Features and advances of Morse taper connection in oral implant / 中华口腔医学杂志

Dental implants have been widely accepted as a predictable and reliable tool for dental reconstruction with the development of the economy. The design of implant-abutment connections has influence on mechanical properties and biological characteristics of implants. There are two types of implant-abutment connections, the external and the internal connections. Morse taper connection is one of the internal connections and its conical shape creates significant friction via the high propensity of parallelism between the two structures within the joint space. Several studies showed that Morse taper connection performed well in terms of survival rate, stability, bacterial seal and marginal bone loss. Recently, clinical studies indicate implants combining Morse taper connection with platform switching are helpful in reducing marginal bone absorption. This review aims at analyzing the features and advantages of Morse taper connection.

Reabilitação de maxila atrófica com implantes individualizados de conexão morse ­ quatro anos de acompanhamento / Rehabilitation of an edentulous atrophic maxillary arch using non-splinted morse cone dental implants ­ a 4-year case report

O objetivo deste trabalho foi demonstrar, através de um caso clínico, o passo a passo da reabilitação de maxila atrófica por meio de implantes individualizados de conexão cone-morse (OBL). Uma paciente do sexo feminino, com 62 anos de idade, apresentava uma relação maxilomandibular de Angle classe II, bastante perda óssea na maxila e falta de suporte ósseo para o tecido gengival, queixando-se de desconforto funcional e estético da prótese total superior convencional e com o anseio de ter todos os dentes de volta, da forma mais natural possível, através de implantes osseoin- tegráveis. A paciente foi submetida à reconstrução óssea com área doadora extraoral de crista ilíaca, com a finalidade de aumento na espessura óssea, o que levaria à maior oferta de tecido duro para instalação de implantes, além de melhor suporte para os tecidos moles. Quatro meses após a reconstrução, foram instalados 12 implantes individualizados cone-morse (OBL). Todos os implantes tiveram torque final acima de 45 Ncm e foram ancorados em tecido ósseo enxertado e remanescente. Com a reabertura dos implantes, foi confeccionada uma prótese fixa provisória. Neste momento, mais dois implantes foram colocados. Após seis meses de temporização, foram cimentadas as coroas individualizadas de cerâmica sobre os pilares personalizados cone-morse (OBL). O acompanhamento clínico de mais de quatro anos demonstrou que esta técnica de individualização de coroas sobre implantes se constitui em uma alternativa segura e, a cada dia, mais desejada pelos pacientes, uma vez que, na busca pela maior mimetização de uma arcada com dentes naturais, a possibilidade de ter coroas separadas os remete a um sorriso mais natural. Por outro lado, é preciso entender que vários são os aspectos a serem considerados antes de se optar por esta forma de reabilitação.

The objective of this study was to demonstrate, through a clinical case report, the step by step rehabilitation of an atrophic maxillary arch using non-splinted morse cone dental implants (OBL). First, a 62 years-old female patient presented with a class II Angle relationship, extensive bone loss and concomitant lack of support for the gingival tissue, also complaining of functional and esthetic discomfort due to her conventional dentures. Second, the patient stated her desire to "have all teeth back in their most natural way through dental implants". In this way, the patient was submitted to bone reconstruction using the iliac crest graft approach, to increase bone thickness, which would be enough supply for implant placement and better soft tissue support as well. Four months after the reconstruction surgery, 12 non-splinted Morse cone implants were installed (OBL). All implants had final insertion torque above 45 Ncm being anchored in grafted and native areas. After implant exposure, a provisional fixed prosthesis was delivered. At this point, two additional implants were placed. Six months individual ceramic crowns were cemented over customized morse cone abutments (OBL). The clinical follow-up now has more than four years and has showed that this technique constitutes a safe alternative and even more desired by patients since the seek for greater mimetics and the possibility to have single crowns lead to a more natural smile. On the other hand, it is necessary understand that there are several aspects to be considered before opting for rehabilitation protocol.

Measurement of loosening torque of prosthetic components in Morse taper connection implants

AIM: The aim of this study was to verify two different types of interfaces in Morse taper connection implants, relating the mechanical resistance to a loosening torque that is required to separate or move the prosthetic abutment. MATERIAL AND METHODS: Ten Morse taper connection implants and their respective abutments were divided into two groups (n = 5), DH (double hexagon) interface and OI (octagonal implant) interface. A standard insertion of implants was performed in a stainless steel base, where each abutment received a sequence of two consecutive tightening torques at a 10-minute interval, followed by a loosening torque, which was measured using a digital torque gauge. The Student's t-test with a 5% significance level was used for data analysis. RESULTS: The results showed a statistically significant difference in the loosening torque values compared with DH torque values (p < 0.05). However, the difference between tightening and loosening torque values was not statistically significant in the OI group (p = 0.465). CONCLUSION: The study concluded that there was a difference in the torque required to loosen the abutment screws between the DH group and the OI group, with the latter showing better results.