Mandibular overdenture retained by four one-piece titanium-zirconium mini implants: A 2-year follow-up on prosthodontic outcomes.

OBJECTIVE: This 2-year prospective study reports the incidence of prosthetic complications and maintenance events after treatment with mandibular overdenture retained by four mini implants opposed to a maxillary denture. METHODS: Implant intervention included flapless or flapped surgery combined with immediate or delayed loading, as part of a randomized clinical trial. Four one-piece titanium-zirconium mini-implants (Straumann Mini Implant System) were inserted, and the retentive PEEK elements (Optiloc) were incorporated into the overdenture using chairside procedures. Prosthodontic complications and maintenance events were recorded over a 2-year follow-up, and the final outcome was defined according to standardized criteria. Data analysis included descriptive statistics, incidence and incidence density rates, and Kaplan-Meier survival. RESULTS: 73 out of 74 patients (64.9 % female), mean age of 64 (SD=8.2) years, completed the study follow-up (one withdrew after 9 months). Implant survival was 100 %. A total of 163 prosthodontic events occurred in 53 patients (72.6 %), and 20 patients had no clinical complaints or maintenance needs. The most common procedures were adjustment/repair of the overdenture base (47.0 %), replacement of retentive inserts (19.8 %), and laboratory relining (12.9 %). A high prosthodontic success rate was achieved (93.2 %), and all patients presented serviceable overdentures and continuous use after the resolution of prosthodontic complications. The incidences of matrix replacement and laboratory relines were low in the first year, while denture base adjustments were common within the first year, especially in the first 6 months. CONCLUSION: The mini implant system showed high prosthodontic success rates. Minor adjustments/repairs during the initial follow-up were common. Relines and matrix replacements tend to occur after one year of overdenture use, and matrix replacements may occur as a consequence of the need for relining.

One-time definitive attachment connection versus healing abutment placement for an implant-retained mandibular overdenture: Peri-implant metabolic activity.

STATEMENT OF PROBLEM: Unscrewing the healing abutment can affect the soft tissue integration and apical migration of the biological width, which may compromise the integrity of peri-implant soft tissue. PURPOSE: The purpose of this clinical study was to determine the level of glycosaminoglycan (GAG) detected in the peri-implant crevicular fluid (PICF) between the test group (1-time abutment) and control group (healing abutment) for implant-retained mandibular overdentures. MATERIAL AND METHODS: Two dental implants were installed in the canine regions of the mandibular ridge of 18 healthy completely edentulous participants using 2-stage surgery and a delayed loading protocol. At the second stage surgery, the implant on the right side was exposed, and a healing abutment was screwed onto the implant (control group), while on the left side the definitive ball abutment was screwed onto the implant (test group). After 10 days, the healing abutment in the control group was unscrewed and replaced with the definitive ball abutment. For both groups, the ball attachment was directly picked up to incorporate the attachment house to the mandibular denture. PICF samples were collected from the participants at 7 days, 3 months, and 6 months after overdenture use. Statistical analysis was done with an independent samples t test (α=.05). RESULTS: A significant difference was found in the volume of PICF and the level of GAG between the test and control groups at the 7-day evaluation period (P=.008, P=.002, respectively), while the volumes of PICF and the levels of GAG were not significantly different (P>.05) at the other evaluation periods. CONCLUSIONS: The 1-time abutment protocol offers biochemical and economic advantages compared with the conventional method of using the healing abutment before placement of the definitive attachment for an implant-retained overdenture with single attachments.

Otimização das etapas de confecção do protocolo Branemark com carga tardia utilizando o guia multifuncional / Optimization of the Branemark protocol late load preparation steps using the multifunctional guide

O "planejamento reverso" em implantodontia busca alcançar um melhor prognóstico para a reabilitação do paciente, permitindo uma maior previsibilidade para o tratamento a partir do momento em que se planeja a reabilitação oral protética antes mesmo de planejar os implantes osseointegráveis. O dispositivo de resina acrílica chamado guia multifuncional representa a disposição final dos dentes na reabilitação e auxilia demasiadamente na etapa protética em casos em que não é possível a carga imediata. Ainda, otimiza o número de consultas do tratamento pois orienta a relação maxilomandibular, dimensão vertical e correta posição dos dentes. O presente trabalho tem como objetivo apresentar um caso clínico da utilização do guia multifuncional para moldagem dos implantes em caso de protocolo Branemark com dois tempos cirúrgicos, mostrando sua utilidade para diminuição do número de consultas na etapa de confecção da prótese total inferior definitiva. Diante dos resultados obtidos na realização do caso, foi possível concluir que nos casos de protocolo Branemark quando não é possível realizar a carga imediata, o guia multifuncional pode ser aproveitado e utilizado com sucesso, para a moldagem e confecção da prótese definitiva, diminuindo o número de consultas e otimizando o tratamento.

Reverse planning in implantology aims to improve patient's rehabilitation prognosis allowing greater treatment predictability from the prosthetic planning and before the implants installation. The acrylic resin device called multifunctional guide represents the final teeth disposition and is very useful in the prosthetic step when immediate loading is not possible. And it optimizes appointments treatment number since it guides the maxillomandibular relation, vertical dimension and correct teeth position. The aim of this study was to present a clinical case using the multifunctional guide for implant molding a two steps Branemark protocol, showing its usefulness to reduce the appointments number during the inferior total denture preparation step. Based on these results, it was possible to conclude that in Branemark protocol, when it immediate loading is not possible, the multifunctional guide can be used successfully for molding and making the final prosthesis, reducing the number of visits and optimizing treatment.

Fatores associados ao não uso da prótese total inferior e seu impacto em idosos brasileiros / Factors associated with not using the lower denture and its impact on elderly Brazilians / Factores asociados con la no utilización de la dentadura postiza inferior y su impacto en los ancianos brasiliños

Introdução:Grande parte dos idosos caracteriza a reabilitação com prótese total como satisfatória. Entretanto, algunsse mostram insatisfeitos devido a dificuldades com a adaptação, principalmente em relação a prótese total mandibular. Objetivo:Identificar a prevalência e os fatores associados ao não uso da prótese total inferior em idosos. Ademais, verificou-se o impacto do não uso dessa prótese na autopercepção de saúde bucal e na dificuldade de se alimentar. Método:Trata-se de um estudo de base populacional e transversal. Para a sua realização, foi utilizado a base de dados da última Pesquisa Nacional de Saúde realizada no Brasil. Inicialmente, o teste Qui-quadrado foi usado para a análise dos dados. Em seguida, uma análise multivariada do tipo regressão múltipla de Poisson foi realizada para o ajuste das razões de prevalência. Resultados:Participaram 4.582 idosos brasileiros, dos quais 27,1% não faziam uso da prótese total inferior. Onão uso da prótese esteve associada aos idosos mais velhos (p=0,001), aos sem instrução (p=0,001), aos que não possuem plano de saúde (p=0,019), aos que fumam (p=0,012) e aos que não realizavam higiene bucal todos os dias (p<0,001). O não uso da prótese total inferior impactou em uma pior autopercepção de saúde bucal (p=0,001) e em maiores dificuldades de se alimentar (p<0,001). Conclusões:Onão uso de prótese total inferior está associado a piores condições socioeconômicas e a um pior estilo de vida, fortemente ligado ao ato de fumar. Ademais, o não uso da prótese impacta negativamente na autopercepção de saúde bucal e na alimentação (AU).

Introduction:A large part of the elderly characterizes rehabilitation with total prosthesis as satisfactory. However, some are dissatisfied due to difficulties with adaptation, mainly in relation to total mandibular prosthesis.Objective:To identify the prevalence and factors associated with not using the lower denture in the elderly. In addition, the impact of not using this prosthesis on self-perceived oral health and the difficulty of eating was verified.Methods:This is a population-based and cross-sectional study. For its realization, the database of the last National Health Survey carried out in Brazil was used. Initially, the Chi-square test was used for data analysis. Then, a multivariate analysis using Poisson multiple regression was performed to adjust the prevalence ratios.Results:4,582 elderly Brazilians participated, of which 27.1% did not use the lower total prosthesis. Failure to use the prosthesis was associated with older elderly people (p=0.001), those without education (p=0.001), those who do not have health insurance (p=0.019), those who smoke (p=0.012) and those who they did not perform oral hygiene every day (p<0.001). Failure to use the lower denture impacted worse self-perceived oral health (p=0.001) and greater difficulties in eating (p<0.001). Conclusions:Failure to use a lower denture is associated with worse socioeconomic conditions and a worse lifestyle, strongly linked to smoking. In addition, the non-use of the prosthesis has a negative impact on self-perception of oral health and food (AU).

Introducción:Una gran parte de los ancianos caracteriza la rehabilitación con prótesis total como satisfactoria. Sin embargo, algunos están insatisfechos por dificultades de adaptación, principalmente en relación con la prótesis total mandibular.Objetivo:Identificar la prevalencia y los factoresasociados a la no utilización de la prótesis inferior en el anciano. Además, se verificó el impacto de no utilizar esta prótesis sobre la salud bucal autopercibida y la dificultad para comer. Método:Se trata de un estudio poblacional y transversal. Para su realización se utilizó la base de datos de la última Encuesta Nacional de Salud realizada en Brasil. Inicialmente, se utilizó la prueba de Chi-cuadrado para el análisis de datos. Luego, se realizó un análisis multivariado utilizando regresión múltiple de Poisson para ajustar las razones de prevalencia.Resultados:Participaron 4.582 ancianos brasileños, de los cuales el 27,1% no utilizó la prótesis total inferior. La falta de uso de la prótesis se asoció con ancianos (p=0,001), sin educación (p=0,001), sin seguro médico (p=0,019), con tabaquismo (p=0,012) y con los que no realizaban tratamiento oral. higiene todos los días (p<0,001). La no utilización de la dentadura inferior repercutió en una peor salud bucal autopercibida (p=0,001) y mayores dificultades para comer (p<0,001).Conclusiones:La no utilización de una dentadura inferior se asocia con peores condiciones socioeconómicas y un peor estilo de vida, fuertemente ligado al tabaquismo. Además, la no utilización de la prótesis tiene un impacto negativo en la autopercepción de la salud bucal y la alimentación (AU).

Overdentures as an alternative to conventional dentures: a micro-costing analysis for Public Health Service in Brazil / Overdentures como alternativa às próteses convencionais: uma análise de micro-custeio para o Sistema Único de Saúde

Abstract This study aimed to estimate cost and compatibility with public financial incentives of two technologies for treating the edentulous mandible: lower complete dentures (CD) and overdentures retained by two dental implants (OD). This study consisted of a partial economic evaluation, with a micro-costing bottom-up approach for the calculation of direct costs. The estimates involved the number of consultations, proportion of materials, equipment, instruments' lifetime, and human resources, described in the price panel website of the Ministry of Economy in Brazil. Complementary information was obtained from a panel of experts. A sensitivity analysis was based on 20% variation. The estimated cost of a CD was R$ 189.89 (base scenario), and this varied between R$ 151.91 and R$ 227.89 according to sensibility analysis. The cost of an OD was R$ 663.05 (ranging from R$ 795.66 to R$ 530.44 - 1US=R$ 3.80/July 2019). The Ministry of Health covers appropriately the costs of the CD and OD. Both technologies showed costs that are within the limits of financial public incentives obtained by municipalities. The technologies are economically viable and should be induced through public policies due to their positive impacts on several functional domains of health.

Resumo Estimar os custos e a compatibilidade dos incentivos públicos de duas tecnologias para o tratamento da mandíbula edêntula: prótese total convencional (PTC) e overdenture retida por dois implantes (OD). Este estudo consistiu em uma avaliação econômica parcial, com abordagem "bottom-up" para o cálculo dos custos diretos. As estimativas levaram em consideração o número de consultas, proporção de materiais, equipamentos, vida útil dos instrumentais e recursos humanos. Os custos foram baseados no painel de preços do Ministério da Economia do Brasil e informações complementares foram obtidas de um painel de especialistas. Uma análise de sensibilidade foi baseada na variação de 20% dos custos. Os custos da PTC foram estimados em R$ 189,89 (cenário base) com variação entre R$ 151,91 e R$ 227,89 na análise de sensibilidade. Os custos da OD foram R$ 663,05 (variando de R$ 795,66 a R$ 530,44). O Ministério da Saúde cobre apropriadamente os custos de ambas as tecnologias nos cenários base e mais otimista. Ambas as tecnologias apresentaram custos dentro dos limites dos incentivos públicos recebidos. As tecnologias são economicamente viáveis e devem ser induzidas por políticas públicas diante do impacto positivo em vários domínios funcionais da saúde.

General health status of Dutch elderly receiving implant-retained overdentures: A 9-year big data cross-sectional study.

BACKGROUND: Very little information is available on the general health of elderly who are provided with an implant-retained overdenture (IOD). PURPOSE: The general health status of three groups of elderly (≥75 years) were compared: those with a natural dentition (ND), those treated with an implant-retained overdenture (IOD), and those wearing a conventional denture (CD). MATERIALS AND METHODS: Data on healthcare costs were obtained from records of Dutch health insurers that are collected by Vektis. Data on general health (chronic diseases, medication use, and polypharmacy) were acquired for elderly patients with a ND, an IOD, and a CD in 2009 and 2017. Data on the general health of elderly who received an IOD were also acquired from 2010 through 2016. RESULTS: On average, the general health of elderly who received an IOD was comparable to general health of elderly with a ND and was better than the general health of elderly with a CD (lower prevalence of diabetes, cardiac disease, and hypertension). The general health profile of elderly receiving an IOD was consistent during all years. CONCLUSIONS: The general health of elderly with a ND or IODs is better than those with CDs.

Effect of an implant-retained complete overdenture on the hearing ability of edentulous patients: A clinical pilot study.

STATEMENT OF PROBLEM: Edentulism has been associated with sensoneurinal hearing reduction, but whether hearing is improved by the provision of an implant-retained overdenture is unclear. PURPOSE: The purpose of this pilot clinical study was to provide completely edentulous participants with implant-retained complete overdentures and to evaluate the effect on their hearing ability by pure tone audiometry (PTA). MATERIAL AND METHODS: Fifteen completely edentulous first-time denture wearers were enrolled, and their hearing was evaluated with PTA for air conduction and bone conduction at 6 time intervals: before denture insertion (R1), after denture insertion (R2), 1 month after denture insertion (R3), on the day of suture removal after implant surgery (R4), 3 months later, at the time of loading (R5), and 1 month after implant loading (R6). The Friedman test was performed to find significant differences in the measurements from the completely edentulous state to rehabilitation with a complete denture and an implant-retained complete overdenture. The post hoc Tukey test was used for multiple comparisons (α=.05). RESULTS: Significant differences were found between R1 and R6, between R2 and R6, between R3 and R6, and between R4 and R6 in PTA in multiple comparisons (P<.05). The post hoc test revealed significant difference in the R1and R6 and R3 and R6 pairs (P<.05) at 500 Hz, 1 kHz, and 8 kHz, whereas only between R1 and R6 (P<.05) at 2 kHz for the air conduction test. In the bone conduction test, a significant difference was observed between the R1 and R6 and the R3 and R6 pairs (P<.05) at 500 Hz and 4 kHz, but only between R3 and R6 (P<.05) at 1 kHz and 2 kHz. CONCLUSIONS: The study showed that the placement of dental implants improved hearing acuity via the acoustic pathway through air and bone conduction.

An Investigation of the Characteristics of Edentulous Patients Who Choose or Refuse Implant Treatment.

PURPOSE: To investigate whether pretreatment patient satisfaction, oral health-related quality of life, or diagnostic complexity are predictive of a decision to choose implant treatment. MATERIALS AND METHODS: Edentulous patients requesting dentures were enrolled in a prospective observational study. All subjects were provided with conventional dentures and then given the option to proceed with the placement of two mandibular implants and to have their prosthesis modified into an implant overdenture. Subjects were classified according to the Prosthodontic Diagnostic Index (PDI-CE) and asked to complete a Denture Satisfaction Questionnaire and the Oral Health Impact Profile for edentulous patients (OHIP-EDENT) at pretreatment, following the provision of new dentures, and following modification to overdentures. RESULTS: Of the 125 subjects who had conventional dentures, 15 proceeded with implant treatment. The subjects who decided to have implants were not significantly different in terms of diagnostic complexity or level of satisfaction. Those who chose implants were significantly younger, had newer dentures, and had higher OHIP-EDENT scores at baseline. The most common reason for not being satisfied with dentures but avoiding implants was fear of surgery. CONCLUSION: The majority of subjects in this study were satisfied with conventional denture treatment, despite registering its limitations. Subjects who were more anatomically compromised were not more likely to choose implant treatment. It remains to be shown whether fear of surgery can be overcome in order to increase the uptake of implant treatment and improve patient outcomes.

Reinforcement of Single Implant-Retained Mandibular Overdenture with a Cobalt-Chromium Framework before Implant Surgery.

Previous clinical research has shown promising results in oral rehabilitation of elderly adults by a single implant-retained mandibular overdenture; however, the high incidence of fracture in the anterior region of these overdentures is a concern for clinicians. To minimize catastrophic overdenture fracture, we propose a technique to insert an individualized metal framework in single implant-retained overdentures prior to implant surgery.

Immediate Loading of Mandibular Overdentures Retained by Two Mini-Implants: A Case Series Preliminary Report.

PURPOSE: This preliminary case series report sought to evaluate the efficacy of an immediate loading protocol for mandibular overdentures retained by two mini-implants with the outcome measures patient satisfaction, masticatory cycles, and masticatory efficiency at 1 year. MATERIALS AND METHODS: A convenience sample of 11 patients was recruited, and the clinical protocol consisted of immediately loading two mini-implants (10 mm long and 2.4 mm or 2.9 mm in diameter) via a mandibular overdenture connection with Locator attachments. Each patient completed a satisfaction questionnaire and underwent masticatory cycle recordings and masticatory efficiency tests. Implant-related evaluations were carried out by assessing probing depth (PD), Plaque Index (PI), bleeding on probing (BOP), mobility, and pain. All tests and evaluations were carried out six times: before implant surgery (T0), just before implant surgery with patient under anesthesia (T1), following implant insertion with patient still under anesthesia (T2), and at 3 months (T3), 6 months (T6), and 1 year (T12) after implant insertion. RESULTS: Implant survival rate was 95%, and statistically significant increases (P < .05) in masticatory cycle patterns, masticatory efficiency, comfort, stability, and phonetics were also recorded. CONCLUSION: The employed treatment protocol suggests promise as a viable treatment option that in the short term provides improved prosthesis stability, comfort, and function while decreasing surgical invasiveness. Long-term follow-up outcomes in larger patient sample studies will be required to confirm and validate the merits of this preliminary report.

Factors associated with the non-wear of mandibular dentures in the Brazilian public primary health care

Abstract This study investigated factors that affect the use of complete conventional mandibular dentures (CCMD) by patients of the Brazilian Public Health Service. For this, two hundred and thirty one subjects who received CCMD in the Primary Health Care of the Public Health Service in Belo Horizonte - Brazil were evaluated and divided in Group 1 - irregular/non-wear; Group 2 - regular wear. Multivariate logistic regression analysis was used to create predictive models for CCMD non-wear and included socio-demographic and biological variables, technical quality of CCMD, and user satisfaction. The prevalence of CCMD non-wear was 41.10%. The mean score of CCMD quality was 54.97 (0-100). Not wearing the CCMD was significantly associated with user satisfaction and technical quality (p < 0.05). The lack of retention of the CCMD was the most important factor in the evaluation of satisfaction and quality. The final predictive model (specificity = 92.65%; AROC = 0.8759) for not wearing the CCMD retained the variables CCMD stability (OR = 0.888; 95%CI = 0.827-0.954), freeway space (OR = 0.916; 95%CI = 0.860-0.976), satisfaction with speech (OR = 0.694; 95%CI = 0.612-0.786), and irregular CCMD edges (OR = 3.185; 95%CI = 1.478-6.864). Socio-demographic and biological variables were not associated with patients not wearing the CCMD, whereas technical quality and user satisfaction were strongly associated.

One-year prospective clinical study comparing patient satisfaction and masticatory performance of mandibular overdentures supported by one versus two implants

Abstract There is a lack of clinical evidence on mandibular overdentures (MOD) supported by a single implant. Objective: To compare patient satisfaction and masticatory performance in MOD supported by one versus two implants in a two-group parallel randomized clinical trial. Material and Methods: Twenty-one patients wearing new maxillary and mandibular complete dentures (CDs) were randomly divided to receive one (GI, n = 11) or two (GII, n = 10) implants in the mandibular arch. Four months after implant placement, o-ring abutments were installed in the implants, and matrix attachments were placed in the lower complete dentures. Patient satisfaction with their dentures and masticatory performance were compared at baseline, 3, 6, and 12 months after the procedure. Data on patient satisfaction were analyzed using the Friedman test and the Mann-Whitney U test. Data on masticatory performance were analyzed using one-way repeated measures analysis of variance (ANOVA) and Student's t test (α=0.05). Results: Both groups exhibited a significant increase in overall patient satisfaction in all periods evaluated (p<0.05), except for GI after 12 months, which had values similar to baseline (p=0.74). Satisfaction levels of GI and GII were similar at baseline, 3 and 6 months, but GII showed higher satisfaction levels (p=0.01) than GI at 12 months. GI and GII exhibited a significant increase (p<0.05) in masticatory performance for all periods relative to baseline. However, GII had higher masticatory performance with dentures than GI, regardless of the period (p<0.05). Conclusion: MOD supported by two implants demonstrated better patient satisfaction in the follow-up at 12 months and better masticatory performance than MOD supported by one implant.

Como utilizar o conceito da Zona Neutra para otimizar a Prótese / Using the Neutral Zone concept to improve the lower complete

Este artigo descreve os passos para a utilização da filosofia da Técnica da Zona Neutra. Através dessa filosofia, procura-se localizar uma área, em boca, onde as forças geradas pela língua são neutralizadas pelas forças geradas pelos lábios e bochechas, estabilizando assim a prótese.

This article describes step-by-step the application of the Neutral Zone technique philosophy. It is based upon the concept that for each individual patient, there is within the denture space a specific area where the function of the musculature will not unseat the denture and where forces generated by the tongue are neutralized by the forces generated by the lips and cheeks.

Digital Workflow for Fixed Implant Rehabilitation of an Extremely Atrophic Edentulous Mandible in Three Appointments.

OBJECTIVE: To present a rationale to reduce treatment complexity, number of surgeries, and overall treatment time for patients with extreme mandibular ridge deficiency. CLINICAL CONSIDERATIONS: A 67-year-old fully edentulous male presented with a chief complaint of poor retention and stability of the mandibular complete denture with consequent discomfort and inability to chew. A novel 3-appointment protocol from guided implant placement to definitive prosthesis delivery was implemented. At the first appointment, a guided surgery protocol with the All-on-4 concept was used in the mandible. Implant placement was followed by immediate loading with a fixed provisional prosthesis providing the patient with immediate function. Final impression, cast verification and articulation, determination of VDO, and interocclusal records were obtained in the same appointment. In the second appointment, the framework try-in was performed and a pick-up impression was taken after a new CR record. The third appointment included the delivery of the final screw-retained, one-piece, full-arch prosthesis opposed by a maxillary complete denture. CONCLUSION: This expedited protocol allows for implant placement with a surgical template generated from preoperative virtual planning of the implants and the CAD/CAM prosthodontic rehabilitation using a digital workflow. The patient was satisfied with the esthetic and functional outcome and was enrolled into a 6-month recall program. CLINICAL SIGNIFICANCE: This article describes an expedited protocol illustrating a digital workflow for full arch implant rehabilitation of the extremely atrophic mandible. Flapless implant placement with a surgical template generated from virtual planning was followed by immediate loading with a fixed prosthesis. Digital impression/digitization of the working cast and CAD/CAM technology were used to mill the definitive prosthesis. From guided surgery to the definitive rehabilitation only three appointments were necessary. This digital workflow can enhance patient acceptance and comfort and serve as an alternative treatment in the indicated clinical scenario. (J Esthet Restor Dent 29:178-188, 2017).

Randomized study on the effect of single-implant versus two-implant retained overdentures on implant loss and muscle activity: a 12-month follow-up report.

The objective was to evaluate and compare single- and two-implant retained overdentures for the rehabilitation of the edentulous mandible. Fifty-six edentulous subjects were eligible for inclusion. Using a random sampling system, a single implant or two implants were placed in the mandible. After 3 months, locator attachments were connected to the implants and the denture delivered with the retentive components incorporated in the denture base. Implant failure and muscle activity were evaluated at the 3-, 6-, and 12-month follow-up examinations. The study sample comprised 56 patients (32 male, 24 female), with a mean age of 58.2 years. A total of 84 implants were placed (28 in the single-implant group and 56 in the two-implant group). All patients completed the 12 months of follow-up. No significant differences were found between subjects in the two groups with respect to implant failure. With regard to improvements in muscle activity, the two-implant group showed statistically significant but perhaps not clinically important differences. Single-implant mandibular overdentures may be suggested as an alternative treatment modality for the rehabilitation of edentulous patients who cannot afford the cost of a two-implant overdenture.

Clinical and Histologic Evaluations of SLA Dental Implants.

The goal of this investigation was to evaluate the efficacy of dental implants with a surface that was sandblasted with large grit and acid etched in a human model. Seven patients volunteered to allow the biopsy of a small implant in exchange for complete dental rehabilitation at no cost. All biopsy sites received soft and hard tissue reconstruction, and this report provides observation of successful bone-to-implant contact and successful prosthesis construction for the patient. The patients enthusiastically reported improved quality of life as a result of participation in this study. The surgeons' confidence in this implant was reflected by the clinical and histologic result of the study.

Reabilitação oral ­ parte 1: prótese total implantossuportada na mandíbula associada a próteses cerâmicas na maxila / Oral rehabilitation ­ part 1: mandibular implant-supported denture associated to maxillary ceramic dental prostheses

A presente coluna teve como objetivo apresentar um relato de caso clínico de reabilitação oral envolvendo diferentes possibilidades em prótese dentária: uma prótese total fixa implantossuportada (PTF) na mandíbula; e restaurações cerâmicas com infraestruturas de dissilicato de lítio sobre os dentes remanescentes e infraestruturas de zircônia sobre os implantes. O tratamento foi desenvolvido em quatro etapas: i) restabelecimento da dimensão vertical de oclusão (DVO); ii) PTF na mandíbula; iii) reabilitação temporária superior; e iv) próteses cerâmicas superiores. A coluna foi dividida em duas partes: 1) etapas i, ii e iii; e 2) etapa iv. Após o acompanhamento clínico de quatro anos da PTF na mandíbula e seis meses das próteses cerâmicas superiores, a reabilitação apresentou-se satisfatória do ponto de vista estético e funcional.

The purpose of this column was to present a clinical case report of oral rehabilitation involving different possibilities in dental prosthesis: a fixed implant-supported denture (FD) on the jaw; and ceramic restorations with lithium disilicate frameworks on the remaining teeth and zirconia frameworks on the implants. The treatment was developed in four steps: i) reestablishment of the vertical occlusion dimension (OVD); ii) FD on the jaw; (iii) maxil-lary temporary rehabilitation; and iv) ceramic prostheses on the maxillary. The column was divided into two parts: 1) steps i, ii and iii; and 2) step iv. After the four-year of FD clinical follow-up and six months of the superior ceramic prostheses, the rehabilitation was considered aesthetic and functional satisfactory.

Clinical and radiological investigations of mandibular overdentures supported by conventional or mini-dental implants: A 2-year prospective follow-up study.

STATEMENT OF PROBLEM: Conventional dental implants are not applicable in the mandibular interforaminal region if bone volume is limited. Mini-dental implants offer an alternative means of supporting mandibular overdentures in a narrow residual ridge, without additional surgery. PURPOSE: The purpose of this nonrandomized clinical trial was to compare the ability of mini-dental implants with that of conventional dental implants in supporting mandibular overdentures during a 2-year clinical follow-up. Bone quality, bone resorption, implant stability, and oral health were assessed radiographically. MATERIAL AND METHODS: A total of 32 participants with edentulism were included. Twenty-two participants (99 implants) received 4 to 5 mini-dental implants (diameter: 1.8-2.4 mm; length: 13-15 mm, study group), and 10 participants (35 implants) received 2 to 4 conventional dental implants (diameter: 3.3-3.7 mm; length: 11-13 mm, control group). The selection of the participants in the study or control group was based on the available bone volume in the mandible. The selection was not randomized. The density of cortical bone thickness was measured in Hounsfield units (HU) from computed tomography data, and patients were followed for 2 years. The participants were examined 3, 6, 12, and 24 months after surgery. Primary stability immediately after the insertion of dental implants (Periotest), secondary stability 6 months after implantation, modified plaque, bleeding on probing indices, and probing depth were measured and analyzed statistically (α=.05). RESULTS: The mean HU value 6 months after implantation in the participants who received mini-dental implants was significantly (P=.035) higher (1250 HU) than that in the participants who received conventional dental implants (1100 HU). The probing depths around the conventional dental implants (1.6 and 1.8 mm, respectively) were significantly higher than those around the mini-dental implants (1.3 and 1.2 mm, respectively) 12 and 24 months after surgery, respectively (P<.001). The mean primary and secondary stability values for conventional dental implants were -4.0 and -4.9, respectively. The primary and secondary stability values for the mini-dental implants were -0.3 and -1.4, respectively. The Periotest values of the primary (measured immediately after implant insertion) and secondary implant stabilities (measured 6 months after implant insertion) were significantly higher for the conventional dental implants than for the mini-dental implants (P<.001). CONCLUSIONS: Based on this 2-year clinical trial, patients receiving mini-dental implants had clinical outcomes similar to those of patients receiving conventional dental implants to support overdenture prostheses.

Comparative Clinical Study of Conventional Dental Implants and Mini Dental Implants for Mandibular Overdentures: A Randomized Clinical Trial.

BACKGROUND: Dental implant-retained overdentures have been chosen as the treatment of choice for complete mandibular removable dentures. Dental implants, such as mini dental implants, and components for retaining overdentures, are commercially available. However, comparative clinical studies comparing mini dental implants and conventional dental implants using different attachment for implant-retained overdentures have not been well documented. PURPOSE: To compare the clinical outcomes of using two mini dental implants with Equator® attachments, four mini dental implants with Equator attachments, or two conventional dental implants with ball attachments, by means of a randomized clinical trial. MATERIALS AND METHODS: Sixty patients received implant-retained mandibular overdentures in the interforaminal region. The patients were divided into three groups. In Groups 1 and 2, two and four mini dental implants, respectively, were placed and immediately loaded by overdentures, using Equator® attachments. In Group 3, conventional implants were placed. After osseointegration, the implants were loaded by overdentures, using ball attachments. The study distribution was randomized and double-blinded. Outcome measures included changes in radiological peri-implant bone level from surgery to 12 months postinsertion, prosthodontic complications and patient satisfaction. RESULTS: The cumulative survival rate in the three clinical groups after one year was 100%. There was no significant difference (p < 0.05) in clinical results regarding the number (two or four) of mini dental implants with Equator attachments. However, there was a significant difference in marginal bone loss and patient satisfaction between those receiving mini dental implants with Equator attachments and conventional dental implants with ball attachments. The marginal bone resorption in Group 3 was significantly higher than in Groups 1 and 2 (p < 0.05); there were no significant differences between Groups 1 and 2. There was no significant difference in patient satisfaction between Groups 1 and 2 but it was significantly higher than that in Group3 (p < 0.05). CONCLUSIONS: Two and four mini dental implants can be immediately used successfully for retaining lower complete dentures, as shown after a 1-year follow up.

Short implants to support mandibular complete dentures - photoelastic analysis

Abstract This study evaluated the stress behavior around short implants in edentulous atrophic mandibles. Six groups included implants with two diameters regular and wide (4 and 5 mm) and three lengths (5, 7 and 9 mm) as follows: Ci9 (9 x 4 mm), Ci7 (7 x 4 mm), Ci5 (5 x 4 mm), Wi9 (9 x 5 mm), Wi7 (7 x 5 mm) and Wi5 (5 x 5 mm). These groups were compared to the control group CG (11 x 4 mm). The analysis was performed with the photoelastic method (n = 6). Each model comprised 4 implants with the same length and diameter connected by a chromium-cobalt bar that simulates a fixed denture. A 0.15 kg force was applied at the end of the cantilever (15 mm), and the maximum shear stress was recorded around the distal and subsequent implants. The stress values were determined, and the quantitative data (Fringes®) were submitted to statistical analysis with one-way ANOVA and the Dunnett test (p < 0.05). It was observed that the reduction in implant length increased stress values with a significant difference (p < 0.05) between CG Ci7 and Ci5, while the increase in implant diameter reduced the stress values without any differences found between short and long implants. Implants with 5 and 7 mm with regular diameter increased stress levels while short implants with larger diameters experienced similar stress to that of longer implants.