Gotowa bibliografia na temat „Crestal Bone Resorption”

The aim of this study is to analyze the resorption rate of bone graft materials after crestal sinus floor elevation, study its influencing factors, and improve the long-term success rate of implants after crestal maxillary sinus floor elevation. Measurement and analysis were conducted at six postoperative timepoints (0 months, 6 months, 12 months, 18 months, 24 months, and 30 months) using cone beam computed tomography (CBCT) data on 31 patients from the Chenghuaxinguanghua Dental Clinic who underwent crestal maxillary sinus floor elevation, involving 38 graft sites. The materials resorption rates of the bone graft height (BH) and bone graft width (BW) were assessed. BH and BW resorption rates followed the same trend (p = 0.07), with BH and BW resorption rates decreasing with time (rBH = −0.32, p < 0.01; rBW = −0.18, p < 0.01), and were maximal in the 0–6 month interval, with BH and BW resorption rates of 3.42%/mth and 3.03%/mth, respectively. The average monthly BH and BW resorption rates in the 6–12 month interval rapidly decreased to 1.75%/mth and 1.29%/mth, respectively. The monthly BH and BW resorption rates in the 12–30 month intervals stabilized at 1.45%/mth (p > 0.05) and 1.22%/mth (p > 0.05), respectively. The higher the initial bone graft height (BH0), the lower the BH resorption rates (rBH = −0.98, p < 0.05), and the BW resorption rate was different for different graft sites (p = 0.01). The resorption rates of bone graft materials implanted through crestal maxillary sinus floor elevation decreased rapidly within the first 12 months post operation and remained stable after 12 months. BH0 was identified as a significant factor influencing the resorption rates of bone graft materials. These results could suggest dentists should pay attention to the trend of resorption rates over time and carefully manage the initial height of bone grafts and inspire the research of new bone grafting materials for crestal maxillary sinus floor elevation.

Stability of crestal bone around dental implants is a major concern for oral surgeons and dentists. It is a key factor for success of dental implant treatment. Crestal bone is more prevented from resorption when surrounding tissues are thicker. Aim of the study – to find out the mean of crestal bone loss around supracrestally placed dental implants with matching platform in vertically thick soft tissues. The final patient sample included 34 patients (17 female and 17 male), who received 34 two piece dental implants in total. All 34 implants integrated successfully as evaluation under implant success criteria was applied. Implants were restored by single-unit crowns, using metal-ceramic prostheses. After 1 year thick soft tissues maintain stable crestal bone around dental implants in lower jaw. Minor bone resorption of 0.28 ± 0.36 mm mm could be seen during early bone remodelling phase.

Background and Objectives: The purpose of this study is to assess the long-term maintenance of each approach of sinus elevation, the crestal approach and lateral approach, by comparing the radiographic results of each technique. Materials and Methods: In total, 103 patients who had undergone an implant procedure with either the crestal approach or lateral approach method applied to their maxillary molar edentulous area were included. Using orthopantomographs, the radiographic changes were consistently evaluated over 3 years after the procedure (immediately after procedure and 1 year, 2 years and 3 years after implant placement) Results: The radiographic evaluation after 3 years of implantation with sinus elevation showed a significant amount of bone formation (8.07 mm for crestal approach and 12.00 mm for lateral approach method). The largest amount of grafted height loss occurred during the 1 year, but the resorption was minimal (0.98 mm for crestal approach and 0.95 mm for lateral approach method) over the entire 3 years. Conclusions: Although the lateral approach showed more bone growth, the amount of bone resorption was similar to that of the crestal approach. Both methods showed the highest amount of bone resorption in the first year, and the amount of change thereafter was insignificant. It is judged that both methods can be used according to the situation to help implant placement.

<abstract> <p>The objective of this evaluation was to measure the width and length of connective tissue (CT) and crestal bone resorption (CBR) related to minicono® abutment inserted in conical connection dental implants, which were placed crestal and subcrestally in a dog's mandible.</p> <sec> <title>Materials and Methods</title> <p>Forty-eight Top DM implants with the same coronal diameter were placed at the crestal level, 1 mm (test 1 group) and 2 mm (test 2 group) positions underneath buccal-lingual bone crests. Dental implants used in the study were separated into three groups of 16 implants each. The implants were randomly inserted into healed bone after two months post-extraction sockets of three lower premolars, and first molar, bilaterally in six male fox hound dogs. One 3 mm minicono height abutment was connected to conical connection implants placed at the crestal level (control), 1 mm (test 1) and 2 mm (test 2) positions under buccal-lingual crests.</p> </sec><sec> <title>Results</title> <p>All abutments and implants used were clinically and histologically integrated into the bone-soft tissue. Soft tissue behavior was observed at eight and 12 weeks in all test groups, displaying similar quantitative findings with significant differences (p > 0.05). However, crestal bone loss was significantly greater at the buccal side around that control group compared to the test 1 and 2 groups. The difference values between groups at the implant shoulder to the top of the lingual bone crest (IS-LBC) and the implant shoulder to the top of the buccal bone crest (IS-BBC) were significantly greater for the test 2 group in comparison with the other two groups (p < 0.05) at eight weeks. In addition, crestal bone resorption (CBR) increased in the crestal group at twelve weeks, but it was reduced for the test 1 and test 2 groups in implants placed sub-crestally (p < 0.05).</p> </sec><sec> <title>Conclusions</title> <p>Crestal bone loss could be reduced using a 3 mm high abutment on implants submerged below the bone crest from 1 to 2 mm positions.</p> </sec></abstract>

Abstract Among the factors that contribute to the papilla formation and crestal bone preservation between contiguous implants, this animal study clinically and radiographically evaluated the interimplant distances (IDs) of 2 and 3 mm and the placement depths of Morse cone connection implants restored with platform switch. Bilateral mandibular premolars of 6 dogs were extracted, and after 12 weeks, the implants were placed. Four experimental groups were constituted: subcrestally with ID of 2 mm (2 SCL) and 3 mm (3 SCL) and crestally with ID of 2 mm (2 CL) and 3 mm (3 CL). Metallic crowns were immediately installed with a distance of 3 mm between the contact point and the bone crest. Eight weeks later, clinical measurements were performed to evaluate papilla formation, and radiographic images were taken to analyze the crestal bone remodeling. The subcrestal groups achieved better levels of papillae formation when compared with the crestal groups, with a significant difference between the 3 SCL and 3 CL groups (P = .026). Radiographically, the crestal bone preservation was also better in the subcrestal groups, with statistically significant differences between the 2SCL and 2CL groups (P = .002) and between the 3SCL and 3CL groups (P = .008). With the present conditions, it could be concluded that subcrestal implant placement had a positive impact on papilla formation and crestal bone preservation, which could favor the esthetic of anterior regions. However, the IDs of 2 and 3 mm did not show significantly different results.

Background: This study aims to explore the detailed correlation between the movement of maxillary and mandibular central incisors and alveolar bone resorption in adults who had orthodontic premolar extraction treatment. Methods: A total of 63 adult patients (mean age, 24.41 years) who received orthodontic treatment with the extraction of four first premolars were included in this study. CBCT images were obtained before and after treatment. Three-dimensional evaluations of the movement of 252 central incisors (126 maxillary and 126 mandibular incisors) and alveolar bone changes were conducted. Four points were used to describe the incisor movement: C (cusp point), R (root apex point), M (mid-point of root neck), and L (labial cementoenamel junction point). The thickness of labial and palatal alveolar bone was assessed at the crestal, mid-root, and apical levels of incisors. The results were analyzed with Spearman’s correlation and multilinear regression. Results: Matching the measurements of central incisor movement and alveolar bone resorption, significant correlations could be observed. For maxillary central incisors, the labial alveolar bone resorption at the crestal level was correlated with the movement of Point L (r = 0.290, p < 0.05), and the labial alveolar bone resorption at the apical level was correlated with Point M (r = 0.387, p < 0.05). For mandibular central incisors, the labial alveolar bone resorption at the apical level was correlated with the movement of Point M (r = 0.493, p < 0.05) and R (r = 0.498, p < 0.01); the palatal alveolar bone resorption at the mid-root level with Point M (r = -0.170, p < 0.01); and the palatal alveolar bone resorption at the apical level with Point R (r = 0.177, p < 0.01). Conclusions: This study investigated the concrete correlations between central incisor movement and alveolar bone resorption in adults after orthodontic treatment with premolar extraction. It is potentially helpful for orthodontists to have a relatively accurate prediction of alveolar bone resorption based on the specific movements of central incisors and to reduce the risk of alveolar bone resorption by better adjusting the three-dimensional movement types of incisors.

ABSTRACTThe aim of this study was to conduct a literature review on the potential benefits with the use of Morse taper dental implant connections associated with small diameter platform switching abutments. A Medline bibliographical search (from 1961 to 2014) was carried out. The following search items were explored: “Bone loss and platform switching,” “bone loss and implant-abutment joint,” “bone resorption and platform switching,” “bone resorption and implant-abutment joint,” “Morse taper and platform switching.” “Morse taper and implant-abutment joint,” Morse taper and bone resorption,” “crestal bone remodeling and implant-abutment joint,” “crestal bone remodeling and platform switching.” The selection criteria used for the article were: Meta-analysis; randomized controlled trials; prospective cohort studies; as well as reviews written in English, Portuguese, or Spanish languages. Within the 287 studies identified, 81 relevant and recent studies were selected. Results indicated a reduced occurrence of peri-implantitis and bone loss at the abutment/implant level associated with Morse taper implants and a reduced-diameter platform switching abutment. Extrapolation of data from previous studies indicates that Morse taper connections associated with platform switching have shown less inflammation and possible bone loss with the peri-implant soft tissues. However, more long-term studies are needed to confirm these trends.

Objectives: This study was aimed to compare the histological pattern of bone modeling on either periodontal or periosteal side induced by lateral orthodontic tooth movement in different age groups. Material and Methods: A total of 50 male Sprague-Dawley rats (25 rats in the adult group – 52 weeks and 25 rats in the young group – 10 weeks) were utilized in this study. Each age group was classified into the control, 3 days, 7 days, 14 days, and 21 days groups (five rats in each) by the duration of experimental device application. A double-helical spring was produced using 0.014” stainless steel wire to provide 40 g lateral force to the left and right incisors. Hematoxylin-eosin staining, proliferating cell nuclear antigen (PCNA) immunohistochemical staining, fibroblast growth factor receptor 2 (FGFR2) immunohistochemical staining, and Masson trichrome staining were performed; and the slides were subject to histological examination. Results: In 7 days, active bone modeling represented by the scalloped surface was observed on the periosteal side of the crestal and middle alveolus at the pressure side in the young group, while similar changes were observed only on the crestal area in the adult group. In the young group, the number of PCNA-positive cells increased significantly on the crestal area and middle alveolus on the 3, 7, and 14 day groups, with subsequent decrease at 21 days. In the adult group, PCNA-positive cells were localized on the crestal area throughout the period. In the young group, FGFR2-positive cells were observed mainly on the crestal and middle alveolus at 3, 7, and 14 days than the control group. In the adult group, these cells appeared on the crestal and middle alveolus in the 3 days group, but mainly on the crestal area at 14 days. In the young group, FGFR2-positive cells were observed on the crestal and middle alveolus on the 3, 7, and 14 days groups more than on the control group. In the adult group, these cells appeared on the crestal and middle alveolus in the 3 days group, but mainly on the crestal area in the 14 days group. In Masson trichrome stain, an increased number of type I collagen fibers were observed after helical spring activation in both age groups. Large resorption lacunae indicating undermining bone resorption were progressively present in both young and adult groups. Conclusion: According to these results, orthodontic tooth movement may stimulate cell proliferation and differentiation primarily on the periosteal side according to progressive undermining bone resorption on the periodontal side. This response may lead to prominent bone modeling during tooth movement in the young group, compared to the relatively delayed response in the adult group.

Background. The purpose of this systematic review was to accurately assess the procedural success of ridge preservation technique through the application of strict inclusion and exclusion criteria. Data Sources. A methodical search of PubMed of the US National Library of Medicine and the Cochrane Central Register of Controlled Trials was conducted for applicable articles. Only randomized controlled trials comparing ridge preservation treatment with a nongrafting control, ten-subject minimum sample size, and three or more months of follow-up were included in our study. Types of Studies Reviewed. In a screening between January 1980 and September 2017, articles meeting predetermined criteria were further examined in a qualitative data analysis. A thorough search of the databases provided 1876 articles. Of these records, 174 were assessed for eligibility through the systematic employment of inclusion and exclusion criteria. Results. Two records were appropriate for further data analysis. One study used a mixture of a deproteinized cancellous bovine bone and porcine collagen fibers in a block form (DBB/CF), while the other study used leukocyte-platelet-rich fibrin (L-PRF). The use of DBB/CF reduced the magnitude of vertical bone resorption, yet the study showed high risk of bias. The use of L-PRF reduced the magnitude of both the horizontal and vertical crestal bone resorption; however, the low sample size created wide standard deviations between the test and control groups. Inherent weaknesses were present in both studies. Through methodical analysis of both records, the dissimilarities prevented the conduction of a meta-analysis. Implications of Key Findings. Within the limitations of this systematic review, L-PRF reduced the magnitude of vertical and horizontal bone resorption, which places L-PRF as a potential material of choice for ridge preservation procedures. Conclusions. Within the limitations and weaknesses of both studies, the use of DBB/CF prevented the vertical crestal bone resorption while the L-PRF prevented both the horizontal and vertical crestal bone resorption. More randomized controlled clinical trials are needed to eliminate all the confounding factors, which bias the outcome of ridge preservation techniques.

Trabalho apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária<br>Introdução: Implantes com plataforma tipo Cone Morse (CM) baseiam-se no princípio mecânico do “cone dentro de cone” que proporciona uma grande superfície de contacto entre o pilar protético e o implante. Vários autores concluíram que o uso destes implantes representa um procedimento de sucesso na reabilitação de arcos totais ou parcialmente edêntulos. Objectivo: Abordar as vantagens da utilização do implante CM, enquadrando-as no contexto biomecânico e microbiológico. Material e Métodos: A pesquisa bibliográfica foi feita sem qualquer tipo restrições temporais, e foram utilizados os motores de busca, Pubmed, Science direct e B on. Os critérios de selecção utilizados para os artigos incluíram meta análises, ensaios controlados randomizados e outros artigos de revisão escritos em Inglês e Português, foram seleccionados 72 artigos. Conclusão: Face à escassez de estudos relativamente a este tipo de conexão, e reconhecendo o papel do infiltrado inflamatório a este nível, apenas podemos concluir que existem vantagens no uso da conexão tipo cone morse e Plataforma Switching (PS), ao nível microbiológico e biomecânico e no impacto ao nível da estabilidade dos tecidos duros e moles circunjacentes. Introduction: Implants with platform type Morse Cone are based inside on the mechanical principle of the “cone of cone” that provides to a great faying surface between the prosthetic pilar and the implant. Some authors had concluded that the use of this type of implants represents a procedure of success in the whitewashing of total or partially arcs. Objective: To approach the advantages of the cone-morse implants use fitting in the biomechanic and microbiology context. Methods: Bibliography review was made without any type of time limits and had been used through search engines as Pub-med, Scielo Forums, Science Direct and B on, The used criteria for the papers had been the analyzed goal, random controlled tests and others papers of revision written in English and Portuguese, was selected 72 papers. Conclusion: Face to the scarcity of studies relatively to this type of connection, and recognizing the paper of the inflammatory at this level, we only can conclude that there are advantages in the use of the connection type cone morse and platform switching, at the microbiological and biomechanic level and in the impact at the level of the stability of the hard and soft tissues.

The aim of this study is evaluate on radiographic examination bone resorption on tilted implants placed with a minimal angulation of 15 degrees compared with the occlusal plane. The purpose is to demonstrate if a correlation between tilted implants and crestal bone resorption exist. In this study we evaluated orthopantomography done at T0 moment when implants have been loaded and at T1 moment: between 1 and 10 years from loading. Values are calculated using a specific program: we have measured the importance of bone resorption in mm both mesial and distal from the implant surface and catalogued only implants with more then 15 degrees angulation. This study demonstrated that the use of tilted implants is safe and is not associated to a higher marginal bone loss as compared to axially placed implants: no statistically significant difference in implant success was observed. Obviously is compulsory evaluate different aspects: for example if the implant is rehabilitated individually or if is in a full-arch fixed restoration, or if the implant is located in natural bone or in presence of bone grafted. This study demonstrate that increasing of angulation of implant insertion doesn’t mean necessary an increasing of implant failure; considering different variables is necessary to obtain a predictable study. New studies with a larger number of patients and implants inserted are essentials.

The purpose of this prospective, randomized, controlled clinical investigation is to evaluate the performance of the Motorized Ridge Expanders (MRE), and to compare its results with the ones achieved utilizing lateral ridge augmentation (LRA). Eight subjects with bilateral ridge deformities were selected. One technique was used on the right site and the other on the left site. Implants were placed six months after the bone augmentation procedures. All the measurements were recorded at 2 and 5 mm from the most coronal part of the crest. The augmentation achieved with both techniques was statistically significant, 1.2 mm in the LRA, 1.5 mm in MRE at 2 mm from the crest; 1.5 mm and 1.6 mm respectively at 5mm from the crest. The differences between the two techniques were statistically insignificant. The amount of expansion achieved in the MRE site appears to be negatively correlated (P-Value <0.05) with the thickness of the cancellous bone, and it is not affected by the thickness of the cortical plate. The MRE technique appears to be as effective as the LRA technique in augmenting the thickness of atrophic ridges. The defect treated with the MRE showed less bone width contraction during the first 6 months of healing. Histologically, the regenerated bone was vital, trabecular in nature and in direct contact with bone graft particles.<br>El propósito de esta investigación clínica prospectiva y aleatoria es comparar el aumento horizontal de la cresta alveolar obtenido con el uso de los expansores motorizados de cresta (EMC) y con regeneración ósea guiada (ROG). Fueron selecccionados ocho pacientes con deformidades horizontales del reborde alveolar bilaterales que iban a recibir implantes dentales. Una técnica de regeneración se utilizó en el lado derecho y la otra en el lado izquierdo, para un total de 23 muestras, 13 en el lado experimental (EMC) y 10 en el lado control (ROG). Los implantes fueron colocados seis meses después de los procedimientos de aumento óseo, y se obtuvo una muestra de hueso para estudio histológico. Todas las mediciones clínicas se registraron a los 2 y 5 mm de la parte más coronal de la cresta. El aumento logrado con ambas técnicas fue estadísticamente significativo, de 1,2 mm en la ROG y 1,5 mm con los EMC a 2 mm de la cresta; y 1,5 mm y 1,6 mm, respectivamente, a 5mm de la cresta. Las diferencias entre las dos técnicas no fueron estadísticamente significativas. La cantidad de expansión lograda en el sitio de los EMC parece tener una correlación negativa (p <0,05) con el grosor del hueso esponjoso, y no se ve afectada por el grosor de la cortical. Histológicamente se observó osteoconductividad del injerto óseo y más partículas residuales del mismo en el lado experimental. La técnica de los EMC parece ser tan eficaz como la técnica de ROG en el aumento de la anchura de las crestas atróficas. Los defectos tratados con los EMC mostraron una menor contracción del injerto óseo durante los 6 meses de cicatrización.<br>El propòsit d'aquesta recerca clínica prospectiva i aleatòria és comparar l'augment horitzontal de la cresta alveolar obtingut amb l'ús dels expansors motoritzats de cresta (EMC) i amb regeneració òssia<br/>guiada (ROG). Es van selecccionar vuit pacients amb deformitats horitzontals bilaterals de la cresta alveolar on es col.locaren implants dentals. Una tècnica de regeneració es va emprar en el costat dret i l'altra a la banda esquerra, per a un total de 23 mostres, 13 al costat experimental (EMC) i 10 en el costat control (ROG). Els implants van ser col.locats sis mesos després dels procediments d'augment ossi, i es va obtenir una mostra d'os per estudi histològic.Totes les mesures clíniques es van registrar als 2 i 5 mm de la part més coronal de la cresta. L'augment aconseguit amb ambdues tècniques va ser estadísticament significatiu, de 1,2 mm a la ROG i 1,5 mm amb els EMC a 2 mm de la carena, i 1,5 mm i 1,6 mm, respectivament, a 5mm de la cresta. Les diferències entre les dues<br/>tècniques no van ser estadísticament significatives. La quantitat d'expansió aconseguida en el lloc dels EMC sembla tenir una correlació negativa (p<0,05) amb el gruix de l'os esponjós, i no es veu afectada per el gruix de la cortical. Histològicament es observar osteoconductividad l'empelt ossi i més partícules residuals d'aquest en el costat experimental. La tècnica dels EMC sembla ser tan eficaç com la tècnica de ROG en l'augment de l'amplada de les crestes atròfiques. Els defectes tractats amb els EMC mostrar una menor contracció de l'empelt ossi durant els 6 mesos de cicatrització.

SURGICAL-RADIOGRAPHIC PART:The aim of the present retrospective chart review was to determine the relationship between nonvascularized osseous graft remodeling and the three-dimensional (3D) features of grafts and recipient sites, the anatomical recipient regions and different graft procedures. 18 iliac crest were onlay-positioned in the mandible or maxilla or used in sinus lift procedures. CT scans, taken before implant positioning and after 1 year, revealed a mean volume resorption of 40%. For iliac crest grafts, the average resorption was 36% when the onlay was positioned in the anterior maxilla, 77% when it was positioned in the posterior mandible and 17% in sinus lift procedures. GENIC PART: This part of the study aims to identify and rank genes involved in osseous augmentation or bone remodeling to obtain groups with more numerous predicted associations called the leader gene clusters. An iterative search (consisting of a consecutive expansion-filtering loop) was performed for which only genes involved in a specific process were identified. For each gene, predicted associations with all other involved genes were obtained from a Web-available database (Search Tool for the Retrieval of Interacting Genes/Proteins) and the weighted number of links (WNL), given by the sum of only high-confidence predicted associations (results with a score > or =0.9), allowing gene ranking. A total of 161 genes potentially involved in bone-volume augmentation and 128 genes connected with the bone-remodeling phenomenon were identified.

In dental debilitating conditions, such as edentulism, the patient must have sufficient alveolar crest bone mass to guarantee the possibility of corrective interventions, such as implants. The decrease in bone tissue is caused by the body's natural reabsorption, which begins after tooth loss. Some surgical techniques could be used to solve this problem, such as guided bone regeneration. In this technique, a membrane developed with biomaterials is used, which aims to act as physical barrier to prevent the appearance of soft tissue and maintain the bone defect space, ensuring maximum regeneration. This membrane must be biocompatible, have specific rigidity to maintain the space, prevent the migration of epithelial cells and ensure the resorption time after bone tissue regeneration. This chapter will address the polymeric materials most used in the development of membranes for guided bone regeneration process, addressing their physicochemical characteristics, advantages, disadvantages, among other important aspects.