The effect of the interproximal contour of single external hexagon implant restorations on the prevalence of peri-implantitis: A retrospective study.

PURPOSE: The objective of this retrospective study was to evaluate the effect of the interproximal contour of single external hexagon implant restorations on the prevalence of peri-implantitis. MATERIAL AND METHODS: Records of 96 patients and 148 external hexagon (EH) implants with time in function ranging from 1 to 17 years were included in the study. The most recent clinical and radiographic data were collected from records and the prevalence of peri-implantitis was defined according to the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. Marginal bone level (MBL), emergence angle (EA), emergence profile (EP), and crown/implant platform horizontal ratio (CIHR) were obtained from periapical radiographs. Dichotomous variables at the patient- and implant level were compared with association tests. Mann-Whitney U-Test was performed to compare continuous quantitative values between the studied groups. Binomial logistic regression was conducted to identify risk indicators associated with the peri-implantitis event at the patient- and implant level, with the significance level set at 5% for all tests. RESULTS: Nineteen patients (19.2%) and 24 implants (16.2%) with a mean time in function of 5.0 ± 4.7 years were classified as having peri-implantitis. No statistically significant differences concerning gender, mean age, implant location in the jaw, or time in function were observed between patients with or without peri-implantitis (p > 0.05). Of 24 implants with peri-implantitis 10 (41.7%) displayed EA ≤ 30° (16.4%) while 14 (58.3%) presented EA > 30° with no statistical difference between the groups (p > 0.05). No statistically significant associations were identified between EA, EP, or CIHR and the prevalence of peri-implantitis. CONCLUSION: The findings seem to indicate that the EA, EP, and CIHR of single restorations over external hexagon implants are not associated with the presence of peri-implantitis. However, prospective studies with larger samples are required to better ascertain such an association in the long term.

An in vitro study using confocal laser scanning microscopy to evaluate the marginal misfits of different implant-supported frameworks.

PURPOSE: This study aimed to develop and evaluate a simple, non-destructive method for assessing the misfit and passivity of implant-retained prostheses frameworks. MATERIALS AND METHODS: To simulate the rehabilitation of a mandible posterior partially edentulous area using 3-unit screw-retained frameworks supported by two implants were fabricated and divided into the following five groups (n = 10 in each group): OP = one-piece framework cast in Co-Cr with the conventional method (control-group); Co-Cr frameworks sectioned and welded by laser (=LAS) or tungsten inert gas (=TIG); Co-Cr CAD-CAM = milled Co-Cr framework; Zir CAD-CAM = milled zirconia framework. The horizontal |X| and vertical |Y| misfits were measured using confocal laser scanning microscopy with one or both screws tightened. Data were analyzed by a two-way ANOVA with repeated measures and Bonferroni correction (α = 0.05). RESULTS: The greatest |X| misfit was observed in the OP group with both screws tightened (290 µm) and one screw tightened (388 and 340 µm). The conventional casting groups sectioned and welded by laser or TIG had lower mean values (235.35 µm, both screws tightened; and 275 µm, one screw tightened) than the OP framework. However, these values still exceeded those of the milled Co-Cr and zirconia frameworks (190 and 216 µm with both screws tightened). Across all reading conditions, every framework subjected to testing consistently maintained vertical |Y| misfit levels below the threshold of 53 µm; however, the milled frameworks exhibited higher vertical misfits than the frameworks obtained by the conventional cast method. CONCLUSIONS: The frameworks, whether cast and sectioned with laser welding or milled from Co-Cr, exhibit improved marginal misfit and enhanced passive fit when compared to other fabrication methods. Additionally, the use of confocal laser scanning microscopy is highly effective for passivity and misfit analysis.

A Stereophotogrammetry Face Study Between Dentate and Edentulous Adults Rehabilitated with Either a Conventional Complete or an Implant-Supported Fixed Complete Denture.

Quantifying in edentulous patients the facial collapse and whether complete conventional denture (CCD) and implant-supported fixed complete denture (ISFCD) can restore the facial proportions to match those of a dentate patient (CG) is relevant for clinical dentists. One hundred and four participants were enrolled and divided into edentulous (n=56) and CG (n=48). The edentulous participants were rehabilitated with CCD (n=28) or ISFCD (n=28) in both arches. Anthropometric landmarks in the face were marked and captured by stereophotogrammetry. Linear, angular, and surface measurements were analyzed and compared among groups. The statistical analysis was performed by an independent t-test, the one-way ANOVA, and Tukey's test. The significance level was set at 0.05. The facial collapse was quantified as a significant shortening of the lower third of the face affecting facial aesthetics in all parameters evaluated and the same was observed in comparison among CCD, ISFCD, and CG. The CCD presented statistical differences with the CG group in the lower third of the face and labial surface, and the ISFCD showed no statistical differences with the CG and CCD. The facial collapse in edentulous patients could be restored through oral rehabilitation with an ISFCD similar to those of dentate patients.

The effect of abutment material stiffness on the mechanical behavior of dental implant assemblies: A 3D finite element study.

PURPOSE: This study aimed to evaluate the stress distribution and microgap formation in implant assemblies with conical abutments made of different materials under an oblique load. MATERIALS AND METHODS: The mechanical behavior of an implant assembly with a titanium abutment was analyzed and compared with that of an assembly with a Y-TZP abutment using finite element analysis (FEA). A torque of 20 Ncm was first applied to the abutment screw, followed by oblique loads of 10 N-280 N applied to the prosthesis placed on the implant. The maximum stress in the abutment screw, the microgap formation process, and the critical load for bridging the internal implant space were evaluated. RESULTS: No significant difference in stress distribution between the two cases was observed, with the stresses being mainly concentrated at the top half of the screw (the predicted maximum von Mises stress was approximately 1200 MPa at 280 N). The area in contact at the implant-to-abutment interface decreased with increasing load for both abutments, with the critical load for bridging the internal implant space being roughly 140 N. The maximum gap size being was approximately 470 µm with either abutment. CONCLUSION: There was no significant difference in the stress distribution or microgap formed between implant assemblies with titanium and Y-TZP abutments having an internal conical connection.

In Silico Mechanical Effort Analysis of the All-On-4 Design Performed With Platform-Switching Distal Short Dental Implants.

Short dental implants with platform matching connection have been used for the rehabilitation of atrophic jaws whenever standard-length dental implants cannot be placed without prior bone augmentation. Yet, there remains a lack of data regarding the risk of technical failures when the all-on-4 configuration is performed in atrophic jaws with platform-switching distal short dental implants. Thus, the current study used the finite element method to evaluate the mechanical behavior at the level of the prosthetic components of the all-on-4 concept performed in atrophic mandible using short-length distal implants with platform switching (PSW) connection. Three models of the all-on-4 configuration were generated in human atrophic mandibles. The geometric models consisted of PSW connection tilted standard (AO4T; θ = 30 deg; 11 mm-length), straight standard (AO4S; θ = 0 deg; 11 mm-length) and straight short (AO4Sh; θ = 0 deg; 8 mm-length) distal implants. A resultant force of 300 N was performed obliquely in the left side and posterior region of the prosthetic bar. The von Mises equivalent stress (σvm) and maximum and minimum principal stresses (σmax and σmin) were performed at level of the prosthetic components/implants and peri-implant bone crest, respectively. The general displacement of the models was also evaluated. The stress analysis was performed on the side of load application. The AO4S configuration showed the lowest values of σvm in the mesial left (ML) and distal left (DL) abutments (37.53 MPa and 232.77 MPa, respectively) and dental implants (91.53 MPa and 231.21 MPa, respectively). The AO4Sh configuration showed the highest values of σvm in the bar screw (102.36 MPa), abutment (117.56 MPa), and dental implant (293.73 MPa) of the ML area. Among the models, the highest values of σmax and σmin were noticed in the peri-implant bone crest of the AO4T design (131.48 MPa and 195.31 MPa, respectively). All models showed similar values of general displacements, which were concentrated in the mandible symphysis. The all-on-4 configurations designed with PSW connection and tilted standard (AO4T; θ = 30 deg; 11 mm-length), straight standard (AO4S; θ = 0 deg; 11 mm-length) or straight short (AO4Sh; θ = 0 deg; 8 mm-length) distal implants were not associated with higher odds of technical failures. The AO4Sh design may be a promising option for the prosthetic rehabilitation of atrophic jaws.

Radiographic evaluation of the success of implant-supported total prostheses on conical external hexagon implants and 6-month follow-up after installation of the prostheses

The development of dental implants has revolutionized the rehabilitation possibilities for partially or totally edentulous patients. The long-term success of the dental implant depends on osseointegration and this is achieved by the combination of two essential stabilities: primary and secondary. Implant-supported prostheses are a great evolution for these treatments, positively interfering in the quality of life of the population, as they generate function and aesthetics for the patient. Thus, the present study aimed to radiographically evaluate complete dentures supported by an external hexagon conical implant in the anterior region of the mandible. More specifically, to evaluate the feasibility of using these implants in cortical bone of the mandible, to verify the success rate regarding the significance of peri-implant bone loss and to compare peri-implant bone loss between patients.

Halitosis and Pain Threshold of Peri-Implant Tissues: An Observational Cohort Study

Abstract In this study, we aimed to evaluate the halitosis and pain threshold of the peri-implant soft tissues in individuals rehabilitated with implant-supported prostheses. Forty-eight subjects were divided into four groups (n = 12) according to their prosthetic rehabilitation: single-tooth fixed prosthesis, multi-tooth fixed prosthesis, overdentures, and the Brånemark protocol. Halitosis was measured using a halimeter, whereas the pain threshold was measured using Von Frey monofilaments. Measurements were taken before (t0) and 30 days after (t1) placement of healing caps, and at the time of (t2) and 30 days after (t3) prosthetic placement. Halitosis data were analyzed using the chi-square test and Bonferroni correction (p < 0.05). Two-way ANOVA and Tukey's test (p < 0.05) were used to analyze pain threshold data. We noted an association between halitosis and time for the Brånemark protocol [X2(6) = 18.471; p = 0.005] and overdenture groups [X2(6) = 17.732; p = 0.007], and between halitosis and type of prosthesis only at t0 [X2(6) = 12.894; p = 0.045]. The interaction between time and the type of prosthesis significantly interfered with the mean pain threshold values (p = 0.001). At most time points, the majority of participants in each group had clinically unacceptable halitosis. After 30 days of using the prostheses, the overdenture group had a lower pain threshold compared to the Brånemark protocol group.

Resumo Este estudo teve como objetivo avaliar a halitose e o limiar de dor dos tecidos moles peri-implantares em indivíduos reabilitados com próteses implantossuportadas. Um total de 48 indivíduos foram divididos em quatro grupos (n=12), de acordo com as reabilitações: prótese fixa unitária, prótese fixa multidentária, sobredentadura e protocolo de Brånemark. A halitose foi medida com um halímetro, enquanto o limiar de dor foi medido com monofilamentos de von Frey. As medições foram feitas antes (t0) e 30 dias após (t1) a colocação das tampas de cicatrização e no momento (t2) e 30 dias após (t3) a colocação da prótese. Os dados de halitose foram analisados por meio do teste qui-quadrado e correção de Bonferroni (p < 0,05). ANOVA de duas vias e o teste de Tukey (p < 0,05) foram usados para analisar os dados do limiar de dor. Observou-se associação entre halitose e tempo para o protocolo de Brånemark [X2(6) = 18,471; p = 0,005] e grupos overdenture [X2(6) = 17,732; p = 0,007], e entre halitose e tipo de prótese apenas em t0 [X2(6) = 12,894; p = 0,045]. A interação entre o tempo e o tipo de prótese interferiu significativamente nos valores médios do limiar de dor (p = 0,001). Na maioria dos pontos de tempos, a maioria dos participantes de cada grupo apresentava halitose clinicamente inaceitável. Após 30 dias de uso das próteses, o grupo overdenture apresentou menor limiar de dor em comparação ao grupo do protocolo de Brånemark.

Transición de prótesis removible a rehabilitación fija de arco completo sobre implantes: Impacto en el perfil facial. Reporte de caso / Transition from removable denture to a fixed full-arch implant-supported dental prosthesis: Impact on facial profile. Case report

El perfil facial de un paciente con prótesis total removible podría no ser óptimo cuando el paciente tiene rebordes óseos conservados tridimensionalmente, planteando la necesidad de una prótesis dentaria y no dentogingival. El objetivo de este reporte es describir la transición y tratamiento de una paciente desdentada maxilar, usuaria de prótesis removible con excesivo soporte labial y disponibilidad ósea favorable. En la planificación se prueban parámetros estéticos mediante una ordenación dentaria sin flanco y en base a esta se planifica una "Cirugía de Implantes Protésicamente Guiada" para rehabilitación fija de arco completo sobre implantes en posiciones 1.6, 1.3, 1.1, 2.1, 2.3 y 2.6. Se concluye que con la técnica descrita se puede realizar una evaluación clínica veraz de la propuesta protésica, lo que se traspasa a la guía radiográfica y quirúrgica. Lo anterior permite consistencia entre planificación, cirugía, provisonalización y prótesis definitiva.

The facial profile of a patient with a complete removable denture may not be optimal when the patient has a three-dimensionally preserved bone ridge, raising the need for a dental rather than dentogingival prosthesis. The objective of this report is to describe the transition and treatment of a maxillary edentulous patient, user of a removable prosthesis with excessive lip support and favorable bone availability. In the planning phase, aesthetic parameters are tested using a dental set-up without flank. Based on this, a "Prosthetically Driven Implant Surgery" is planned for a fixed full-arch implant-supported prosthesis with implants located in 1.6, 1.3, 1.1, 2.1, 2.3 and 2.6. It is concluded that, with the described technique, a truthful clinical evaluation of the prosthetic proposal can be performed, and then transferred to the radiographic and surgical guide. This allows consistency between planning, surgery, provisionalization and final prosthesis.

Single implant overdenture reinforced with a metallic framework: A 2-year clinical follow-up.

INTRODUCTION: To prevent single-implant overdenture (SIO) fracture, the inclusion of a framework in the overdenture has been suggested. However, no investigations verified their benefits. OBJECTIVE: To evaluate prosthetic maintenance events, patient satisfaction, and mastication of SIO reinforced by metallic framework users. MATERIAL AND METHODS: Fifteen volunteers had a new set of complete dentures converted into an SIO containing a framework. Maintenance events were recorded, while patient satisfaction was assessed using a visual analog scale. Masticatory performance (MP) was evaluated using the sieving method, maximum bite force (MBF) by pressure sensors, and masseter thickness by ultrasound. Measurements were performed 2, 12, and 24 months after SIO use. Repeated-measures ANOVA and paired Student's t-tests (p < 0.05) were applied. RESULTS: Matrix exchange was the most prevalent maintenance event (83.6%), and no SIO was fractured during the entire follow-up. Satisfaction with the SIO stability decreased (p < 0.01) after 12 months. MP did not change between evaluations (p > 0.05). Conversely, MBF and masseter thickness improved after 12 and 24 months of SIO use (p < 0.05). CONCLUSIONS: Reinforced SIO did not fracture during 2 years but requires maintenance. It improves bite force and muscle thickness, maintaining MP values. Satisfaction with SIO stability decreased in the first year of use.

Implant and prosthesis survival rates of full-arch immediate prostheses supported by implants with and without bicortical anchorage: Up to 2 years of follow-up retrospective study.

OBJECTIVES: To compare implant and prosthesis survival rates between full-arch immediate prostheses supported by 4 hydrophilic implants with bicortical anchorage and by 5 or 6 hydrophilic implants placed without bicortical anchorage. MATERIAL AND METHODS: The sample was retrospectively selected and comprised completely edentulous patients treated with full-arch immediate prostheses supported by Morse Taper hydrophilic implants. The selected patients were divided into four groups, according to the region of implant placement and type of anchorage. Differences in implant and prosthesis survival rates between groups, as well as the influence of bicortical anchorage on implant primary stability, were verified using Fisher's exact tests (significant at p < .05). RESULTS: The sample comprised 392 implants, 72 were placed in the maxilla with bicortical anchorage, and 85 were placed without. In the mandible, 140 implants were placed with and 95 were placed without bicortical anchorage. The follow-up period was up to 24 months. A 98.8% implant survival rate was observed for the group of implants placed without bicortical anchorage in the maxilla, and of 100% for the other groups. The overall implant survival rate was 99.7% (391 of 392 implants). Prosthesis survival rate was 100% for all groups. No differences were observed between groups with respect to implant and prosthesis survival rates. Significantly higher primary stability was observed for implants placed with bicortical anchorage in both jaws. CONCLUSION: Predictable results and high survival rates were achieved within the period evaluated by the present retrospective study, with immediate full-arch prostheses when only four hydrophilic implants are placed bicortically.

[Prosthetic intermediaries in oral implantology: Literature review]. / Intermediarios protésicos en implantología oral. Revisión de la literatura.

Prosthetic intermediaries in oral implantology are attachments that allow connection between the implant and the prosthesis itself. Although this rehabilitation has a high success rate; the selection of the prosthetic abutment represents is important in implant treatment. Currently, there is a great variety of intermediate abutments, corresponding to various techniques and materials. Prosthetic intermediaries can be classified according to the type of connection, their retention to the prosthesis, their axial relationship with the implant body, the manufacturing material and type of manufacture, or whether rehabilitation is single or multiple. This scenario can lead to doubts as to the selection of the ideal implant attachment in each case in order to achieve satisfactory rehabilitation, as well as functional and aesthetic requirements and the preservation of biological principles. Indeed, oral implantology has revolutionized dentistry and will continue to expand the range of possibilities; therefore, it is important to classify the prosthetic options available. The present literature review aims to demonstrate the different alternatives and options available for the intermediate abutments most used in implant prostheses.

Prótesis sobre implantes: ¿atornillada o cementada? / Implant supported prosthesis: screw retained or bonded?

El objetivo de este artículo es revisar la evidencia científica existente acerca de los tipos de retención protética fija sobre implantes: atornillada, cementada y cemento-atornillada. Fueron evaluadas sus ventajas y desventajas a fin de facilitar al clínico la elección del sistema de retención en el tratamiento rehabilitador con implantes. Si bien la evidencia científica no es concluyente, la prótesis atornillada presentaría más complicaciones técnicas, y las cementadas, más complicaciones biológicas. Por ello, las prótesis cemento-atornilladas podrían ser en la actualidad una opción de elección, por su versatilidad en la rehabilitación implanto-soportada, combinando las ventajas de cada tipo de retención (AU)

The objective of this article is to review the existing scientific evidence about the different types of retention of fixed prosthetic on implants: screwed, cemented and cement-screwed. The advantages and disadvantages of them were evaluated in order to facilitate the clinician's choice of the retention system in the rehabilitation treatment with implants. Although the scientific evidence is inconclusive, the screwed prosthesis would present more technical complications, while the cemented, more biological complications. Therefore, cement-screwed prostheses could be an option of choice, due to their versatility when rehabilitating an implant, combining the advantages of each type of retention (AU)

Occlusion in implant- At a glance

Objectives: Occlusion is a critical and very important component for the clinical success and longevity of dental implants. This review article focuses on the various aspects of implant protective occlusion. Our scientific literature regarding implant occlusion, particularly in implant-supported fixed dental prostheses remains controversial. Materials and methods: A search strategy was performed in MEDLINE/PubMed, Scopus and Google Scholar with keywords ­ 'implants' and 'occlusion', 'implants' and 'fixed prosthesis, 'implants' and 'fixed dental prostheses', 'implants' and 'partial edentulism', 'implants' and 'complications', 'implants' and 'failures', 'implants' and 'cantilever', 'implants' and 'occlusal load'. Results: 135 articles were retrieved. After hand search a total of 290 articles were identified. Ultimately, 30 articles were selected and summarized and discussed as they met the selection criteria. Conclusion: Most of the available clinical data are controversial. Implant-protected occlusion can be accomplished by decreasing the width of the occlusal table and improving the direction of force. By doing these things, we can minimize overload on bone-implant interfaces and implant prostheses, to maintain an implant load within the physiological limits of individualized occlusion, and ultimately provide long-term stability of implants and implant prostheses. Current clinical practices rely heavily on principles extracted from the natural dentition or removable dental prostheses on complete edentulous patients and on expert opinions.

A importância do planejamento reverso em reabilitações com implantes dentários / The importance of reverse planning in rehabilitation with dental implants

As reabilitações orais sempre foram um grande desafio para a Odontologia e atualmente têm atingido grande destaque na Implantodontia, em especial quando se trata de elementos a serem repostos. Desse modo, é possível substituir cada elemento perdido com implante no respectivo espaço onde houve a perda dental ou até mesmo confecção de próteses totais fixas e sustentadas por implantes osseointegráveis por meio de protocolos reabilitadores. O planejamento reverso do tratamento reabilitador é fundamental para o sucesso do tratamento e tem por função a visualização, diagnóstico, prevenção e eliminação de problemas que possam comprometer a reabilitação final do paciente por meio de complicações estéticas e função das futuras restaurações implantossuportadas. Assim, o objetivo do presente trabalho foi relatar o plano de tratamento de uma paciente que necessita de reabilitação oral com prótese implantossuportada, seguindo técnicas e indicações baseadas na literatura, enfatizando a importância do planejamento reverso. Realizou-se uma cirurgia com implantes osseointegráveis seguindo os princípios de uma correta instalação, usando guias cirúrgicas, próteses diagnósticas para ampliar a previsibilidade de tratamento. Concluiu-se que o sucesso do tratamento reabilitador está diretamente relacionado com o planejamento inicial e correta abordagem clínica multidisciplinar (AU).

Oral rehabilitations have always been a great challenge for Dentistry and nowadays it has achieved great prominence in Implantology, especially in relation to elements replacement. Thus, it is possible to replace each lost element with implant in the respective space where there was dental loss or even the manufacture of prosthesis total fixed and supported by osseointegratable implants through rehabilitation protocols. The reverse planning of the rehabilitation treatment is essential to treatment success and has as its function the visualization, diagnosis, prevention, and elimination of problems that could impair patient final rehabilitation due to aesthetic and function complications of the future implant-supported restorations. Thus, the objective of the present study was to report the treatment plan of a patient who needs oral rehabilitation with implant-supported prosthesis, following techniques and indications based on the literature, emphasizing the importance of reverse planning. Osseointegrated implants surgery was performed following the principles of a correct installation, using surgical guides diagnostic prosthesis to increase treatment predictability. It was concluded that rehabilitation treatment success is directly related to the initial planning and correct multidisciplinary clinical approach (AU).

Influence of transmucosal height in abutments of single and multiple implant-supported prostheses: a non-linear three-dimensional finite element analysis.

The aim of this study was to analyze the influence of three different transmucosal heights of the abutments in single and multiple implant-supported prostheses through the finite element method. External hexagon implants, MicroUnit, and EsthetiCone abutments were scanned and placed in an edentulous maxillary model obtained from a tomography database. The simulations were divided into two groups: (1) one implant with 3.75 × 10 mm placed in the upper central incisor, simulating a single implant-supported fixed prosthesis with an EsthetiCone abutment; and (2) two implants with 3.75 × 10 mm placed in the upper lateral incisors with MicroUnit abutments, simulating a multiple implant-supported prosthesis. Subsequently, each group was subdivided into three models according to the transmucosal height (1, 2, and 3 mm). A static oblique load at an angle of 45 degrees to the long axis of the implant in palatal-buccal direction of 150 and 75 N was applied for multiple and single implant-supported prosthesis, respectively. The implants and abutments were assessed according to the equivalent Von Mises stress analyses while the bone and ceramics were analyzed through maximum and minimum principal stresses. The total deformation values increased in all models, while the transmucosal height was augmented. The transmucosal height of the abutments influences the stress values at the bone, ceramics, implants, and abutments of both the single and multiple implant-supported prostheses, with the transmucosal height of 1 mm showing the lowest stress values.

Avaliação da transmissão de temperatura da resina acrílica para os ossos cortical e medular por meio de redes de Bragg / Evaluation of the temperature transmission of the acrylic resin to the cortical and medullary bones through the Bragg's grating

O objetivo do estudo foi avaliar a alteração de temperatura nos ossos cortical e medular gerados pela resina acrílica na união dos transferentes por meio das redes de Bragg. Foram selecionados dois implantes cone morse Titamax (Neodent) 4 mm x 15 mm. Os implantes foram inseridos em um osso artificial da marca Sawbones, de acordo com as instruções do fabricante, cuja localização dos pilares foi referente aos dentes 44 e 46 com ausência do dente 45. Sobre os implantes foram instalados transferentes para a técnica aberta. Os transferentes foram esplintados por meio de um fio dental e aplicação de resina acrílica pela técnica de Nealon. Foram selecionadas duas resinas acrílicas: Duralay e GC Pattern LS. Dois sensores de fibra ótica foram posicionados, sendo um próximo à região cervical e outro na região apical do implante. Os sensores mensuraram a transferência de calor para o osso cortical e medular com o auxílio de uma pasta térmica (Implastec). Os dados foram submetidos à análise estatística por meio dos testes de normalidade de Shapiro-Wilk, ANOVA a dois critérios e teste de múltiplas comparações post hoc LSD (p<0,05). Foram encontradas diferenças significativas entre Duralay apical eGC Pattern LS cervical, GC Pattern LS cervical eGC Patternapical (p<0,05). As redes de Bragg apresentaram-se sensíveis para a mensuração da transferência de temperatura do transferente para os ossos cortical e medular. A partir dos resultados obtidos, pode-se afirmar que não há risco de necrose óssea (AU).

The purpose of the study was to evaluate the temperature change in the cortical and medullary bones generated by the acrylic resin in the union of transferents through the Bragg's grating. Two cone morse Titamax (Neodent) 4 mm x 15 mm implants were selected. The implants were inserted into a Sawbones artificial bone according to the manufacturer's instructions, abutment location were teeth 44 and 46 with absence of tooth 45. On the implants tranfers were installed for the open technique. The transfers were splined by means of a dental floss and acrylic resin application by the Nealon technique. Two acrylic resins were selected: Duralay and GC Pattern LS. Two fiber optic sensors were positioned, one near the cervical region and other at the implant apical region. The sensors measured the heat transfer to the cortical and medullary bones with the help of a thermal paste (Implastec). Data were submitted to statistical analysis using Shapiro-Wilk normality tests, two way ANOVA, and post hoc LSD multiple comparisons (p <0.05). Significant differences were found between Duralay apical and GC Pattern LS cervical, GC Pattern LS cervical and GC apical Pattern (p <0.05). The Bragg's grating were sensitive to temperature transference measurement from transfers to the cortical and medullary bones. From the results obtained, it is possible to ssure that there is no risk of bone necrosis (AU).

Reabilitação estética associando pilar personalizado sobre implante e laminados cerâmicos - relato de caso / Aesthetic rehabilitation associating personalized abutment on implants and ceramic veneers ­ case report

Reabilitações por meio de coroas implanto-suportadas em pacientes que perderam um elemento dentário em região anterior é uma abordagem bem consolidada e pode ser associada a outras técnicas, como o uso de laminados cerâmicos. No entanto, alcançar um resultado estético satisfatório por meio da associação dessas duas abordagens pode ser um desafio para o clínico e o técnico. Objetiva-se relatar um caso clínico de reabilitação estética por meio de laminados cerâmicos, descrevendo uma técnica de confecção de pilar personalizado para laminados sobre implante. Paciente gênero feminino apresentava falta de harmonia da prótese sobre implante do elemento 21 com os demais dentes superiores e apresentava o anseio pela obtenção de dentes com a aparência mais natural. Elaborou-se um planejamento clínico com a realização de adequação do meio bucal seguida por cirurgia periodontal para correção da margem gengival, troca da coroa sobre implante do elemento 21 por um pilar personalizado para receber um laminado cerâmico e confecção de laminados cerâmicos dos dentes 14 a 24. Esse desenho diferenciado do pilar do elemento 21 foi motivado pela dificuldade de acerto de cor, visando uma aparência natural, uma vez que a espessura da cerâmica utilizada para a confecção dos laminados e das coroas totais, e os substratos em que elas são cimentadas são diferentes. A associação de um pilar personalizado sobre implante aos laminados cerâmicos permitiu uma melhor caracterização de cor, otimizando os resultados estéticos.

Pilar personalizado de zircônia: técnica de confecção do pilar definitivo baseado no perfil de emergência da restauração provisória ­ relato de caso / Zirconia custom abutment: technique for Replicating the Profile of a Provisional Implant Crown on the Definitive Implant Crown ­ case

O objetivo deste trabalho foi descrever uma técnica para confecção de pilar personalizado de zircônia híbrido baseado no perfil de emergência da restauração provisória através de um relato de caso clínico. O caso descrito teve a seguinte ordem de tratamento: diagnóstico e planejamento; exodontia e instalação de implante com coroa provisória imediata parafusada e preenchimento do gap com biomaterial. Após seis meses, moldagem personalizada utilizando transfer de moldagem modificado; confecção do pilar de zircônia com mesmo perfil de emergência da coroa provisória; instalação do pilar de zircônia; cimentação da coroa livre de metal. Os resultados obtidos preencheram todos os requisitos estéticos e funcionais. Concluiu-se que a técnica descrita apresenta previsibilidade e excelentes resultados estéticos.

The aim of this work was to present through a clinical case report, a technique for manufacturing a customized zirconia hybrid abutment, based on the emergency profile restoration. The case was treated following the subsequent clinical treatment protocol: diagnostic and treatment planning; extraction of 22; implant placement and immediate screw provisional crowns. After six months, fabrication of zirconia custom hybrid abutments with the same emergency profile of provisional crowns; custom hybrid abutments placement and new cemented provisional crowns on the abutments; cementation of the metal free crowns. The results met all the aesthetic and functional requirements. This technique showed predictability and excellent aesthetics results.

Estética e higiene em próteses do tipo protocolo superior ­ relato de caso / Aesthetics and cleansing in upper protocol-type prostheses ­ case report

Para obter estética e funcionalidade em prótese implantada, vários detalhes devem ser observados. Um detalhe importante em próteses do tipo protocolo é a presença de espaço para higienização. Este caso clínico relata um caso em que a paciente utilizava uma prótese do tipo protocolo superior e prótese parcial removível inferior Classe I de Kennedy. Contudo, a paciente estava insatisfeita com sua prótese superior em relação à estética e dificuldade para higienização. Durante a consulta para diagnóstico e planejamento esses problemas reportados pela pacientes ficaram evidentes: mal posicionamento dos dentes, falta de espaço para corredor bucal e desvio de linha média. foi proposto a paciente a confecção de novas próteses superior e inferior, que seguiram todos os passos necessários para alcançar estética e funcionalidade. A etapa de prova de dentes superiores foi realizada três vezes, até que estivesse ideal. Após a acrilização da prótese superior foram criadas pequenas canaletas para guiar a passagem do fio dental entre os implantes, facilitando o processo de higienização. Este caso clínico demonstra que todos os parâmetros necessários para a confecção de uma prótese total adequada devem ser respeitados durante a confecção de uma prótese do tipo protocolo sobre implantes. Além disso, a confecção das canaletas para higienização permite que o paciente realize esse processo de forma satisfatória, podendo aumentar o tempo de sucesso do tratamento.

To achieve good aesthetics and function in implant-supported dental prosthesis several details must be observed. One important detail for protocol-type prosthesis is the presence of a cleansing space. This paper reports the case of a patient with upper protocol-type prosthesis and an inferior partial Kennedy Class I removable prosthesis. however, the patient was unsatisfied with the aesthetics of the upper prosthesis as well as with the difficulty of cleaning it. During consultation for diagnosis and planning the problems reported by the patient became evident: wrong positioning of the teeth, lack of buccal corridor and midline deviation. The recommendation was to manufacture new lower and upper prostheses, following all the required steps in order to achieve satisfactory aesthetics and function. for the upper teeth try-in stages were performed, until the ideal fit was reached. After acrylic cure of the upper prosthesis was performed, furrows were created in the region between the implants, serving as guide to facilitate the passage of dental floss, making it easier to clean the prosthesis. The aim of this study was to demonstrate, that all the parameters observed in the manufacture of a conventional complete denture should be followed in the confection of protocol type prosthesis. Also, the furrows allow proper hygiene, which may increase the duration of the treatment success.

Influence of Cyclic Fatigue in Water on Screw Torque Loss of Long-Span One-Piece Implant-Supported Zirconia Frameworks.

PURPOSE: It is still unclear whether four, six, or more implants should be used when restoring fully edentulous maxillae. This research evaluated the in vitro screw torque loss of zirconia frameworks supported by six implants and cantilevered zirconia frameworks supported by four implants. MATERIALS AND METHODS: Computer aided design/computer-assisted machining was used to fabricate 10 one-piece frameworks. Standardized pressable porcelain crowns were fabricated and luted to the frameworks. Specimens were divided into two groups (n = 5): AO4, cantilevered 12-unit full-arch fixed dental prosthesis supported by four implants; AO6, 14-unit supported by six implants. An opposing mandibular dental arch was fabricated with bis-acrylic composite resin. Specimens were submitted to 200 N underwater cyclic load at 2-Hz frequency for 1 × 106 cycles in a controlled 37°C temperature. A digital torque gauge assessed the initial and postload screw removal torque. Linear mixed-effects model was used for statistical analysis (α = 0.05). RESULTS: Significant screw torque loss was found for AO6 after cyclic loading (before: 36.20%/after: 52.82%; p < 0.05). Group AO6 (36.20%) presented lower preload loss before the cyclic loadings compared with AO4 (60.10%) (p < 0.05). CONCLUSIONS: Cyclic loading and lower implant-to-replaced-units ratio do not seem to compromise screw stability compared with higher implant-to-replaced-units ratio; however, a steep drop in preload was found before cyclic loading for both groups.