Desempenho clínico de restaurações CAD-CAM monolíticas em zircónia suportadas por dentes : uma revisão sistemática

Introdução: Restaurações zircónia-cerâmica são amplamente utilizadas para restaurar dentes extensamente destruídos. Esta situação apresenta vantagens estéticas, mas também uma ocorrência significativa de fratura da cerâmica de revestimento. De forma a ultrapassar este fenómeno, foram introduzidas, particularmente neste séc. XXI, as restaurações em zircónia monolítica, i.e., materiais que não são recobertos com uma cerâmica vítrea. Deste modo, o objetivo desta investigação é avaliar a taxa de sobrevivência, o desempenho e comportamento clínico de coroas unitárias suportadas por dentes, efetuadas em zircónia monolítica, com tecnologia CAD/CAM. Metodologia: Foi efetuada uma pesquisa eletrónica utilizando as bases de dados Medline/PubMed®, Embase® e Cochrane Library com uma estratégia de pesquisa específica combinando termos controlados (MeSH and Emtree) e linguagem natural, de acordo com as especificações de cada base de dados. A conclusão da pesquisa sucedeu-se no dia 10 de maio. Dois revisores (C.L. e L.A.) realizaram, de forma independente, a pesquisa e seleção dos estudos. Resultados: Este estudo incluiu um total de 594 participantes e 1657 restaurações unitárias em função clínica, durante um tempo médio de observação de 1,07 anos. Cinco estudos prospetivos e quatro estudos retrospetivos foram analisados. Todos os estudos apresentaram nível moderado de qualidade, com consequente possibilidade moderada de viés, através da escala Newcastle-Ottawa (NOS). Na regressão linear desenvolvida (correlação entre taxa de sobrevivência, tipo de cimentação e a média de anos de follow-up) não houve significância estatística (respetivamente, p=0.730 e p=0.454). Verificou-se alta heterogeneidade entre estudos (I2=93,74% e Q=79,672). Conclusão: A taxa de sobrevivência global das restaurações unitárias fabricadas com a tecnologia CAD/CAM foi alta e, portanto, apesar das limitações inerentes ao presente estudo, podemos concluir que restaurações monolíticas fabricadas com tecnologia CAD/CAM podem ser uma opção viável e aceitável, particularmente na zona posterior.Introduction: Indirect zirconia-ceramic restorations are largely used to restore widely destroyed teeth, usually in the form of total crowns. However, these restorations can suffer from chipping, i.e., a fracture of the covering ceramic of the high strength zirconia infrastructure. In order to overcome this phenomenon, monolithic zirconia restorations were introduced, particularly in this XXI century. The aim of this systematic review is to evaluate the survival rate, performance and clinical behavior, marginal adaptation, and bleeding on probing of single crowns supported by teeth, made in monolithic zirconia, with CAD/CAM technology. Methodology: An extensive electronic search was conducted through Medline/PubMed®, Embase® and Cochrane Library databases with a platform-specific search strategy combining controlled terms (MeSH and Emtree) and natural language, according to each database specifications. An additional manual search was performed on the references of included articles to identify relevant publications. Deadline date to conclude every search was May 10th. Two reviewers (C.L. and L.A.) independently performed the selection and electronic and manual search. Results: The search yield a total of 594 participants and 1657 single-tooth restorations with a mean exposure time of 1.07 years. Five studies were prospective and four studies were retrospective. All studies showed a moderate level of quality, with a consequent moderate possibility of bias associated, using the Newcastle-Ottawa Scale (NOS). The linear regression showed that there was no statistical correlation between survival rate with the type of cementation and the average years of follow-up (p=0.730 e p=0.454). There was high heterogeneity between studies (I2 = 93.74% and Q = 79.672). Conclusion: The overall survival rate of single-tooth restorations fabricated with CAD/CAM technology was high and therefore, despite the restrictions inherent to the present study, we can conclude that monolithic restorations manufactured with CAD/CAM technology can be a viable and acceptable option for restoring single crowns, especially in the posterior zone

Clinical performance of monolithic CAD/CAM tooth-supported zirconia restorations: systematic review and meta-analysis

Purpose: The purpose of this systematic review was to evaluate the survival rate, biological complications, technical complications, and clinical behavior of single crowns supported by teeth made up in monolithic zirconia with CAD/CAM technology. Study selection: An extensive electronic search was conducted through Medline/PubMed, Embase, and Cochrane Library databases. Additional manual search was performed on the references of included articles to identify relevant publica- tions. Two reviewers independently performed the selection and electronic and manual search. Results: From nine articles included, there was a total of 594 participants and 1657 single-tooth restorations with a mean exposure time of 1.07 years, and follow-up period between 0.3 and 2.1 years. All studies showed a moderate level of qual- ity, with a consequent moderate possibility of associated bias, using the Newcastle-Ottawa Scale (NOS), with survival rate (SR) ranging between 91% to 100%. Bleeding on probing (BOP) were reported with an average value of 29.12%. Marginal integrity showed high success rate values for the observation periods, except for one that included patients with bruxism which obtained a SR of 31.60%. Failures and/or fractures, mostly total and requiring replacement, were observed in three studies. Linear regression showed that there was no statistical correlation between survival rate and type of cementation and the average years of follow-up (p=0.730 e p=0.454). There was high heterogeneity between studies (I2 = 93.74% and Q = 79.672). Conclusions: Within the limitation of this study, monolithic zirconia might be considered as a possible option for restoring single crowns, especially in the posterior zone.info:eu-repo/semantics/publishedVersio

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved