One-Stage Lateral Sinus Floor Elevation Using Different Grafts: A Systematic Review of Controlled Clinical Trials.

PURPOSE: The purpose of this systematic review was to assess histological and imaging outcomes related to new bone formation around implants, inserted simultaneously with sinus augmentation, comparing different types of grafts. MATERIALS AND METHODS: Systematic Review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta- Analysis (PRISMA), and the Cochrane Handbook for Systematic Reviews of Interventions. LILACS/BVS, Medline/PubMed, Cochrane Library and Embase databases, including gray literature and manual investigation, were searched to identify clinical trials reporting human histological and imaging data of bone formation around implants, inserted into the maxillary sinus at the same moment of the elevation and augmentation procedure, using several materials. Study selection, risk of bias (Rob 2.0 or ROBINS I), quality of evidence (GRADE), and data collection were performed by two independent reviewers. RESULTS: Of the 1101 potentially eligible articles, 44 were retrieved, 12 were assessed for eligibility and 5 were included in this systematic review (4 randomized and one controlled clinical trials). As a result, 130 grafted sinuses with 179 installed implants in 103 patients, aged between 24 and 79 years and followed up from 6 to 15 months, were analyzed. The heterogeneity between studies did not allow the data to be combined for meta-analyses. All graft materials proved to be viable options for the intervention. The use of BCP was related to higher bone-to-implant contact. CONCLUSION: All the assessed grafts are viable options for the intervention addressed. The use of some material is justified to maintain the sinus volume and allow bone formation in the apical site of implants under the sinus membrane. Longer chair time and the morbidity of the donor site should be considered when choosing autogenous bone. Synthetic biphasic materials can be selected for this intervention due to superior values of %BIC when compared to DBB.

The effect of micro-osteoperforations on the rate of maxillary incisors' retraction in orthodontic space closure: a randomized controlled clinical trial.

BACKGROUND: This single-centered randomized controlled clinical trial aimed to evaluate the effectiveness of micro-osteoperforations (MOPs) in accelerating the orthodontic retraction of maxillary incisors. METHODS: Forty-two patients aged 16-40 were recruited and randomly assigned into two groups, one which underwent MOPs (MOPG) in the buccal and palatal region of all maxillary incisors immediately before the start of retraction and one which did not (CG). Eligibility criteria included the orthodontic need for maxillary first premolars extraction and space closure in two phases. The primary outcome of the study consisted of measuring the rate of space closure and, consequently, the rate of incisors' retraction using digital model superimposition 14 days later and monthly thereafter for the next 4 months. The secondary outcomes included measuring anchorage loss, central incisors' inclination, and root length shortening, analyzed using cone beam computed tomography scans acquired before retraction and 4 months after retraction. Randomization was performed using QuickCalcs software. While clinical blinding was not possible, the image's examinator was blinded. RESULTS: Twenty-one patients were randomly assigned to each group. However, due to various reasons, a total of 37 patients (17 male and 20 female) were analyzed (mean age: 24.3 ± 8.1 years in the MOPG; 22.2 ± 4.2 years in the CG) during the trial. No statistically significant difference was found between the MOPG and the CG regarding the incisors' retraction measured at different time points at the incisal border (14 days, 0.4 mm vs. 0.5 mm; 1 month, 0.79 mm vs. 0.77 mm; 2 months, 1.47 mm vs. 1.41 mm; 3 months, 2.09 mm vs. 1.88 mm; 4 months, 2.62 mm vs. 2.29 mm) and at the cervical level (14 days, 0.28 mm vs. 0.30 mm; 1 month, 0.41 mm vs. 0.32 mm; 2 months, 0.89 mm vs. 0.61 mm; 3 months, 1.36 mm vs. 1.10 mm; 4 months, 1.73 mm vs. 1.39 mm). Similarly, no statistically significant differences were detected in the space closure, anchorage loss, central incisors' inclination, and radicular length between groups. No adverse effect was observed during the trial. CONCLUSIONS: MOPs did not accelerate the retraction of the maxillary incisors, nor were they associated with greater incisor inclination or root resorption. Trial registration ClinicalTrials.gov NCT03089996. Registered 24 March 2017- https://clinicaltrials.gov/ct2/show/NCT03089996 .

Is the computed tomography exam important for planning mini-implant installation?

Background: Mini-implants are devices used to provide absolute and temporary anchorage for tooth movement. Objectives: The present study was carried out to compare the use of periapical radiographs and computed tomography (CT) for planning mini-implants performed by orthodontists. Material and Methods: Five radiographs and five CT scans of premolars and molars regions. These were analyzed by ten Orthodontists. Initially (T1), the evaluators indicated the preferred location for the insertion of a mini-implant, as well as the diameter and length of the device, using only a periapical radiograph. After 30 days (T2), the same evaluation was performed. Sixty days later (T3), the orthodontists reassessed the radiographs in association with the CT scans. Finally, after 90 days (T4), the evaluation was performed with the same exams. The comparison of the chosen diameter and length of the mini-implants was performed using the Student's t-test. The evaluation of the chosen insertion sites was analyzed by the Wilcoxon test. For both tests, the level of significance was 5%. The kappa concordance test was also performed for the intra- and inter-examiner evaluations. Results: The results of the study showed substantial or perfect intra-examiner and reasonable to perfect inter-examiner agreement. Considering the length and diameter of the mini-implants, no statistical difference was found between the groups. Regarding the insertion site, more than 20% of the treatment plans were changed when the CT scan was associated. Conclusions: The results showed that the association of a CT scan with radiography frequently leads the professional to change the insertion point for the installation of mini-implants. Key words:Orthodontic anchorage procedures. Mini Dental Implants. Bone Screws. Cone-beam computed tomography. Periapical radiography.

Effectiveness of Extra-Short (< 6 mm) Implants Compared to Standard-Length Implants Associated with Bone Graft: Systematic Review.

Purpose: To evaluate the effectiveness of extra-short implants compared to standard-length implants in graft regions at different longitudinal follow-up times. Materials and Methods: A systematic review was performed, following PRISMA criteria. LILACS, MEDLINE/PubMed, Cochrane Library, and Embase databases, including gray literature and manual searches, were conducted without language or date restrictions. Study selection, risk of bias (Rob 2.0), quality of evidence (GRADE), and data collection were performed by two independent reviewers. Disagreements were resolved by a third reviewer. Data were combined using the random-effects model. Results: A total of 1,383 publications were identified, including 11 publications from 4 randomized clinical trials that evaluated 567 implants (276 extra-short and 291 regular implants with graft) in 186 patients. The meta-analysis showed that losses (risk ratio [RR]: 1.24; 95% CI: 0.53 to 2.89; P = .62; I2: 0%) and prosthetic complications (RR: 0.89; 95% CI: 0.31 to 2.59; P = .83; I2: 0%) were similar in both groups. Biologic complications were significantly higher in regular implants with graft (RR: 0.48; CI: 0.29 to 0.77; P = .003; I2: 18%), which also had lower peri-implant bone stability in the mandible at the 12-month follow-up (mean deviation [MD]: -0.25; CI: -0.36 to 0.15; P < .00001; I2 = 0%). Conclusion: Extra-short implants showed similar effictiveness compared to standard-length implants placed in grafted regions at different longitudinal follow-up times and present reduced biologic complications, shorter treatment times, and greater peri-implant bone crest stability.

Grafting biomaterials associated to topical glucocorticoid: effects on pre-osteoblastic cells (MC3T3-E1).

The topical glucocorticoid budesonide has been prescribed before and after sinus lift surgery as adjuvant drug treatment for maxillary sinus membrane inflammation. However, there is no study on the effects of budesonide on the regenerative process of bone grafting biomaterials. We investigated the effect of the association of budesonide with some biomaterials on the growth and differentiation capacity of pre-osteoblastic cells (MC3T3-E1 subclone 4). Xenogeneic (Bio-Oss and Bio-Gen) and synthetic hydroxyapatites (Osteogen, Bonesynth, and HAP-91) were tested in conditioned medium (1% w/v). The conditioned medium was then supplemented with budesonide (0.5% v/v). Cell viability was assessed using the MTT assay (48, 96, and 144 h), and mineralized nodules were quantified after 14 days of culture using the Alizarin Red Staining. Alkaline phosphatase activity was assessed through the release of thymolphthalein at day seven. All biomaterials showed little or no cytotoxicity. The Bio-Gen allowed significantly less growth than the control group regardless of the experimental time. Regarding differentiation potential of MC3T3-E1, the HAP-91-conditioned medium showed remarkable osteoinductive properties. In osteodifferentiation, the addition of budesonide favored the formation of mineral nodules when cells were cultured in medium conditioned with synthetic materials, whereas it weakened the mineralization potential of cells cultured in xenogeneic medium. Regardless of whether budesonide was added or not, Osteogen and Bio-Oss showed higher alkaline phosphatase activity than the other groups. Budesonide may improve bone formation when associated with synthetic biomaterials. Conversely, the presence of this glucocorticoid weakens the mineralization potential of pre-osteoblastic cells cultured with xenogeneic hydroxyapatites.

Grafting biomaterials associated to topical glucocorticoid: effects on pre-osteoblastic cells (MC3T3-E1)

Abstract The topical glucocorticoid budesonide has been prescribed before and after sinus lift surgery as adjuvant drug treatment for maxillary sinus membrane inflammation. However, there is no study on the effects of budesonide on the regenerative process of bone grafting biomaterials. We investigated the effect of the association of budesonide with some biomaterials on the growth and differentiation capacity of pre-osteoblastic cells (MC3T3-E1 subclone 4). Xenogeneic (Bio-Oss and Bio-Gen) and synthetic hydroxyapatites (Osteogen, Bonesynth, and HAP-91) were tested in conditioned medium (1% w/v). The conditioned medium was then supplemented with budesonide (0.5% v/v). Cell viability was assessed using the MTT assay (48, 96, and 144 h), and mineralized nodules were quantified after 14 days of culture using the Alizarin Red Staining. Alkaline phosphatase activity was assessed through the release of thymolphthalein at day seven. All biomaterials showed little or no cytotoxicity. The Bio-Gen allowed significantly less growth than the control group regardless of the experimental time. Regarding differentiation potential of MC3T3-E1, the HAP-91-conditioned medium showed remarkable osteoinductive properties. In osteodifferentiation, the addition of budesonide favored the formation of mineral nodules when cells were cultured in medium conditioned with synthetic materials, whereas it weakened the mineralization potential of cells cultured in xenogeneic medium. Regardless of whether budesonide was added or not, Osteogen and Bio-Oss showed higher alkaline phosphatase activity than the other groups. Budesonide may improve bone formation when associated with synthetic biomaterials. Conversely, the presence of this glucocorticoid weakens the mineralization potential of pre-osteoblastic cells cultured with xenogeneic hydroxyapatites.

Automated Identification of Dental Implants Using Artificial Intelligence.

PURPOSE: To develop and evaluate the accuracy of a computer-assisted system based on artificial intelligence for detecting and identifying dental implant brands using digital periapical radiographs. MATERIALS AND METHODS: A total of 1,800 digital periapical radiographs of dental implants from three distinct manufacturers (f1 = 600, f2 = 600, and f3 = 600) were split into training dataset (n = 1,440 [80%]) and testing dataset (n = 360 [20%]) groups. The images were evaluated by software developed by means of convolutional neural networks (CNN), with the aim of identifying the manufacturer of the dental implants contained in them. Accuracy, sensitivity, specificity, positive and negative predictive values, and the receiver operating characteristic (ROC) curve were calculated for detection and diagnostic performance of the CNN algorithm. RESULTS: At the final epoch (25), system accuracy values of 99.78% were obtained for group training data, 99.36% for group testing data, and 85.29% for validation data. The latter value corresponded to the actual accuracy of carrying out the system learning process. CONCLUSION: This study demonstrated the effectiveness of CNN for identifying dental implant manufacturers, which was proven to be a precise method of great clinical significance.

Bone changes in the mandibular incisors after orthodontic correction of dental crowding without extraction: A cone-beam computed tomographic evaluation.

PURPOSE: This study aimed to evaluate changes of the alveolar bone and interdental bone septum of the mandibular incisors through cone-beam computed tomography (CBCT) after orthodontic treatment of mandibular dental crowding without dental extraction. MATERIALS AND METHODS: The sample consisted of 64 CBCT images (32 pre-treatment and 32 post-treatment) from 32 adult patients with class I malocclusion and an average age of 23.0±3.9 years. The width and height of the alveolar bone and interdental septum, the distance between the cementoenamel junction (CEJ) and the facial and lingual bone crests, and the inclination of the mandibular incisors were measured. RESULTS: The distance between the CEJ and the marginal bone crest on the facial side increased significantly (P<0.05). An increased distance between the CEJ and the bone crest on the facial and lingual sides showed a correlation with the irregularity index (P<0.05); however, no significant association was observed with increasing mandibular incisor inclination (P>0.05). The change in the distance between the CEJ and the marginal bone crest on the facial side was correlated significantly with bone septum height (P<0.05). CONCLUSION: Bone dehiscence developed during the treatment of crowding without extraction only on the incisors' facial side. Increasing proclination of the mandibular incisor was not correlated with bone dehiscence. The degree of dental crowding assessed through the irregularity index was associated with the risk of developing bone dehiscence. The interdental septum reflected facial marginal bone loss in the mandibular incisors.

ImplantoPUC: an educational application for mobile computing devices aimed at patients and professionals in the field of Implantology / ImplantoPUC: aplicativo para orientação de pacientes, estudantes e cirurgiões-dentistas sobre os implantes osseointegráveis

ABSTRACT Objective: development of an application for mobile computer devices, mobile phones and tablets, which contains educational material for patients and professionals in the area of Implantology. The use of ImplantoPUC at PUC Minas implant dentistry clinics aims at a more effective communication between professionals and patients, with better visualization of the proposed treatments, improving the understanding of patients. Methods: for the development of ImplantoPUC, a responsive technology was used, and the application windows can adapt to different screen formats, consequently, the application can be made available on different platforms such as: Web, Android and Apple. The application size is 13.4 MB and was developed using the OutSystems platform using Apache Cordova. The prototype of the ImplantoPUC application can already be accessed through the link https://includesistemas.outsystemcloud.com/implantpuc/homescreen. Results: the application is still under test at PUC Minas implant dentistry clinics, but due to the pandemic its use is still below expectations. In the Play Store your rating has a maximum rating of 5.0, with more than 50 downloads so far. Conclusion: Implanto PUC makes the task of informing more interactive and easy to understand for patients, also assisting professionals in the area in obtaining updated information and at the reach of hands, and can also be used in other Dentistry Educational Institutions, becoming a reference in the area of implant dentistry.

RESUMO Objetivo: desenvolvimento de um aplicativo para dispositivos móveis de informática, celulares e tablets, que contém material educacional para os pacientes e profissionais da área da Implantodontia. A utilização do ImplantoPUC nas clínicas de Implantodontia da PUC Minas visa uma comunicação mais efetiva entre profissionais e pacientes, com melhor visualização dos tratamentos propostos, melhorando o entendimento dos pacientes. Métodos: Para o desenvolvimento do ImplantoPUC foi utilizado uma tecnologia responsiva, podendo as janelas do aplicativo se adaptarem a diferentes formatos de telas, consequentemente, o aplicativo pode ser disponibilizado em diferentes plataformas como: Web, Android e Apple. O tamanho do aplicativo é de 13,4 MB e foi desenvolvido utilizando a plataforma OutSystems, utilizando a Apache Cordova. O protótipo do aplicativo ImplantoPUC já pode ser acessado através do link https://includesistemas.outsystemcloud.com/implantpuc/homescreen Resultados: O aplicativo ainda continua em teste nas clínicas da PUC Minas, mas em virtude da pandemia o seu uso está abaixo do esperado. Na Play Store a sua avaliação tem nota máxima 5,0, com mais de 50 downloads até o momento. Conclusão: O ImplantoPUC torna a tarefa de informar mais interativa e de fácil compreensão para os pacientes, auxiliando também os profissionais da área na obtenção de informações atualizadas e ao alcance das mãos, podendo também ser utilizado em outras instituições de ensino da Odontologia, tornando-se uma referência na área da Implantodontia.

Effect of amount of biomaterial used for maxillary sinus lift on volume maintenance of grafts.

BACKGROUND: Regardless of the kind of biomaterial used for the graft, it is clear that, over time, the graft undergoes dimensional changes that could influence the final bone volume obtained, which could alter the stability of the installed implants. The aim of the present study was to compared and correlated the graft behavior with the amount (in grams) of xenogeneic and alloplastic biomaterials used in grafts for maxillary sinus lift. MATERIAL AND METHODS: This retrospective cohort study used 148 CBCT images of 74 grafts from 68 maxillary sinuses lift patients in a university, post-graduate clinic. The weights of biomaterials, categorized in intervals according to amount used, were correlated with the graft volumes at V1 (10 days) and V2 (180 days). Kruskal-Wallis test was used to evaluate the possible bias effect of weight on graft maintenance. RESULTS: Mean weights of biomaterials used were: Bio-Oss Small® (1.58g); Bio-Oss Large® (1.35g); Endobon® (0.72g); BoneCeramic®+Emdogaim® (0.96g); Cerasorb® (1.13g) and Osteogen® (2.70g). No significant differences (p>0.05). Were found for the influence of these mean amounts in graft maintenance: Bio-Oss Small® (18); Bio-Oss Large® (10); Endobon® (17); BoneCeramic®+Emdogaim® (10); Cerasorb® (11); and Osteogen® (08) at V1 and V2. However, when biomaterials were categorized by intervals, all Cerasorb® interval groups showed statistically significant differences (p<0.001) in graft volume at V2. CONCLUSIONS: The amounts of the biomaterials used could influence the final volume; depending on the biomaterial characteristics. Implant installation was possible with all studied grafts, although graft volume shrinkage should be considered when selecting biomaterial for sinus lift. Key words:Biocompatible materials; cone beam computed tomography; maxillary sinus; hydroxyapatites.

Extra short 4mm implants used to rehabilitation of atrophic posterior mandible. A serial case reports.

Rehabilitation of patients through implants in areas with severe bone resorption in the posterior mandible is a challenge in implant dentistry. In this context, extra short implants configure a treatment option for this type of patient, as they can avoid increased financial cost, treatment time and patient morbidity. The present study evaluated the marginal bone stability in individualized extra-short implants for masticatory function in the posterior mandible. Using digitized periapical radiographs of 13 extra-short implants performed on 7 patients. The mesial and distal regions of each implant were selected, from the bone crest to the region parallel to the apex, and the bone stability of this crest was measured using the Image J software immediate T1 and 1 year after rehabilitation (T2). The height of the bone crest remained stable, showing no statistically significant difference between T1 and T2 (p> 0.005) for both the mesial bone crest and the distal bone crest in individual or united crowns rehabilitation. Marginal bone stability was observed in extra short implants, corroborating the biological and biomechanical stability of these implants presented in the literature. Despite the limited sample size and proservation time, extra-short implants are predictive treatment options for patients with severe bone atrophy in the posterior mandible. Key words:Extra-short implants, marginal bone loss, mandibular bone atrophy.

Evaluation of Different Heights of Prosthetic Crowns Supported by an Ultra-Short Implant Using Three-Dimensional Finite Element Analysis.

PURPOSE: To apply finite element analysis (FEA) to investigate the stress distribution in a 4-mm-high ultrashort implant when supporting crowns of different heights in order to test the possibility of using this implant unitarily in the posterior edentulous mandible. MATERIALS AND METHODS: Three models of atrophic mandibles were created (M1, M2, and M3). Each model contained a 4-mm-length implant of a titanium-zirconium alloy, screw-type with internal connection, supporting nonsplinted screwed-in crowns of 10, 12.5, and 15 mm in height. Axial and oblique loads were simulated in the three model crowns. RESULTS: In an oblique load, the stress tended to be concentrated in the lingual region. In the qualitative results of the axial load, peaks of tension occurred in the lower angle between the inner groove and the inner conical portion of the implant. Regarding the differences in crown height, the 15-mm height produced a higher stress peak due to the lever effect of the crown under an oblique load. CONCLUSION: Within the limits of this study, the results suggest the possibility of using single crowns of proposed heights with unitary ultrashort implants installed in the posterior edentulous mandible, so long as there is no oblique load on the crown.

Blood clot stability and bone formation following maxillary sinus membrane elevation and space maintenance by means of immediate implant placement in humans. A computed tomography study.

OBJECTIVE: The present controlled clinical pilot study proposed to assess blood clot contraction and bone neo-formation following maxillary sinus lift (MSL) with immediate implant placement without using grafts using cone beam tomography exams. MATERIALS AND METHODS: Ten implants were placed in ten patients with a residual bone crest height ≥4 and ≤ 7 mm, in maxillary premolars or 1st or 2nd molars regions, using MSL and immediate implant placement without grafts, by means of the lateral window approach. A resorbable membrane (Bio-Gide®, Geistlich, USA) was used to close the window. Computed tomography images were taken after 15 (T1) and 180 (T2) days to assess the rate of blood clot contraction and bone neo-formation. The images were analysed by OsirixMD software. The Shapiro Wilk test was used to verify the normality hypothesis and the data were submitted to Student's paired t-test. RESULTS: The mean of bone clot height in mesial, apical and distal area referred to implant, presented 4.77 mm, 0.77 mm and 5.30 mm respectively. The mean measurements of new bone formation presented 2.95 mm, 0.44 mm and 3.45 mm. The height contraction (coagulum/new bone formation), between T1 and T2, presented 38%, 43% and 35% respectively, with a significant statistical value p < 0.05. The volume measurements at T1 presented a mean volume of 0.90 cm3 sd ± 0.60 cm3 and at T2 a mean volume of 0.75 cm3 sd ± 0.62 cm3, with a significant volume contraction between T1 and T2, p < 0.005. The mean blood clot contraction was 16.52% ± 8.60%. CONCLUSION: The present study demonstrates consistent bone formation around all assessed implants, although with significant contraction of the blood clot. The need for longitudinal studies to establish a long-term prognosis in different modalities of prosthetic rehabilitation of those implants is strongly suggested.

Variables related to periodontal disease and peri-implant bone loss / Variáveis relacionadas à doença periodontal prévia e perda óssea peri-implantar

ABSTRACT The replacement of missing teeth by implant retained prostheses is a predictable form of rehabilitation in the population as a whole. Due to thesimilarity between periodontal disease and peri-implantitis, the hypothesis is inferred that patients with a history of periodontal disease would be more susceptible to peri-implantitis. This concept has been discussed and supported by new scientific evidence. The purpose of this review was to evaluate whether there is any relationship between periodontitis and greater peri-implant bone loss in periodontally compromised patients. The pertinent literature has concluded that rehabilitation by means of implants in patients with a history of periodontal disease was predictable and has shown success rates similar to those obtained in patients with no history of periodontitis.

RESUMO A substituição dos dentes ausentes, por próteses implanto retidas, é uma forma previsível de reabilitação na população como um todo. Devido à similaridade da doença periodontal com a periimplantite, infere-se a hipótese de que pacientes com histórico de doença periodontal seriam mais suceptíveis a periimplantite. Este conceito vem sendo discutido e suportado por novas evidencias científicas.O objetivo desta revisão é avaliar se pacientes historicamente periodontalmente comprometidos apresentam relação com maior perda óssea peri-implantar. A literatura pertinente conclui que a reabilitação por meio de implantes em pacientes com histórico de doença periodontal é previsível e com índice de sucesso semelhantes pacientes sem histórico de periodontite.

Importância do complexo osteomeatal no planejamento do levantamento de seio maxilar / Importance of the evaluation of the osteomeatal complex in the planning of maxillary sinus lift

O desvio de septo nasal, concha bolhosa e a obstrução do óstio são alterações do complexo osteomeatal, que podem interferir no volume dos seios maxilares, em sua oxigenação, drenagem adequada de fluidos e nos resultados de cirurgias nessa região. A adoção de um protocolo de avaliação do complexo osteomeatal envolvendo uma equipe multidisciplinar no planejamento de cirurgias de levantamento de seio maxilar pode proporcionar a diminuição do surgimento de complicações pós-operatórias relacionadas à drenagem e ventilação, prejudicadas pelo desvio de septo nasal, concha bolhosa e obstrução do óstio.

Nasal septum deviation, concha bullosa and ostium obstruction are alterations of the osteomeatal complex that may interfere with the volume of the maxillary sinuses, their oxygenation, adequate drainage of fluids and the results of surgeries in this region. The adoption of a protocol for evaluation of the osteomeatal complex involving a multidisciplinary team in the planning of surgeries of maxillary sinus can provide a reduction in the appearance of postoperative complications related to drainage and ventilation impaired by nasal septum deviation, concha bullosa and obstruction of the ostium.

Assessment of Dental Implant Stability in Areas Previously Submitted to Maxillary Sinus Elevation.

This study aimed to compare the primary and secondary stability, measured by resonance frequency analysis (RFA), in implants of different lengths installed in areas submitted to maxillary sinus lift. Correlation between RFA and implant insertion torque was also assessed. Twenty implants of 9 and 11 mm were inserted in areas submitted to maxillary sinus lift. The insertion torque was measured by the Bien Air motor. Osstell, through RFA, determined the implant stability quotient (ISQ) 2 times: the day of implant installation (T1) and 90 days after implant installation (T2). No differences were observed in the ISQ between T1 and T2 when the 20 implants were grouped, nor when the 9 mm implants were evaluated separately. In contrast, when the 11 mm values were evaluated separately, the ISQ was significantly higher in T2 than in T1 ( P < .05). In T1, 9 mm implants had a higher ISQ than 11 mm ones ( P < .05), whereas in T2, the implants of 11 mm showed a higher ISQ than did the 9 mm implants ( P < .05). There was no difference in insertion torque between 9 and 11 mm implants ( P > .05), nor was there a correlation between ISQ and insertion torque ( P > .05). In conclusion, longer implants (11 mm) presented a significant increase in ISQ values during the healing period when installed in areas previously submitted to maxillary sinus lift. This phenomenon was not observed for shorter implants (9 mm). Finally, no correlation was observed between ISQ and insertion torque.

Hyaluronic acid on collagen membranes: An experimental study in rats.

OBJECTIVE: The aim of this study was to evaluate the effect of hyaluronic acid (HA) in the structure and degradation patterns of BioGide® and OsseoGuard™ collagen membranes. HA mediates inflammation and acts in cell migration, adhesion, and differentiation, benefitting tissue remodeling and vascularization. These are desirable effects in guided regeneration procedures, but it is still unknown whether HA alters the barrier properties of absorbable membranes. DESIGN: Bone defects were created in the calvaria of rats, which were treated with HA gel 1% (HA group) or simply filled with blood clot (control group), and covered with BioGide® or OsseoGuard™. The animals were euthanized after 1, 30, and 60days, and their calvarias were processed for histological analysis. RESULTS: BioGide®, in both HA and control groups, showed vascularization, intense cell colonization, bone formation, and tissue integration at 30 and 60days. In contrast, Osseoguard™ presented minimal cellular colonization, and inflammatory reaction associated to foreign body reaction in both time points and groups. The HA group of BioGide® showed higher cell colonization (574.9±137.6) than the control group (269.1±70.83) at 60days (p<0.05). Despite this finding, the structure and degradation pattern were similar for BioGide® and Osseoguard™ in the HA and control groups. CONCLUSION: The results suggest that HA did not interfere with tissue integration and structural degradation of BioGide® and Osseoguard™ membranes.

Vertical augmentation of the posterior atrophic mandible by interpositional grafts in a split-mouth design: a human tomography evaluation pilot study.

OBJECTIVE: Using computed tomography, to compare vertical and volumetric bone augmentation after interposition grafting with bovine bone mineral matrix (GEISTLICH BIO-OSS® ) or hydroxyapatite/tricalcium phosphate (STRAUMANN® BONECERAMIC) for atrophic posterior mandible reconstruction through segmental osteotomy. MATERIAL AND METHODS: Seven patients received interposition grafts in the posterior mandible for implant rehabilitation. The computed tomography cone beam images were analysed with OsiriX Imaging Software 6.5 (Pixmeo Geneva, Switzerland) in the pre-surgical period (T0), at 15 days post-surgery (T1) and at 180 days post-surgery (T2). The tomographic analysis was performed by a single trained and calibrated radiologist. Descriptive statistics and nonparametric methods were used to analyse the data. RESULTS: There was a significant difference in vertical and volume augmentation with both biomaterials using the technique (P < 0.05). There were no significant differences (P > 0.05) in volume change of the graft, bone volume augmentation, or augmentation of the maximum linear vertical distance between the two analysed biomaterials. CONCLUSIONS: The GEISTLICH BIO-OSS® and STRAUMANN® BONECERAMIC interposition grafts exhibited similar and sufficient dimensional stability and volume gain for short implants in the atrophic posterior mandible.

Morphological Analysis of Resorbable Collagen Membranes by Scanning Electron Microscopy.

OBJECTIVE: : The composition and morphology of the internal and external surfaces of membranes are important for preventing migration of epithelial and connective cells, and allow the installation of osteogenic cells for bone growth. The objective of this study was to analyze the morphology and composition of three types of commercially available resorbable collagen membranes. METHODS: Three types of collagen membranes, with different compositions and coming from different animals, were used: 1) Dental Surgidry F (bovine collagen type I); 2) Bio-Gide® (porcine collagen type I and III); and 3) OsseoGuard™ (bovine collagen type I). These membranes were analyzed using scanning electron microscopy and energy dispersive spectrometry. RESULTS: The membranes showed distinct superficial architectures, porosities and chemical compositions. The membranes exhibited different surfaces and thicknesses, ranging from 0.32 mm to 0.75 mm. The chemical compositions exhibited a high percentage of niobium (Nb) in the Surgidry and OsseoGuard™ membranes; the Bio-Gide® membrane showed a greater proportion of calcium and aluminum relative to other elements. CONCLUSION: Different types of resorbable collagen membranes exhibit different morphologies and chemical composition, which could lead to differences in the mode and time of resorption of the membranes used for guided tissue regeneration procedures.