• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.761-776
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• 2005

The purpose of the present study was to examine the relationship between the form of the clinical crowns in the maxillary anterior segment and the clinical feature of gingiva such as morphological characteristics and the gingival thickness. Fifty periodontally healthy subjects were clinically examined regarding the probing depth, the thickness of the free gingiva, and the width of the keratinized gingiva. From study models of the maxillary anterior region, the width at cervical third(CW) and the length(CL) of the clinical crown, the papillary height, and the gingival angle of the 6 anterior teeth were measured. Each tooth was classified into 4 groups (longnarrow, NL; narrow, N; wide, W; short-wide, WS) according to CW/CL ratio and all the data were compared between groups NL and WS using independent t-test. Stepwise multiple regression analysis was performed for each tooth region with the gingival thickness at the level of sulcus bottom, the width of keratinized gingiva, and gingival angle as the dependent variables. As the results, the NL group of the upper anterior teeth displayed, higher papilla height, and narrower keratinized gingiva, more acute gingival angle resulting in pronounced "scalloped" contour of the gingival margin, compared to the WS group. There was no significant difference between groups NL and WS with respect to probing depth and the gingival thickness. The regression analyses demonstrated that the gingival thickness in central incisors was significantly associated to the mesio-distal width and bucco-lingual width of the crown, and labial probing depth. The width of keratinized gingiva was significantly associated with labial probing depth in central incisors and with proximal probing depth and gingival angle in lateral incisors, and with labial and proximal probing depth, and gingival angle in canines. The gingival angle was significantly associated with papillary height and CW/CL ratio and additionally with proximal probing depth in central incisors, with the width of keratinized gingiva in lateral incisors, and with labial probing depth and the width of keratinized gingiva in canines. These results indicate that the form of clinical crown in upper anterior region could influence the clinical feature of gingiva and the influencing factors might be different according to the tooth region.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.791-803
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• 2007

The purpose of this study was to evaluate exophytically vertical bone formation in residual ridge of the beagle dog by the concept of guided bone regeneration with a titanium reinforced e-PTFE membrane combined with irradiated cancellous human bone. Twelve male beagle dogs(mean age 1.5 years and mean weight 12kg) were used for this study. The alveolar ridges after extraction of all mandibular premolars were surgically and horizontally removed. At 8 weeks after extractions, full-thickness flap was reflected and cortical bone was removed with round bur and copious irrigation. Rectangular parallelepiped(10mm in length, 5mm in width, and 4mm in height) bended with titanium-reinforced e-PTFE(TR e-PTFE) membrane was placed on the decorticated alveolar ridge, fixed with metal pins and covered with full-thickness flap and assigned as a control group. Test groups ere treated with TR e-PTFE membrane filled with irradiated cancellous human bone. Of twelve beagle dogs, four control dogs and four test dogs without membrane exposure to oral cavity were sacrificed at 8 and 16 weeks respectively. The surgical sites were dissected out, fixed in 4% buffered formaldehyde, dyed using a Villanueva staining technique, and processed for embedding in plastic resin. The cutting and grinding methods were routinely processed for histologic and histomophometric analyis of exophytic bone formation as well as statistical analysis. The results of this study were as follows: 1. Exophytic bone formation in the both of experimental groups was increased respectively after surgery from 23.40% at 8 weeks to 46.26% at 16 weeks in the control groups, from 40.23% at 8 weeks to 47.11% at 16 weeks in the test groups(p<0.05). 2. At 8 weeks after surgery, exophytic bone formation was made 40.23% in the test groups and 33.40% in the control groups. Exophytic bone formation was significantly made in the test group more than in the control group. At 16 weeks after surgery, exophytic bone formation was made 44.11% in the test groups and 46.26% in the control groups. Exophytic bone formation was made in the test groups more than in the control groups, but there was no statistically significant differences. 3. The membrane was fixed with metal pins to closely contact it to the bone surface. So, collapse and deviation of the membrane could be prevented and in growth of connective tissue also could be blocked from the periphery of the membrane. On the basis of these findings, wee suggest that intraoral experimental model for exophytic bone formation may be effective to evaluate the effect of bone graft material. And it indicates that combined use of membrane and ICB graft material is more effective than use of membrane only for exophytic bone formation.

• Journal of Periodontal and Implant Science
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• 제49권4호
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• pp.215-227
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• 2019

Purpose: To histologically characterize periodontal healing at 8 weeks in surgically created dehiscence defects in beagle dogs that received a collagen matrix with periodontal ligament (PDL) progenitor cells. Methods: The bilateral maxillary premolars and first molars in 6 animals were used. Standardized experimental dehiscence defects were made on the buccal side of 3 premolars, and primary culturing of PDL progenitor cells was performed on the molars. Collagen matrix was used as a scaffold and a delivery system for PDL progenitor cells. The experimental sites were grafted with collagen matrix (COL), PDL progenitor cells with collagen matrix (COL/CELL), or left without any material (CTL). Histologic and histomorphometric analyses were performed after 8 weeks. Results: The defect height from the cementoenamel junction to the most apical point of cementum removal did not significantly differ across the CTL, COL, and COL/CELL groups, at $4.57{\pm}0.28$, $4.56{\pm}0.41$, and $4.64{\pm}0.27mm$ (mean ${\pm}$ standard deviation), respectively; the corresponding values for epithelial adhesion were $1.41{\pm}0.51$, $0.85{\pm}0.29$, and $0.30{\pm}0.41mm$ (P<0.05), the heights of new bone regeneration were $1.32{\pm}0.44$, $1.65{\pm}0.52$, and $1.93{\pm}0.61mm$ (P<0.05), and the cementum regeneration values were $1.15{\pm}0.42$, $1.81{\pm}0.46$, and $2.57{\pm}0.56mm$ (P<0.05). There was significantly more new bone formation in the COL/CELL group than in the CTL group, and new cementum length was also significantly higher in the COL/CELL group. However, there were no significant differences in the width of new cementum among the groups. Conclusions: PDL progenitor cells carried by a synthetic collagen matrix may enhance periodontal regeneration, including cementum and new bone formation.

• Journal of Periodontal and Implant Science
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• 제53권2호
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• pp.120-134
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• 2023

Purpose: We investigated whether repeated irradiation with light-emitting diodes (LEDs) at a combination of 470 nm and 525 nm could suppress the progression of experimental periodontitis. Methods: A experimental periodontitis model was established in the second, third, and fourth premolars of the mandible in beagle dogs for 2 months. The spontaneous progression of periodontitis was monitored under the specified treatment regimen for 3 months. During this period, the animals were subjected to treatments of either plaque control only (control) or plaque control with LED application (test) at 2-week intervals. The clinical parameters included the probing pocket depth (PPD), gingival recession (GR), and the clinical attachment level (CAL). Histomorphometric analysis was performed using measurements of the length of the junctional epithelium, connective tissue (CT) zone, and total soft tissue (ST). Results: There were significant differences in PPD between the control and test groups at baseline and 12 weeks. When the change in PPD was stratified based on time intervals, it was shown that greater differences occurred in the test group, with statistical significance for baseline to 12 weeks, 6 to 12 weeks, and baseline to 6 weeks. There was no significant difference in GR between the control and test groups at any time points. Likewise, no statistically significant differences were found in GR at any time intervals. CAL showed a statistically significant difference between the control and test groups at baseline only, although significant differences in CAL were observed between baseline and 12 weeks and between 6 and 12 weeks. The proportion of CT to ST was smaller for both buccal and lingual areas in the control group than in the test group. Conclusions: Repeated LED irradiation with a combination of 470-nm and 525-nm wavelengths may help suppress the progression of periodontal disease.

• Journal of Periodontal and Implant Science
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• 제54권1호
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• pp.13-24
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• 2024

Purpose: This study investigated the adjunctive effect of light-emitting diodes (LEDs) in the treatment of experimental periodontitis. Methods: Experimental periodontitis was induced by placing ligatures around the mandibular second, third, and fourth premolars of 6 beagles for 3 months. After ligature removal, periodontitis progressed spontaneously for 2 months. The animals' hemimandibles were allocated among the following 3 groups: 1) no treatment (control), 2) scaling and root planing (SRP), and 3) SRP with LED irradiation at 470-nm and 630-nm wavelengths (SRP/LED). The probing pocket depth (PPD) and gingival recession (GR) were measured at baseline, 6 weeks, and 12 weeks. The clinical attachment level (CAL) was calculated. After 12 weeks, histological and histomorphometric assessments were performed. The distances from the gingival margin to the apical extent of the junctional epithelium (E) and to the connective tissue (CT) attachment were measured, as was the total length of soft tissue (ST). Results: PPD and CAL increased at 12 weeks compared with baseline in the control group (6.31±0.43 mm to 6.93±0.50 mm, and 6.46±0.60 mm to 7.61±0.78 mm, respectively). PPD and CAL decreased at 12 weeks compared with baseline in the SRP group (6.01±0.59 to 4.81±0.65 mm, and 6.51±0.98 to 5.39±0.93 mm, respectively). PPD and CAL decreased at 12 weeks compared with baseline in the SRP/LED group (6.03±0.39 to 4.46±0.47 mm, and 6.11±0.47 to 4.78±0.57 mm, respectively). The E/ST and CT/ST ratios significantly differed among the 3 groups (P<0.05). The clinical parameters and histologic findings demonstrated that 470-nm and 630-nm wavelength LED irradiation accompanying SRP could improve treatment results. Conclusions: Within the study limitations, 470 nm and 630 nm wavelength LED irradiation might provide additional benefits for periodontitis treatment.

• Journal of Periodontal and Implant Science
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• 제26권3호
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• pp.605-624
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• 1996

Various bonegraft materials and the technique of guided tissue regeneration have been used to regenerate lost periodontal tissue. Calcium sulfate has been known as a bone graft material because of good biocompatibility, rapid resorption and effective osteoinduction. It has been known that calcium sulfate works as a binder to stabilize the defect when it is used with synthetic graft materials. The effects on the regeneration of pericxiontal tissue were studied in dogs after grafting 3-wall intrabony defects with calcium carbonate and calcium sulfate and covering with calcium sulfate barrier. The 3-wall intrabony defectstdmm width, 4mm depth, 4mm length) were created in anterior area and treated with flap operation alone(contol group), with porous resorbable calcium carbonate graft alonetexperirnental group 1), with calcium sulfate graft alonetexperimental group 2) and with composite graft of 80% calcium carbonate and 20% calcium sulfate with calcium sulfate barriertexperimental group 3). Healing responses were histologically observed after 8 weeks and the results were as follows: 1. The alveolar bone formation was $0.59{\pm}0.19mm$ in the control group, $1.80{\pm}0.25mm$ in experimental group 1, $1.61{\pm}0.21mm$ in experimental group 2 and $1.94{\pm}0.11mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(P<0.05). There were statistically significant differences between experimental group 1 and group 2 (P<0.05). 2. The new cementum formation was $0.48{\pm}0.19mm$ in the control group. $1.72{\pm}0.26mm$ in experimental group 1, $1.43{\pm}0.17mm$ in experimental group 2, $1.89{\pm}0.15mm$ in experimental group 3 with statiscally significant differences between control group and all experimental groups (p<0.05). There were statistically significant differences between experimental group 1 and group 2, and between experimental group 2 and group 3(P<0.05). 3. The length of junctional epithelium was $1.61{\pm}0.20mm$ in the contol group, $0.95{\pm}0.06mm$ in experimental group 1, $1.34{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.11mm$ in experimental group 3 with statiscally significant differences between control group and experimental group 1. and btween control group and experimental group 3(p<0.05). There were statistically significant differences between experimental group 1 ,and group 2, and between experimental group 2 and group 3(P<0.05). 4. The connective tissue adhesion was $1.67{\pm}O.20mm$ in the control group, $1.33{\pm}0.24mm$ in experimental group 1. $1.23{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.14mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(p<0.05). There were nostatistically significant differences between all experimental groups. As a result, epithelial migration was not prevented when calcium sulfate was used alone, but new bone and cementum formation were enhanced. Epithelial migration was prevented and new bone and cementum formation were also enhanced when calcium carbonate was used alone and when both calcium carbonate and calcium sulfate were used.

• Journal of Periodontal and Implant Science
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• 제26권4호
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• pp.779-797
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• 1996

치주 질환에 의해 상실된 치주 조직의 재생과 기능 회복을 위해 골 이식재의 사용을 포함한 많은 치료법들이 이용되었다. 골 이식술을 위해 자가골 이식, 동종골 이식, 이종골 이식, 골 대체 물둥이 이용되어왔다. 이중 탈회 냉동 건조 동종골은 약 20년 전부터 치주 영역에서 사용되어 왔으나 탈회 냉동 건조 동종골의 골내 치주낭 이식의 효과에 대한 연구는 찬반 양론이 대립된다. 탈회 냉동 건조골은 제작 방법 중 특히, 탈회에 의해 탈회 냉동 건조골의 생물학적 성격이 결정되며 이에 따라 치주 조직 재생 능력에도 변화가 있을 수 있다. 이에 본 연구에서는 탈회 시간에 따른 탈회 냉동 건조골 이식이 성견의 3면 골내 치주낭에서 치주 조직 재생에 미치는 영향을 알아보고자 성견의 전치부에 $4mm{\times}4mm{\times}4mm$크기의 3면 골 내낭을 형성한 후 치주 수술만 시행한 군을 대조군으로, 탈회를 시키지 않은 냉동 건조골을 이 식한 군을 실험 I 군으로, 12 시간 탈회시킨 탈회 냉동 건조골을 이식한 군을 실험 n군으로, 24시간 탈회시킨 탈회 냉동 건조골을 이식한 군을 실험 III군으로 설정하여 14주 후에 치유 결과를 조직학적으로 비교 관찰하여 다음과 같은 결과를 얻었다. 1. 결합 조직 유착은 대조군에서 $0.62{\pm}0.14mm$, 실험 I 군에서 $0.42{\pm}0.11mm$, 실험 n군에서 $0.63{\pm}0.43mm$, 실험 III군에서 $0.52{\pm}0.11mm$로 계측되었으며 대조군과 실험군간에 유의성 있는 차이는 없었다. 2. 신생골 형성은 대조군에서 $3.17{\pm}0.24mm$, 실험 I군에서 $3.15{\pm}0.56mm$, 실험 n 군에서 $3.22{\pm}0.36mm$, 실험 III군에서 $3.28{\pm}0.74mm$ 로 계측되었으며 대조군과 실험군간에 유의성 있는 차이는 없었다. 3. 신생 백악질 형성은 대조군에서 $4.19{\pm}0.46mm$, 실험 I군에서 $3.23{\pm}0.64mm$, 실험 II군에서 $4.13{\pm}1.82mm$, 실험 III군에서 $3.13{\pm}0.62mm$로 계측되었으며 대조군과 실험군간에 유의성 있는 차이는 없었다.

• 대한정형외과학회지
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• 제52권1호
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• pp.25-32
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• 2017

목적: 고령 환자에서 발생한 불안정성 대퇴골 전자간부 골절의 치료 시 골수강내 금속정의 길이에 따른 방사선적, 임상적 치료 결과를 비교 분석하고자 한다. 대상 및 방법: 2009년 8월부터 2014년 12월까지 방사선 영상상 AO/OTA 분류 31-A2 대퇴골 전자간부 골절로 진단되어 골수강 내 금속정을 이용한 내고정을 시행한 뒤 최소 1년 이상 추시가 가능하였던 65세 이상의 환자 139예를 대상으로 후향적 대조군 연구를 시행하였다. 대상군을 짧은 골수정(I군)과 긴 골수정(II군)을 사용한 군으로 분류하였으며 각각 106예, 33예로 조사되었다. 방사선적인 평가로 골절의 정복 정도, 골유합까지의 기간, 합병증 발생을 조사하였으며 수술 전 혈색소, 수술 시간, 수술 중 출혈량, 수혈 유무, 입원 기간 및 최종 추시 시 Charnley 고관절 점수를 통한 임상적 평가를 시행하였다. 결과: 수술 후 단순 방사선 검사상 전 예에서 good 또는 acceptable한 정복 상태를 얻었다. 골유합까지 평균 4.8개월이 걸렸으며 두 군 간의 차이는 없었다. II군(57.87분)이 I군(45.65분)보다 수술 시간이 길었던 것으로 확인되었다(p=0.003). 수술 중 출혈량의 경우 II군(288.78 ml)이 I군(209.90 ml)보다 많은 것으로 확인되었다(p=0.046). 최종 추시 시 임상적 결과는 두 군 모두 만족스러웠다. 결론: 고령의 환자에서 발생한 후내측 골편을 동반한 불안정성 대퇴골 전자간부 골절의 치료 시 골절 부위의 정복을 잘 시행한 경우 긴 골수정과 짧은 골수정 모두 만족스러운 방사선적, 임상적 결과를 보였다.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.851-870
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• 2000

The major goals of periodontal therapy is the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. There have been increasing interest on the chitosan made by chitin. Chitin is second only to cellulose as the most abundant natural biopolymer. It is a structural component of the exoskeleton of invertebrates(e.g., shrimp, crabs, lobsters), of the cell wall of fungi, and of the cuticle of insects. Chitosan is a derivative of chitin made by deacetylation of side chains. Many experiments using chitosan in various animal models have proven its beneficial effects. The aim of this study is to evaluate the osteogenesis of chitosan on the calvarial critical size defect in Sprague Dawley rats. An 8 mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into two groups: Untreated control group versus experimental group with 50mg of soluble chitosan gel. The animals were sacrificed at 2, 4 and 8 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric and radiodensitometric analyses. The results are as follows: 1. The length of newly formed bone in the defects was $102.91{\pm}25.46{\mu}m$, $219.46{\pm}97.81{\mu}m$ at the 2 weeks, $130.95{\pm}39.24{\mu}m$, $212.39{\pm}89.22{\mu}m$ at the 4 weeks, $181.53{\pm}76.35{\mu}m$ and $257.12{\pm}51.22{\mu}m$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. But, there was no statistically significant difference between the two groups. 2. The area of newly formed bone in the defects was $2962.06{\pm}1284.48{\mu}m^2$, $5194.88{\pm}1247.88{\mu}m^2$ at the 2 weeks, $5103.25{\pm}1375.88{\mu}m^2$, $7751.43{\pm}2228.20{\mu}m^2$ at the 4 weeks and $8046.20{\pm}818.99{\mu}m^2$, $15578.57{\pm}5606.55{\mu}m^2$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. 3. The density of newly formed bone in the defects was $14.26{\pm}6.33%$, $27.91{\pm}6.65%$ at the 2 weeks, $20.06{\pm}9.07%$, $27.86{\pm}8.20%$ at the 4 weeks and $22.99{\pm}3.76%$, $32.17{\pm}6.38%$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. These results suggest that the use of chitosan on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself

• 대한치과교정학회지
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• 제41권5호
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• pp.312-323
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• 2011

본 연구는 동일한 환자에서 촬영한 측모두부계측방사선 사진과 전산화단층촬영 영상을 비교하여 미니 임플랜트 식립 시 측모두부계측방사선 사진을 통해 상악 구개부 골두께를 예측하기 위한 목적으로 시행되었다. 안모가 양호한 정상교합자 남녀 총 30명의 전산화단층촬영 영상을 3D model로 변환하고 측모두부계측방사선 사진과 동일부위의 골두께를 계측하기 위하여 프랑크프루트 평면에 대해 수직이고 상악 제2소구치와 제1대구치 인접면을 지나는 기준평면을 설정한다. 3D model에서 횡적으로 2 mm 간격으로 11개 부위의 구개부 골두께를 계측하고 측모두부계측방사선 사진과 비교하여 다음과 같은 결과를 얻었다. 3D model에서 골두께는 남녀 모두 정중구개부위에서 가장 컸고 측방으로 멀어질수록 작아지다가 남성는 측방 6 mm 여성는 측방 8 mm 부위에서 가장 최소값을 보인 후 다시 커지는 양상이 관찰되었다. 측모두부방사선 사진상 골두께는 남성이 $4.21{\pm}1.03mm$, 여성은 $2.71{\pm}1.62mm$로 남성이 여성보다 유의성 있게 컸다. 측모두부계측방사선 사진상 골두께와 3D model에서 횡적인 부위별로 측정한 골두께는 남성은 정중구개부와 측방 2 mm 부위를 제외한 나머지 부위에서 유의성 있는 상관관계를 보였고 여성은 모든 부위에서 유의성 있는 상관관계를 보였다. 또한 측모두부계측방사선 사진상 골두께와 3D model에서 상관관계를 보이는 부위에 대하여 회귀분석을 시행하였다. 이상의 횡적인 부위별 회귀분석을 통해 미니 임플랜트 식립 시 안전한 스크류의 길이를 결정하기 위한 골두께 예측에 도움이 될 것이다.