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@#The reconstruction effect of peri-implantitis bone defects depends on their morphological characteristics. This paper reviews the morphological classification and treatment of peri-implantitis bone defects. A literature review shows that the morphological classification of bone defects in peri-implantitis includes morphology classification and clinical classification. At present, the Renvert classification is more commonly used in the clinic and is divided into four-wall bone pockets, three-wall bone pockets, two-wall bone pockets, one-wall bone pocket and dehiscence according to the number of bone walls. This has guiding significance in the treatment plan of peri-implantitis. The treatment of peri-implantitis depends on the severity of peri-implant bone defects. Peri-implantitis with mild bone defects is treated by nonsurgical treatment, peri-implantitis with severe bone defects is recommended to remove the implant, and peri-implantitis with moderate bone defects is further judged according to the shape of the bone defects. Four-wall bone pockets, three-wall bone pockets and dehiscence are mostly treated by bone regenerative surgery. For shallow two-wall bone pockets, one-wall bone pockets and horizontal bone resorption, bone resection is often used. However, most peri-implantitis has a variety of bone defect forms at the same time, which need to be treated with bone regenerative surgery and bone resection surgery.
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@#Berberine is a natural isoquinoline alkaloid extracted from Rhizoma Coptidis and other Chinese herbal medicines. Since berberine has a variety of biological effects, such as bacteriostasis, anti-inflammatory, anti-bone resorption and blood sugar-lowering effects, and is associated with few side effects, studies are increasingly discovering its potential application in the prevention and treatment of periodontitis. This review summarizes the relevant research progress of berberine in the prevention and treatment of periodontitis in recent years, aiming to provide a new strategy for the clinical prevention and treatment of periodontitis. The results of the literature review showed that berberine could prevent the occurrence and development of periodontitis by inhibiting periodontal pathogens, reducing periodontal tissue inflammation and inhibiting alveolar bone resorption. However, the mechanism of periodontitis is complicated, and current research remains limited. In the future, more in vivo and in vitro studies are needed to further explore the mechanism of berberine in inhibiting the occurrence and development of periodontitis, and more large-sample prospective clinical studies should be conducted to confirm the effect of berberine on the prevention and treatment of periodontitis.
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Objective@#To analyze changes in proteoglycan and its correlation with alveolar bone resorption in periodontitis. @*Methods @#Twelve eight-week-old C57BL/6J male mice were selected, and the periodontitis model was established by ligating the right maxillary second molar with 6-0 silk thread. The nonligated part of the left maxilla was used as the control. The mice were killed 14 days after the operation. Micro-CT was used to assess alveolar bone resorption. HE staining was used to observe the alveolar bone profile, and TRAP staining was conducted to examine the positive rate of osteoclasts. The expression of proteoglycan-related genes, such as aggrecan (ACAN), biglycan (BGN), versican (VCAN), decorin (DCN), osteoclast-related genes, such as cathepsin K (CTSK), matrix metalloprotein-9 (MMP-9), and receptor activator of nuclear factor kappa-B ligand (RANKL), and inflammation-related genes, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), was detected by real-time quantitative PCR. Additionally, the correlation of the expression of proteoglycans with osteoclast-related genes and inflammation-related genes was evaluated by Pearson correlation analysis.@* Results@#The resorption of alveolar bone on the periodontitis side increased. TRAP staining showed that the number of osteoclasts was substantially increased in the maxilla with periodontitis. Real-time quantitative PCR demonstrated that compared with the control side, the expression of proteoglycan-related genes, such as ACAN, BGN, and DCN, was decreased, whereas the expression of the VCAN gene was significantly increased in the periodontitis side. Meanwhile, the expression of osteoclast-related genes, such as CTSK, MMP-9, and RANKL, and inflammation-related genes, such as IL-1β, IL-6, and TNF-α, was markedly increased in the periodontitis side (P<0.05). Pearson correlation analysis indicated a negative correlation between the expression of proteoglycans and the mRNA levels of osteoclast-related genes and inflammation-related genes (P<0.05). @*Conclusion @#The expression of proteoglycan was closely related to alveolar bone resorption in a periodontitis model.
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@#The rapid absorption of labial alveolar bone after tooth extraction not only reduces the aesthetic effect of implant repair but also affects the long-term success rate of implants. The socket shield technique is reported as the latest alveolar preservation technique in the aesthetic zone from both domestic and international case reports and shows a high success rate of short-term osseointegration and excellent aesthetic effects. However, some investigations have shown short- and long-term complications with the socket shield technique, such as failure of osseointegration, loss of crestal bone and buccal bone, inflammation, etc. In this review, the socket shield technique will be reported in detail with its pros and cons. Although the socket shield technique has achieved good clinical effects and short-term success rates in many cases, there are still no conclusions regarding the surgical procedure, such as the thickness, the position of the shield, whether to put the graft material between the shield and implant, etc. Due to the lack of long-term research or a large amount of clinical literature support and technical sensitivity, the socket shield technique should be carefully used in clinical application to reduce unexpected risks.
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Objective@# Establish a murine model for hyperuricemia (HU) and periodontitis to explore whether there is correlation between them and provide a basis for periodontal treatment.@*Methods@#Fourteen male KM mice were divided into 2 groups; the HU group (n=7) was fed food supplemented with potassium oxonate and uric acid, the NC group (n=7) was fed standard food, and the induction period was 35 days. On the 25th day, the molars on one side were ligated to induce periodontitis (P side), while the opposite was true for the control (C side). Baseline and terminal serum uric acid (UA) levels were detected, and alveolar bone resorption was analyzed by micro-CT.@*Results@#The serum UA level of HU mice was (112.94 ± 26.82 )mol/L, that of the NC group was (72.21 ± 19.95) μmol/L, and the difference in UA level was statistically significant (P < 0.05). The P side bone volume fractions of the HU and NC groups were( 29.01 ± 11.09)% and (29.56 ± 15.27)%, respectively, which were not significantly different (t=-0.072, P=0.944). The P side bone mineral densities of the HU and NC groups were(0.53 ± 0.16) g/cm3 and (0.52 ± 0.14) g/cm3, respectively, which were not significantly different (t=0.038, P=0.970). Additionally, there was no correlation between HU or serum UA and alveolar bone resorption (P > 0.05). @* Conclusion @#This research established a murine model for HU and periodontitis, but based on micro-CT analysis of alveolar bone, no relationship between HU or UA levels and periodontitis was found.
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Objective@# To investigate the etiology, diagnosis and treatment principles of inherited permanent tooth embryo necrosis caused by alveolar bone resorption due to severe periapical periodontitis of deciduous teeth, in order to provide a reference for clinical diagnosis and treatment@*Methods@#The clinical data and related literature of a rare case of permanent tooth embryo necrosis were analyzed retrospectively.@*Results @#This case was a 5-year-old girl. Physical examination and X-ray examination revealed chronic periapical inflammation in 75. X-ray showed that the periodontal bone of tooth 75 was extensively destroyed; additionally, the permanent tooth germ of tooth 35 was incomplete and the development was delayed compared to that of tooth 45 because of severe periapical periodontitis in the primary teeth. The initial diagnosis was that-- the embryo of tooth 35 stopped developing due to inflammation and was necrotic after tooth 75 was extracted. The postoperative pathological examination report showed that most bone around the embryos of tooth 35 was sequestrated. Through literature review and analysis, it was found that the degree of periapical lesions in the primary teeth and the developmental stage of the tooth embryo have a great impact on the formation of permanent tooth embryos. Conservative methods such as root canal therapy are usually adopted as treatment. Permanent tooth embryo necrosis caused by periapical periodontitis of deciduous teeth is rare in the clinic, so it is necessary to judge the degree of inflammatory infiltration and of tooth embryo damage as soon as possible according to the clinical symptoms and imaging manifestations; and to make a correct treatment plan.@*Conclusion@#There are no objective and clear diagnostic and treatment criteria for the clinical diagnosis of the pathological state of permanent tooth embryo, thus, methods such as etiology elimination and follow-up observation are usually adopted for abnormal permanent tooth embryo development. Future research should focus on prevention and finding addtional effective methods for diagnosis and treatment.
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Objective: To study the effects of root grooves on alveolar bone resorption of maxillary premolar in elderly patients with periodontitis. Methods: 31 pairs of the first premolar with root groove (group A) and second premolar without root groove (group B) of the same side from 19 elderly patients with chronic periodontitis were included. The pattern and degree of alveolar bone resorption were measured by CBCT at 6 sites of each tooth. The relation of root groove with the bone resorption patterns and degree was analyzed. Results: The oblique alveolar bone resorption of group A and B was observed at 36 sites and 31 sites respectively (P ＜ 0. 05), at M site the alveolar bone resorption (mm) of group A and B was 3. 85 ± 1. 31 and 3. 37 ± 0. 86 (P ＜ 0. 05) . Conclusions: Root groove of maxillary first premolar can promote local alveolar bone resorption in elderly patients with periodontitis.
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Conventional denture impression techniques have limitations for edentulous patients with severe alveolar bone resorption and can cause problems from excessive border extension. Especially when a patient has movable tissue it is difficult to make accurate impression, thus might interrupt stable seating of complete denture. Fabrication of complete denture using closed mouth technique for edentulous patient with severe ridge resorption is thought to provide better stability and retention. In this case, an 86-year-old patient had both edentulous jaws with epulis fissuratum on maxillary anterior ridge and severe mandibular ridge resorption. Thus, tentative vertical dimension was determined by using Centric tray and individual tray attached with gothic arch tracer was fabricated. Complete denture was fabricated using closed mouth technique and the patient was satisfied with better stability and retention of the complete denture.
Subject(s)
Aged, 80 and over , Humans , Bone Resorption , Denture, Complete , Dentures , Gingival Diseases , Jaw, Edentulous , Mouth , Vertical DimensionABSTRACT
When an implant-supported maxillary full-arch fixed prosthesis is planned for patients with the horizontal and vertical bone resorption induced by periodontal disease, it is necessary to consider the masticatory function, esthetics and phonetics when placing implants. For this reason, thorough clinical and radiological diagnosis is necessary. Extensive bone and soft tissue grafting may be required as well. Since there is no clear guideline for proper number of implants, segment or splinting of substructure and method of retaining prosthesis, these should be considered during diagnostic process. This clinical report describes a patient who has experienced several tooth extractions and periodontal treatment due to severe periodontitis on maxilla and mandible. With bone and soft tissue graft before dental implant placement, the patient have satisfactory result in esthetic and functional aspect with the implant-supported maxillary full-arch fixed prosthesis opposing mandibular natural dentition.
Subject(s)
Humans , Bone Resorption , Dental Implants , Dentition , Diagnosis , Esthetics , Mandible , Maxilla , Periodontal Diseases , Periodontitis , Phonetics , Prostheses and Implants , Splints , Tissue Transplantation , Tooth Extraction , TransplantsABSTRACT
Statement of problem. Higher fracture rates were reported for Branemark implants placed in the maxilla and for 3.75 mm diameter implants installed in the posterior region. Purpose. The purpose of this study was to investigate the fracture of a fixture by finite element analysis and to compare different diameter of fixtures according to the level of alveolar bone resorption. Material and Methods. The single implant and prosthesis was modeled in accordance with the geometric designs for the 3i implant systems. Models were processed by the software programs HyperMesh and ANSA. Three-dimensional finite element models were developed for; (1) a regular titanium implant 3.75 mm in diameter and 13 mm in length (2) a regular titanium implant 4.0 mm in diameter and 13 mm in length (3) a wide titanium implant 5.0 mm in diameter and 13 mm in length each with a cementation type abutment and titanium alloy screw. The abutment screws were subjected to a tightening torque of 30 Ncm. The amount of preload was hypothesized as 650 N, and round and flat type prostheses were 12 mm in diameter, 9 mm in height were loaded to 600 N. Four loading offset points (0, 2, 4, and 6 mm from the center of the implants) were evaluated. To evaluate fixture fracture by alveolar bone resorption, we investigated the stress distribution of the fixtures according to different alveolar bone loss levels (0, 1.5, 3.5, and 5.0 mm of alveolar bone loss). Using these 12 models (four degrees of bone loss and three implant diameters), the effects of loading offset, the effect of alveolar bone resorption and the size of fixtures were evaluated. The PAM-CRASH 2G simulation software was used for analysis of stress. The PAM-VIEW and HyperView programs were used for post processing. Results. The results from our experiment are as follows: 1. Preload maintains implant-abutment joint stability within a limited offset point against occlusal force. 2. Von Mises stress of the implant, abutment screw, abutment, and bone was decreased with increasing of the implant diameter. 3. With severe advancing of alveolar bone resorption, fracture of the 3.75 and the 4.0 mm diameter implant was possible. 4. With increasing of bending stress by loading offset, fracture of the abutment screw was possible.
Subject(s)
Alloys , Alveolar Bone Loss , Bite Force , Bone Resorption , Cementation , Finite Element Analysis , Joints , Maxilla , Prostheses and Implants , Titanium , TorqueABSTRACT
Objective:To establish an experimental model of residual ridge resorption after mandibular incisor extraction and to study the occurrence mechanisms.Methods:Thirty male Wistar rats were used, the edge of the right mandibular incisor was cut every three days(a total of three times) and the incisor was extracted at three days after the final cut. The animals were sacrificed 0,1,2,4,8,12 weeks respectively after the extraction and the mandibles were dissected out. The length of the alveolar bone and the ratio of extracted side length to unextracted side length were measured on soft X-ray photographs and the mandibles were processed for histomorphometry.Eighteen male Wistar rats were used to observe the morphologic alteration of periodontal tissues by hematoxylin and eosin when the incisor crown was cut at different time intervals.Results:As compared with the unextracted side, the length of alveolar ridge of the extracted side was significantly decreased at 4,8,12 weeks;the ratio of extracted side length to unextracted side length significantly decreased at 4 week after tooth extraction(P
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The purpose of this study was to evaluate root resorption and alveolar bone resorption pattern by jiggling movement. adult cats were divided into 4 groups (6, 12, 18, 24 days). ln test side, mesio-distal jiggling force was applied in right maxillary 1st premolar in 3 days cycle. ln control side, mesial force was applied in left maxillary 1st premolar, Radiographic and histologic observation were formed in 6, 12, 18, 24 days after force application. The results were as follow: Alveolar bone resorption was more severe by jiggling force than by unidirectional force. Root resorption pattern was not different between jiggling force and unidirectional force. Combined pattern of bone resorption and new bone formation appeared in jiggling group. New bone formation began to appear at periapical area of jiggling group after 24 days, because alveolar bone resorption was severe and extrusion resulted.