Assessment of a novel electrochemically deposited smart bioactive trabecular coating (SBTC®): a randomized controlled clinical trial.

OBJECTIVES: A randomized controlled clinical trial of dental implants was conducted to compare the clinical properties of a novel electrochemically deposited calcium phosphate coating to those of a common marketed surface treatment. MATERIAL AND METHODS: Forty implants of the same brand and type were placed in 20 fully edentulous participants requiring mandibular implantation. The two study groups were defined by the surface treatment of the implants. 20 implants in the control group were coated via a commercial electrochemical surface treatment that forms a mixture of brushite and hydroxyapatite, while the remaining 20 in the test group were coated with a novel electrochemical Smart Bioactive Trabecular Coating (SBTC®). A split-mouth design was employed, with each participants receiving one control implant in one mandibular side and a test implant in the other. To mitigate potential operator-handedness bias, control and test implants were randomly assigned to mandibular sides. All cases underwent digital planning, implant placement with a static surgical guide, and participants received locator-anchored full-arch dentures. The primary outcome was implant stability (measured using Osstell ISQ) assessed at insertion, loading, and then 3 months, 9 months, and 2 years post-insertion. The secondary outcome was bone level change (in millimeters) over the 2-year observation period. Oral health-related quality of life (OHRQL) was monitored using the OHIP-14 questionnaire. Complications and adverse events were recorded. RESULTS: Successful osseointegration and implant stability were achieved in all cases, allowing loading. ISQ values steadily increased throughout the observation period. While no significant differences were observed between the SBTC® and control coatings, the test group exhibited a higher ISQ gain. Bone resorption was somewhat lower in the SBTC® but not significantly so. Patients' OHRQL significantly improved after denture delivery and remained stable throughout the follow-up. No complications or adverse events were observed. CONCLUSIONS: Based on the study results, we conclude that the new surface treatment is a safe alternative to the widely used control surface, demonstrating similar osseointegrative properties and time-dependent bone level changes. Further research may explore the broader implications of these findings. TRIAL REGISTRATION: The study is registered on clinicaltrials.gov under the identifier ID: NCT06034171.

Cost-Effectiveness Analysis of Implant-Supported Single Crown and Tooth-Supported Fixed Dental Prostheses in Türkiye.

OBJECTIVES: The most cost-effective option for replacing lost teeth is not evident because there is a dearth of evidence-based information on implant-supported single crowns versus tooth-supported fixed dental prostheses. This study conducted the analysis of cost-effectiveness of implant-supported single crown and tooth-supported fixed dental prostheses from a social perspective in Türkiye. METHODS: Costs were calculated in the analysis from a social perspective for 2021. Costs and quality-adjusted prosthesis year (QAPY) values were computed over a 20-year period in the study using the Markov model. The computed values were discounted by 5%. The results are presented as the incremental cost-effectiveness ratio. To assess the impact of uncertainty on cost-effectiveness analyses, a tornado diagram and Monte Carlo simulations were created. RESULTS: Throughout the 20-year time horizon, tooth-supported fixed dental prostheses cost $985.58 cumulatively, whereas implant-supported single crown cost $2161.64 (US $1 = 9.22 ₺ as of 15 October 2021). The calculated incremental cost-effectiveness ratio is 1.333 per QAPY. Compared with the implant-supported single crown tooth-supported fixed dental prostheses, it offers a QAPY of 0.882 over a 20-year period, while costing an additional $1176.06. CONCLUSIONS: These results suggest that the implant-supported single crown provided higher QAPY value but was costlier. When the research's findings are compared with the literature, it becomes clear that Türkiye has lower dental care expenses than most other nations.

In vitro assessment of polyetheretherketone for an attachment component for an implant-retained overdenture.

STATEMENT OF PROBLEM: Frequent maintenance because of the limited lifetime of overdenture attachments with O-rings has led to the development of materials that might improve their functionality and longevity. However, testing of newly developed attachment materials is lacking. PURPOSE: The purpose of this in vitro study was to evaluate a newly developed attachment made of polyetheretherketone (PEEK) for an implant-retained overdenture. MATERIAL AND METHODS: Specimens of PEEK, polyacetal, and Teflon O-ring materials were prepared for analysis of roughness, surface hardness, and compressive strength. For the fatigue resistance test, new specimens based on acrylic resin were subjected to 2880 insertion and removal cycles. Compression and roughness data were compared with the Kruskal-Wallis and Dunn post hoc test; hardness data with ANOVA and t test; and fatigue and stereomicroscopy with ANOVA with repeated measures, t test, and Bonferroni adjustment (α=.05). RESULTS: Polyacetal had the lowest surface roughness (P=.038). There was a significant difference in hardness among the materials (P<.05). PEEK presented the highest compressive strength among the materials (P<.001). For the fatigue resistance, only polyacetal showed a difference between the initial time-point (P<.05) and subsequent time-points. Polyacetal had a higher fatigue resistance than Teflon (P<.001) and PEEK (P<.05). Regarding the internal deformation of the attachments, a significant difference was observed among the materials (P<.05). CONCLUSIONS: PEEK showed promising results regarding the physicomechanical properties necessary for use as an overdenture attachment when compared with other evaluated materials. In addition, the PEEK attachment showed results comparable to those in the control group (O-rings) in terms of retention.

Cost-effectiveness of implant-supported dental prosthesis compared to conventional dental prosthesis.

OBJECTIVE: To conduct a cost-effectiveness analysis of alternatives for rehabilitation treatment of mandibular edentulism in the context of the Brazilian Unified Health System (implant-supported total dental prosthesis versus conventional total dental prosthesis). METHODS: A Markov model was developed to capture long-term clinical and economic outcomes. The model's population was comprised of a hypothetical cohort of 1,000,000 patients, aged 55 years, with total mandibular edentulism and without medical contraindications for performing surgical procedures. The adopted analysis perspective was that of the Brazilian Unified Health System. Based on the proposed model, we calculated cost - in BRL, and effectiveness - measured by quality-adjusted prosthesis year (QAPY). The time horizon of the analysis was 20 years. RESULTS: Considering a 5% discount in costs and effects, the incremental cost-effectiveness ratio of implant-supported total dental prostheses compared to conventional total dental prosthesis (BRL 464.22/QAPY) was lower than the willingness to pay threshold adopted in the model (BRL 3,050.00/QAPY). CONCLUSIONS: The results of this economic analysis showed that the rehabilitation of mandibular edentulous patients by implant-supported total prosthesis is very cost-effective when compared to conventional complete prosthesis, considering the cost-effectiveness limits employed.

Cost-effectiveness of implant-supported dental prosthesis compared to conventional dental prosthesis / Custo-efetividade da prótese implanto-suportada comparada à prótese total convencional

ABSTRACT OBJECTIVE To conduct a cost-effectiveness analysis of alternatives for rehabilitation treatment of mandibular edentulism in the context of the Brazilian Unified Health System (implant-supported total dental prosthesis versus conventional total dental prosthesis). METHODS A Markov model was developed to capture long-term clinical and economic outcomes. The model's population was comprised of a hypothetical cohort of 1,000,000 patients, aged 55 years, with total mandibular edentulism and without medical contraindications for performing surgical procedures. The adopted analysis perspective was that of the Brazilian Unified Health System. Based on the proposed model, we calculated cost - in BRL, and effectiveness - measured by quality-adjusted prosthesis year (QAPY). The time horizon of the analysis was 20 years. RESULTS Considering a 5% discount in costs and effects, the incremental cost-effectiveness ratio of implant-supported total dental prostheses compared to conventional total dental prosthesis (BRL 464.22/QAPY) was lower than the willingness to pay threshold adopted in the model (BRL 3,050.00/QAPY). CONCLUSIONS The results of this economic analysis showed that the rehabilitation of mandibular edentulous patients by implant-supported total prosthesis is very cost-effective when compared to conventional complete prosthesis, considering the cost-effectiveness limits employed.

RESUMO OBJETIVO Conduzir uma análise de custo-efetividade das alternativas para tratamento reabilitador do edentulismo mandibular no contexto do Sistema Único de Saúde (prótese total implanto-suportada e prótese total convencional). MÉTODOS Foi desenvolvido um modelo de Markov para captar os resultados clínicos e econômicos de longo prazo. A população do modelo consistiu em uma coorte hipotética de 1.000.000 pacientes, com 55 anos, desdentados totais mandibulares e sem contraindicações médicas para a realização de procedimentos cirúrgicos. A perspectiva de análise adotada foi a do Sistema Único de Saúde. Com base no modelo proposto, calculamos o custo (em reais) e a efetividade, medida pelo ano de prótese ajustado à qualidade (QAPY). O horizonte temporal da análise foi de 20 anos. RESULTADOS Considerando o desconto de 5% nos custos e efeitos, a razão de custo-efetividade incremental da prótese total implanto-suportada em relação à prótese total convencional (R$ 464,22/QAPY) foi menor que o limiar de disposição a pagar adotado no modelo (R$ 3.050,00/QAPY). CONCLUSÕES Os resultados desta análise econômica mostraram que a reabilitação de edêntulos mandibulares por meio da prótese total implanto-suportada é muito custo-efetiva em comparação à prótese total convencional, de acordo com os limites de custo-efetividade empregados.

Clinical and Radiographic Assessment of Three-Implant-Supported Fixed-Prosthesis Rehabilitation of the Edentulous Mandible: Immediate Versus Delayed Loading.

PURPOSE: To evaluate and compare the clinical and radiographic outcomes of mandibular rehabilitation with fixed prostheses on three implants with immediate versus delayed loading. MATERIALS AND METHODS: The sample comprised 21 patients who underwent treatment with immediate loading and 23 who received delayed loading. All had worn their prostheses for at least 18 months. Radiographic evaluation of bone loss was carried out in Adobe Photoshop CS5 by a single calibrated examiner using digitized panoramic radiographs. Clinical examination of the technical conditions of the prosthetic device assessed the condition of the acrylic resin base, dental occlusion, metal framework, presence of cover screws, screw fixation of the prosthesis and abutments, length of cantilever (effort) and resistance arms, presence of plaque on prosthetic abutments, and hygiene of the prosthesis. RESULTS: One implant failed in each group, resulting in a 95.23% treatment success rate with immediate loading and 95.65% with delayed loading (no statistically significant between-group difference). In the immediate-loading group, the mean bone loss was 1.96 ± 0.73 mm around central implants and 1.64 ± 0.84 mm at distal implants. In the delayed-loading group, the mean bone loss was 1.85 ± 0.67 mm around central implants and 1.70 ± 0.77 mm at distal implants. According to Student t test, there was no significant within-group difference in bone loss and no difference between the immediate-loading and delayed-loading groups. The only prosthesis-related complications that differed significantly between groups were "condition of the acrylic base," "occlusion," and "presence of right cover screw." There was no statistically significant association of lever arm ratio with peri-implant bone loss or bone loss on the mesial surfaces compared to the distal surfaces of the distal implants. CONCLUSION: The three-implant-supported fixed prosthesis protocol tested in this study proved to be a viable therapeutic strategy for mandibular edentulous patients with maxillary complete dentures, regardless of whether loading was immediate or delayed, with no difference in peri-implant bone loss.

Outcomes Assessment of Treating Completely Edentulous Patients with a Fixed Implant-Supported Profile Prosthesis Utilizing a Graftless Approach. Part 1: Clinically Related Outcomes.

PURPOSE: To assess outcomes of treating completely edentulous patients with a fixed implant-supported profile prosthesis utilizing a graftless approach for the maxilla and for the mandible, with emphasis on clinically related outcomes, specifically implant and prosthesis survival. MATERIALS AND METHODS: This was a retrospective study with the following inclusion criteria: completely edentulous patients rehabilitated with a fixed implant-supported profile denture utilizing a graftless approach. Patients fulfilling the inclusion criteria were asked to participate in the study during their follow-up visits, and hence a consecutive sampling strategy was used. Data regarding implant and prosthesis cumulative survival rates (CSRs) were gathered and calculated. RESULTS: Thirty-four patients were identified with a total of 220 implants placed. An overall CSR of 98.2% was recorded with an observation of up to 10 years. For tilted, axial, and zygomatic implants, CSRs of 96.9%, 98.0%, and 100%, respectively, were observed for up to 10 years. For provisional prostheses, CSRs of 92.3% at 1 year, and 84.6% at 2 years were observed. For final prostheses, a CSR of 93.8% was observed at 10 years. CONCLUSION: The results suggest that treating completely edentulous patients with a fixed profile prosthesis utilizing a graftless approach in the maxilla and the mandible can be a reliable treatment option.

Assessment of Long-Term Survival of Immediately Loaded Tilted Implants Supporting a Maxillary Full-Arch Fixed Prosthesis.

PURPOSE: To analyze the long-term outcome of fixed prostheses supported by six implants, two of which were tilted, placed in the maxilla and immediately loaded more than 10 years earlier. MATERIALS AND METHODS: A retrospective review of implants placed between May 29, 2003 and February 12, 2005 and used to support immediately loaded fixed dental prostheses in the maxilla was conducted. The features of failed implants were analyzed. In the most recent follow-up visits, survival of individual implants and prostheses was verified, and modified Plaque Index as well as modified Sulcular Bleeding Index were assessed. Patients also filled out a questionnaire requiring graded responses from 0 (poor) to 10 (excellent) that was designed to assess their quality of life. RESULTS: A total of 162 implants were placed between May 29, 2003 and February 12, 2005 to support immediately loaded maxillary fixed prostheses of 27 totally edentulous patients (19 female, 8 male). Three patients (1 male, 2 female) dropped out, so 144 implants were followed up. Seven of the 144 original implants failed, corresponding to a survival rate of 95.1% over 10 years. All the failures occurred within 2 years after surgery. Patients' responses to the questionnaire produced an average score of 8.4 to 8.8, showing a relevant degree of satisfaction. CONCLUSION: Based upon this study of 27 patients who received immediately loaded maxillary full-arch fixed implant-supported prostheses supported by two tilted and four axial implants, it appears that this is a reliable procedure with a high long-term survival rate and a high level of patient satisfaction.

Does a large dehiscent implant surface at placement affect the 5-year treatment outcome? An assessment of implants placed to support a maxillary overdenture.

The aim of this study was to assess the 5-year clinical and radiographic outcome of implants with a dehiscent surface at implant placement. A total of 26 consecutive patients (mean age 61.6 years; SD 8.0 years) with at least one implant with a dehiscent implant surface of ≥ two thirds of the implant length on the labial side were included. All implants were placed to support a maxillary overdenture. The implants were placed with adequate primary stability and the dehiscent surface was covered with autologous bone, inorganic bovine bone and a resorbable membrane. Outcome measures were soft tissue conditions, change of radiographic marginal bone level and implant survival. Baseline data (at loading, T0) were compared with 1-year (T1) and 5-year (T5) post loading data. Of the 116 implants, 40 implants had no dehiscence, 16 had a buccal dehiscence < two thirds of the implant length, and 60 implants had a dehiscence ≥ two thirds. The peri-implant tissues were healthy and 5-year marginal bone changes were well within normal limits (-0.4 mm; range: -0.8 to -0.1). One implant was lost during the osseointegration period. Even when implants are placed with a dehiscence ≥ two thirds of the buccal implant surface, favorable 5-year peri-implant health can be achieved provided these dehiscences are covered with autologous bone, inorganic bone and a resorbable membrane, and there is good initial stability of the implants.

All-on-4® Treatment Concept for the Rehabilitation of the Completely Edentulous Mandible: A 7-Year Clinical and 5-Year Radiographic Retrospective Case Series with Risk Assessment for Implant Failure and Marginal Bone Level.

BACKGROUND: Studies are needed to evaluate long-term outcomes of the All-on-4® treatment concept (Nobel Biocare AB) for rehabilitation of edentulous mandibles by assessing marginal bone levels and risk indicators for implant failure. PURPOSE: To evaluate 7-year clinical outcomes and 5-year radiographic outcomes of the All-on-4 treatment concept. MATERIALS AND METHODS: This retrospective case series included patients admitted for implant rehabilitations in the mandible, who were followed for 7 years clinically and 5 years radiographically. Primary outcome measures were cumulative prosthetic and implant survival using patient as the unit of analysis (Kaplan-Meier product limit estimator). Secondary outcome measure was marginal bone level (MBL) at 5 years. Variables associated with implant failure were analyzed using the Cox proportional hazards regression model to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Binary logistic regression was used to compute odds ratio (OR) with 95% CIs for variables associated with MBL ≥2.8 mm at 5 years. RESULTS: A total of 324 patients (194 women, 130 men, average age = 58.9 years) were rehabilitated with 1,296 implants supporting 324 full-arch fixed immediately loaded mandibular prostheses. Sixty-four patients (19.8%) were lost to follow-up. Prosthetic survival was 323/324 (99.7%), and 14 patients lost 18 implants, with an estimated cumulative survival rate of 95.4% at 7 years. Variables associated with implant failure were smoking (HR = 5.28; 95% CI: 1.33, 20.91]) and the learning curve effect (0.69 < HR < 0.33 for more experienced levels). Mean MBL at 5 years was 1.81 mm (95% CI: 1.70, 1.92), and smoking was associated with MBL ≥2.8 mm (OR = 2.4; 95% CI: 1.02, 5.62). CONCLUSIONS: The high implant and prosthetic survival rates and excellent MBL outcome confirm the predictability and safety of the All-on-4 treatment concept over a longer term than previously reported.

Avaliação dos contatos oclusais em próteses provisórias unitárias implantossuportadas confeccionadas com e sem arco facial / Evaluación de los contactos oclusales en prótesis temporales unitarias implantosoportadas montadas en articuladores semiajustables con arco facial / Assessment of occlusal contacts in implant-based single temporal prostheses in a semi-adjusted articulator using the facial arch

O presente estudo avaliou o número dos contatos oclusais obtidos em próteses provisórias unitárias sobre implantes posteriores, montadas em articulador semi-ajustável a partir da utilização de arco facial e de plano de Camper. Dez pacientes que procuraram uma clínica particular foram selecionados para confecção de próteses sobre implantes unitários previamente instalados. Para cada paciente foram confeccionadas duas próteses provisórias, obtidas sob diferentes condições: (1) montagem dos modelos utilizando arco facial e (2) montagem com plano de Camper. As próteses foram confeccionadas e ajustadas em laboratório, e instaladas por um único operador. Os contatos oclusais obtidos em cada condição foram evidenciados e fotografados, sendo então submetidos à avaliação e quantificação por um segundo profissional, cego para as condições de montagem. Os números obtidos foram submetidos ao teste de Mann Witney, e um nível de 5 por cento de significância foi utilizado. Não houve diferença estatisticamente significante entre os números de contatos oclusais, quando as próteses foram confeccionadas com arco facial ou plano de Camper (p> 0,05). Para confecção de próteses provisórias unitárias sobre implantes posteriores, o uso do plano de Camper para montagem em articulador não diferiu significantemente do arco facial, considerando o número de contatos oclusais(AU)

Este estudio evaluó el número de los contactos oclusales obtenidos en las prótesis temporales, montados en articulador semiajustable por el uso de arco facial y el plano de Camper. Diez pacientes que buscaron una clínica privada fueron seleccionados para las prótesis de implantes unitarios previamente instalados. Para cada paciente se hicieron dos prótesis temporales, que fueron obtenidas bajo condiciones diferentes: montaje de modelos con uso de arco facial y montaje con plano de Camper. Las prótesis fueron hechas, ajustadas e instaladas por un solo operador en el laboratorio. Los contactos oclusales obtenidos en cada condición fueron fotografiados y sometidos a la evaluación y cuantificación a través de un segundo profesional, ciego a las condiciones de montaje. Los números obtenidos fueron analizados mediante el examen de Mann-Whitney y un nivel de 5 por ciento de significación fue utilizado. No hubo diferencia estadísticamente significativa entre el número de contactos oclusales cuando las prótesis fueron hechas con arco facial o plano de Camper (p= 0,113). Para la confección de la prótesis dental temporal más tarde, el uso de montaje articular con plano de Camper no difirió significativamente del arco facial, respecto al número de contactos oclusales(AU)

To assess the number of occlusal contacts achieved in temporal prostheses mounted in a semi-adjusted articulator using the facial arch and the Camper plane. Ten patients treated in a private clinic were selected to be rehabilitated with prostheses in previously placed single implants. For each patient two temporal prostheses were designed obtained under different conditions: (1) model mounting using facial arch and (2) Camper plane mounting. Prostheses were made and adjusted in the laboratory and placed only by an operator. The occlusal contacts achieved in each condition were photographed being assessed and quantified by a second professional not involved with the mounting conditions. Results obtained were analyzed by Mann-Whitney test with a 5 percent significance level. There was not a statistically difference between the number of occlusal contacts when prostheses were made with facial arch or Camper plane (p= 0.113). The temporal dental prosthesis confection for single implants, semi-adjusted articulator using the Camper plane, not differ very much from the facial arch use, according to the number of resulting occlusal contacts(AU)

Avaliação da anatomia neurovascular da mandíbula por meio de tomografia computadorizada de feixe cônico / Assessment of neurovascular anatomy of the mandible through cone-beam computed tomography

A prescrição crescente de exames de imagem tridimensionais em Odontologia especialmente para procedimentos cirúrgicos na mandíbula como a inserção de implantes justifica o grande interesse na reavaliação dos reparos anatômicos nas imagens obtidas por tomografia computadorizada de feixe cônico (TCFC). O reconhecimento das variações anatômicas relacionadas à neurovascularização mandibular nestas imagens é de grande importância, uma vez que injúrias a estas estruturas podem resultar em danos, complicações e insucessos cirúrgicos. Este estudo, realizado em três etapas, se propôs a avaliar aspectos relacionados à anatomia neurovascular da mandíbula em imagens de TCFC. Na primeira etapa, avaliou-se a ocorrência de FM adicionais (FMA) e suas características. A prevalência encontrada foi de 9,4% e um total de 32 FMA foi registrado. Destes, 14 possuíam diâmetro correspondente a pelo menos 50% do diâmetro do FM ipsilateral e suas localizações foram variáveis. Dois casos de ausência de FM foram relatados. Na segunda etapa os CM foram avaliados quanto à presença de CM bífidos, alças anteriores do nervo mentual (AA) e corticalização. Também foi avaliado o trabeculado ósseo na região da fóvea submandibular (FSM). A prevalência de CM bífidos foi de 19%. Dos 19 casos observados, 14 estavam associados a FMA. Três casos estavam associados a forames retromolares associados a bifurcações do CM foram observados. Entre 22% e 28% da amostra apresentava AA e de 4% a 8% apresentava extensão anterior da AA significativa, maior que 4mm. Na região da FSM observou-se um trabeculado ósseo diminuído ou ausente na maioria dos casos, associados a maior frequência de ausência de corticalização do CM. Na terceira etapa, a imagem da radiografia panorâmica foi comparada à TCFC na visualização de variações anatômicas relevantes para o planejamento de implantes na região entre os forames. Houve grande discrepância entre os métodos nas observações referentes à presença de...

Current increase on prescription of sectional diagnostic imaging for surgical procedures involving the mandible, such as implant placement, has brought much interest in revisiting neurovascular anatomy with cone-beam computed tomography (CBCT) technology recently. Acknowledgement of such anatomical variations is quite important due to possible injuries to these structures leading to surgical complications and failures. The present study was carried out in three phases and aimed to assess different aspects related to neurovascular anatomy of the mandible on CBCT images. For phase one, occurrence of additional mental foramina (AMF) and their features were assessed. Prevalence was 9.4% and a total of 32 AMF were found. The diameter of the AMF was at least 50% the diameter of ipsilateral MF in 14 cases. Location of AMF was quite variable. Two cases showing absence of MF were registered. For phase two, MC was evaluated regarding the presence of bifid MC, anterior loop of the mental nerve (AL), and corticalization. Additionally, the bone trabeculation in the submandibular gland fossa region (SGF) was assessed. Prevalence of bifid MC was 19% (19 cases). Most cases (n=14) was associated with AMF and 3 cases were associated with retromolar foramina. Between 22% and 28% showed AL, and 4%-8% presented anterior extension of AL bigger than 4mm. SGF region presented decreased or absent trabeculation in most cases, which were associated with more frequent absence of MC corticalization. For phase three, panoramic radiographs (PR) were compared to CBCT regarding assessment of anatomical variations relevant for implant planning. Major discrepancies between PR and CBCT observations were noted regarding presence of AL, incisive canal, and FMA, as well as estimation of safe distance for implant placement. It is concluded that major anatomical variability related to mandibular neurovascularization and limitation of PR in displaying such variations point out to the importance of...

Avaliação da anatomia neurovascular da mandíbula por meio de tomografia computadorizada de feixe cônico / Assessment of neurovascular anatomy of the mandible through cone-beam computed tomography

A prescrição crescente de exames de imagem tridimensionais em Odontologia especialmente para procedimentos cirúrgicos na mandíbula como a inserção de implantes justifica o grande interesse na reavaliação dos reparos anatômicos nas imagens obtidas por tomografia computadorizada de feixe cônico (TCFC). O reconhecimento das variações anatômicas relacionadas à neurovascularização mandibular nestas imagens é de grande importância, uma vez que injúrias a estas estruturas podem resultar em danos, complicações e insucessos cirúrgicos. Este estudo, realizado em três etapas, se propôs a avaliar aspectos relacionados à anatomia neurovascular da mandíbula em imagens de TCFC. Na primeira etapa, avaliou-se a ocorrência de FM adicionais (FMA) e suas características. A prevalência encontrada foi de 9,4% e um total de 32 FMA foi registrado. Destes, 14 possuíam diâmetro correspondente a pelo menos 50% do diâmetro do FM ipsilateral e suas localizações foram variáveis. Dois casos de ausência de FM foram relatados. Na segunda etapa os CM foram avaliados quanto à presença de CM bífidos, alças anteriores do nervo mentual (AA) e corticalização. Também foi avaliado o trabeculado ósseo na região da fóvea submandibular (FSM). A prevalência de CM bífidos foi de 19%. Dos 19 casos observados, 14 estavam associados a FMA. Três casos estavam associados a forames retromolares associados a bifurcações do CM foram observados. Entre 22% e 28% da amostra apresentava AA e de 4% a 8% apresentava extensão anterior da AA significativa, maior que 4mm. Na região da FSM observou-se um trabeculado ósseo diminuído ou ausente na maioria dos casos, associados a maior frequência de ausência de corticalização do CM. Na terceira etapa, a imagem da radiografia panorâmica foi comparada à TCFC na visualização de variações anatômicas relevantes para o planejamento de implantes na região entre os forames. Houve grande discrepância entre os métodos nas observações referentes à presença de...

Current increase on prescription of sectional diagnostic imaging for surgical procedures involving the mandible, such as implant placement, has brought much interest in revisiting neurovascular anatomy with cone-beam computed tomography (CBCT) technology recently. Acknowledgement of such anatomical variations is quite important due to possible injuries to these structures leading to surgical complications and failures. The present study was carried out in three phases and aimed to assess different aspects related to neurovascular anatomy of the mandible on CBCT images. For phase one, occurrence of additional mental foramina (AMF) and their features were assessed. Prevalence was 9.4% and a total of 32 AMF were found. The diameter of the AMF was at least 50% the diameter of ipsilateral MF in 14 cases. Location of AMF was quite variable. Two cases showing absence of MF were registered. For phase two, MC was evaluated regarding the presence of bifid MC, anterior loop of the mental nerve (AL), and corticalization. Additionally, the bone trabeculation in the submandibular gland fossa region (SGF) was assessed. Prevalence of bifid MC was 19% (19 cases). Most cases (n=14) was associated with AMF and 3 cases were associated with retromolar foramina. Between 22% and 28% showed AL, and 4%-8% presented anterior extension of AL bigger than 4mm. SGF region presented decreased or absent trabeculation in most cases, which were associated with more frequent absence of MC corticalization. For phase three, panoramic radiographs (PR) were compared to CBCT regarding assessment of anatomical variations relevant for implant planning. Major discrepancies between PR and CBCT observations were noted regarding presence of AL, incisive canal, and FMA, as well as estimation of safe distance for implant placement. It is concluded that major anatomical variability related to mandibular neurovascularization and limitation of PR in displaying such variations point out to the importance of...

[Prosthetic dilemmas. Choice of superstructure for the edentulous maxilla]. / Prothetische dilemma's. Suprastructuurkeuze in de edentate bovenkaak.

Patients with an edentulous maxilla can experience problems with a full upper denture. The most common problems are a lack of retention and the stability of the denture, but also other factors, such as an extreme gagging reflex, influence satisfaction. Attachment of a prosthesis on dental implants is a reliable solution to solve or diminish the above mentioned problems. The choice of the kind of superstructure, a removable overdenture or a fixed prosthesis, depends on a variety of factors, such as degree of resorption of the maxilla, cleaning possibilities, patients'wishes and financial possibilities

Prosthodontic rehabilitation of oral function in head-neck cancer patients with dental implants placed simultaneously during ablative tumour surgery: an assessment of treatment outcomes and quality of life.

The aim of this prospective study was to assess treatment outcome and impact on quality of life of prosthodontic rehabilitation with implant-retained prostheses in head-neck cancer patients. Fifty patients were evaluated by standardized questionnaires and clinical assessment. All received the implants during ablative tumour surgery in native bone in the interforaminal area. About two-thirds of the patients (n=31) needed radiotherapy post-surgery. Both in irradiated and non-irradiated bone two implants were lost 18-24 months after installation. Peri-implant tissues had a healthy appearance. No cases of osteoradionecrosis occurred. In 15 patients no functional implant-retained lower dentures could be made for various reasons. The other 35 patients all functioned well, with an improvement in quality of life. Major improvement was observed in the non-irradiated patients. In the irradiated patients, less improvement in many functional items was observed, while items related to the oral sequelae of radiotherapy did not improve. Similar to the quality-of-life assessments, denture satisfaction was improved and tended to be higher in non-irradiated than irradiated patients. Implant-retained lower dentures can substantially improve the quality of life related to oral functioning and denture satisfaction in head-neck cancer patients. This effect is greater in non-irradiated than irradiated cancer patients.

Oral rehabilitation between reality and paradigm.

The oral rehabilitation represents the integrative concept which re-establishes every segment of the dental-jaw system that is affected by edentation in different clinical forms, without eluding the induced complications and the influence of general status within the chosen therapy algorithm. Despite the significant development of knowledge and techniques, it is still controversial to which degree the therapy solutions of oral rehabilitation approach the therapy's ideal, and also the way in which particular aspects of the prosthetic treatment, the general status and socioeconomic criterion influence the clinical result. The implant-prosthetic therapy represents the state of art in modern treatment of edentulous patients, starting from the simplest cases and ending up with complex situations. However the problem of choosing the best treatment option remains, the patient being confused between several possibilities and numerous limits. In the best of cases, the patient understands, accepts and can afford the adequate treatment option. In other cases, choosing the therapeutically solution can be made only under the impulse of external factors. In critical situations, the patient's fear, disbelief, the restrained economic possibilities exclude the ideal solution and compromise the long-term success of the treatment. Several complex cases that were treated accordingly to the ideal option, using complex integrated algorithms, support the idea that future economic development and improved education should surpass present obstacles, the reality becoming a paradigm.

Treatment planning of the edentulous mandible.

Edentulism can be a debilitating handicap. Zarb described endentulous individuals who could not function as 'denture cripples'.(1) Most difficulty with complete denture prostheses arises from the inability to function with the mandibular prostheses. Factors that adversely affect successful use of a complete denture on the mandible include: 1) the mobility of the floor of the mouth, 2) thin mucosa lining the alveolar ridge, 3) reduced support area and 4) the motion of the mandible (Figs 1,2). These factors alone can explain the difficulty of wearing a denture on the mandibular arch compared to the maxillary arch. The maxilla exhibits much less mobility on the borders of the denture than the mandible, moreover having a stable palate with thick fibrous tissues available to support the prostheses and resist occlusal forces. These differences explain most of the reasons why patients experience difficulty with using a complete denture on the mandibular arch compared to the maxillary arch.

Prosthetic complications in fixed endosseous implant-borne reconstructions after an observations period of at least 40 months.

One hundred and seventy-two fixed reconstructions (317 prosthetic units), made on 283 ITI implants in 105 patients (age range 25-86 years) with a minimum follow-up period of 40 months, were taken into the study to analyse technical complication rate, complication type and costs for repair. The mean evaluation time was 62.5 +/- 25.3 months. Eighty were single crowns and 92 different types of fixed partial dentures (FPDs). In 45 cases the construction was screw retained and in 127 cases cemented with zinc phosphate cement or an acrylic-based cement. Complications occurred after a minimum period of 2 months and a maximum period of 100 months (mean: 35.9 +/- 21.4 months). Fifty-five prosthetic interventions were needed on 44 constructions (25%) of which 88% in the molar/premolar region. The lowest percentage of complications occurred in single crowns (25%), the highest in 3-4 unit FPDs (35%) and in FPDs with an extension (44%). Of the necessary clinical repair, 36% was recementing and 38% tightening the screws. Of all interventions, 14% were classified as minor (no treatment or <10 min chair time), 70% as moderate (>10 min but <60 min chair time) and 14% as major interventions (>60 min and additional costs for replacement of parts and/or laboratory). For seven patients the additional costs ranged from euro 28 to euro 840. Bruxing seemed to play a significant role in the frequency of complications. Longer constructions seemed to be more prone to complications. The relatively high occurrence of technical complications should be discussed with the patient before the start of the treatment.