• Journal of Periodontal and Implant Science
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• 제44권5호
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• pp.216-221
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• 2014

Purpose: This retrospective study compares the amount of bone resorption around implants between an autogenous tooth bone graft (AutoBT) and a synthetic bone graft after a bone-added crestally approached sinus lift with simultaneous implant placements. Methods: In all, 37 patients participated in this study. Seventeen patients were grouped as group I and underwent an AutoBT-added sinus lift using the crestal approach. The remaining 20 patients were grouped as group II and underwent synthetic bone grafting. Both groups received the implant placements simultaneously. Of the 37 participating patients, only 22 patients were included in the final results: Eleven patients of group I and 11 patients of group II. Before the surgery, the distance from the alveolar crest to the sinus floor was measured using panoramic radiography. After the surgery, the distance was measured again from the neck of the implant thread to the most superior border of the added graft materials. Then, the amount of sinus lift was calculated by comparing the two panoramic radiographs. After a year, a panoramic radiograph was taken to calculate the resorption of the bone graft material from the radiograph that was taken after the surgery. The significance of the resorption amount between the two types of graft materials was statistically analyzed. Results: The bone height was increased to an average of 4.89 mm in group I and 6.22 mm in group II. The analysis of panoramic radiographs 1 year after the surgery showed an average bone resorption of 0.76 mm and 0.53 mm, respectively. However, the degree of lifting (P=0.460) and the amount of bone-grafted material resorption (P=0.570) showed no statistically significant difference. Conclusions: Based on this limited study, AutoBT can be considered a good alternative bone graft to a synthetic bone graft in a bone-added sinus lift, when extraction is necessary prior to the surgery.

• 구강회복응용과학지
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• 제25권2호
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• pp.139-155
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• 2009

연구목적: 원추형(Superline) 임플란트를 발치와에 1회법으로 즉시 식립한 후 주변 조직의 생물학적 안정성을 관찰하는 것이다. 연구 방법: 치근부에 명백한 병적 소견이 있는 경우는 제외한 기타 치아의 발치와에 원추형 임플란트를 즉시 식립한다. 1회법을 식립한 후 임플란트 주변 연조직의 치유를 도모한다. 수술 후 32주에 획득한 표준화된 방사선상에서, 임플란트 주변골의 변화(depth of the distance from the implant shoulder (IS) and from the alveolar crest (AC) to the bottom of the defect (BD)) 등을 관찰했다. 결과 : 13명의 피검자 (남자 10명/ 여자 3명)를 선별하여 15개의 원추형 임플란트를 발치와에 즉시 식힙하였으며 모든 임플란트의 초기 고정은 양호했다. 평균 수술시간은 $41{\pm}10.0$분이었다. 모든 임플란트survival rate 는100% 였다. Mean ISQ values 는 상대적으로 안정했으며, 술 후 32주까지 계속 관찰에, 임플란트 인접 치조골 감소량은 $1.69{\pm}1.2mm$ (mesial), $1.65{\pm}1.2mm$ (distal) 로 나타났다. FMPS, FMBS, PPD와 각 은의 폭의 유의한 변화는 없었다. 결론: 파절이나, 근관치료의 실패 등의 이유로 해서 치아를 발치할 경우 치근형 (Superline)임플란트를 발칭하에 1회법으로 즉시 식립하는 술식은 임상적으로 예지성있는 치료법으로 판단된다.

• Journal of Periodontal and Implant Science
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• 제50권3호
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• pp.146-158
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• 2020

Purpose: The aim of this study was to investigate and identify the main causes of periodontal tissue change associated with labial gingival recession by examining the anterior region of patients who underwent orthodontic treatment. Methods: In total, 45 patients who had undergone orthodontic treatment from January 2010 to December 2015 were included. Before and after the orthodontic treatment, sectioned images from 3-dimensional digital model scanning and cone-beam computed tomography images in the same region were superimposed to measure periodontal parameters. The initial labial gingival thickness (IGT) and the initial labial alveolar bone thickness (IBT) were measured at 4 mm below the cementoenamel junction (CEJ), and the change of the labial gingival margin was defined as the change of the distance from the CEJ to the gingival margin. Additionally, the jaw, tooth position, tooth inclination, tooth rotation, and history of orthognathic surgery were investigated to determine the various factors that could have affected anterior periodontal tissue changes. Results: The mean IGT and IBT were 0.77±0.29 mm and 0.77±0.32 mm, respectively. The mean gingival recession was 0.14±0.57 mm. Tooth inclination had a significant association with gingival recession, and as tooth inclination increased labially, gingival recession increased by approximately 0.2 mm per 1°. Conclusions: In conclusion, the IGT, IBT, tooth position, tooth rotation, and history of orthognathic surgery did not affect labial gingival recession. However, tooth inclination showed a significant association with labial gingival recession of the anterior teeth after orthodontic treatment.

• 대한치과교정학회지
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• 제48권5호
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• pp.283-291
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• 2018

Objective: This study was conducted to perform histomorphometric evaluations of the bone surrounding orthodontic miniscrews according to their proximity to the adjacent tooth roots in the posterior mandible of beagle dogs. Methods: Four male beagle dogs were used for this study. Six orthodontic miniscrews were placed in the interradicular spaces in the posterior mandible of each dog (n = 24). The implanted miniscrews were classified into no loading, immediate loading, and delayed loading groups according to the loading time. At 6 weeks after screw placement, the animals were sacrificed, and tissue blocks including the miniscrews were harvested for histological examinations. After analysis of the histological sections, the miniscrews were categorized into three additional groups according to the root proximity: high root proximity, low root proximity, and safe distance groups. Differences in the bone-implant contact (BIC, %) among the root proximity groups and loading time groups were determined using statistical analyses. Results: No BIC was observed within the bundle bone invaded by the miniscrew threads. Narrowing of the periodontal ligament space was observed in cases where the miniscrew threads touched the bundle bone. BIC (%) was significantly lower in the high root proximity group than in the low root proximity and safe distance groups. However, BIC (%) showed no significant differences among the loading time groups. Conclusions: Regardless of the loading time, the stability of an orthodontic miniscrew is decreased if it is in contact with the bundle bone as well as the adjacent tooth root.

• Journal of Periodontal and Implant Science
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• 제34권1호
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• pp.19-28
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• 2004

Tooth is the most important element in esthetic consideration on facial area. Tooth alignment which is in harmony with gingiva, lips, and face is also key element. The purpose of this study was to give a clinical discipline for restoration of gingival contour, which contains a ratio of maxillary 6 anterior teeth, research for gingival contour etc., in case of rehabilitation of maxillary anterior teeth. 300 Dankook university dental school students ,who is their twenties and free from periodontitis, participate in this study. The result was from each 70 males and females who had normal occlusion and tooth alignment. Length, width and length/width ratio of maxillary 6 anterior teeth were 0.74-0.81 in male, 0.81-0.84 in female. There was significant difference between male and female. The most deepest position of gingiva in maxillary central incisor and canine was located in distal part of teeth and maxillary lateral incisor was middle portion. In maxillary central incisors, gingival line of the most deepest point appeared significant difference between male and female (p<0.01) whereas there was no difference in lateral incisors and canines. Distance between interdental papilla apex and the most deepest portion appeared significant difference between male and female. Distance of the deepest position of gingiva is statistically significant except maxillary central incisors and lateral incisors. Standard deviation and mean of the width of labio-lingual were measured in cervical area and there was a significant difference both male and female.(p<0.01) From this result, we could get the mean of maxillary anterior gingival line and these results have great value in clinical guidance in studying maxillary anterior teeth.

• Journal of Periodontal and Implant Science
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• 제48권3호
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• pp.174-181
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• 2018

Purpose: The aims of the present study were to quantitatively assess graft height changes after sinus lift procedures and to analyze the factors that influenced graft height changes, including the residual bone height before surgery, surgical approach, and tooth type. Methods: A total of 39 maxillary posterior implants placed during a simultaneous sinus lift procedure were evaluated. Panoramic radiographs of all patients were taken immediately after implant installation and at 3 months, 6 months, 1 year, 2 years, and 3 years. To analyze graft height changes over time, we measured the distance between the implant platform and the base of the grafted sinus floor at 3 locations. The radiographs were analyzed by a single examiner. Results: Graft height tended to decrease over time, and a statistically significant difference was observed at 2 years compared to baseline (P<0.05). There was no statistically significant difference in graft height change according to the surgical approach or tooth type. For residual bone height, a statistically significant difference in graft height change was found between those with 4-7 mm of residual bone height and those with ${\geq}7mm$ (P<0.05). Conclusions: Graft height after sinus lift procedures significantly decreased at 2 years compared to baseline after sinus augmentation. Further studies should be done with controlled variables, and prospective studies with 3-dimensional images are needed to clarify the factors that influence graft height changes.

• 대한치과보철학회지
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• 제50권1호
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• pp.10-20
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• 2012

연구 목적: 이 연구의 목적은 텔레스코픽 크라운 하악 임플란트 지지 피개의치와 치아 지지 피개의치에서 지대치의 수와 위치에 따른 응력 분산을 비교하기 위함이다. 연구 재료 및 방법: 본 연구에서는 임플란트를 4개 식립하고 임플란트 지지 피개의치로 설계하였고, 식립 위치를 견치와 소구치 부위에 위치 별로 3개 또는 2개존재시를 실험군으로 설정하였다. 자연치아를 갖는 경우도 견치와 제2소구치 4개를 가진 경우를 대조군으로 설정하고 부위별로 3개 또는 2개를 가지는 경우를 실험군으로 설정하였다. ANSYS Version 10.1(Swanson, Inc., USA)로 분석하였다. 결과: 악골내 응력의 경우, 전반적으로 임플란트(IM)로만 구성된 경우가 치아(TH)로만 구성된 경우에 비해 응력이 크게 발생하였다. 상부구조의 경우, 치아군(TH)과 임플란트군(IM) 사이의 차이는 크게 없었으며 편측 견치와 제2소구치에 지대치 또는 임플란트가 위치하는 경우 가장 큰 응력이 나타났고 바(bar)에서 발생된 응력이 임플란트와 치아에서 발생되는 응력에 비해 상대적으로 훨씬 크게 발생하였다. 지대치와 임플란트의 경우, 치아군(TH)이 임플란트군(IM)보다 응력이 작게 발생하였다. 결론: 본 연구의 결과로부터 지대치(임플란트 또는 치아)를 설정할 때는 하중작용점과 지대치 사이의 거리가 너무 길어지지 않도록 지대치의 수와 위치를 확보해야 하며 소구치 자리에 지대치를 확보하는 것이 유리하다. 앞으로, 실제 임상에 적용하였을 경우, 임플란트 및 자연치아와 악골에 미치는 결과에 대한 연구가 더 필요할 것으로 생각된다.

• 대한치과보철학회지
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• 제52권1호
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• pp.27-33
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• 2014

연구 목적: 본 연구는 임플란트 보철물과 인접치 사이의 식편압입을 호소하는 환자를 대상으로 각종 임상 자료를 분석하여 식편압입의 임상적 발현 양상을 알아보고자 하였다. 연구 재료 및 방법: 식편압입을 주소로 내원한 보철물 장착이 완료된 임플란트 환자 51명을 대상으로 설문조사와 구강검사를 시행하고 방사선 사진과 모형을 채득하여 식편압입과 관련이 있는 요소를 분석한 결과 다음과 같은 결과를 얻었다. 결과: 1. 식편압입은 하악(39.2%)보다 상악(60.7%)에서 많이 나타났다. 2. 식편압입은 자연치아가 임플란트 보철물의 원심 부위(13.7%)에 있는 경우보다 근심 부위(86.2%)에 있는 경우에 많이 나타났다. 3. 식편압입이 나타난 임플란트 보철물과 그 인접치 사이의 접촉점은 긴밀하지 않은 경우(94.2%)가 대부분이었다. 결론: 임플란트 보철물과 인접치 사이에 식편압입이 일어나지 않기 위해서는 임플란트 보철물과 인접치아가 적절한 긴밀도를 가지고 있어야 하겠다.

• Journal of Periodontal and Implant Science
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• 제48권4호
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• pp.236-250
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• 2018

Purpose: Resorption of the alveolar bone is an unavoidable consequence of tooth extraction when appropriate alveolar ridge preservation (ARP) measures are not taken. The objective of this trial was to test the hypothesis that dimensional changes in the alveolar bone after tooth extraction would be reduced by inserting an equine collagen membrane and a collagen cone to fill and seal the alveolus (as ARP), in comparison to extraction with untreated alveoli. Methods: In this randomized clinical trial, 31 patients were directly treated with the collagen material after extraction of a tooth from the maxilla (the ARP group). Twenty-nine patients served as the control group. After extraction, no further treatment (i.e., no socket preservation measures) was performed in the control group. Changes in the alveolar process immediately after extraction and after an 8 (${\pm}1$)-week healing period were evaluated 3-dimensionally. Blinded analyses were performed after superimposing the data from the digitalized impressions and surfaces generated by cone-beam computed tomography. Results: Both the ARP and control groups showed a reduction of bone in the alveolar area after tooth extraction. However, significantly less bone resorption was detected in the clinically relevant buccal region in the ARP group. The median bone reduction was 1.18 mm in the ARP group and 5.06 mm in the control group (P=0.03). Conclusions: The proposed hypothesis that inserting a combination material comprising a collagen cone and membrane would lead to a difference in alveolar bone preservation can be accepted for the clinically relevant buccal distance. In this area, implantation of the collagen material led to significantly less alveolar bone resorption. German Clinical Trials Register at www.drks.de, DRKS00004769.

• Journal of Periodontal and Implant Science
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• 제45권6호
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• pp.216-222
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• 2015

Purpose: After extraction, the alveolar bone tends to undergo atrophy in three-dimensions. The amount of alveolar bone loss in the horizontal dimension has been reported to be greater than the amount of bone loss in the vertical dimension, and is most pronounced in the buccal aspect. The aim of this study was to monitor the predictive alveolar bone level following the extraction of anterior teeth seriously involved with advanced chronic periodontitis. Methods: This study included 25 patients with advanced chronic periodontitis, whose maxillary anterior teeth had been extracted due to extensive attachment loss more than one year before the study. Periapical radiographs were analyzed to assess the vertical level of alveolar bone surrounding the edentulous area. An imaginary line connecting the mesial and the distal ends of the alveolar crest facing the adjacent tooth was arbitrarily created. Several representative coordinates were established in the horizontal direction, and the vertical distance from the imaginary line to the alveolar crest was measured at each coordinate for each patient using image analysis software. Regression functions predicting the vertical level of the alveolar bone in the maxillary anterior edentulous area were identified for each patient. Results: The regression functions demonstrated a tendency to converge to parabolic shapes. The predicted maximum distance between the imaginary line and the alveolar bone calculated using the regression function was $1.43{\pm}0.65mm$. No significant differences were found between the expected and actual maximum distances. Likewise, the predicted and actual maximum horizontal distances did not show any significant differences. The distance from the alveolar bone crest to the imaginary lines was not influenced by the mesio-distal spans of the edentulous area. Conclusions: After extraction, the vertical level of the alveolar ridge increased to become closer to the reference line connecting the mesial and distal alveolar crests.