Osseointegration Period Research Articles

The Bone Buttress Theory: The Effect of the Mechanical Loading of Bone on the Osseointegration of Dental Implants.

Simple SummaryThe bone, as a vertebrate support tissue, is capable of adapting its structure and function to the mechanical demands resulting from the loads that are produced during the performance of its activity. This regulatory action also occurs during the healing processes of a fracture. The purpose of this study was to determine to what extent a dynamic load was capable of modulating the bone healing response around a titanium implant. The study was carried out on experimental rabbits, to which dental implants were placed in the tibiae and there were two test groups, one in which they did not undergo exercise during healing period and another that ran daily during this process on a treadmill. The trail results showed an improvement in the osseointegration process of the implant in the group in which it was subjected to load. The importance of these results is that it opens the door to a better understanding of the mechanisms that can modulate bone healing, especially around dental implants, supporting implant loading protocols that are based on efficiency.Objectives: To determine the effect of mechanical loading of bone on the stability and histomorphometric variables of the osseointegration of dental implants using an experimental test in an animal model. Materials and Methods: A total of 4 human implants were placed in both tibiae of 10 New Zealand rabbits (n = 40). A 6-week osseointegration was considered, and the rabbits were randomly assigned to two groups: Group A (Test group) included 5 rabbits that ran on a treadmill for 20 min daily during the osseointegration period; Group B (Controls) included the other 5 that were housed conventionally. The monitored variables were related to the primary and secondary stability of the dental implants (implant stability quotient—ISQ), vertical bone growth, bone to implant contact (BIC), area of regenerated bone and the percentage of immature matrix. Results: The results of the study show a greater vertical bone growth (Group A 1.26 ± 0.48 mm, Group B 0.32 ± 0.47 mm, p < 0.001), higher ISQ values (Group A 11.25 ± 6.10 ISQ, 15.73%; Group B 5.80 ± 5.97 ISQ, 7.99%, p = 0.006) and a higher BIC (Group A 19.37%, Group B 23.60%, p = 0.0058) for implants in the test group, with statistically significant differences. A higher percentage of immature bone matrix was observed for implants in the control group (20.68 ± 9.53) than those in the test group (15.38 ± 8.84) (p = 0.108). A larger area of regenerated bone was also observed for the test implants (Group A 280.50 ± 125.40 mm2, Group B 228.00 ± 141.40 mm2), but it was not statistically significant (p = 0.121). Conclusions: The mechanical loading of bone improves the stability and the histomorphometric variables of the osseointegration of dental implants.

The influence of implant design on the kinetics of osseointegration and bone anchorage homeostasis

Titanium implants have shown considerable success in terms of achieving quick and long-lasting stability in bone through the process of osseointegration. Further work aims to improve implant success rates by modifying implant design on the nano-, micro-, and macro- scales with the goal of achieving higher levels of bone anchorage more quickly. However, the most frequently used methods of analysis do not investigate bone anchorage as a whole but as a series of discrete points, potentially missing relevant insight which could inform the effects of topography on these 3 scale ranges. Herein we utilize an asymptotic curve fitting method to obtain a biologically relevant description of reverse torque data and compare the anchorage of 12 different implant groups. Implant surface topography had a significant effect on the rate and degree of anchorage achieved during the initial bone formation period of osseointegration but was not found to influence the relative change in anchorage during bony remodeling. Threaded implants significantly decreased the time required to reach peak anchorage compared to non-threaded implants and implants with micro-topographically complex surfaces required greater torque to be removed than implants without such features. Nanotopography increased overall anchorage and decreased the time required to reach peak anchorage but to a lesser degree than microtopography or macrogeometry respectively. The curve fitting method utilized in the present study allows for a more integrated analysis of bone anchorage and permits investigation of osseointegration with respect to time, which may lead to a more targeted approach to implant design.

Stability and marginal bone loss in implants placed using piezoelectric osteotomy versus conventional drilling: systematic review and meta-analysis.

Background The main objective of this systematic review was to compare primary and secondary implant stability between placement with piezoelectric osteotomy and conventional drilling, comparing marginal bone losses as a secondary objective. Material and Methods An electronic search was conducted using PubMed (MEDLINE), Scopus, and Cochrane Library (Wiley) databases, besides a manual search. Results A total of 153 articles were retrieved, 39 from Pubmed, 44 from Scopus, and 70 from the Cochrane Library. After removing duplicates, 112 articles (1 from the manual search) were screened, and 9 were finally selected for qualitative and statistical analyses. Conclusions Piezoelectric surgery is a predictable alternative to conventional drilling for dental implant placement. Medium/long-term survival rates and marginal bone losses are similar between piezoelectric osteotomy and conventional drilling, and there is no difference in ISQ values for primary stability. However, implants placed with ultrasound showed a lower decrease in implant stability quotient (ISQ) during the osseointegration period and a higher ISQ value for secondary stability. This study contributes further information on peri-implant bone tissue at 3 and 6 months after implant placement with piezoelectric osteotomy or conventional drilling and provides an updated meta-analysis of comparative studies. Key words:Piezosurgery, piezoelectric surgery, conventional drill, implant site preparation, dental implant, implant stability, marginal bone loss.

Modifications of Titanium and Zirconium Alloy Surfaces for Use as Dental Implants

The use of dental implants of titanium and its alloys has proved to be effective, through well established and documented parameters, both in the dimensions and in the manufacturing processes and also in the surgical techniques. There are clinical situations where there is a need to reduce the diameter of the implants, below 3.75 mm in diameter. In the current state of art of the implant technology it is desirable that these also have surfaces capable of decreasing the period of osseointegration. In the present work, to improve the mechanical strength of the material, an alloy of 80% of Ti and 20% of Zr % in mass was proposed and elaborated, aiming its use as biomaterial. Physical, chemical, microstructural and mechanical characterization was carried out. The surfaces of the treated samples were observed using: scanning electron microscopy (SEM); semi quantitatively chemically analyzed using dispersive energy spectroscopy (EDS: wettability of the samples was determined and, finally, the roughness was measured using optical profilometry. For the conditions used in the present work, it was concluded, that the best surface treatment for the TiZr 80/20 alloy was acid etching with 1% vol. hydrofluoric acid for 5 minutes, as this treatment presented the most prominent results of wettability and roughness simultaneously.

The Influence of Implant Design on the Kinetics of Osseointegration and Bone Anchorage Homeostasis

Titanium implants have shown considerable success in terms of achieving quick and long-lasting stability in bone through the process of osseointegration. Further work aims to improve implant success rates by modifying implant surface design and geometry on the nano-, micro-, and macro- scales with the goal of achieving higher levels of bone anchorage more quickly. However, the most frequently used methods of analysis do not investigate bone anchorage as a whole but as a series of discrete points, potentially missing out on relevant insight which could inform the effects of topography on these 3 scale ranges. Herein we utilize an asymptotic curve fitting method to obtain a more biologically relevant description of reverse torque data and compare the anchorage of 12 different implant groups. Implant surface topography had a significant effect on the rate and degree of anchorage achieved during the initial bone formation period of osseointegration but was not found to influence the relative change in anchorage during bony remodeling. Threaded implants significantly decreased the time required to reach peak anchorage compared to non-threaded implants and implants with micro-topographically complex surfaces required a greater torque to be removed than implants without micron scale features. Nanotopography increased overall anchorage and decreased the time required to reach peak anchorage but to a lesser degree than microtopographically complex surfaces or threaded implants respectively. The curve fitting method utilized in the present study allows for a more integrated analysis of bone anchorage over time and allows for investigation of specific stages of osseointegration which may lead to a more targeted approach to implant design.

Dual delivery of platelet-derived growth factor and bone morphogenetic factor-6 on titanium surface to enhance the early period of implant osseointegration.

To test the surface properties and in vitro effects of a new sequential release system on MC3T3-E1 cells for improved osseointegration. BMP6-loaded anodized titanium coated with PDGF containing silk fibroin (SF) may improve osseointegration. Titanium surfaces were electrochemically anodized, and SF layer was covered via electrospinning. Five experimental groups (unanodized Ti (Ti), anodized Ti (AnTi), anodized+BMP6-loaded Ti (AnTi-BMP6), anodized+BMP6 loaded+silk fibroin-coated Ti (AnTi-BMP6-SF), and anodized+BMP6-loaded+silk fibroin with PDGF-coated Ti (AnTi-BMP6-PDGF-SF)) were tested. After SEM characterization, contact angle analysis, and FTIR analysis, the amount of released PDGF and BMP6 was detected using ELISA. Cell proliferation (XTT), mineralization, and gene expression (RUNX2 and ALPL) were also evaluated. After successful anodization and loading of PDGF and BMP6, contact angle measurements showed hydrophobicity for TiO2 and hydrophilicity for protein-adsorbed surfaces. In FTIR, protein-containing surfaces exhibited amide-I, amide-II, and amide-III bands at 1600cm-1 -1700cm-1 , 1520cm-1 -1540cm-1 , and 1220cm-1 -1300cm-1 spectrum levels with a significant peak in BMP6- and/or SF-loaded groups at 1100cm-1 . PDGF release and BMP6 release were delayed, and relatively slower release was detected in SF-coated surfaces. Higher MC3T3-E1 proliferation and mineralization and lower gene expression of RUNX2 and ALPL were detected in AnTi-BMP6-PDGF-SF toward day 28. The new system revealed a high potential for an improved early osseointegration period by means of a better factor release curve and contribution to the osteoblastic cell proliferation, mineralization, and associated gene expression.

The effects of a nonsteroidal anti-inflammatory drug on the degree of titanium implant osseointegration

ObjectiveThe aim of this study was to histologically examine the effects of a nonsteroidal anti-inflammatory drug, namely diclofenac sodium (DCS), on the extent of the bone–implant contact (BIC) of titanium implants after four weeks of osseointegration period in a rodent model. Material & methodsFourteen female Sprague-Dawley rats were divided into two groups: the control (n = 7) and experimental (DCS) groups. Fourteen machine-surfaced titanium implants were placed in the right tibial bones of the rats. The DCS (2 mg/kg) was administered by means of oral gavage to the experimental group for 14 days after four weeks of osseointegration. No medication was administered to the control group throughout the six-week study period. At the end of the study, the rodents were sacrificed and block sections were obtained for histologic evaluation. ResultsThe mean BIC ratios for the control and DCS groups were 64.15 ± 6.31% and 61.10 ± 6.08%, respectively. No statistically significant difference in terms of the BIC ratios was found between the two groups. ConclusionThe results of this study demonstrate that DCS did not impair the BIC of the implants after four weeks of osseointegration.

RADIOGRAPHIC EVALUATION OF CRESTAL BONE RESORPTION DURING HEALING &amp; LOADING PERIOD IN IMPLANT SUPPORTED OVERDENTURE BY PLACING IMPLANT THROUGH FLAP TECHNIQUE- IN VIVO STUDY

Aim: The aim of this study was to detect the effect of flap technique on crestal bone resorption during healing and loading period in implant supported overdentures.&#x0D; Material and Methods: A total of 8 patients, 5 male and 3 female, ranging from 50 to 70 years of age, having completely edentulous maxillary and mandibular arches were selected for the study the whole study was conducted in 4 phases. In the 1st phase Clinical Diagnosis, Treatment Planning &amp; Denture Fabrication was done. The selected subjects will be diagnosed and treatment planning for new denture fabrication was done. In the 2nd phase the denture insertion was done and if required occlusal correction was be performed. After initial recall visit, patient was recalled again after one week of denture usage. In this visit 1st stage of implant surgery was conducted. Dental implant in the mid symphyseal region was placed following all the surgical protocols. Immediately after surgery first IOPA with RVG was taken. After the surgery the denture was relieved at the surgical site and patient was asked to use the same denture. Subsequently after 4 weeks and after 12 weeks of healing the second and third IOPA with RVG was taken. The computer software was used for measuring the bone level. After 3 months of Osseointegration period in phase 3, the loading of the implant was done by incorporating O ring attachment. Again after 4 weeks and after 12 weeks of loading the fourth and fifth IOPA with RVG was taken. The magnification error was checked. The data obtained was saved using Paint software used in Microsoft 8.1. The data so obtained for measuring the bone levels with the help of computer software (RVG 5100) was tabled and statistical analysis was done.&#x0D; Results: The mean rate of crestal bone loss with time was more during first month (0.35mm) then it decreased in 3rd month (0.51mm) and further decreased during 4th month (0.59mm) and 6th month (0.70mm) follow up period.&#x0D; Conclusion: The concept of single implant supported overdentures provides another option for completely edentulous elderly patients with severely resorbed mandibular ridge &amp; with economic constraints in developing countries.&#x0D; Keywords: Dental implants, Overdenture, Residual Alveolar Ridge, Crestal Bone loss, Intraoral Digital Radiography (RVG 5100).

The Effect of Age of Titanium Dental Implants on Implant Survival and Marginal Bone Resorption: A 5-Year Retrospective Follow-Up Study.

It has been demonstrated that the osteoconductivity, hydrophilicity, and biological capacity of titanium decreases over time, and this phenomenon was described as the biological aging of titanium. The aim of this study was to evaluate whether the age of sand-blasted and acid-etched (SLA) titanium dental implants (duration from the production date until the date of dental implant surgery) affects marginal bone resorption and implant survival. This nonrandom convenience-sample retrospective pilot study was carried out in 200 implants of 64 patients. Radiographic measurements were performed on intraoral periapical radiographs. Implants were divided into 2 age groups; group 1 = 0-3 months and group 2 = 36-41 months. A P value < .05 was considered statistically significant. Of the implants, 41% (n = 82) were between 0 and 3 months old, and 59% (n = 118) were between 36 and 41 months old. All (n = 200) of the implants survived and maintained their function. The mean mesial marginal resorption measurement was 0.60 ± 0.65 mm, and the mean distal marginal resorption was 0.77 ± 1.07 mm. There was no statistically significant difference between the amount of mesial and distal marginal bone resorption according to implant age (P > .05). In SLA surface titanium implants with adequate initial primary stability and a 3-month osseointegration period before loading, biological aging of titanium did not affect implant survival and marginal bone resorption.

Full-staged digital and prosthetic guided protocol for the insertion of dental implants in autogenous free bone grafts after reconstruction of segmental mandibular defects.

This study aims to evaluate the clinical and radiographic outcomes of dental implants, inserted in consolidated free bone grafts; postsegmental mandibular resection, after following a fully guided staged protocol, which established a systematic approach that correlates the grafted bone and the enclosed implants to the undisturbed mandibular segments and the maxillary occlusal plane. Seven patients were enrolled in the study; all were diagnosed for mandibular locally aggressive tumors. All of the patients were subjected to computer-guided segmental mandibular resections, secondary free iliac crest bone graft; aided by computer-guided harvest and prosthetic guidance of the graft positioning and fixation. Finally, the guided bone grafts; after being consolidated, received twenty-nine computer-guided dental implants. By the end of the period of osseointegration, the predetermined criteria of implant success judged the success of twenty-five implants, versus the failure of four implants, with (86.2%) percentage of success. The clinical and radiographic assessments demonstrated sound base bone grafts, which succeeded not only to restore the native mandibular continuity and configuration but also to direct the fair-sized embedded dental implants into favorable coastal locations and axial projections, which influenced a smooth prosthetic rehabilitation.

Evaluation of Implant Overdenture Retention with Two Different Attachments at 23mm Standard Inter-Implant Distance

Purpose: Evaluation of implant overdenture retention at 23mm standard inter-implant distance using OT Equator and locator attachments. Materials and methods: Twelve completely edentulous patients were selected for this study. For all patients, conventional complete dentures were constructed. Mandibular dentures were replicated into stereolithographic implant placement guide using CBCT. Every participant received 2-implants in the anterior mandibular area with inter-implant distance of 23 mm. After the osseointegration period, the mandibular conventional dentures were converted into implant retained overdentures attached with Locator attachment for (group I) (six patients) and OT Equator attachments for (group II) (six patients). Retention was evaluated for conventional mandibular complete dentures (T0), 3-months (T3) and, 6-months (T6) after overdenture insertion using digital force-meter. Results: Results revealed that there was a statistically significant difference between the study groups representing mean retention force (P&lt;0.05) except at T0 (baseline evaluation with conventional dentures) with higher mean values for group I (Locator attachment) than group II (OT Equator attachment). Conclusion: Regarding the limitations of this study: -Inter-implant distance of 23 mm for 2-implant overdentures could be considered a reliable modality for edentulous mandible. -Locator attachment may be preferable than OT Equator attachment regarding 2-implant overdenture retention at 23 mm inter-implant distance.

Titanium-Prepared Platelet-Rich Fibrin Versus Connective Tissue Graft on Peri-Implant Soft Tissue Thickening and Keratinized Mucosa Width: A Randomized, Controlled Trial

The health of peri-implant tissues is associated with the peri-implant soft tissue thickness (STT) and keratinized tissue width (KTW). Resorptive changes in the crestal bone around implant sites will be affected by the STT. The present randomized prospective study compared the effectiveness of titanium-prepared platelet-rich fibrin (T-PRF) with that of connective tissue graft (CTG) on peri-implant STT, KMW, and crestal bone level. Through simultaneous augmentation of the soft tissue using T-PRF or CTG, 30 implants were placed in 30 patients. The implants were placed in thin, soft tissue areas and thickened simultaneously with a T-PRF membrane in the test group and a CTG in the control group. During surgery (T0) and at 3months postoperatively (T1), the KTW and peri-implant STT were measured at 3 points: occlusal part of the alveolar crest (OAC), midbuccal mucosa level (MBML), and 1mm above the mucogingival junction (MGJ1). The crestal bone changes were evaluated from a periapical radiograph at 3months postoperatively. The baseline STT and KTW measurements showed no significant differences between the 2 groups (P<.05). Comparison of the T0 and T1 measurements from the 2 groups showed a significant increase in KTW and STT (P<.001). Compared with the test group, the control group showed a highly significant increase in the peri-implant STT at the MBML, MGJ1, and KTW levels (P<.05). No significant difference was found between the 2 groups in terms of the OAC changes (P>.05). No crestal bone loss was observed in any of the dental implants. Both groups experienced a greater increase in peri-implant STT at the OAC level, and T-PRF can be considered as an autogenous alternative to CTG. Also, peri-implant STT might prevent crestal bone resorption in the osseointegration period.

Effect of high glucose levels and lipopolysaccharides-induced inflammation on osteoblast mineralization over sandblasted/acid-etched titanium surface.

Poorly controlled diabetes mellitus has been related to higher risk of implant treatment complications due to increased susceptibility to infection and delayed wound healing. Lipopolysaccharides (LPS) stimulate cytokine production leading to chronic inflammation and immunological host response that accentuates the destruction of periodontal tissues. This study aimed to evaluate the effect of different glycemic conditions on secretion and mineralization of bone matrix under sterile inflammation induced by LPS on osteoblasts seeded over sandblasted/acid-etched (SLA) titanium surface. Osteoblast cell viability was performed to determine the influence of different glucose concentrations (5.5, 8, 12, and 24 mM), which were chosen to reflect normal, postprandial, and high glucose values, similar to those typically seen in Diabetes mellitus under clinical conditions. Cells were seeded on titanium SLA discs (Straumann AG, Waldenburg, Switzerland) and exposed to glucose concentrations and LPS (1μg/mL) in order to test inflammatory response (qPCR) and mineralization (Alizarin Red staining). Osteoblast viability was severely decreased when exposed to higher glucose levels (≥12 mM) and LPS (P < .05) compared to control. When the osteoblasts were exposed to LPS and glucose at ≥8 mM, the gene transcripts of inflammatory cytokines were ≈2.5-fold upregulated, while ≤8 mM glucose elicited no significant change compared to control without glucose treatment (P > .05). Osteoblasts exposed to LPS produced sparse extracellular matrix mineralization, especially combined with higher glucose values (≥12 mM), together with decreased calcium deposition compared to control (P < .05). High glucose levels combined with LPS inflammatory stimulation elicited an adverse effect on the volume and quality of mineralized hard tissue formation on SLA titanium surfaces in vitro. Hence, both normal glucose levels and infection control including low levels of circulating LPS during initial osseointegration period may be required to increase the success rate of dental implants.

A 22-Year Follow Up of Immediate Implant Placement without Bone Augmentation: A Case Series Study.

To retrospectively evaluate the treatment outcome of immediate implants placed in fresh extraction sockets without bone augmentation after 22 years of function. The study group received implant therapy in 1997, including surgical placement and prosthodontic rehabilitation. The mean age of the subjects at the time of implant placement was 40 ± 5.54 years. A total of 35 subjects received 36 implants in fresh extraction sockets without bone augmentation. Definitive prostheses were placed 4 to 6 months after implant placement. Implant treatment outcomes were evaluated using clinical and radiographic parameters obtained during follow-up visits at 1, 5, 10, 15, 20, and 22 years after prosthetic loading. Among the 35 treated subjects, five patients moved out of the country and could not be evaluated at the follow-up times. A total of 29 subjects were included in the study with a drop-out rate of 14.1%. Of these, one patient lost the implant during the osseointegration period before prosthodontic treatment. No other implant failure or complication during the rest of the follow-up period was reported, thus giving a cumulative survival rate of 97.2% during the 22-year follow-up. The change in marginal bone level was less than 2 mm in most subjects at the 22-year examination. The mean bone loss from baseline to 22-year follow-up was 1.61 mm, and the mean bone level at the 22-year follow-up examination was situated at 2.13 ± 0.023 mm from the implant platform, which was used as the reference point. Immediate implant placement in extraction sockets exhibits excellent prognosis even when bone augmentation is not performed.

Influence of Resonance Frequency Analysis (RFA) Measurements for Successful Osseointegration of Dental Implants During the Healing Period and Its Impact on Implant Assessed by Osstell Mentor Device.

AIM:This study aimed to investigate and assess primary and secondary dental implant stability during the osseointegration period.METHODS:A total of 77 implants were placed in 42 patients with 26 males and 16 females. The study was conducted by comparing the resonance frequency analysis (RFA) values of the implants inserted in the lower jaw. RFA was done immediately after implant insertion and after 12 weeks. Results were statistically evaluated using SPSS Statistics for Windows, Version 7.1. Level of significance was set at P < 0.05.RESULTS:Significant differences were detected between the primary and secondary stability values, respectively. Maximum RFA value of 88 and the minimum value of 52 were observed. Stability values increased during the following three months, and all implants were successfully integrated without complication.CONCLUSION:Our results indicate and suggest that there is a strong linear correlation between implant stability and ISQ values that can be directly estimated by the RFA, especially in the posterior edentulous mandible. Osstell implant device could represent a useful tool which can be used to identify the risk for implant failure.

Previous reconstruction of severely atrophic maxilla with calvarial bone graft and implant supported fixed partial prosthesis - Case report

Purposes: Autogenous bone graft is still considered the “gold standard” for bone augmentation of the jaws prior to dental implants placement. In cases of major bone defects, we can relinquish reconstructive techniques using grafts from extra buccal donor areas, such as the calvarial bone graft. Although this technique is well established in the literature, many professionals feel insecure in indicating this type of treatment to their patients, due to the high degree of complexity for the execution of the procedure and not acceptance by the patient. Case report: A female patient, 42-year-old, had undergone reconstructive surgery by means of a calvarial bone graft for pre-maxilla reconstruction prior to dental implants placement in regions of 14 to 24. The graft collection procedure was performed in a hospital setting and under general anesthesia. The grafts were transplanted from the calvarial bone to reconstruct the anterior maxilla. After 7 months, 4 dental implants were placed, allowing a future prosthetic rehabilitation. After the period of osseointegration, screw-retained partial fixed prosthesis was made, returning function and aesthetics to the patient. Conclusions: In view of the clinical case and literature presented, it is concluded that patients with severe maxillary bone atrophy can undergo a successful reconstruction process with calvarial bone grafts and dental implants.

Implant-supported metal-ceramic and resin-modified ceramic crowns: A 5-year prospective clinical study

Statement of problemBecause of market demand for innovation, new restoration materials have been introduced without adequate testing; clinical failure may be the consequence, and clinical studies are needed. PurposeThe purpose of this clinical study was to evaluate the biological and mechanical clinical behavior of implant-supported resin-modified ceramic crowns compared with that of metal-ceramic crowns. Material and methodsForty-two participants aged between 35 and 65 years received single implants in posterior edentulous sites. After the osseointegration period, half of the implants (selected randomly) (n=25) were restored with metal-ceramic crowns (MC group) and the other half with resin-modified ceramic crowns (RMC group) bonded with dual-polymerized resin cement onto titanium abutments. The biomechanical state of the restorations and implants was analyzed. ResultsMean peri-implant bone loss after 5 years of functional life was 0.3 ±0.6 mm. The implant clinical survival rate was 98%. RMC crowns had a survival rate of 70%, whereas MC crowns had a 100% survival rate. RMC crowns had more mechanical complications than the MC group (P<.001). Peri-implant bone loss showed no significant differences between crown type (P=.175). ConclusionsAll peri-implant bone loss values were within the range considered acceptable. Metal-ceramic crowns showed better mechanical behavior than resin-modified ceramic crowns. Biological responses of peri-implant tissue would appear to be independent of the type of cemented crown.

RELAÇÃO ENTRE DIABETES MELLITUS E O PROCESSO DE OSTEOINTEGRAÇÃO DE IMPLANTES DENTÁRIOS

introdução: Os implantes osseointegráveis permitiram um grande avanço da odontologia na reabilitação de áreas edêntulos, restabelecendo a função, estética e fonética. Quando a osseointegração está prejudicada ocorre uma falha na qualidade óssea e aposição de tecido fibroso cicatricial entre osso/implante, que pode resultar em mobilidade ou até mesmo a perda do implante. Fatores sistêmicos e locais podem interferir nos eventos celulares que atuam para que ela ocorra. A Diabetes Mellitus, é uma doença metabólica, que exerce uma influência negativa na formação e remodelação óssea. Objetivos: Trazer um levantamento bibliográfico sobre o processo de osseointegração versus a diabetes mellitus. Metodologia: Foi realizado uma varredura nos portais de indexação Web of Scienes e Scopus e foram encontrados 20.000 artigos referentes ao tema. Selecionou-se 50 artigos com maior fator de impacto e citscore. Conclusão: O diabetes não é uma contraindicação absoluta para a colocação de implantes dentários. O importante é o paciente a ser implantado nestas condições mantê-la controlada especialmente durante o período de osseointegração e que haja a administração de antibióticos antes e após a cirurgia e ainda a prescrição de bochechos de clorexidina a 0,12% durante duas semanas após o procedimento cirúrgico. Palavras Chaves: Osseointegração, Diabetes Mellitus. Implantes Osseointegráveis

Reconstruction and Implant-Supported Rehabilitation of an Iatrogenically Caused Maxillary Alveolar Defect.

Defects of the oral and maxillofacial region may arise from several reasons such as trauma, infection, cyst, tumor, medication related osteonecrosis of the jaw, and misuse of some irritant agents. For reconstruction, autogenous grafts remain the gold standard among the alternatives. In our case, a 42-year-old woman referred to our clinic for implant-supported fixed bridge rehabilitation of her edentulous and defected left 2nd premolar and 1st molar region. In examinations, devitalizing agent-dependent large defect was observed. Anterior iliac crest (AIC) grafting technique was preferred for reconstruction. Consecutively, 16-week bone healing and 3-month implant osseointegration periods were uneventful. After fabrication of the implant-supported fixed bridge, the patient was followed up for 2.5 years with no signs of bone resorption, gingival inflammation, and pain. AIC grafting and implant-borne fixed bridges seem stable and satisfactory methods for large maxillofacial defects.

REHABILITATION OF PATIENTS WITH BOUNDED EDENTULOUS SPACES BY NON-REMOVABLE DENTURE STRUCTURES SUPPORTED BY DENTAL IMPLANTS IN CONDITIONS OF INSUFFICIENT BONE MINERAL DENSITY

The state of dental implantation is characterized by high efficiency and a significant spectrum of possibilities when replacing dentition defects. At the same time, prevention of complications of dental implantation associated with the loss of bone tissue around dental implants is of great importance are gaining. It leads to a reduction of both the durability and the period of use of orthopaedic structures supported by dental implants. The aim of the study was to increase the effectiveness of orthopaedic treatment of patients with bounded edentulous spaces with the help of non-removable denture structures supported by dental implants. 49 patients aged 30 to 44 years with bounded edentulous space in the upper jaw were examined using clinical (examination, palpation, percussion) and special (computed tomography, resonance-frequency analysis of implant stability) diagnostic methods. Patients were placed 68 dental implants. After 6 months of the osseointegration period, all patients were divided into two groups according to the choice of loading protocol by permanent orthopaedic structures. Six months after the implants were placed, bone loss was observed in patients from both study groups at the level of 0.823 ± 0.029 mm and 0.612 ± 0.022 mm. The greatest changes regarding the stability of dental implants were noted in patients of both groups in a year. Thus, in group I, where patients had metal ceramic crowns, 6 months after implantation a statistically significant loss of bone tissue (1.297 ± 0.049 mm) was noted. The maximum value reached 1.8 mm. And in group II, where orthopaedic treatment was performed by gradually increasing the occlusal load on the dental implant, a statistically significant (p <0.05) increase in the investigated index (0.651 ± 0.038) was not observed. The gradual load on the dental implant, in conditions of insufficient bone mineral density, helps to maintain a constant amount of bone around it and prolong the life of the orthopedic structure in general.