Concern about the risk of aerosol contamination from ultrasonic scaler: a systematic review and meta-analysis.

BACKGROUND: Many instruments used in dentistry are rotary, such as handpieces, water syringes, and ultrasonic scalers that produce aerosols. The spray created by these instruments can carry, in addition to water, droplets of saliva, blood, and microorganisms, which can pose a risk of infections for healthcare professionals and patients. Due to the COVID-19 pandemic, this gained attention. OBJECTIVE: The aim was to carry out a systematic review of the evidence of the scope of the aerosol produced by ultrasonic scaler in environmental contamination and the influence of the use of intraoral suction reduction devices. DESIGN: Scientific literature was searched until June 19, 2021 in 6 databases: Pubmed, EMBASE, Web of science, Scopus, Virtual Health Library and Cochrane Library, without restrictions on language or publication date. Studies that evaluated the range of the aerosol produced by ultrasonic scaler during scaling/prophylaxis and the control of environmental contamination generated by it with the use of low (LVE) and high (HVE) volume evacuation systems were included. RESULTS: Of the 1893 potentially relevant articles, 5 of which were randomized controlled trials (RCTs). The meta-analysis of 3 RCTs showed that, even at different distances from the patient's oral cavity, there was a significant increase in airborne bacteria in the dental environment with the use of ultrasonic scaler. In contrast, when meta-analysis compared the use of HVE with LVE, there was no significant difference (P = 0.40/CI -0.71[-2.37, 0.95]) for aerosol produced in the environment. CONCLUSIONS: There is an increase in the concentration of bioaerosol in the dental environment during the use of ultrasonic scaler in scaling/prophylaxis, reaching up to 2 m away from the patient's mouth and the use of LVE, HVE or a combination of different devices, can be effective in reducing air contamination in the dental environment, with no important difference between different types of suction devices.

Is a digital surgical guide superior for implant placement in the first molars areas?

Design The study was a randomised clinical trial comparing two independent groups for implant placement. One group was a computer-aided design/computer-aided manufacturing (CAD/CAM) implant guide (digital) and the other one used the traditional implant guide (traditional impression).Aim The study aimed to compare the outcomes of two different methods of guidance for surgical implants for missing first molars. One was prepared by intraoral digital scanning. The other was the conventional impression, which includes time to make an impression and perform surgery, fit of intraoral guide and deviation in screw access channels position. The purpose of the study was not only to find the most suitable implant guide but also to allow dentists to justify their chosen method.Methods The authors of this study included 42 participants with first molars missing and distributed them into two groups, one group using a digital production guide and the other using a traditional impression. The evaluation measured the deviation length and direction of the screw access channel position relative to implant alignments. In addition, labour time for implant guides and the intraoral fit were assessed as secondary outcomes.Results The impression time and implant surgery time for patients in the digital group were shorter than for those in the traditional group. The intraoral first fit of the guide was better for patients who underwent treatment with a digital system than it was for control patients (p <0.05). The one-time satisfaction rate of the digital group was 100%, while five cases in the control group required repetition. The difference between screw access channel positions on the left and right sides for both groups showed no significant differences.Conclusions The digital surgical guide for a first molar implant reduces the clinical, operative time and screw access deviation and therefore improves efficiency. Improved clinical outcomes indicated that there is evidence to support the use of CAD/CAM guides in dental implant placement for a single missing tooth replacement.

Active Tactile Sensibility of Brånemark Protocol Prostheses: A Case-Control Clinical Study.

Few studies have assessed active tactile sensibility in patients rehabilitated with implants. Improved knowledge about functional tactile sensibility will contribute to several clinical applications, such as protocols for immediate loading, prosthesis design, occlusal improvement in implantology, and physiological integration of implant-supported prostheses. The present study evaluated active tactile sensibility in patients rehabilitated with Brånemark-type mandibular prostheses that impede the total mucosa-supported maxillary prosthesis. Thirty-five subjects participated in this study. The experimental group (n = 18) inclusion criteria were as follows: Brånemark-type prosthesis and a total mucosa-supported maxillary prosthesis. The control group (n = 17) was composed of participants with complete healthy dentition. Carbon foils with different thicknesses (12 µm, 24 µm, 40 µm, 80 µm, and 200 µm) were placed in the premolar region to evaluate the brink of active oral tactile sensibility. The researchers assessed the participants 120 times. After evaluation, we observed a statistical difference (p < 0.05) between the groups. Additionally, the degree of sensibility was found for all thicknesses, except for 12 µm, on both sides. There was a more significant increase in perception in the control group as the carbon thickness increased. The tactile sensibility threshold was 2.5 times greater for participants with prostheses. Thus, the tactile sensibility for mandibular implant-supported and maxillary mucosa-supported prostheses is significantly lower than that of dentate patients, which was detected above the thickness of 80 µm; in patients with natural dentition, different thicknesses were seen starting from 24 µm.

Analysis of Active Oral Tactile Sensitivity in Individuals with Complete Natural Dentition.

AIM: To evaluate the active tactile sensitivity in individuals with complete natural dentition, determining the smallest thickness detected by the participants, and clarifying if there is a difference between the thicknesses analyzed. MATERIALS AND METHODS: Active tactile sensitivity was evaluated in 40 research participants. Inclusion criteria included participants with complete natural dentition, without active or history of periodontal disease, absence of temporomandibular disorders, bruxism, and restorations in the evaluated area. Exclusion criteria included age below 18 years. The active tactile perception threshold was evaluated by using carbon sheets of different thicknesses (0, 12, 24, 40, 80, 100, and 200 µm), which were inserted in the participants' premolars, bilaterally. The carbon sheet was inserted so as not to come into contact with the oral soft tissues. Subsequently, the participant occluded and was asked about the perception of the intraocclusal object 20 times in each occlusal contact. The collected data were tabulated considering the amount of positive and negative responses for each carbon thickness. Values of p < 0.05 were considered significant. RESULTS: The results showed that there was linearity in perception, on both sides, besides, the natural dentition was able to perceive difference in thickness from 12 µm. CONCLUSION: We conclude that the 12 µm thickness is noticeable in occlusion and can be differentiated from other thicknesses in natural dentition and that there is no difference between the tactile sensitivity of the right and left sides. CLINICAL SIGNIFICANCE: A better understanding of active oral tactile sensitivity will contribute to numerous clinical applications in dentistry, including occlusal adjustment in dental rehabilitation, dental implants prosthesis design, and survival of prosthetic rehabilitation.

Smoking as a Risk Factor for the Development of Periimplant Diseases.

BACKGROUND: Risk factors associated with periimplant disease have been exhaustively explored in many studies. However, despite the high incidence of smokers in the general population, it is still unclear whether smoking is a risk factor for the development of periimplant diseases. PURPOSE: The aim of this review was to analyze all pertinent literature, including systematic reviews, clinical trials, and long-term follow-up, to evaluate smoking as a real risk factor for periimplant diseases. MATERIAL AND METHODS: A comprehensive search was conducted on MEDLINE through PubMed database of the US National Library of Medicine, for articles published until March 2018. All searches were performed using medical subject headings or free-text words. After screening, data extraction, and duplicate removal from 972 found articles, 19 were included in this review. RESULTS: The influence of smoking on the healing process around implants has been explored for potential disruption of the healing process and periimplant disease development. Despite the discussed results in many studies, most of the analyzed literature shows a scientific basis to determine smoking as a risk factor for periimplant disease development, considering that smoking increases the susceptibility to periimplant disease. However, future studies excluding confounding factors need to be performed. CONCLUSION: This review showed that smoking is a real risk factor that increases the likelihood of development of periimplant disease.

Evaluation of the success rates of immediate implant placement in anterior and posterior regions success rates of immediate implant: a retrospective study

Introdution: Immediate implants placement has shown contradictory results inthe posterior region. Objective: The aim of the study was to compare the successrate and predictability of the short-term treatment using immediate implants inanterior and posterior regions. Methods: A total of 1000 dental charts wereanalyzed, of which 43 were included in the study: anterior (n=20) and posterior(n=23). The inclusion criteria were: tooth extraction indication, immediate single-tooth implant placement and at least twelve months of follow-up with functionalimplant. The success rates were based on the criteria I. and II. from the healthscale for dental implants proposed at the International Congress of Oral ImplantDentistry: no pain; no mobility, until 4 mm of bone loss, no exudate. P-value <0.05was considered significant. Results: The total success rate of immediate implantswas 97.7% for immediate implants in function for at least 12 months. The use ofbiomaterial (p=0.03) and temporary prosthesis (p<0.0001) were significantly higherin the anterior group. There was no significant difference in implant failure betweengroups (p=0.47). There was no statistical difference between the groups, consideringage, sex, extraction reason, initial torque immediately following implantplacement, treatment time and implant platform type (p> 0.05). Conclusion: Itmay be concluded that the anterior and posterior regions present a high short-term success rate when the immediate implant technique was used.

Introdução: A utilização de implante imediato em regiões posteriores temapresentado resultados contraditórios. Objetivo: O objetivo deste estudo foicomparar o índice de sucesso e previsibilidade à curto prazo de implantes imediatosinstalados em regiões anterior e posterior. Métodos: Um total de 1000 prontuáriosforam analisados, dos quais 43 foram incluídos neste estudo: Anterior (n=20) eposterior (n=23). Os critérios de inclusão foram: Indicação de extração dentária,instalação de implantes imediatos unitários, no mínimo doze meses de segmentocom implante funcional. Os critérios de sucesso foram baseados na escala desaúde dos implantes dentários do Congresso Internacional de Implantologia Oral,eixo I. e II.: ausência de dor, ausência de mobilidade, ausência de exudato e perdaóssea de até 4 mm. Valor de p<0.05 foi considerado estatisticamente significante.Resultados: O índice de sucesso dos implantes imediatos foi de 97,7% paraimplantes em função por pelo menos 12 meses. O uso de biomaterial (p=0,03) eprótese provisória (p<0,0001) foi significantemente maior em região anterior.Não foi encontrado diferença significante quanto a falha dos implantescomparando os dois grupos (p=0,47). Não houve diferença estatisticamentesignificante entre os grupos, considerando a idade, gênero, motivo da extração,torque inicial, tempo de tratamento e tipo de plataforma do implante (p>0,05).Conclusão: Pode-se concluir que as regiões anterior e posterior apresentaramalta taxa de sucesso a curto prazo quanto a técnica de implante imediato.

Implantes imediatos em alvéolos infectados ­ relato de caso / Immediate implants in infected socket ­ case report

Para ser a primeira opção em um plano de tratamento, a terapia com implantes deve atender requisitos funcionais e estéticos. A técnica de instalação de implantes imediatos tem sido indicada devido à diminuição do tempo de tratamento, o que traz benefícios para o paciente. Antes de avaliar a viabilidade do implante, é essencial o conhecimento da indicação para uma adequada instalação em área infectada. Áreas de infecção periodontal subaguda, infecção perio-endo, infecção periodontal crônica, lesão periapical crônica e cisto periodontal só devem receber implantes imediatos desde que medidas pré, pós e durante o procedimento cirúrgico sejam tomadas. O presente artigo relata um caso de instalação de implante imediato em alvéolo infectado com a utilização de enxerto autólogo com 18 meses de acompanhamento (AU).

To be the first choice in a treatment planning, implant therapy must join both functional and aesthetic requirements. Implant installation technique has been indicated due to the reduction of time treatment, which brings benefits to the patient. Before evaluating the viability of the implant, it is essential to know the proper indication of the immediate implant installation in an infected area. Areas of subacute periodontal infection, endo-perio lesion, chronic periodontal infection, chronic periapical lesion, and periodontal cyst should only receive immediate implants provided that measures are taken pre, post, and during surgical procedures. The present article reports 18 months follow up after the installation of an immediate implant in infected socket associated to autologous graft (AU).

Chronic Periodontitis and RANKL/OPG Ratio in Peri-Implant Mucosae Inflammation

Abstract tHistory of chronic periodontitis (CP) is a risk factor for oseointegration failure. The osteoclastogenesis system (RANK, RANKL and OPG) is critical for bone homeostatic control. We investigated the levels of OPG and RANKL in peri-implant tissues from volunteers with and without a history of CP and their association with mucosae inflammation. This is a single-blind case-contro study. Diagnosis of a history of CP and peri-implant examination was performed on 46 volunteers, divided into control (without history of CP, n=26) and CP group (with history of CP, n=20). Gingival biopsies were harvested during implant exposure. Quantitative PCR evaluated OPG/RANKL mRNA expressions. OPG and RANKL proteins were analyzed by western blot and immunohistochemistry assay. The chi-square test analyzed the significance of nominal variables between groups while continuous variables were analyzed by T-test or Mann-Whitney test, after Shapiro-Wilk test evaluation. The 2-ΔΔCT Livak method calculation evaluated the gene expression. Values of p<0.05 were considered statistically significant. Volunteers with CP history had 23 times higher chance of developing mucosae inflammation. High mucosae levels of RANKL (p=0.04) and RANKL/OPG (p=0.001) mRNA expressions were observed in CP group. CP volunteers showed increased RANKL protein levels in opposition to decreased OPG expression. Even without active periodontitis, volunteers with a history of CP had elevated gingival levels of RANKL/OPG and higher correlation with peri-implant mucosae inflammation and implant loss.

Resumo A história de periodontite crônica (CP) é um fator de risco para falhas na osseointegração. O sistema de osteoclastogênese (RANK, RANKL e OPG) é crucial para o controle da homeostase óssea. O objetivo deste estudo foi investigar os níveis de OPG e RANKL no tecido peri-implantar de voluntários com e sem histórico de CP e sua associação com inflamação da mucosa. Este é um estudo tipo caso-controle. O exame para diagnóstico de CP e na região peri-implantar foi realizado em 46 voluntários, divididos em controle (sem história CP, n=26) e grupo CP (com histórico de CP, n=20). Descartes gengivais foram obtidos durante a exposição do implante. PCR quantitativo avaliou a expressão do RNAm de OPG/RANKL. As proteínas OPG e RANKL foram analisadas por western blot e imunohistoquímica. O teste do qui-quadrado analisou a significância entre as variáveis nominais enquanto as variáveis contínuas foram analisadas pelo teste-t e Mann-Whitney, após o teste de Shapiro-wilk. O método do Livak 2--ΔΔCT avaliou a expressão gênica. Os voluntários com CP apresentaram 23 vezes mais chances de desenvolver inflamação da mucosa. Expressão elevada no RNAm de RANKL (p=0.04) e RANKL/OPG (p=0.001) foram observadas no grupo CP. Voluntários com CP mostraram aumento dos níveis da proteína RANKL em contraste com diminuída expressão de OPG. Mesmo sem periodontite ativa, voluntários com histórico de CP apresentaram elevado nível gengival de RANKL/OPG e alta correlação com inflamação peri-implantar e perda do implante.

Chronic Periodontitis and RANKL/OPG Ratio in Peri-Implant Mucosae Inflammation.

tHistory of chronic periodontitis (CP) is a risk factor for oseointegration failure. The osteoclastogenesis system (RANK, RANKL and OPG) is critical for bone homeostatic control. We investigated the levels of OPG and RANKL in peri-implant tissues from volunteers with and without a history of CP and their association with mucosae inflammation. This is a single-blind case-contro study. Diagnosis of a history of CP and peri-implant examination was performed on 46 volunteers, divided into control (without history of CP, n=26) and CP group (with history of CP, n=20). Gingival biopsies were harvested during implant exposure. Quantitative PCR evaluated OPG/RANKL mRNA expressions. OPG and RANKL proteins were analyzed by western blot and immunohistochemistry assay. The chi-square test analyzed the significance of nominal variables between groups while continuous variables were analyzed by T-test or Mann-Whitney test, after Shapiro-Wilk test evaluation. The 2-ΔΔCT Livak method calculation evaluated the gene expression. Values of p<0.05 were considered statistically significant. Volunteers with CP history had 23 times higher chance of developing mucosae inflammation. High mucosae levels of RANKL (p=0.04) and RANKL/OPG (p=0.001) mRNA expressions were observed in CP group. CP volunteers showed increased RANKL protein levels in opposition to decreased OPG expression. Even without active periodontitis, volunteers with a history of CP had elevated gingival levels of RANKL/OPG and higher correlation with peri-implant mucosae inflammation and implant loss.

Haplotypes in BMP4 and FGF Genes Increase the Risk of Peri-Implantitis.

Despite the success of osseointegrated implants, failures have increased significantly, associated with development of peri-implantitis. Multiple factors influence the peri-implant bone loss, including environmental and genetic causes. BMPs (Bone morphogenetic proteins) are growth factors that induce bone formation. FGF (fibroblast growth factors) and their receptors (FGFRs) play important roles by controlling the levels of cell proliferation, differentiation and migration. BMP/FGF relationship is responsible for promoting bone regeneration and bone loss. The aim of this study was to analyze the correlation between BMP4, FGF3, FGF10 and FGFR1 genes and peri-implant bone loss. Two hundred and fifteen volunteers, with 754 dental implants, were submitted to oral examination and divided in healthy group (n=129) and peri-implantitis group (n=86). Thirteen polymorphisms in BMP4, FGF3, FGF10 and FGFR1 genes were analyzed individually and in haplotype. The chi-square test correlated genotypes, allelic and haplotype frequencies. Values of p<0.05 were considered significant. Volunteers with peri-implantitis demonstrated high incidence of total edentulism (p<0.0001) and thin peri-implant phenotype (p<0.04). Higher incidence of spontaneous bleeding, plaque and implant mobility was observed in peri-implantitis group (p<0.0001 for all). The TT polymorphic genotype for BMP4 rs2761884 was associated with healthy peri-implant (p=0.01). FGF3 rs4631909 (TT+CT genotype) also showed association with the control group (p=0.04). The frequency of C allele for FGF3 rs4631909 showed a tendency for association with peri-implantitis (p=0.08). FGF10 CCTG (p=0.03), BMP4 GAAA (p=0.05) and GGGA (p=0.02) haplotypes were associated with peri-implantitis (p=0.03). Therefore, it may be concluded that BMP4 and FGF10 haplotypes are associated with peri-implantitis.

Haplotypes in BMP4 and FGF Genes Increase the Risk of Peri-Implantitis

Abstract Despite the success of osseointegrated implants, failures have increased significantly, associated with development of peri-implantitis. Multiple factors influence the peri-implant bone loss, including environmental and genetic causes. BMPs (Bone morphogenetic proteins) are growth factors that induce bone formation. FGF (fibroblast growth factors) and their receptors (FGFRs) play important roles by controlling the levels of cell proliferation, differentiation and migration. BMP/FGF relationship is responsible for promoting bone regeneration and bone loss. The aim of this study was to analyze the correlation between BMP4, FGF3, FGF10 and FGFR1 genes and peri-implant bone loss. Two hundred and fifteen volunteers, with 754 dental implants, were submitted to oral examination and divided in healthy group (n=129) and peri-implantitis group (n=86). Thirteen polymorphisms in BMP4, FGF3, FGF10 and FGFR1 genes were analyzed individually and in haplotype. The chi-square test correlated genotypes, allelic and haplotype frequencies. Values of p<0.05 were considered significant. Volunteers with peri-implantitis demonstrated high incidence of total edentulism (p<0.0001) and thin peri-implant phenotype (p<0.04). Higher incidence of spontaneous bleeding, plaque and implant mobility was observed in peri-implantitis group (p<0.0001 for all). The TT polymorphic genotype for BMP4 rs2761884 was associated with healthy peri-implant (p=0.01). FGF3 rs4631909 (TT+CT genotype) also showed association with the control group (p=0.04). The frequency of C allele for FGF3 rs4631909 showed a tendency for association with peri-implantitis (p=0.08). FGF10 CCTG (p=0.03), BMP4 GAAA (p=0.05) and GGGA (p=0.02) haplotypes were associated with peri-implantitis (p=0.03). Therefore, it may be concluded that BMP4 and FGF10 haplotypes are associated with peri-implantitis.

Resumo Apesar do alto índice de sucesso em implantodontia, falhas tem aumentado drasticamente, estando associadas ao desenvolvimento de peri-implantite. A perda óssea peri-implantar é influenciada por múltiplos fatores, incluindo causas genéticas e ambientais. As BMPs (proteínas ósseas morfogenéticas) são fatores de crescimento indutores da formação óssea. Os FGFs (fatores de crescimento dos fibroblastos) e seus receptores (FGFRs) desenvolvem importante função na proliferação, diferenciação e migração celular. A relação BMP/FGF é responsável pela regeneração e perda óssea. O objetivo deste estudo foi estudar a possível correlação entre os genes BMP4, FGF3, FGF10 e FGFR1 e a perda óssea peri-implantar. Duzentos e quinze voluntários, com 754 implantes, foram submetidos ao exame oral e divididos em grupo saúde (n=129) e peri-implantite (n=86). Treze polimorfismos nos genes BMP4, FGF3, FGF10 e FGFR1 foram analisados individualmente e como haplótipos. O teste do qui-quadrado correlacionou as frequências dos genótipos, alelos e haplótipos. Valores de p<0,05 foram considerados estatisticamente significantes. Voluntários com peri-implantite mostraram alta incidência de edentulismo total (p<0,0001) e biotipo periodontal fino (p<0,04). Sangramento espontâneo, placa e mobilidade do implante foram altamente incidentes no grupo peri-implantite (p<0,0001). O genótipo polimórfico TT para BMP4 rs2761884 foi associado com saúde peri-implantar (p=0,01). FGF3 rs4631909 (genótipos TT+CT) mostraram associação com o grupo controle (p=0,04). A frequência do alelo C para FGF3 rs4631909 mostrou uma tendência de associação com peri-implantite (p=0,08). Os haplótipos FGF10 CCTG (p=0,03), BMP4 GAAA (p=0,05) e GGGA (p=0,02) foram associados com peri-implantite (p=0,03). Sendo assim, conclui-se que os haplótipos BMP4 e FGF10 estão associados com peri-implantite.

Desadaptação entre implantes e pilares protéticos de zircônia, titânio e níquel-crômio: estudo por microscopia eletrônica de varredura / Marginal vertical misft at zirconia, titanium, and Ni-Cr prosthetic implant/abutment interfaces: a scanning electron microscopy study

Objetivo: avaliar, por meio da microscopia eletrônica de varredura, a desadaptação vertical entre análogos de implantes HE (hexágono externo) e diversos tipos de pilares protéticos. Material e métodos: quatro tipos de pilares foram usados: a) pilares pré-usinados de titânio; b) pilares personalizados de zircônia usinados pelo sistema CAD/CAM; c) pilares calcináveis com cinta metálica; e d) pilares calcináveis sem cinta metálica. Sete modelos de estudo foram confeccionados, cada um com quatro análogos 4,1 mm de diâmetro, conectados a um dos tipos de pilar mencionados anteriormente (28 corpos-de-prova). Os pilares de zircônia foram instalados com torque de 20 Ncm, e os metálicos com torque de 30 Ncm, conforme recomendação do fabricante. As imagens das interfaces análogos/pilares foram obtidas em MEV para geração de 144 medições das desadaptações mais 100 fotomicrografias dos corpos-de-prova. Resultados: as médias de desadaptação em micrômetros foram: a) 11,19 ± 5,54; b)2,62 ± 5,12; c) 11,31 ± 4,62; d) 18,04 ± 9,93. O teste Kruskal-Wallis mostrou diferença significativa entre os grupos analisados (p=0,005). O teste Student Newman-Keuls mostrou que pilares zircônia CAD/CAM apresentaram adaptação significativamente superior em relação aos demais tipos de pilares. Não houve diferença significativa quando foram utilizados os pilares calcináveis (com ou sem cinta metálica) ou os pilares pré-usinados em titânio. Conclusão: as imagens mostraram que existem diferenças significativas entre os pilares analisados. Apesar dos pilares zircônia CAD/CAM mostrarem os melhores resultados, excessos horizontais na base destes pilares foram detectados em relação à plataforma do análogo.

Objective: to perform a SEM evaluation of the vertical margin misfit at the implant/abutment interface of several prosthetic modalities. Material and methods: 4 abutment types were used: a) prefabricated titanium; b) CAD/CAM customized abutments; c) castable abutments with prefabricated metal collar, and d) castable abutments with no metallic collars. Seven models were fabricated, each one with 4.1 mm HE implant analogs (28 samples). The zirconia abutments were fastened with 20 Ncm torque and the metallic abutments with a 30 Ncm according to the manufacturer recommendations. The SEM images at the implant/abutment interfaces provided 144 measurements of margin misfit based on 100 electromicrographs. Results: the mean misfit values were (in micrometers): a) 11.19 ± 5.54; b) 2.62 ± 5.12; c) 11.31 ± 4.62; d) 18.04 ± 9.93. The Kruskal-Wallis test demonstrated a signifi cant difference among groups (p=0.005). The Student-Newman-Keuls test showed that the zirconia abutments were superior when compared among groups. No differences were seen for castable abutments (with/without metal collar) or for prefabricated titanium abutments. Conclusion: the images demonstrated significant differences among the analyzed abutment types. Although the zirconia CAD/CAM abutments had provided the best results, horizontal overhangs were also detected in relation to the analog platform.

Guidelines for positioning external hexagon implants in screw-retained multiple prostheses using rotational abutment-type components.

PURPOSE: This study measured the maximum angulation between 2 implants allowed by the internal walls of the component in screw-retained multiple prostheses using rotational abutment-type components. MATERIALS AND METHODS: Thirty specimens of 3 different brands (Conexão; Neodent; and SIN), consisting of titanium rotational abutments connected to external hexagon abutment analogs with standard platforms, were divided into 3 groups. The specimens were internally filled with polyester resin, screw retained, torque, and sectioned to assess the space existing between the internal wall of the rotational abutment component, edge, and vertex of the hexagon. The measurements were performed using 3-dimensional equipment. RESULTS: When the implant hexagons were oriented edge-to-edge, groups 1, 2, and 3 presented 40.75, 45.00, and 31.89 degrees, respectively. Vertex-to-vertex hexagon orientation showed 9.79, 18.18, and 3.27 degrees for groups 1, 2, and 3, respectively. CONCLUSIONS: The maximum mean angulation in the mesio/distal direction between the 2 implants with hexagon-oriented vertex-to-vertex is 10.41 degrees, and hexagon-oriented edge-to-edge is 39.54 degrees. This study suggests guidelines for positioning external hexagon implants for interference-free screw-retained multiple prostheses using rotational abutment-type components.

In vitro comparative analysis of resistance to compression of laboratory resin composites and a ceramic system.

BACKGROUND: Restorative materials must be capable not only of restoring the patient's masticatory function, but also to rescue the self-esteem of those maculated by a disharmonious smile. Among the esthetic materials available on the market, the choice frequently lies between ceramic or indirect laboratory resin restorations. AIM: This study assessed the resistance to compression of two laboratory resins found on the market, namely Artglass and Targis, considering Omega 900 ceramic from Vita as control. MATERIALS AND METHODS: With the aid of stainless steel matrices, with internal dimensions of 8.0 mm diameter at the base, 9.0 mm in the top portion and 4.0 mm height, 15 test specimens were made, being 5 of each material to be tested. The test specimens were kept in distilled water for 72 hours and submitted to an axial load by the action of a point with a rounded tip 2 mm in diameter, adapted to an EMIC 500 universal test machine. The compression speed was 0.5 mm/min, with a load cell capacity of 200 Kgf. RESULTS: The means of the results were calculated in kilogram-force (Kgf). The results found were treated by analysis of variance (ANOVA) and the differences found among the groups were identified by the Tukey test (5%). CONCLUSION: It was observed that the material Omega 900 (R) offered significantly greater resistance to compression than the other two materials, which did not present statistically significant difference between them.

Prótese inferior implanto-suportada com carga imediata: relato de caso clínico com acompanhamento de dois anos / Inferior Implant supporter total prosthesis and immediate load: a clinical case with a two year follow-up

A reabilitação com prótese total fixa inferior implanto-suportada com carga imediata vem sendo realizada como uma alternativa viável, com excelente prognóstico e comodidade para o paciente, já que é concluída em um espaço de tempo curto, modificando-se desta forma o protocolo de dois estágios cirúrgicos para a instalação dos implantes e a instalação posterior da prótese. Tal procedimento se torna viável devido ao alto índice de sucesso da técnica, com resultados bastante satisfatórios. O propósito deste trabalho é relatar um caso clínico de carga imediata em implantes osseointegráveis utilizando prótese total fixa inferior com acompanhamento de dois anos.

Tensile strength of cementing agents on the CeraOne system of dental prosthesis on implants.

PURPOSE: The aim of this in vitro study was to evaluate the tensile strength of titanium cylinders cemented on stainless steel abutment mock-ups by the Cerazone system. METHODS AND MATERIALS: Four types of cements were used: glass ionomer, Fuji I (GC); zinc phosphate, Cimento LS (Vigodent); zinc oxide without eugenol, Rely x Temp NE (3M ESPE); and resin cement, Rely x ARC (3M ESPE). Four experimental groups were formed, each composed of 5 test specimens. Each test specimen consisted of a set of 1 cylinder and 1 stainless steel abutment mock-up. All cements tested were manipulated in accordance with manufacturers' instructions. A static load of 5 Newtons (N) for 2 minutes was used to standardize the procedure. The tensile tests were performed by a mechanical universal testing machine (EMIC DL500MF) at a crosshead speed of 0.5 mm/min. RESULTS: The highest bonding values resulting from the experiment were obtained by Cimento LS (21.86 MPa mean), followed by the resin cement Rely x ARC (12.95 MPa mean), Fuji I (6.89 MPa mean), and Rely x Temp NE (4.71 MPa mean). The results were subjected to analysis of variance (ANOVA) and the Student's t test. CONCLUSION: The cements differed amongst them as regards tensile strength, with the highest bonding levels recorded with zinc phosphate (Cimento LS) and the lowest with the zinc oxide without eugenol (Rely x Temp NE).

Técnicas cirúrgicas pré-protéticas para o tratamento dos tecidos moles: relatos clínicos / Preprosthetical surgical techniques of soft tissue treatment: clinical report

No presente trabalho os autores apresentam casos clínicos em que foram utilizados técnicas cirúrgicas pré-protéticas para tratamento de tecidos moles. Estas técnicas foram aplicadas no aprofundamento do sulco mucogengival e frenoplastia: para aumento de área chapeável e mucosa queratinizada assim como confecção de sobredentaduras sobre-implantes. Utilizou-se a técnica de vestibuloplastia de Kazanjian e a técnica de frenoplastia da zetaplastia com resultados satisfatórios, demonstrando-se a viabilidade destes procedimentos na prática clínica

Implante zigomático: relato de um caso clínico / Zigoma fixture: a clinical report

Os autores apresentam um relato cirúrgico de um caso clínico em que foi utilizado implantes zigomáticos e implantes osseointegrados convencionais, com objetivo de uma reabilitação total de maxila

Tratamento e reabilitação da maxila posterior com implantes osseointegrados / Treatment and rehabilitation of posterior maxilla with osseointegrated implants

Neste trabalho os autores discutem aspectos importantes relacionados com a reabilitação da região de maxila posterior. Apresentaram um estudo clínico retrospectivo de 82 implantes osseointegrados de três sistemas diferentes que foram instalados nesta região utilizando várias técnicas cirúrgicas tais como: protocolos modificados de preparo de leito e instalação de implantes; elevação de assoalho de seio maxilar e implantes na tuberosidade maxilar com ancoragem pterigopalatina. Constataram por meio dos resultados encontrados que a região posterior da maxila oferece condições previsíveis para as reabilitações com implantes osseointegrados