Mapping the osseointegration using immuno-driven biological processes: evidences from a systematic review and a randomized clinical trial with focus on occlusal loading of implant-retained mandibular overdentures wearers

The dental implant osseointegration occurs due to the process triggered by the host immune response, however the biomarkers that modulate this process have not yet been determined. In order to investigate and understand ossointegration through the biomarkers, two studies were designed: I) Systematic Review (SR) focusing on the evaluation of peri-implant crevicular fluid collection (FCPI) during bone healing after dental implants insertion; II) Longitudinal Randomized Clinical Trial according to the occlusal loading, immediate (IML) or conventional (CL), of implant retained mandibular overdentures. The study II evaluated the clinical and biological behavior of narrow diameter implants (NDR) osseointegration submitted to IML or CC, inserted in 20 totally edentulous patients, with a high edentulism time and limited mandibular bone availability. The SR selected 30 clinical studies and identify 52 biomarkers reported during osseointegration. The most studied biomarkers were interleukin (IL) -1β, tumor necrosis factor alpha (TNF-α) and nitric oxide (NO). PICF collections were performed immediately after implant insertion up to 16 weeks, prior to occlusal loading. Through the data collected, it was not possible to identify the mechanism by which inflammatory and bone biomarkers are released during osseointegration. However, it was possible to associate cellular and molecular events triggered with osseointegration with the results of available clinical studies. The data summarized can guide researchres to design future clinical studies and can help selecting target biomarkers already quantified. The study "II” showed that IML group presented implant stability 8.95% lower than the CL, until week 12 (p <0.05). The calculus presence in IML group was 50% higher than the CL at week 1 (p = 0.006), and 30% lower at week 8 (p = 0.017). The IML probing in depth was about 21.49% lower than in the CL group for all evaluated periods (p = 0.05). The bleeding on probing was 28.9% higher for IML at week 12 (p = 0.044). IML group presented the highest TNF-α concentration by week 4 (p <0.05) and 57.78% more IL-1β after week 4 to 12 than the CL group. The IL-6 concentration was 53.94% lower for IML group until week 8. The IL-10 concentration had a significant progressive and similar increase for both groups until week 8, and at week 12 the IML group had 45.74% higher concentration than the CL group (p = 0.003). The implant survival rate was 90% for IML and CL. The implants immediately loaded showed more stable clinical results, however presented unstable biological resposnes during bone healing. Therefore, the rehabilitation of the population with low bone availability in the anterior region of the mandible using implant retained mandibular overdentures seems to be safer when CL is adopted based on the inflammatory biomarker release.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESA osseointegração de implantes dentários ocorre devido ao processo desencadeado pela resposta imune do hospedeiro, entretanto os biomarcadores que modulam esse processo ainda não foram determinados. Com o intuito de investigar e compreender a ossointegração por meio dos biomarcadores foram delineados dois estudos: I) Revisão sistemática (RS) com foco na avaliação de coleta de fluido crevicular peri-implantar (FCPI) durante a cicatrização de óssea após a inserção de implantes dentários; II) Estudo clínico longitudinal randomizado de acordo com o carregamento oclusal, carga imediata (CI) ou convencional (CC), de overdentures mandibulares. O estudo II avaliou o comportamento clínico e biológico da osseointegração de implantes de diâmetro reduzido (IDR) submetidos a CI ou CC, inseridos em 20 pacientes desdentados totais, com elevado tempo de edentulismo e limitada disponibilidade óssea mandibular. Na RS foram selecionados 30 estudos clínicos e identificados 52 biomarcadores durante o período de osseointegração. Os biomarcadores mais estudados foram interleucina (IL) -1β, fator de necrose tumoral alfa (TNF-α) e óxido nítrico (NO). As coletas de FCPI foram realizadas imediatamente após inserção do implante até 16 semanas antes do carregamento oclusal. Através dos dados coletados nesta RS, não foi possível identificar qual o mecanismo pelos quais os biomarcadores inflamatórios e ósseos são liberados durante a osseointegração. No entanto, eventos já conhecidos da osseointegração foram associados com os resultados dos estudos clínicos disponíveis, sendo este, um guia aos futuros pesquisadores, devido o mapeamento de todos os biomarcadores já avaliados durante esse processo. No estudo “II”, o grupo CI apresentou estabilidade 8,95% menor que o CC, até a semana 12 (p<0,05). O cálculo no CI foi 50% maior que no CC na semana 1 (p=0.006), e 30% menor na semana 8 (p=0.017). A profundidade a sondagem do CI foi em média 21,49% inferior ao grupo CC em todos os períodos avaliados (p=0.05). O sangramento a sondagem foi 28,9% maior para o CI na semana 12 (p=0,044). Implantes que receberam CI apresentaram a concentração de TNF-α 40,75% maior até a semana 4 (p<0.05) e 57,78% mais IL-1β, após a semana 4 até a 12 que o grupo CC. A concentração de IL-6 foi 53,94% menor para o CI, até a semana 8. A concentração de IL-10 teve aumento progressivo significativo e similar para ambos os grupos até a semana 8, na semana 12 o grupo CI teve 45,74% maior concentração do que o grupo CC (p=0.003). A taxa de sobrevivência foi de 90% para ambos os grupos. Os implantes que receberam CI apresentaram resultados clínicos mais estáveis, mas resultados biológicos mais instáveis durante a cicatrização óssea. Diante disso, a reabilitação da população com baixa disponibilidade óssea em região anterior de mandíbula com overdentures mandibulares é mais segura quando feita com CC, pois a resposta inflamatória foi mais controlada neste grupo

A comparison between inflammation-related markers in the peri-implant crevicular fluid and clinical parameters during osseointegration in edentulous jaws

To investigate the clinical parameters, implant stability and the cytokine levels in peri-implant crevicular fluid (PICF) during the early bone healing process after implant placement. A total of 60 narrow implants were placed in the anterior region of the mandible in 30 edentulous patients (aged 67.23 ±7.66 years). Bone type, insertion torque and primary stability were registered during surgery. Clinical measurements of peri-implant health were recorded and samples from the peri-implant crevicular fluid (PICF) were collected 1, 2, 4, 8 and 12 weeks after the surgery. Levels of IL-1ß, IL-6, IL-10 and TNF-a in the PICF were analyzed by enzyme-linked immunosorbent assay (ELISA). Implant stability was assessed by resonance frequency measurements (RFA). Mean time of edentulism in the mandible was 24.53 (±13.29) years and mandibular bone atrophy was diagnosed in 15 patients. A total of 12 implants failed at different periods of osseointegration. In the healthy implants, the gingival index displayed significantly different outcomes between the first week the following period (p= 0.05). Significant increasing in the plaque index was observed only between the week 4-8 and 8-12. Significant differences in Probing on Depth (PD) were observed at all intervals. The RFA reduced significantly over time after the 4th week. The highest levels of TNF-a were recorded in the first 2 weeks (non-atrophic patients) and 4 weeks (atrophic patients), after which the concentrations declined (p<0.05). Patients with bone atrophy had significantly higher TNF-a levels in weeks 4 and 8, compared to their non-atrophic counterparts. IL-1ß concentrations increased only after 12 weeks (p=0.003), and IL-1ß levels were significantly higher for patients with atrophy during the first two weeks. IL-6 concentrations peaked in the first week (p<0.05; p=0.005) and were significantly higher for patients with bone atrophy in weeks 1, 2 and 4. IL- 10 concentrations progressively increased over time, with the highest concentration in the 12th week (p < 0.005). Smoking, bone atrophy and bone type seems differently influence the cytokines concentrations during the healing time. Although the clinical measurements presented differences between the evaluation periods, they were not indicative of early dental implant failure or peri-implant diseases. The variations in the cytokine concentrations and their predominant role can be attributed to healing balance in different periods of time.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESEste estudo investigou parâmetros clínicos, a estabilidade do implante e as concentrações de citocinas relacionadas ao processo inflamatório no fluido crevicular peri-implantar (PICF) após a instalação de implantes durante o período de cicatrização óssea. Um total de 60 implantes instalados na região anterior de mandíbula de 30 pacientes desdentados totais (idade média 67,23 ±7,66 anos) foram monitorados até a osseointegração. O tipo ósseo, o torque de inserção e a estabilidade primária foram registrados durante o processo cirúrgico. O registro de escores clínicos de saúde peri-implantar (índice de placa visível, presença de cálculo, grau de inflamação, profundidade de sondagem e índice de sangramento a sondagem), a estabilidade secundária dos implantes e coletas de amostras de PICF foram realizados nos períodos de 1, 2, 4, 8 e 12 semanas após a cirurgia. Os níveis de IL-1ß, IL-6, IL-10 e TNF-a no PICF foram analisados por ensaio por enzimas imuno-adsorvidas (ELISA). A estabilidade do implante foi mensurada pelo método de análise de frequência de ressonância (RFA). O tempo médio de edentulismo na mandíbula foi 24,53 (±13,29) anos e atrofia óssea mandibular foi diagnosticada em 15 pacientes. Um total de 12 implantes falharam em diferentes períodos da osseointegração. Nos implantes saudáveis, o índice inflamação gengival apresentou resultados significativamente diferentes entre a primeira semana e a seguinte (p = 0,05). Foi observado um aumento significativo no índice de placa entre as semanas 4-8 e 8-12. Já a profundidade sondagem teve diferenças significativas em todos os intervalos de avaliação. Após a quarta semana a estabilidade secundária reduziu significativamente ao longo do tempo. Níveis significativamente elevados de TNF-a foram registrados na segunda semana, em pacientes não-atróficos, e na quarta semana (em pacientes atróficos); após estes períodos suas concentrações diminuíram (p<0,05). Entretanto, pacientes com atrofia óssea tinham níveis significativamente mais elevados de TNF-a nas semanas 4 e 8. As concentrações de IL-1ß aumentaram somente após 12 semanas (p=0,003), e os níveis de IL-1ß foram significativamente maiores para os pacientes com atrofia óssea durante as primeiras duas semanas. O pico de concentração de IL-6 foi observado na primeira semana (p<0,05; p=0,005) e foi significativamente mais elevado em pacientes com atrofia óssea nas semanas 1, 2 e 4. As concentrações de IL-10 aumentaram progressivamente ao longo do tempo, sendo a concentração mais elevada no 12ª semana (p<0,005). O hábito de fumar, o quadro de atrofia óssea mandibular e o tipo ósseo, parecem influenciar de diferentes formas as concentrações de citocinas durante o período de cicatrização. Embora as medidas clínicas apresentarem diferenças entre os períodos de avaliação, eles não foram indicativos de falha precoce do implante ou de doenças peri-implantares. As variações nas concentrações das citocinas e as características predominantes para cada uma podem ser atribuídas ao equilíbrio de cicatrização em diferentes períodos de tempo

Short-term quality of life change perceived by patients after transition to mandibular overdentures

Abstract The aim of this longitudinal observational study was to evaluate the oral health-related quality of life (OHRQoL) following patient rehabilitation with implant-retained mandibular overdentures (IMO) and to identify the contribution of the different domains to OHRQoL. The Oral Health Impact Profile (OHIP-EDENT), Dental Impact on Daily Living (DIDL), and Geriatric Oral Health Assessment Index (GOHAI) questionnaires were completed twice by 25 patients: after 3 months of rehabilitation with complete dentures (CD) and after 3 months of IMO loading using stud abutments. The evaluation after IMO rehabilitation showed significant improvement in three DIDL domains: appearance (p = 0.011), eating and chewing (p = 0.003), and general performance (p = 0.003). The GOHAI results showed significant differences in two domains: psychosocial (p = 0.005) and pain and discomfort (p = 0.0004). The OHIP-EDENT outcomes showed significant improvements in five domains: functional limitation (p = 0.0001), physical pain (p = 0.0002), physical disability (p = 0.0010), and psychological disability and handicap (p = 0.032). The largest observed effect sizes were close to one standard deviation and were observed in the eating and chewing domain (0.93) of the DIDL; the pain and discomfort domain (0.83) of the GOHAI, and the functional limitation (0.89), physical pain (1.02), physical disability (0.84) domains of the OHIP-EDENT. The percentage of satisfied patients increased in all domains. Self-reported OHRQoL of CD wearers was significantly improved after 3 months of treatment with IMO, especially concerning the functional and pain-related aspects

Simplified micrometric surface characterization of different implant surfaces available on the Brazilian market

is study characterized the implant surfaces available on the Brazilian market in terms of topography, chemical composition, and roughness. Methods: The following brands were selected according to their surfaces: Kopp (Ko), Signo Vinces (Sv), Neodent (Ne), Osseotite (Os), Nanotite (Nt), SIN (Si), Titanium Fix (Tf), conventional Straumann (Str), SLActive (SLA). The morphological analysis and the alloy impurities and implant surface contaminants were analyzed by SEM-EDS. Surface roughness parameters and 3-D reconstructions were obtained by laser microscopy (20x). Two distinct areas were evaluated: i) the cervical portion (no surface treatment), and ii) the middle third (treated surface). Results: The characterization of the implant surfaces by SEM showed morphological differences between the thread geometries and surface morphology at 800x and 2000x magnification. The EDS elemental analysis showed a predominance of titanium (Ti) for all implants. The SLA surface showed only peaks of Ti while other implants brands showed traces of impurities and contaminants including Al, C, PR, F, Mg, Na, Ni, O, P, and SR. The implant surface roughness in the cervical portion did not exceed Ra 0.51.0 &#956;m, constituting a minimally rough surface and obtaining acceptable standards for this region. Only Nt, Str, and SLA presented Ra above 2 &#956;m in the middle third area showing a rough surface favorable for osseointegration. Conclusion: This study concluded that there is no established standard for morphology, chemical composition and implant surface roughness that allows a safe comparison between the available dental implant surfaces. National implant brands generally contain more impurities and surface contaminants than their international counterparts and were consequently more sensitive to the surface treatment techniques

Simplifying the Treatment of Bone Atrophy in the Posterior Regions: Combination of Zygomatic and Wide-Short Implants—A Case Report with 2 Years of Follow-Up

The rehabilitation of maxillary and mandibular bone atrophy represents one of the main challenges of modern oral implantology because it requires a variety of procedures, which not only differ technically, but also differ in their results. In the face of limitations such as deficiencies in the height and thickness of the alveolar structure, prosthetic rehabilitation has sought to avoid large bone reconstruction through bone grafting; this clinical behavior has become a treatment system based on evidence from clinical scientific research. In the treatment of atrophic maxilla, the use of zygomatic implants has been safely applied as a result of extreme technical rigor and mastery of this surgical skill. For cases of posterior mandibular atrophy, short implants with a large diameter and a combination of short and long implants have been recommended to improve biomechanical resistance. These surgical alternatives have demonstrated a success rate similar to that of oral rehabilitation with the placing of conventional implants, allowing the adoption of immediate loading protocol, a decrease in morbidity, simplification and speed of the treatment, and cost reduction. This case report presents complete oral rehabilitation in a patient with bilateral bone atrophy in the posterior regions of the maxilla and mandible with the goal of developing and increasing posterior occlusal stability during immediate loading

Clinical Versatility of the Facility-Equator Implant System as Mandibular Overdenture Retainers

The use of mandibular overdentures (MO) for the rehabilitation of totally edentulous individuals with limited bone availability is widespread and has proven clinical success. Narrow diameter implants (NDI) are available on the market as MO retainers to solve problems related to limited bone availability and bone thickness, providing a low-cost, minimally invasive treatment option. This technique evolved over the years, and changes frequently involved the number of implants used as MO retainers, as the adoption of a smaller number of implants can generate biomechanical disadvantages, contributing to the increased stress in peri-implant tissues, which may accelerate marginal bone loss (MBL), in addition to reducing masticatory capacity and satisfaction with rehabilitation. Some studies pointed out that the use of 3 or more implants as MO retainers improves the biomechanics. Thus, the objective of this study was to report 3 different clinical cases where 3 or more NDI were adopted to retain mandibular overdentures in association with diverse loading protocols: (i) 3 implants adopting conventional loading, (ii) 4 implants using progressive loading, and (iii) 4 implants with hybrid loading. The case with 4 implants and progressive loading showed a slight worsening of masticatory function at 1 year, in addition to a more pronounced MBL compared to other cases, but with improvements in satisfaction and oral health-related quality of life. Thus, NDI can be used as MO retainers with predictability and clinical success, using different numbers of implants and loading protocols