Strain Behavior of Implant-Supported Full-Arch Fixed Dental Prostheses Supported by Four or Five Implants.

PURPOSE: Strains transferred to the supporting simulated bone structure by implant-supported full-arch fixed dental prostheses (FAFDPs) were analyzed by digital image correlation (DIC). MATERIALS AND METHODS: Polyurethane models were made using 3.75 × 11-mm implants and divided into the following groups with different implant numbers and design: EH5 (five implants/external hexagon), MT5 (five implants/internal taper), EH4 (four implants/external hexagon), and MT4 (four implants/internal taper). Both qualitative and quantitative (one-way analysis of variance [ANOVA] statistical comparison) analyses were performed by the DIC method after the application of a 250-N load in the central fossa of the mandibular first molar. Different regions of interest were selected in the polyurethane model for comparison between groups. RESULTS: Compressive strains were found in the cervical region of the models, and tensile strains were found in the apical region of the models. Significant differences were found in the different analyzed regions of interest for the different number of supporting implants and implant designs (P < .05). CONCLUSION: Groups with five implants showed more regions with less strain concentration compared to groups with four implants, but strain distribution was similar between groups. The different tested implant designs showed similar strain concentration and distribution to the supporting structures.

Comparative analysis of elastomeric die materials for semidirect composite restorations.

AIM: Die silicone materials are used to build chairside composite restorations. The purpose of this study was to compare the flowability, dimension accuracy, and tear strength of four elastomeric die materials. MATERIAL AND METHODS: Materials were divided into four groups: Mach-2 (M2), Scan Die (SD), GrandioSO Inlay System (GIS), and Impregum-F (IM). Flowability analysis was carried out using the shark fin test (SFT). For dimension accuracy, impressions were taken from a premolar Class I preparation and an elastomeric model was cast. Composite resin restorations were built and positioned into the premolar for gap measurement. The mean gap length was divided into three levels: acceptable (A), not acceptable (NA), and misfit (M). For tear strength, strip specimens were made with a V-shaped notch (n = 6). The specimens were tested in a universal machine until tear. All data were analyzed statistically with a confidence interval of 95%. RESULTS: GIS showed the lowest flowability values, with no differences between IM, M2, and SD. For dimension accuracy, IM showed 100% 'A' gap values, followed by M2 (80%), SD (60%), and GIS (60%). For tear strength, IM showed the highest values, followed by M2, GIS, and SD. CONCLUSIONS: M2, SD, and IM had similar flowability, while GIS had the lowest. IM presented higher tear strength than M2, followed by GIS and SD. IM showed the highest degrees of acceptable gap filling, followed by M2.

REANATOMIZAÇÃO DE DENTE CONÓIDE COM RESINA COMPOSTA POR MEIO DE TÉCNICA DE APLICAÇÃO SIMPLIFICADA / RESHAPING OF CONOID TOOTH WITH COMPOSITE RESIN USING A SIMPLIFIED APPLICATION TECHNIQUE

O sorriso com aparência agradável exerce grande influência na harmonia facial, eleva a autoestima e produz nas pessoas um sentido de autoafirmação social. Assim, fatores que interferem de modo significativo no sorriso, como dentes conóides, podem contribuir negativamente para o bem-estar e autoafirmação provenientes de um sorriso harmônico e, portanto, requerem intervenção, desde que o paciente manifeste o desejo de corrigir o problema. Dentes conóides têm alteração de tamanho, estrutura e forma, o que causa desarmonia na composição do sorriso. O presente trabalho apresenta um caso clínico de reanatomização por meio de técnica adesiva direta de um incisivo lateral, a fim de auxiliar na instalação de aparelho para correção ortodôntica. A técnica utilizada foi a preconizada pelo grupo Styleitaliano ® , como o objetivo desta técnica é simplificar os passos operatórios, apenas duas resinas de cor e uma de efeito foram utilizadas para restabelecer tamanho e forma dental. O trabalho concluiu que foi importante a integração entre a ortodontia e a estética para finalização de casos clínicos com características de alteração de forma.

A beautiful smile is often considered to have an important role on people's lives, since it contributes to self-confidence and social relationships. Therefore, dental discrepancies such as conoid teeth could affect negatively one's life and, as long as the patient desires, intervention should take place. Conoid teeth have significant alterations of basic anatomy, size and shape, which lead to a non-proportional smile. This case report regards to a reshape of a conoid lateral incisor, using direct composites, in order to help the orthodontic work. The chosen technique to provide this reshape was developed by the Styleitaliano ® group, in order to simplify the restorative steps, using only three composite shades (one for dentin, one for enamel and one for optical effect). This case report emphasizes that different dentistry areas, such as Cosmetic Dentistry and Orthodontics must perform together in order to achieve good results, especially in cases that require shape changes.

Color stability and surface roughness of composite resins submitted to brushing with bleaching toothpastes: An in situ study.

OBJECTIVE: To evaluate, in situ, the color stability (CS) and surface roughness (SR) of composite resins after toothbrushing with whitening toothpaste. MATERIALS AND METHODS: Specimens (6 × 2 mm/) of composite resin (Tetric N-Ceram, Z250 and Z350) were randomly fixed on thirty participants' upper molars (buccal surface). For an initial standardization (7 days), participants used a soft toothbrush and nonwhitening toothpaste (SDB - Sorrisos Dentes Brancos). Initial CS (Easyshade) and SR (Surfcorder RS) measurements were performed. For SR, impressions of specimens were taken (Express, 3 M ESPE) to produce replicas in polyurethane resin (Axon F16, Abcol). Participants were randomly separated into three groups (n = 10) regarding used toothpaste (SDB; Close up White Now - CWN; Colgate Luminous White - CLW). After 90 days, CS and SR measurements were obtained, and data were analyzed (2-way ANOVA, repeated measures, Bonferroni, P < .05). RESULTS: Z250 showed higher (P < .05) color change than Z350. Tetric N-Ceram presented an intermediary value for ΔE, however, it also demonstrated higher SR (P < .05) after brushing with CLW, compared with SDB and CWN. CONCLUSIONS: The SR change of composite resin after toothbrushing with a whitening toothpaste is material dependent, but the toothpaste abrasiveness does not change the CS. CLINICAL SIGNIFICANCE: Whitening toothpaste do not change the color stability of composites; however, it can alter the restorative composite surface roughness.

Breakage of a catheter in the epidural space.

BACKGROUND AND OBJECTIVES: Breakage of epidural catheters during their removal is rare, but it has been described. The anesthesiologist should be aware of the complications and proper handling of those catheters. The objective of this report was to present a case of breakage of an epidural catheter in labor analgesia. CASE REPORT: A 33-year old female, gravida II, I delivery, was admitted to the maternity ward in labor. After two hours, the patient requested analgesia. On physical exam, the patient was in labor, with cervical dilation of 5 cm, regular uterine dynamics, broken amniotic membrane, and pain of 10 by the Visual Analog Scale (VAS). Labor analgesia was instituted using combined double puncture technique. During labor evolution, one analgesia complementation through the catheter. Catheter removal was somewhat difficult, leading to breakage of the catheter. Axial CT and X-ray of the lumbar spine did not show the fragment of the catheter. Since the patient was asymptomatic, without signs of radicular irritation, pain, or infection, proper precautions were taken and the patient was discharged from the hospital. CONCLUSIONS: Epidural catheters in the lumbar region are, occasionally, hard to remove. Factors that increase the chances of knot formation and the risk of breakage of catheters were listed. In the present case, one of the main factors was the excessive introduction of the epidural catheter. Luckily, neurologic complications are even less frequent, and applying gentle traction, in the absence of paresthesias, the catheter is usually successfully removed.

Quebra de cateter no espaço peridural / Rotura de catéter en el espacio epidural / Breakage of a catheter in the epidural space

JUSTIFICATIVA E OBJETIVOS: A quebra do cateter peridural durante sua remoção é rara, porém descrita. O conhecimento das possíveis complicações e o manuseio adequado são responsabilidades do anestesiologista. O objetivo deste relato foi apresentar caso de quebra de cateter peridural em analgesia de parto. RELATO DO CASO: Paciente do sexo feminino, 33 anos, GII, PI, deu entrada na maternidade em trabalho de parto. Após duas horas de evolução, a paciente solicitou analgesia. Ao exame, encontrava-se em fase ativa do trabalho de parto, com dilatação cervical de 5 cm, dinâmica uterina regular, bolsa rota, com dor classificada pela Escala Visual Analógica - VAS 10. Iniciada a analgesia de parto pela técnica combinada com dupla punção. Durante a evolução foi feita uma complementação analgésica pelo cateter. Na retirada houve pequena dificuldade e conseqüente rompimento do mesmo. Optou-se pela realização de uma tomografia axial computadorizada e radiografia da região lombar que não mostrou evidência do fragmento do cateter. Visto que a paciente evoluiu assintomática clinicamente, sem sinais de irritação radicular, dor ou infecção, procedeu-se às devidas orientações e alta hospitalar. CONCLUSÕES: Cateteres peridurais em região lombar são, em ocasiões raras, difíceis de remover. Fatores que podem aumentar as chances de formação de nós e risco de quebra do cateter foram relacionados. Neste caso, um dos principais fatores envolvidos foi a introdução excessiva do cateter peridural lombar. Felizmente, as complicações neurológicas são ainda mais raras, e seguindo as diretrizes de uma tração lenta e suave na ausência de parestesias, na maioria das vezes, o cateter é removido com sucesso.

BACKGROUND AND OBJECTIVES: Breakage of epidural catheters during their removal is rare, but it has been described. The anesthesiologist should be aware of the complications and proper handling of those catheters. The objective of this report was to present a case of breakage of an epidural catheter in labor analgesia. CASE REPORT: A 33-year old female, gravida II, I delivery, was admitted to the maternity ward in labor. After two hours, the patient requested analgesia. On physical exam, the patient was in labor, with cervical dilation of 5 cm, regular uterine dynamics, broken amniotic membrane, and pain of 10 by the Visual Analog Scale (VAS). Labor analgesia was instituted using combined double puncture technique. During labor evolution, one analgesia complementation through the catheter. Catheter removal was somewhat difficult, leading to breakage of the catheter. Axial CT and X-ray of the lumbar spine did not show the fragment of the catheter. Since the patient was asymptomatic, without signs of radicular irritation, pain, or infection, proper precautions were taken and the patient was discharged from the hospital. CONCLUSIONS: Epidural catheters in the lumbar region are, occasionally, hard to remove. Factors that increase the chances of knot formation and the risk of breakage of catheters were listed. In the present case, one of the main factors was the excessive introduction of the epidural catheter. Luckily, neurologic complications are even less frequent, and applying gentle traction, in the absence of paresthesias, the catheter is usually successfully removed.