I (Ra=0.170+/-0.007micrometer, Rt=1.297+/-0.016micrometer) 2) Group II (Ra=0.209+/-0.006micrometer, Rt=1.602+/-0.110micrometer) 3) Group III (Ra=0.179+/-0.001micrometer, Rt=1.429+/-0.055micrometer) 4) Group IV (Ra=0.182+/-0.005micrometer, Rt=1.511+/-0.085micrometer) 5) Group V (Ra=0.301+/-0.008micrometer, Rt=1.882+/-0.131micrometer) 6) Group VI (Ra=0.147+/-0.010micrometer, Rt=1.059+/-0.021micrometer) In Ra values, experimental group II, V, VI were statistically significant different when compared with control. OM and SEM observation showed that experimental group III, IV were minimal changes when compared with control and group VI was smoothest among other experimental groups. The results suggested that plastic curette and plastic tip-ultrasonic scaler were predictable devices to titanium implant surface.