Comparison of implant-abutment interface misfits after casting and soldering procedures.

The aim of this study was to compare vertical and horizontal adjustments of castable abutments after conducting casting and soldering procedures. Twelve external hexagonal implants (3.75 × 10 mm) and their UCLA abutments were divided according their manufacturer and abutment type: PUN (plastic UCLA, Neodent), PUC (plastic UCLA, Conexão), PU3i (plastic UCLA, Biomet 3i), and PUTN (plastic UCLA with Tilite milled base, Neodent). Three infrastructures of a fixed partial implant-supported bridge with 3 elements were produced for each group. The measurements of vertical (VM) and horizontal (HM) misfits were obtained via scanning electron microscopy after completion of casting and soldering. The corresponding values were determined to be biomechanically acceptable to the system, and the results were rated as a percentage. Statistical analysis establishes differences between groups by chi-square after procedures, and McNeman's test was applied to analyze the influence of soldering over casting (α ≤ .05). For the values of VM and HM, respectively, when the casting process was complete, it was observed that 83.25% and 100% (PUTN), 33.3% and 27.75% (PUN), 33.3% and 88.8% (PUC), 33.3% and 94.35% (PU3i) represented acceptable values. After completing the requisite soldering, acceptable values were 50% and 94.35% (PUTN), 16.6% and 77.7% (PUN), 38.55% and 77.7% (PUC), and 27.75% and 94.35% (PU3i). Within the limitations of this study, it can be concluded that the premachined abutments presented more acceptable VM values. The HM values were within acceptable limits before and after the soldering procedure for most groups. Further, the soldering procedure resulted in an increase of VM in all groups.

Photoelastic analysis of stress patterns from different implant-abutment interfaces.

PURPOSE: To investigate the peri-implant stress fields generated from four different implant-abutment interfaces under axial loading applied at the center of the implant and several millimeters away from the implant center via photoelastic analysis. MATERIALS AND METHODS: Similar unthreaded and cylindric implants and abutments were fabricated and embedded in photoelastic resin with four different implant-abutment interfaces: external hex, internal hex, internal taper (11.5 degrees), and solid connection to the abutment (one piece). The samples were submitted to vertical compressive loads; one was applied at the implant center (1.5 kg; centered load), and the other was applied 6.5 mm away from the center, 4.4 mm from the outside of the outer aspect of the implant (0.75 kg; off-centered load). The maximum shear stresses were determined and observed at 46 points around the implants under the centered load and at 61 points under the off-center load in the photoelastic models. Graphics describing the maximum shear stress (y-axis) and the analyzed points (x-axis) were obtained, and areas under the curves were calculated. RESULTS: The centered loading (all points) resulted in small differences. The lowest amounts of stress were observed for the internal-taper implants, and values were minimally greater (0.4% to 3.3%) for the other implants. No statistically significant differences were found between groups for the centered load in any area. Under an off-center load, the internal-hex implants presented the least stress (all points). For off-center loading, the internal-hexagon implants differed significantly from the external-hex and one-piece implants and displayed the lowest stress levels. CONCLUSION: Under an off-center load, the internal-hex interfaces presented the lowest stress concentrations, internal-taper interfaces presented intermediate results, and one-piece and external-hex implants resulted in high stress levels. Centralized axial loads produced similar results.

Relação entre cervicalgia e disfunção temporomandibular / Relation between neck pain and temporomandibular disorder

Alterações na coluna cervical podem interferir no sistema muscular do indivíduo, levando inicialmente a uma compensação na cintura escapular devido à sua ligação óssea e neuromuscular. Apartir daí, as cadeias musculares atuam por uma sucessão de tensões associadas, onde a posição do corpo pode ser capaz de influenciara postura da cabeça e posição mandibular. O propósito deste trabalho foi verificar a presença e o grau de severidade da disfunção temporomandibular (DTM) em pacientes portadores de cervicalgia. Para isso, 32 pacientes da Clínica Escola do Centro Universitário do Triângulo (UNITRI), já diagnosticados com cervicalgia, foram submetidos a uma nova anamnese, exame clínico e preenchimentodos Índices Clínico de Helkimo (ICH) e Protocolo Anamnésicode Fonseca (PAF). Os resultados demonstraram que, em ambosos índices utilizados, 100 por cento dos pacientes apresentavam DTM,dos quais, segundo ICH, 22 por cento com DTM moderada (M) e 78 por centosevera (S). Já para PAF, encontrou-se 21,87 por cento leve (L), 40,62 M e37 por cento S. Tais dados foram submetidos ao teste de Pearson (p < 0,05),observando valores estatisticamente significantes (p = 0,001) entreas correlações efetuadas. Conclui-se que existe uma relação clínica importante entre cervicalgia e DTM, independente do índiceaplicado, e a inspeção do pescoço e avaliação da coluna cervical sãorecomendados em pacientes com DTM.

Alterations in cervical column can interfere in individual muscular system, leading initially to scapular waist compensation due to its osseous and neuromuscular connection. Then, muscular chains act by an associated sequences of tension, and the body position can influence the head posture and mandibular position.The purpose of this work was to verify the presence and severity of temporomandibular disorders (TMD) in patients with cervical pain. 32 patients of Triangle University Center School Clinic(UNITRI) diagnosed as having cervical pain were submitted to a new anamnesis and clinical exam, and filling out Helkimo ClinicalIndex (HCI) and Fonseca’s Anamnesis Protocol (FAP). The results showed that, in both indexes used, 100 percent with cervical pain hadTMD. According to HCI, 22 percent had moderate TMD (M) and 78 percent had severe one (S) and as per FAP 21.87 percent had light (L), 40.62 percent(M) and 37 percent (S). Data were submitted to Pearson test (p < 0.05), observing statistically signifi cant values (p = 0.001) between effected correlations. It was concluded that there was a clinical relation between cervical pain and TMD independently on the appliedindex, and neck examination and cervical column evaluation are recommended on TMD patients.

Rehabilitation of maxillary edentulism with implant-supported milled-bar prostheses.

Implantology has allowed more options for rehabilitation of complete and partially edentulous patients. The professional should describe all possible alternatives to the patient, addressing all the positive and negative aspects of each possibility, such as treatment time, complexity of surgical procedures, and the final cost. The patient should select the best cost-benefit relationship because fixed prostheses are often not the option of choice for the patient. The aim of this article is to present one possible treatment option for the completely edentulous patient by use of implants to support and retain a removable complete or partial prosthesis. The clinical situations were rehabilitated by the use of a milled bar screwed to the implants to support a removable prosthesis with attachments and a milled metallic groove, which provide many advantages to the patient.

Short implants--an analysis of longitudinal studies.

PURPOSE: The purpose of this study was to consider the therapeutic decision whether to use advanced surgery or short implants based on data concerning the use of these implants found in follow-up studies. MATERIALS AND METHODS: The MEDLINE database was consulted for follow-up studies published between the years 1980 and 2004. For those studies that met the inclusion and exclusion criteria, data concerning the number of implants 7, 8.5, or 10 mm long placed and lost, the time at which the failure occurred, and related risk factors were gathered for 33 studies arranged in tables and subjected to analysis. The studies included 16,344 implant placements with 786 failures (4.8%). Implants were analyzed according to the time of failure (i.e., before or after prosthesis seating) and risk factors implicated in the failures. RESULTS: The total rate of failures was 4.8%. Implants 3.75 mm wide and 7 mm long failed at a rate of 9.7%, compared to 6.3% for 3.75 x 10-mm implants. It was found that 54.9% of failures occurred before the prosthesis connection. Finally, 66.7% of all failures were attributed to poor bone quality, 45.4% to the location (maxilla or mandible), 27.2% to occlusal overload, 24.2% to location within the jaw, and 15.1% to infections (an implant could be associated with multiple risk factors). DISCUSSION: The analysis revealed that among the risk factors, poor bone quality in association with short implants seemed to be relevant to failure. The use of implants 4 mm in diameter appeared to minimize failure in these situations. The 3.75 x 7-mm implant presented the highest failure rate (9.7%) of 1894 implants analyzed (excluding implant designs with higher failure rates but few total implants). CONCLUSION: Short implants should be considered as an alternative to advanced bone augmentation surgeries, since surgeries can involve higher morbidity, require extended clinical periods, and involve higher costs to the patient.

Direct restoration of worn maxillary anterior teeth with a combination of composite resin materials: a case report.

Tooth loss, alterations on tooth structure, and reduced vertical dimension are known to severely compromise the stomatognathic system. This case report describes the treatment of a patient who presented with an extremely worn maxillary anterior dentition with a loss of posterior support owing to the loss of almost all the posterior teeth, except the mandibular premolars. Provisional removable partial dentures were used to create an optimum maxillomandibular relationship and to provide restorative space prior to the restoration of the remaining teeth. This restoration was accomplished with a combination of layered hybrid and microfilled composite materials, which restored the maxillary anterior teeth to optimum esthetics and function.