Greater Primary Stability Research Articles

Major approaches and clinical outcomes of bone regeneration for dental implants: a systematic review

Introduction: In the last decades, the number of dental implant procedures has increased in the world, with about 1.0 million dental implants per year. When a tooth is lost in the posterior region of the maxilla, there is a natural resorption of the alveolar process. There are several surgical techniques that can be used to reconstruct the atrophic alveolar ridge. Objective: A systematic review was carried out to present the key considerations of bone regeneration and bone, cellular and molecular grafts for adequate bone formation for successful dental implants. Methods: The present study followed a systematic review model, following the rules of systematic review – PRISMA. The search strategy was performed in the PubMed, Cochrane Library, Web of Science and Scopus, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: The total of 132 articles were found. A total of 74 articles were fully evaluated and 31 were included in this study. Normal bone formation and tissue repair involve coordinated interaction between bone-forming cells and biological signals. TNF-α stimulates bone and cartilage resorption and inhibits collagen and proteoglycan synthesis. IL-1 induces the expression of a wide variety of cytokines. LIF and IL-6 are two such molecules that are known to stimulate the differentiation of mesenchymal progenitor cells into the osteoblastic lineage. The bioactivation of the dental implant surface with FRP has been described and discussed by the scientific community as a surface treatment for the stimulation and acceleration of the osseointegration process, as well as to achieve greater primary stability to the implant. The combination of FRP and Bio-Oss® has been studied with good clinical results, reducing healing time from 180 days to approximately 106 days. The use of bone grafts significantly improves the residual alveolar ridge regardless of the membrane used. Furthermore, implants placed in fresh extraction sockets with and without elevation of the mucoperiosteal flap can be successfully performed with augmentation procedures.

Influências dos perfis das roscas dos implantes osseointegráveis

In the manufacturing of osseointegrated dental implants there is no technical standard that defines the body shape and the threads fillets profiles (spirals). Dental implant manufacturers develop implant shapes to increase the implant-bone contact surface area, to improve primary stability, and to promote better distribution of oral forces to bone. The aim of this study was to characterize the dental implant of thread fillets profiles made in Brazil and to analyze the influence on primary stability and force distribution on the implant-bone interface. Seven groups of dental implants with cylindrical (Master Screw®), conical (Flash®, Master Grip®, and Conect Conic®), and hybrid (Easy Grip®, AR-Torq®, and AR Morse®) body shapes were inserted in polyethylene, polyurethane, and in swine bone. The results showed that tapered implants present greater primary stability, the threads profiles must be rounded, the square thread induces highest compressive stresses in the bone, and the microthreads in the cervical reduce the concentration of stresses.

Osseodensificação em maxila atrófica para posterior instalação de implantes dentários

A colocação de implantes na maxila apresenta particularidades diferentes das encontradas na mandíbula. Um dos desafios da instalação dos implantes mais freqüente é a atrofia da maxila após a perda parcial ou total das unidades dentárias. Como resultado há uma diminuição significativa na altura e volume do osso disponível na região posterior da maxila. Atualmente diversas técnicas são empregadas para melhora na qualidade óssea e consequentemente a estabilidade primária do implante, desde as consagradas como a técnica da expansão óssea de Summers, por meio de osteótomos, quanto as mais atuais como a osseodensificação através de brocas multilaminadas DensahÒ Bur, que consiste na condensação das paredes do tecido ósseo confeccionado durante o preparo. O objetivo do trabalho foi apresentar um caso clínico com a utilização da técnica de osseodensificação na maxila atrófica, para posterior instalação de implantes dentários na maxila sem a utilização da técnica de Summers e enxertos ósseos. Após a colocação dos implantes foi utilizado o Osstell® para avaliação da estabilidade primária. Concluímos que a osseodensificação é uma nova técnica de preparação biomecânica que mantém a integridade do rebordo alveolar e permite a colocação de implantes com maior estabilidade primária, permite uma menor morbidade e um menor tempo para finalização do tratamento reabilitador.

Estabilidade primária do implante dental

Primary stability derives mainly from mechanical involvement with the cortical bone and the lack of mobility in the bone bed at the insertion of the implant and depends on the quantity and quality of the bone, the surgical technique, and the design of the implant. The titles were captured in the database PubMed, Scielo, and relevant Brazilian magazines to identify the primary stability, after the insertion of the implant in the region indicated in the protocol. Tapered implants showed greater primary stability compared to cylindrical implants, when placed under bone density conditions. The geometry of the implant is an important factor in the degree of primary stability. Based on this, large threads are desirable in cases of poor bone quality. The insertion torque values are very important for the clinical determination of the levels of primary stability and the absence of micro movements whenever an immediate load is applied. The implant, used as if it were the last cutter, when correctly inserted, penetrates with pressure in the bone store if its diameter is larger than that of the cutter perforation. The implant design plays an influential role in achieving its primary stability.

Examination of the influence of a reverse tapered body shift on the mechanical performance of dental implants in extraction sockets

Background As a result of continuous development, changes in the macro geometry of dental implants over time have had a profound influence on their mechanical behaviour and the osseointegration process. Aim/Hypothesis The objective of the present in vitro study was to evaluate the mechanical performance of dental implants with macro geometric changes to the apical region, relative to conventional implants. Material and Methods Comparative insertion torque measurements were conducted between conventionally tapered implants and the newly designed reverse tapered body shift implants (see Figure 1). All implants were placed in simulated extraction sockets created in orthopaedically-certified synthetic bone blocks with a density of 0.32 g/cm3. The simulated extraction sockets were created by drilling a 5 mm deep osteotomy with a diameter of 5.3 mm, to ensure that the coronal section of the implants had no influence on the insertion torque performance. Thereafter, the osteotomies for the implants were prepared as per the manufacturers guidelines. For the sake of comparison, all implants had a total length of 11.5 mm and a coronal diameter of 3.0 mm, whereas the newly designed implant had a reverse tapered body shift with a diameter of 3.5 mm. Results In total, 40 insertion torque measurements were recorded (20 in the control group and 20 in the test group). The average insertion torque for the conventionally tapered implants was 8.45 Ncm (SD = 0.69), whereas the average insertion torque in the test group was 12.55 Ncm (SD = 1.61). To convert these in vitro results to a more clinically relevant situation, the percentage increase in insertion torque between the two groups was calculated. On average, the newly designed reverse taper body shift implant achieved 49% greater insertion torque, compared with a conventional implant of the same coronal diameter and length. Conclusions and Clinical Implications Reverse tapered body shift implants achieve an average of 49% greater primary stability in extraction sockets than conventionally tapered implants with the same coronal diameter and length. This may overcome issues with primary stability in cases of immediate placement. FIGURE 1

Stability of Osseointegrated Bone Conduction Systems in Children

To obtain objective data of bone conduction implant stability and osseointegration in children; to compare in pediatric subjects the stability and osseointegration of the novel TiOblast-coated implant system (BI300) to the previous generation, as-machined model. Multicenter, controlled, nonrandomized, longitudinal, prospective study. Tertiary referral center. IIIb Ten subjects were enrolled, aged younger than 16 years and without comorbidities that negatively affect osseointegration. All patients were implanted "single stage": 5 received the previous generation, pure titanium fixture (control group), and 5 were implanted the BI300, TiOblast-coated fixture (test group). Measurement of implant stability and osseointegration. Implant stability and osseointegration as measured by means of resonance frequency analysis intraoperatively, at 1 week, 2 weeks, 1 month, and every month till processor loading 6 months after surgery. BI300 is, on average, more stable than the control fixture, both intraoperatively and over time till processor loading. Over the 6 months' follow-up, a stability increase was observed with both models, although it resulted statistically not significant. The BI300 implant system has a greater primary stability as compared with the previous generation model, but its faster osseointegration could not be definitely verified. It is reasonable to assume that the BI300 fixture will enable surgeons to perform single-stage surgery more safely and with a lower failure rate. The possibility of an earlier processor loading remains to be confirmed in a greater sample.