The predictability of transverse changes with Invisalign.

OBJECTIVES: To investigate the predictability of arch expansion using Invisalign. MATERIALS AND METHODS: Sixty-four adult white patients were selected to be part of this retrospective study. Pre- and posttreatment digital models created from an iTero scan were obtained from a single orthodontist practitioner. Digital models from Clincheck were also obtained from Align Technology. Linear values of upper and lower arch widths were measured for canines, premolars, and first molars at two different points: lingual gingival margins and cusp tips. A paired t-test was used to compare expansion planned on Clincheck with the posttreatment measurements. Variance ratio tests were used to determine if a larger change planned was associated with larger error. RESULTS: For every maxillary measurement, there was a statistically significant difference between Clincheck and final outcome (P < .05), with prediction worsening toward the posterior region of the arch. For the lower arch measurements at the gingival margin, there was a statistically significant difference between the Clincheck planned expansion and the final outcome (P < .05). Points measured at the cusp tips of the lower arch teeth showed nonstatistically significant differences between Clincheck prediction and the final outcome (P > .05). Variance ratios for upper and lower arches were significant (P < .05). CONCLUSIONS: The mean accuracy of expansion planned with Invisalign for the maxilla was 72.8%. The lower arch presented an overall accuracy of 87.7%. Clincheck overestimates expansion by body movement; more tipping is observed. Overcorrection of expansion in the posterior region of the maxillary arch seems appropriate.

Performance of titanium alloy sintered porous-surfaced (SPS) implants supporting mandibular overdentures during a 20-year prospective study.

OBJECTIVE: This study was undertaken to assess short, sintered porous-surfaced (SPS), press-fit implants with mandibular overdentures to restore edentulous patients with severe mandibular resorption. MATERIALS AND METHODS: Implant lengths of 7, 8, 9, and 10 mm were used, all with 2-mm polished collars, making the designed intrabony lengths 5, 6, 7, and 8 mm. Each patient received three non-splinted implants placed using a two-stage protocol. RESULTS: Only 22 (with 53 implants) of the original 52 patients were available after 20 years. All but one of these patients was functioning with their implant-retained overdentures. Life table analysis accounted for all patients and implants, and showed a 20-year survival of 73.4%. Analysis of carefully standardized radiographs revealed mean cumulative bone loss after 20 years of 0.67 mm relative to the polished collar-SPS junction. CONCLUSIONS: Short SPS implants with mandibular overdentures can provide an acceptable treatment over a 20-year period for fully edentulous patients with severe alveolar resorption.

Peri-implant crestal bone loss: a putative mechanism.

Purpose. The immunological mechanisms of peri-implant crestal bone loss have, hitherto, not been elucidated. We hypothesized that bacterial products from the microgap cause upregulation of cytokines in otherwise healthy peri-implant cells, which results in osteoclast formation and, ultimately, in bone resorption. Materials and Methods. We used RT-PCR and ELISA to assay mediators of osteoclastogenesis in rat and human macrophages (r-and hMO); bone marrow derived stromal cells (r-and hBMCs); and human gingival fibroblasts (hGF)-with or without stimulation by LPS. TRAP positive multinucleate cells were assessed for their resorptive ability. Results. We show that IL-1α, IL-1ß, and IL-6 were expressed by all examined cell types, and TNF-α was upregulated in hGF. Secretion of IL-1α and IL-1ß proteins was stimulated in hMO by LPS, and IL-6 protein secretion was highly stimulated in hBMCs and hGF. Both LPS and RANKL stimulated macrophages to form osteoclast-like TRAP positive cells, which resorbed calcium phosphate substrates. Conclusion. Taken together, the results of our study support the hypothesis that bacterial endotoxins upregulate enhanced mediators of osteoclastogenesis in resident cells found in the healthy peri-implant compartment and that the local synergistic action of cytokines secreted by such cells results in the genesis of resorptively active osteoclasts.

Performance of sintered, porous-surfaced, press-fit implants after 10 years of function in the partially edentulous posterior mandible.

This article updates the results of a prospective clinical trial of press-fit, sintered, porous-surfaced dental implants placed in the posterior mandible of partially edentulous patients. Implants used had overall lengths (including transgingival collar regions) of 7 or 9 mm with designed intrabony lengths (lengths of sintered surface in contact with bone) of 6 or 8 mm. Forty-eight implants were placed in 24 patients, the majority of which replaced molar teeth, and the mean crown-to-root ratio was 1.4. Over 10 years of implant function, 2 patients with 3 implants died and 3 patients with 4 implants were lost to follow-up because of infirmity or relocation. The survival and success rates were both 95.5%. Two implants failed; the mean cumulative crestal bone loss (measured from the implant-abutment interface) for the remaining implants was 1.2 mm. Crestal bone loss was not affected by the crown-to-root ratio, prosthesis design, or whether an implant was the most distal unit in a sextant. However, there was a trend for greater crestal bone loss when implants were opposed by implants rather than by natural teeth.

Use of sintered porous-surfaced dental implants to restore single teeth in the maxilla: a 7- to 9-year follow-up.

This report from a prospective study discusses the status of a group of 20 single maxillary sintered porous-surfaced (SPS) dental implants after 7 to 9 years in function restored with screw-retained crowns. Twenty patients each received a single SPS implant placed in a two-stage surgical approach; 65% replaced premolar or molar teeth, while the remainder replaced anterior teeth. Patients were examined annually. Standardized radiographs were used to assess peri-implant crestal bone levels and to determine an implant success rate. Jemt Papilla Index scores were used to assess the extent of papilla reformation between each implant and its two contiguous teeth. After 7 to 9 years, 17 implants were available for assessment (one patient had died, and two patients had moved away). One implant was removed after the 9-year visit because of progressive bone loss, giving a survival rate of 92.9%. The failure of this implant was related to deficiency in initial alveolar ridge width with loss of the remaining thin buccal cortical plate. With the exception of the failed implant, no significant changes in mean annual crestal bone loss were noted from years 1 to 9, giving a similar success rate (92.9%). Jemt Papilla Index scores of 2 or 3 were assigned for the majority of papillae. SPS implants can be used effectively to replace single missing maxillary teeth.

An assessment of crown-to-root ratios with short sintered porous-surfaced implants supporting prostheses in partially edentulous patients.

PURPOSE: Implant length, implant surface area, and crown-to-root (c/r) ratio and their relationship to crestal bone levels were analyzed in 2 groups of partially edentulous patients treated with sintered porous-surfaced dental implants. MATERIALS AND METHODS: One hundred ninety-nine implants were used to restore 74 partially edentulous patients with fixed prostheses. Implants were categorized according to their length ("short" versus "long") and estimated surface area ("small" versus "large"). "Short" implants had lengths of 5 or 7 mm, while "long" implants were either 9 or 12 mm in length. "Small" implants had estimated surface areas of < or = 600 mm2, while "large" implants had estimated surface areas > 600 mm2. Other data collected included c/r ratio (measured on articulated diagnostic casts), whether or not the implants were splinted, and standardized sequential radiographs. RESULTS: The mean c/r ratio was 1.5 (SD = 0.4; range 0.8 to 3.0), with 78.9% of the implants having a c/r ratio between 1.1 and 2.0. Neither c/r ratio nor estimated implant surface area (small or large) affected steady-state crestal bone levels. However, implant length and whether the implants were splinted did appear to affect bone levels. Long implants had greater crestal bone loss (0.2 mm more) than short implants; splinted implants showed greater crestal bone loss (0.2 mm more) than nonsplinted ones. These differences were statistically significant. DISCUSSION AND CONCLUSIONS: Sintered porous-surfaced implants performed well in short lengths (7 mm or less) in this series of partially edentulous patients. The data suggested that long implants and/or splinting can result in greater crestal bone loss; longer implants and splinted implants appeared to favor greater crestal bone loss in this investigation. These conclusions are, of course, specific to the implants used and would not be relevant to other implant types.

Porous-surfaced dental implants in the partially edentulous maxilla: assessment for subclinical mobility.

Fifty patients received 151 short, porous-surfaced implants in the partially edentulous maxilla. Periotest values (PTV) were recorded at baseline and after 6 months and 1 and 2 years. For this, prostheses were removed and a standard abutment attached and tightened (20-Ncm force) to each implant. Data analysis indicated significant relationships between time in function vs PTV and implant diameter (3.5, 4.1, or 5.0 mm) vs PTV There was no relationship between PTV and implant length. PTVs were more favorable in the posterior than anterior maxilla, and better PTVs were obtained with nonsplinted as opposed to splinted implants.

Ten-year results of a prospective study using porous-surfaced dental implants and a mandibular overdenture.

BACKGROUND: Numerous investigators have used osseointegrated dental implants as retention for mandibular overdentures, but few have reported 10-year outcomes or incorporated carefully standardized radiographs to document crestal bone loss. PURPOSE: The purpose of this study was to use a prospective clinical trial design to assess the performance of short sintered porous-surfaced dental implants with a mandibular complete overdenture when all patients in the trial had undergone 10 years of continuous function. MATERIALS AND METHODS: Fifty-two fully edentulous patients, most with advanced alveolar ridge resorption, each received three free-standing Endopore implants (7-10 mm in length, mean length, 8.7 mm; Innova Corporation, Toronto, ON, Canada) in the mandibular symphysis region. After 10 weeks of submerged healing, these implants were used to support an overdenture. Carefully standardized radiographs, using a customized stainless steel filmholder attached to each implant and the x-ray tube, were collected at baseline, 3 months, 6 months, yearly to 5 years, and then again at 7and 10 years. RESULTS: Life table analysis revealed a 10-year implant survival of 92.7% and a mean annual bone loss after year 1 of 0.03 mm. CONCLUSION: Short free-standing dental implants with a sintered porous surface used for implant fixation are a predictable and effective means of retaining a mandibular overdenture in patients with advanced mandibular ridge resorption.

Managing the posterior mandible of partially edentulous patients with short, porous-surfaced dental implants: early data from a clinical trial / Gerenciamento da mandíbula posterior de pacientes parcialmente desdentados com superfície porosa: primeiros dados de um processo clínico

Forty-eight endopore dental implants were placed in the posterior mandibles of 24 partially edentulous patients. Seventeen of these implants replaced premolar teeth, while 31 replaced molars. Only 7-mm and 9-mm implants were used, and the majority of prosthetic restorations (83 percent) were single crowns. After a mean functional time of 32.6 months (range, 8.2 to 50.3 months), the implant survival rate was 100 percent and assessment of available radiographic data showed minimal to no crestal bone loss

Avaliaçäo sobre o ensino da Prótese Parcial Removível em faculdades de Odontologia públicas e particulares do estado de Säo Paulo / Evaluation of the teaching of Removable Partial Prosthodontics in public and private schools of Dentistry in the state of Säo Paulo

Neste estudo avaliou-se, através de questionários aplicados a professores de faculdades de Odontologia do estado de Säo Paulo, o ensino da disciplina de Prótese Parcial Removível, observando-se que os cursos de graduaçäo, nos quais os alunos adquirem os princípios básicos para a confecçäo dessas próteses, estäo adequados aos padröes esperados, näo havendo diferenças significantes entre os diversos estabelecimentos de ensino odontológico (particulares ou públicos). O aspecto da biomecânica é um dos fatores mais críticos, sendo necessário acrescentar um maior tempo de atividade clínica para os alunos, adequando o currículo escolar à realidade dos consultórios

Estudo da espessura esmalte/dentina em funçäo de idade, grupo de dentes e distância em relaçäo à porçäo externa da coroa clínica / Study of the enamel/dentin thickness considering age, group of teeth and distance to the external portion of the clinical crown

A finalidade deste trabalho foi a de estudar a espessura esmalte/dentina em funçäo de idade, grupos de dentes e sua respectiva relaçäo com a porçäo externa da coroa clínica. Nesse sentido, foram selecionados 64 dentes superiores (incisivos, caninos, pré-molares e molares), com características clínicas normais, obtidos de pacientes de quatro diferentes faixas etárias. Foram tomadas radiografias periapicais individuais e padronizadas, com os raios principais incidindo na área central da porçäo coronária. Os filmes foram projetados com uma distância projetor/parede estabelecida em 1,25 metros, determinando-se um aumento de 10 vezes para a projeçäo, e, em seguida, essas medidas da espessura esmalte/dentina foram aferidas com um paquímetro micrométrico em 5 diferentes regiöes: colo mesial, diagonal mesial, horizontal, diagonal distal e colo distal, sendo transformadas em valores correspondentes ao tamanho normal dos dentes (1/10). Os resultados estatísticos obtidos permitiram concluir que: a espessura esmalte/dentina aumenta gradativamente com a idade; a velocidade desse aumento é grande nas faixas etárias mais jovens, diminuindo em intensidade, paulatinamente, nas faixas etárias mais adultas, com tendência à estabilizaçäo; a maior espessura esmalte/dentina foi encontrada nos incisivos centrais e a menor espessura, nos caninos; a menor espessura esmalte/dentina foi encontrada nas distâncias distais

Relaçöes entre sensibilidade muscular e distúrbios craniomandibulares em pacientes edentados parciais unilaterais inferiores, com e sem próteses parciais removíveis / Relationship between muscle tenderness and craniomandibular disorders in unilateral free end dental arch subjects with and without removable partial dentures

A finalidade deste estudo foi a de comparar a relaçäo entre sensibilidade muscular e distúrbios craniomandibulares (DCM) em pacientes edentados parciais (n=60), portadores ou näo de próteses parciais removíveis (PPR), no que diz respeito a prevalência e severidade dos sintomas de DCM, utilizando uma metodologia de testes de escores. O exame clínico consistiu na avaliaçäo da sensibilidade dolorosa à palpaçäo muscular (intra-oral, externa e do pescoço) através de trinta e seis procedimentos para ambos os hemiarcos. Trinta outros pacientes atuaram como grupo controle. Após a comparaçäo estatística dos dados utilizando testes näo paramétricos de análise de variância, chegou-se à conclusäo de que näo houve diferença significativa na incidência de sensibilidade dolorosa à palpaçäo muscular no arco como um todo entre os três grupos estudados. Avaliando-se, porém, os sintomas em hemiarcos de cada paciente, isoladamente foi encontrado um aumento significativo no grau de severidade da sensibilidade dolorosa à palpaçäo muscular nos hemiarcos correspondentes ao lado edentado dos pacientes näo portadores de PPR. Para os três grupos, foi prevalente a sensibilidade dolorosa do músculo pterigóideo lateral

Reabsorção óssea nas removíveis: técnicas de análise para extremidades livres / Bone resorption with removable dentures: techniques to evaluate free-end partial prosthesis

Os autores estudaram as diversas técnicas de medição de reabsorção óssea sob as selas das próteses parciais removíveis de Classe I de Kennedy que envolvem numerosas técnicas radiográficas, estudo dos modelos e marcações nos dentes suportes e selas das referidas próteses. Concluíram que o uso de radiografias periapicais com a técnica do paralelismo em suportes individualizados, proporcionam um melhor detalhamento da imagem e são confiáveis para este enfim

Movimentos mandibulares (MM) e disfunçäo temporomandibular (DTM) em pacientes edentados parciais com e sem prótese parcial removível (PPR) / Mandibular movements (MM) and temporomandibular dysfunction (TMD in Shortened dental arches (SDA) with and without removable partial dentures (RPD)

Com a finalidade de obter um maior número de informaçöes no que diz respeito às disfunçöes temporomandibulares (DTM) em pacientes edentados parciais, todos sintomáticos, com e sem prótese parcial removível (n = 60), foi realizado um estudo clínico transversal com metodologia baseada na mensuraçäo das variáveis derivadas dos movimentos funcionais da mandíbula, por meio de 16 procedimentos para cada um dos pacientes examinados. Para a comparaçäo dos dados, utilizaram-se testes näo paramétricos de análise de variância e acoplou-se um terceiro grupo (n = 30) de pacientes dentados, que atuou como controle. Os resultados indicaram que DTMs conseqüentes a alteraçöes funcionais dos movimentos mandibulares mostraram-se significativamente prevalentes em pacientes edentados parciais sem PPR e que a açäo terapêutica das PPRs apresentou resultados positivos, minimizando a severidade dos sinais e sintomas das DTMs

Avaliaçäo da faixa etária e sexo de pacientes dentados e edentados unilaterais (Classe II de Kennedy) com e sem prótese parcial removível (PPR), todos portadores de sinais e sintomas de desordem craniomandibular (DCM) / Evaluation of age and sex in dentulous patients and in shortened dental arch patients (Classe II of Kennedy's classification) with and without removable partial dentures (RPD), all with signs and symptoms of craniomandibular disorders

No presente trabalho, foi realizado um estudo clínico em 102 pacientes, homens e mulheres, com a idade variando de 18 a 61 anos, todos apresentando algum tipo de sinal ou sintoma de desordem craniomandibular (DCM), em funçäo do grupo etário e sexo. Com esse objetivo, os pacientes foram divididos em grupos de 34 cada, assim constituídos: a) pacientes portadores de prótese parcial removível (PPR) corretiva para arcos com ausência unilateral de dentes; b) pacientes edentados unilaterais, sem tratamento protético, e c) pacientes com a presença de todos os elementos dentais. Foram analisados e comparados os dados obtidos, e verificou-se que houve diferenças estatisticamente significantes com relaçäo à faixa etária entre pacientes portadores e näo portadores de PPR quando comparados com os pacientes com todos os dentes presentes no arco, situando-se a maioria dos pacientes dos dois primeiros grupos numa faixa etária entre 31 e 50 anos e idade média de 40,5 e 39,5 anos respectivamente. No terceiro grupo (pacientes com todos os dentes), foi encontrada uma idade média de 31 anos, e a maioria situou-se dentro de uma faixa de 21 a 40 anos, caracterizando uma perda progressiva significativa num espaço de tempo relativamente curto (cerca de 10 anos). Já com relaçäo ao sexo, nos três grupos estudados, houve prevalência de mulheres em relaçäo a homens numa proporçäo aproximada de três para um

Prevalência de sensibilidade dolorosa à palpaçäo na regiäo da articulaçäo temporomandibular (ATM) e desordens craniomandibulares (DCM) entre pacientes edentados unilaterais, portadores e näo portadores de prótese parciais removíveis (PPR) / Prevalence of tenderness upon palpation of the temporomandibular joint (TMJ) region and craniomandibular disorders (CMD) among unilateral edentulous patients wearing or not removable partial dentures (RPD)

Cento e dois pacientes, homens e mulheres, com idades variando de 18 a 61 anos, todos apresentando algum tipo de sinais ou sintomas de desordem craniomandibular (DCM), foram avaliados clinicamente com a finalidade de analisar comparativamente a prevalência de sensibilidade dolorosa na regiäo da cápsula da articulaçäo temporomandibular (ATM). Com essa finalidade, os pacientes foram divididos em grupos de 34 cada, assim constituídos: a) pacientes com ausência unilateral de dentes inferiores (Classe II de Kennedy) portadores de PPR, e b) pacientes edentados unilaterais näo portadores de PPR. Um terceiro grupo de indivíduos (c), totalmente dentados, apresentando também algum sinal ou sintomatologia de DCM, atuou como grupo controle. Procedeu-se à anamnese e ao exame clínico, particularmente dirigido à palpaçäo da regiäo da cápsula da ATM, e estabeleceu-se um método de escores, com a finalidade de avaliar as respostas positivas ou negativas dos pacientes. Compararam-se estatisticamente os dados obtidos e concluiu-se que houve variaçöes significativas entre os grupos estudados, com prevalência desse distúrbio em pacientes edentados posteriores inferiores sem PPR quando comparados com pacientes totalmente dentados ou indivíduos edentados unilaterais portadores de PPR