Management of internal derangement of temporomandibular joint disc displacement with reduction using two different lines of treatment / Manejo do desarranjo interno do deslocamento de disco temporomandibular com redução utilizando dois tipos diferentes de tratamento

Objetive: This study was to compare the effectiveness of arthrocentesis versus the insertion of anterior repositioning splint (ARS) in improving the mandibular range of motion (MRM) for patients with the temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). Methods: 36 patients diagnosed as ADDwR were recruited and divided randomly into two groups. The first group (G1) was treated by arthrocentesis, and the second (G2) was treated using ARS. All patients were reexamined after six months. Results: Except that for protrusive movement, there were significant differences between the two groups for the percentage changes of the MRM as measured by the amount of pain free opening, unassisted opening, maximum assisted opening, right lateral and left lateral movements (p < 0.05). Conclusion: Within the context of the current study, the non-invasive, lower cost ARS, provided better results in improving the MRM when managing ADDwR cases. (AU)

Objetivo: O presente estudo comparou a eficácia da Artrocentese em relação à inserção da Placa Reposicionadora Anterior (PRA) na melhoria da Amplitude de Movimento Mandibular (AMM) para pacientes que apresentam Deslocamento de Disco Anterior com Redução (DDAcR) da Articulação Temporomandibular (ATM). Método: 36 pacientes diagnosticados como DDAcR foram recrutados e divididos aleatoriamente em dois grupos. O primeiro grupo (G1) foi tratado através da Artrocentese e o segundo (G2), tratado com a PRA. Todos os pacientes foram reexaminados após seis meses. Resultados: Com exceção do movimento protrusivo, houve diferenças significativas entre os dois grupos para as mudanças percentuais das medidas de AMM pela quantidade de abertura sem dor, abertura sem assistência, abertura máxima com assistência, movimentos laterais direitos e laterais esquerdos (p < 0,05). Conclusão: Dentro do contexto do estudo atual, a PRA, não invasiva e de menor custo, proporcionou melhores resultados na melhoria da AMM no gerenciamento de casos de DDAcR (AU)

Glass Ionomer Subgingival Matrix Technique to Restore a Tooth with Severe Root Resorption for Implant Site Development.

Here, we present the multidisciplinary, patient-specific management of a patient with severe external root resorption and bone loss in a maxillary anterior tooth. The tooth was provisionally noninvasively restored with glass ionomer subgingival matrix in preparation for forced orthodontic extrusion, papillary preservation, and implant placement. This approach enables clinicians to control infection within and around the resorbed tooth and then to use it as an anchor for slow forced tooth eruption to correct bone and mucogingival deformities. Aesthetic and functional outcomes were clinically and radiographically satisfactory. The advantages and disadvantages of this technique are discussed.

Angled Abutment Transfer Jig: A Technical Report.

AIM: To introduce an angled abutment transfer jig that splints abutments securely together to facilitate easy and quick orientation. BACKGROUND: Transferring angled abutments from cast to patients' mouth could be tasking and time-consuming. Transfer jigs are often used to facilitate orientation of abutments into implant fixtures. However, with the available jigs, abutments could move out of place and thus pose a hassle in repositioning. TECHNIQUE: This technical report introduces an angled abutment transfer jig that consists of two impression copings screwed onto angled abutments which are splinted together with red acrylic resin. Access to abutment screws is feasible through slots created in the impression copings. CONCLUSION: The introduced jig is rigid and thus ensures very accurate and easy transfer of abutments into implants followed by accurate prosthesis seating. CLINICAL SIGNIFICANCE: This transfer jig design allows clinicians to transfer the orientation of angled abutments from cast to patients' mouth with optimal speed and precision.

Effect of SiO2 and Al2 O3 nanoparticles on wear resistance of PMMA acrylic denture teeth / Efeito das nanopartículas de SiO2 e Al2 O3 na resistência ao desgaste de dentes em acrílico PMMA para prótese

Objetivo: Este estudo teve como objetivo avaliar a resistência ao desgaste de dentes em acrílico para próteses contendo nanopartículas de dióxido de silício (nano-SiO2 ) e dióxido de alumínio (nanoAl2 O3 ). Material e Métodos: O material em polimetilmetacrilato (PMMA) foi utilizado para fabricar 84 amostras (n=10) contendo nano-SiO2 e nano-Al2 O3 nas concentrações 0,1% em peso, 0,3% em peso e 0,5% em peso de pó acrílico. Uma máquina de teste de desgaste de dois corpos e um microscópio digital foram usados para medir as mudanças na perda de peso e rugosidade da superfície, respectivamente. Testes de ANOVA a um fator e testes de comparações múltiplas de Tukey foram utilizados para análise dos dados (α = 0,05). Resultados: O material modificado com nano-SiO2 demonstrou um aumento significativo na perda de peso em comparação com o material acrílico artificial convencional (p ˂ 0,05) enquanto o material modificado com nano-Al2 O3 demonstrou aumento não significativo na perda de peso, exceto no subgrupo 0,5% (p < 0,05). Não há diferenças significativas em relação à alteração da rugosidade após a simulação de desgaste entre todos os grupos testados (p > 0,05). Conclusão: As nanopartículas de nano-Al2 O3 exibem menos efeito negativo que o nanoSiO2 , podendo ser usado com cautela, se necessário. (AU)

Objective: This study aimed to evaluate the wear resistance of acrylic denture teeth containing silicon dioxide (nano-SiO2 ) and aluminum dioxide (nano-Al2 O3 ) nanoparticles. Material and Methods: Poly methyl methacrylate (PMMA) denture tooth material was used to denture tooth material was used to fabricate 84 specimens (n=10) containing nano-SiO2 and nano-Al2 O3 in concentrations 0.1wt%, 0.3wt%, and 0.5wt% of acrylic powder. A two-body wear testing machine and digital microscope were used to measure the changes in weight loss and surface roughness respectively. One-way ANOVA and pair-wise Tukey's post-hoc tests were used for data analysis (α = 0.05). Results: Nano-SiO2 modified teeth material demonstrated a significant increase in weight loss in comparison conventional artificial acrylic teeth material (p ˂ 0.05) while nanoAl2 O3 modified teeth material demonstrated non-significant increase in weight loss except for 0.5% subgroup (p ˂ 0.05). There is no significant differences regarding roughness change after wear simulation among all tested groups (p > 0.05). Conclusion: Nano-Al2 O3 nanoparticles exhibit less negative effect than nano-SiO2 so; it could be used with caution if necessary. (AU)

Implant-abutment interface: a comparison of the ultimate force to failure among narrow-diameter implant systems.

STATEMENT OF PROBLEM: Limited available alveolar ridge bone and space deficiencies are some of the challenging scenarios that have led many dental implant manufacturers to develop narrow-diameter implants of various designs. Clinicians may have concerns about the durability and function of the narrow-diameter implants. PURPOSE: The purpose of this study was to explore and compare the ultimate failure resistance of the smallest diameter of the 2-stage type implant provided by 5 commonly used dental implant systems. MATERIAL AND METHODS: Thirty implants, Astra OsseoSpeed 3.0 mm and 3.5 mm, Straumann Bone Level 3.3 mm, Zimmer Tapered Screw-Vent 3.7 mm, Full Osseotite Certain 3.25 mm, and NobelSpeedy Replace 3.5 mm, 5 of each type, were tested in this study. A rigid clamp was used to hold the implants at a 30-degree angle to a static load vector. The load continued until the specimen broke or obviously deformed. Peak loads were recorded at that point for all the studied implant systems. Student t test and 1-way ANOVA were used to compare the mean peak load values (α=.05). RESULTS: The mean fracture/deformation peak load values were 367.20 N ± 98.05 for Astra OsseoSpeed 3.0 mm; 568.80 N ± 85.24 for Astra OsseoSpeed 3.5 mm; 679.00 N ± 81.09 for Full Osseotite Certain 3.25 mm; 553.4 N ± 56.96 for NobelSpeedy Replace 3.5 mm; 802.80 N ± 134.50 for Zimmer Tapered Screw-Vent 3.7 mm; and 576.20 N ± 71.45 for Straumann Bone Level 3.3 mm. Generally, a higher load was required to cause failure in implants with larger diameters than in narrower-diameter implants, and more force was necessary to cause failure in Ti6Al4V alloy implants than in commercially pure titanium implants. CONCLUSIONS: With regard to implant diameter and ultimate failure strength, Osseotite Certain 3.25 mm was considered to be more advantageous in comparison with the other implants tested.

A technique for retrieving fractured implant screws.

The use of dental implants as a source of support and retention for fixed restorations is common. This report describes the use of a fragment removal instrument together with the use of ultrasonic instrumentation to retrieve a screw fragment.

Salvaging an angled implant abutment with damaged internal threads: a clinical report.

This clinical report describes a technique to fit an existing fixed detachable implant-supported prosthesis to a zygomatic implant abutment with stripped internal threads. The threads of the abutment were retapped and a wide diameter/wide head retaining screw was used to secure the existing prosthesis on the abutment. Care is needed in the retrieval of broken screws so as not to damage the internal threads of the implants, which might lead to irreversible complications.