UNIVERSIDADE FEDERAL FLUMINENSE FACULDADE DE ODONTOLOGIA
LONGEVIDADE DAS RESTAURAÇÕES DIRETAS CL I E CLII EM DENTES POSTERIORES, UMA META ANÁLISE.
Niterói 2015
UNIVERSIDADE FEDERAL FLUMINENSE FACULDADE DE ODONTOLOGIA
LONGEVIDADE DAS RESTAURAÇÕES DIRETAS CL I E CL II EM DENTES POSTERIORES, UMA META ANÁLISE.
CHEUNG KA FAI
Dissertação apresentada à Faculdade de Odontologia da Universidade Federal Fluminense, como parte dos requisitos para obtenção do título de Mestre, pelo Programa de Pós-Graduação em Odontologia.
Área de Concentração: Clínica Odontológica
Orientador: Prof. Dr. Gustavo Oliveira dos Santos.
Niterói 2015
BANCA EXAMINADORA
Prof(a). Dr(a). Gustavo Oliveira dos Santos Instituição: Universidade Federal Fluminense
Decisão: _________________________Assinatura: ________________________ Prof(a). Dr(a). Raphael Vieira Monta Alto
Instituição: Universidade Federal Fluminense
Decisão: _________________________Assinatura: ________________________
Prof(a). Dr(a). Rafael Ferrone Andreiuolo
Instituição: Universidade Federal do Rio de Janeiro
DEDICATÓRIA
.
Ao Grande, Eterno, Soberano, Majestoso e Misericordioso DEUS que me concedeu ser seu filho através de JESUS CRISTO, o autor da minha salvação!
A minha esposa Michele Gerhardt Schulze Fernandes Cheung que sempre será até o último suspiro da minha vida, minha inspiração pois sua determinação, paciência e incondicional amor, me fez chegar até aqui.
Aos meus filhos Matheus Clark e Gabriel Poshan, vocês alegram a minha vida com seus testemunhos, sempre me inspirando a sonhar.
Ao meu pai Cheung Po Shan minha força e meu amigo, seus ensinamentos me fazem ser um homem melhor, você é um exemplo!
A minha mãe Ho Shuet Hung, pois sem suas correções, amor e paciência, certamente minha vida teria sido mais difícil.
A querida professora Elizabeth, sempre em meu coração a quem muito me ensinou.
Ao meu orientador Gustavo Oliveira dos Santos, muito mais do que um amigo, um camarada, um cavalheiro.
AGRADECIMENTOS
Ao Amigo, Professor, Orientador, Camarada, Gustavo Oliveira dos Santos, que me estendeu o braço para aprimorar meus conhecimentos, que me inspira com seu talento em fazer odontologia, sempre serei grato a ti!
Ao Professor Raphael Vieira Monte Alto, pois seus trabalhos me inspiraram e continuam inspirando ao crescimento. É um prazer estar neste grupo de amigos, a turma de quinta! Obrigado!
Ao Amigo, Mestre, Vittorio Moraschi que sem sua colaboração, seria o curso de mestrado um desafio hercúleo, mas que com sua convicção, fez tornar este sonho em realidade! Sou grato a ti!
Ao Professor Almiro Reis, que me possibilitou através dos cursos científicos do Conselho Regional de Odontologia do Rio de Janeiro ter outro olhar nesta tão nobre carreira, a docência!
Ao Presidente do Conselho Regional de Odontologia do Rio de Janeiro Afonso Fernandes que sempre apoiou o crescimento dos profissionais em odontologia, em especial a classe dos Cirurgiões Dentistas!
Ao Professor Willian Níveo que ministrou aula na minha graduação e depois de uma geração, auxiliou-me e orientou num propósito maior, obrigado!
A colega Débora Martins, que muito atendeu minhas solicitações sempre disposta a ajudar, obrigado!
A Universidade Federal Fluminense que me recebeu e permitiu todos os recursos necessários para que este trabalho se concretizasse!
Ao PPGO, a Professora Monica Calazans, em especial João e Lucy que sempre foram prestativos e acima de tudo, amigos nas horas mais necessárias!
Ao Professor Luis Narciso Baratieri, sua dedicação e amor a Odontologia, seus livros e trabalhos são motivos de admiração!
Ao Professor Antônio Eberienos, pois sendo conhecido como homem reto e de expressões fortes, estendeu-me a mão e me permitiu realizar sonhos!
Ao Professor Sergio Wayne, meu orientador na graduação, um cavalheiro! Espécime raro de ser humano!
A Professora Katlen Maia, uma pessoa que semeou em mim o fazer bem na Odontologia!
A todos os meus amigos e colaboradores, em especial meu amigo Alexandre Amaral que sem titubiar, assumiu minhas responsabilidades, me permitindo ter o privilégio de fazer esta Pós-Graduação.
RESUMO
Fai CK Longevidade em restaurações diretas posteriores CL I e CL II em dentes permanentes, uma Meta Análise. Niterói: Universidade Federal Fluminense, Faculdade de Odontologia; 2015.
O objetivo do presente estudo foi avaliar a hipótese de não haver diferença na incidência de falhas, cáries secundárias e fraturas entre restaurações posteriores classe I e II de Black em amálgama e resina composta de acordo com o período de acompanhamento. Os questionamentos clínicos foram formulados e organizados de acordo com a estratégia PICOS. Uma busca eletrônica sem restrição de datas ou idiomas foi realizada no PubMed/MEDLINE, Cochrane Central Register of Controlled Trials e Web of Science até março de 2015. Os critérios de inclusão foram estudos clínicos em humanos com no mínimo 12 meses de acompanhamento que compararam a longevidade entre restaurações em amálgama e resina composta. A pesquisa inicial resultou em 938 títulos no PubMed/MEDLINE, 89 títulos no Cochrane Central Register of Controlled Trials e 172 no Web of Science. Após a avaliação inicial e criteriosa leitura, 8 estudos publicados entre os anos de 1992 a 2013, foram incluídos nesta revisão. Os resultados dessa revisão sugerem que as restaurações em resina composta para dentes posteriores ainda apresentam menor longevidade e um maior número de cáries secundárias quando comparadas as restaurações em amálgama. Em relação a fraturas, não houve uma diferença estatisticamente considerável entre os dois materiais restauradores em relação ao tempo de acompanhamento. Atualmente existe uma tendência mundial pela substituição das restaurações de amálgama por materiais livres de mercúrio, que sejam adesivos, e que promovam estética. Esse estudo buscou por evidências que fornecessem a longevidade de restaurações em amálgama quando comparadas às resina composta.
ABSTRACT
Fai CK Longevity in later direct restorations CL I and CL II in permanent teeth, a Goal Analysis. Niterói: Fluminense Federal University, School of Dentistry; 2015.
The aim of this study was to evaluate the hypothesis of no difference in the incidence of failures, secondary caries and fractures among posterior restorations class I and II Black amalgam and composite resin according to the follow-up period. Clinical questions were formulated and organized according to the PEAKS strategy. An electronic search without blackout dates or languages was performed in PubMed / MEDLINE, Cochrane Central Register of Controlled Trials and Web of Science to March 2015. Inclusion criteria were clinical studies in humans with at least 12 months of follow-up comparing the longevity between amalgam restorations and composite resin. The initial search resulted in 938 titles in PubMed / MEDLINE, 89 titles in the Cochrane Central Register of Controlled Trials and 172 in Web of Science. After the initial reading and careful evaluation, 8 studies published between the years 1992 to 2013 were included in this review. The results of this review suggest that the composite resin restorations for posterior teeth still have less longevity and a greater number of secondary caries when compared to amalgam restorations. Regarding fractures, there was no statistically significant difference between the two restorative materials in relation to the observation period. Currently there is a worldwide trend for replacing amalgam fillings by mercury-free materials that are adhesives, and that promote aesthetic. This study sought to provide evidence for the longevity of amalgam restorations when compared to composite.
1 - INTRODUÇÃO
Durante décadas, diversos materiais vem sendo utilizados em restaurações diretas em dentes posteriores, como por exemplo o amálgama e a resina composta. Nos últimos anos, por conta de um crescente apelo por restaurações estéticas, os compósitos ganharam um grande destaque na odontologia restauradora. Contudo, apesar de os requisitos estéticos serem fundamentais, as propriedades mecânicas e a longevidade devem ser os critérios mais importantes no momento da escolha do material restaurador.1
Apesar das restaurações de amálgama ainda serem as de maior durabilidade funcional,2 seu uso tem sido questionado nas últimos décadas pela a incorporação de mercúrio na liga metálica.3 Além disso, a necessidade de maior desgaste dentário, necessária para promover maior retenção às restaurações, fazem do amálgama um material não elegível para uma odontologia conservadora. Por essas razões, as resinas compostas são atualmente o material de primeira escolha4 e mais utilizado em todo mundo para a restauração direta de dentes posteriores.5
A maior sensibilidade na técnica de confecção, somada a limitações como a contração de polimerização e possibilidade de formação de gaps marginais, podem ser fatores críticos para a durabilidade dos compósitos.6 Contudo, estudos recentes,7,8 demonstraram uma baixa média de falha anual das resinas compostas em restaurações classe I e II, variado de 1 a 3%. O motivo mais frequente para o insucesso são cáries recorrentes ou secundárias nas margens das restaurações,9 evidenciando assim possíveis falhas no processo de adesão. Em contrapartida, as restaurações em amálgama reduzem com o tempo a possibilidade de cáries secundárias pela formação de óxidos na margem das cavidades em decorrência de corrosão natural do material, principalmente em ligas com alto teor de cobre.
Os dados de estudos clínicos longitudinais que comparam a longevidade de restaurações, principalmente em dentes posteriores, devem ser interpretados com cautela, pois inúmeros fatores de confusão podem estar envolvidos. A experiência e habilidade do profissional executante, tamanho das cavidades, qualidade e indicação correta dos materiais e tipo de oclusão do paciente, são fatores que podem influenciar no desempenho das restaurações. Por conta dessas variáveis, os
estudos clínicos randomizados (RCTs) tornam-se os trabalhos elegíveis para esse tipo de pesquisa. Contudo, até o presente momento, poucos RCTs compararam a longevidade de restaurações de amálgama versus resina composta.
O objetivo dessa revisão sistemática, foi comparar a sobrevivência, o número médio de falhas anuais e as complicações como cáries secundárias e fraturas entre restaurações de amálgama e resina composta.
2 – MATERIAL E MÉTODOS
A metodologia desse estudo seguiu as recomendações do Chrochrane Handbook for systematic reviews of interventions,10 e do PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).11 Os questionamentos clínicos foram decompostos e organizados utilizando a estratégia PICOS.
2.1 Objetivos
O objetivo do presente estudo foi avaliar a hipótese de não haver diferença na incidência de falhas, cáries secundárias e fraturas entre restaurações posteriores classe I e II de Black em amálgama e resina composta de acordo com o período de acompanhamento.
2.2 Questionamento principal
Qual é a longevidade de restaurações posteriores classe I e II de Black em amálgama e resina composta?
2.3 Estratégia de busca
Uma busca eletrônica sem restrição de datas ou idiomas foi realizada no PubMed/MEDLINE, Cochrane Central Register of Controlled Trials e Web of Science até março de 2015. A estratégia de busca e a ferramenta PICOS podem ser visualizadas na tabela 01. Além disso, a lista de referências dos potenciais estudos a serem incluídos foi acessada em busca de novos estudos.
Essa revisão buscou estudos cohort prospectivos e retrospectivos, estudos clínicos controlados e estudos controlados randomizados (RCTs). Os critérios de elegibilidade incluíram estudos clínicos em humanos com no mínimo 12 meses de acompanhamento que compararam a taxa de falhas entre restaurações classe I e II em amálgama e resina composta. Os critérios de exclusão foram estudos em animais, estudos in vitro, que envolveram restaurações classe II complexas, série de casos, relato de casos e revisões.
2.5 Processo de seleção
O processo de pesquisa e triagem foi realizado por dois autores revisores (C.K.F e V.M.F), primeiramente analisando títulos e resumos. Em uma segunda etapa, artigos completos foram selecionados para leitura criteriosa e analisados segundo os critérios de elegibilidade (inclusão/exclusão), para futura extração dos dados. Divergência entre os revisores foram resolvidas através de criteriosa discussão. A concordância da busca entre os dois revisores foi avaliada pelo teste estatístico Cohen's kappa (k). Os autores dos estudos, quando necessário, foram contatados por e-mail para esclarecimentos de eventuais dúvidas.
2.6 Análise de qualidade
A análise de qualidade dos estudos incluídos foi conduzida de acordo com a escala de Newcastle-Ottawa (NOS), idealizada para ser utilizada em revisões sistemáticas que incluem estudos não randomizados, especificamente estudos cohort.12 Para a análise, três categorias principais são abordadas: seleção, comparação e resultados. Para as categorias de seleção e resultado, os estudos poderão obter uma estrela/ponto para cada item. Para a categoria de comparação, duas estrelas/pontos poderão ser atribuídas. De acordo com a NOS, a pontuação máxima atribuída a um estudo é de nove estrelas/pontos (mais alta evidência científica). Estudos pontuados a partir de 6 estrelas são considerados como de alta qualidade.
Os seguintes dados foram extraídos dos estudos incluídos (quando disponíveis): autores, design do estudo, período de acompanhamento, número de voluntários, número de abandonos, variação e média de idade, tipo e tamanho das cavidades, dentes, número de restaurações, sistema adesivo, técnica restauradora, sistema de amálgama ou resina composta, sobrevivência do amálgama, sobrevivência da resina composta, número total de falhas, cáries secundárias e fraturas.
2.8 Análise estatística
As variáveis binárias (falha das restaurações, cáries secundárias e fraturas) dos estudos incluídos foram analisadas através de meta-análise quando pelo menos dois estudos analisaram os mesmos tipos de dados. A estimativa dos efeitos de intervenção foram expressadas em risk ratio (RR) com um intervalo de confiança (CI) de 95%. O método de variância inverso foi utilizado para modelo de efeito aleatório ou o modelo de efeito fixo. A estatística I2 foi utilizada para expressar a porcentagem da heterogeneidade dos estudos. Valores com até 25% foram classificados como de baixa heterogeneidade e valores de 50 e 70% foram classificados como média e alta heterogeneidade, respectivamente. Quando uma significativa heterogeneidade foi encontrada (P < 0.10), os resultados do modelo de efeito aleatório foram validados. Quando uma baixa heterogeneidade foi verificada, o modelo de efeito fixo foi considerado. O nível de significância estatística foi determinado em P < 0.05.
O viés de publicação foi graficamente explorado através de um funnel plot. A assimetria no funnel plot pode indicar possível viés de publicação.
Os dados foram analisados usando o software estatístico Review Maneger (version 5.2.8; The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark, 2014).
3 - ARTIGOS PRODUZIDOS
(Normatização segundo a Revista: Journal of Dentistry)
Artigo 1
Longevity in later direct restorations CL I and CL II in permanent teeth, a Meta- Analysis.
Cheung Ka Fai1*, MSc Student
Vittorio Moraschini Filho2, MScD, PhD Student Raphael Vieira Monte Alto3, Adjunct Professor Gustavo Oliveira dos Santos5, Adjunct Professor
1Master student, School of Dentistry, Federal Fluminense University, Niterói, RJ, Brazil. 2MScD, PhD Student, School of Dentistry, Federal Fluminense University, Niterói, RJ, Brazil. 3DDS, MScD, PhD, Adjunct Professor of integrated dental Clinic, School of Dentistry,
Universidade Federal Fluminense, Niterói, RJ, Brazil.
4DDS, MScD, PhD, Adjunct Professor of integrated dental Clinic, School of Dentistry,
Universidade Federal Fluminense, Niterói, RJ, Brazil.
*Corresponding author: Dr. Cheung Ka Fai – Rua dos Jacarandás, nº 1160 – Bloco 02 ap 1101, Barra da Tijuca, Rio de Janeiro, RJ, Brazil - CEP 22776-050 - Phone: 55 21 36461793 - Fax: 55 21 24043403 - e-mail: dr.kafai@yahoo.com.br
1 - INTRODUCTION
For decades, various (several) materials have been used in direct restorations in posterior teeth, such as amalgam and composite resin. In recent years, due to an increasing call for aesthetic restorations, composite gained considerable importance in restorative dentistry. Although the aesthetic requirements are fundamental, the mechanical properties and longevity should be the most important criteria when choosing the restorative materials 1.
The amalgam fillings still have the most functional durability2, but its use has been questioned in recent decades by the mercury incorporation in the metallic alloy 3. In addition, its needs for greater tooth wear, required to promote greater retention to restorations, make amalgam one ineligible material for a conservative dentistry. For these reasons, the composites are currently the first choice4 material and also more used worldwide for direct restoration of posterior teeth5.
The highest sensitivity in the preparation technique, coupled with limitations as the polymerization shrinkage and possibility of formation of marginal gaps can be critical to the durability of composites6. However, recent studies7,8 have shown a low average annual failure of composite resin restorations in class I and II, ranged from 1 to 3%. The most common reason for failure is recurrent or secondary caries in the margins of restorations9, showing thus possible failures in the adhesion. On the other hand, the amalgam restorations reduce over time the possibility of secondary caries by the formation of oxides on the edge of the cavities due to natural corrosion of the material, especially in alloys with high copper content.
Data from longitudinal clinical studies comparing the longevity of restorations, especially in posterior teeth, should be interpreted with caution, as many confounding factors may be involved. The experience and skill of the performer professional, cavities size, quality and correct statement of the materials and type of the patient's occlusion, are factors that can influence the performance of the restorations. Because of these variables, randomized clinical trials (RCTs) become the work eligible for this type of research. However, to date, few RCTs compared the
longevity of amalgam restorations versus composite resin.
The purpose of this systematic review was to compare the survival, the average annual number of failures and complications such as secondary caries and fractures between amalgam fillings and composite resin.
2 – METHODOLOGY
The methodology of this study followed the recommendations of Chrochrane Handbook for systematic reviews of interventions10, and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)11 . The clinical questions were decomposed and organized using the PEAKS strategy.
2.1 Objectives
The aim of this study was to evaluate the hypothesis of no difference in the incidence of failures, secondary caries and fractures among posterior restorations class I and II Black amalgam and composite resin according to the follow-up period.
2.2 Main Questioning
What is the longevity of posterior restorations class I and II Black amalgam and composite resin?
2.3 Search strategy
An electronic search without blackout dates or languages was performed in PubMed / MEDLINE, Cochrane Central Register of Controlled Trials and Web of Science by March 2015. The search strategy and the PEAKS tool can be viewed in table 01. In addition, reference list of potential studies for inclusion was accessed for new studies.
2.4 Selection Criteria
studies and randomized controlled trials (RCTs). Eligibility criteria included clinical studies in humans with at least 12 months of follow up that compared the failure rate between class I and II restorations in amalgam and composite resin. Exclusion criteria were studies in animals, in vitro studies involving restorations class II complex, case series, case reports and reviews.
2.5 Selection Process
The process of research and screening was done by two reviewers authors (CKF and VMF), first analyzing titles and abstracts. In a second step, full papers were selected to careful reading and analyzed according to the eligibility criteria (inclusion / exclusion) for future data extraction. Divergence between the reviewers were resolved through careful discussion. The concordance search between the two reviewers was assessed by Cohen's kappa statistic test (k). The authors of the studies, when necessary, were contacted by email for any questions for clarification.
2.6 Quality Analysis
Quality analysis of the included studies was conducted according to the Newcastle-Ottawa scale (NOS), designed for use in systematic reviews that include non-randomized studies, specifically studies cohort.12 For the analysis, three main categories are addressed: selection, comparison and results. For the categories of selection and result, studies may obtain a star / point for each item. For comparison category, two stars / points may be awarded. According to the US, the maximum score for a study is nine stars / points (highest scientific evidence). Studies scored from six stars are considered to be of high quality.
2.7 Data extraction
The following data were extracted from the included studies (when available): authors, study design, follow-up, number of volunteers, number of dropouts, variation
and average age, type and size of the cavities, teeth, number of restorations, system adhesive restorative technique, amalgam or composite resin system, the amalgam survival, survival of the composite resin, the total number of failures, secondary caries and fractures.
2.8 Statistical analysis
The binary variables (failure of restorations, secondary caries and fractures) of the included studies were analyzed by meta-analysis when at least two studies looked at the same data types. The estimation of intervention effects were expressed in risk ratio (RR) with a confidence interval (CI) of 95%. The inverse variance method was used for the random effect model or the fixed effect model. The I2 statistic was used to express the percentage of the heterogeneity of the studies. Values up to 25% were classified as low heterogeneity and values of 50 and 70% were classified as medium and high heterogeneity, respectively. When significant heterogeneity was observed (P <0:10), the results of the random effects model has been validated. When a low heterogeneity was found, the fixed effect model was considered. The level of statistical significance was determined at P <0.05.
Publication bias was explored graphically using a funnel plot. The asymmetry in the funnel plot may indicate possible publication bias.
Data were analyzed using the statistical software Review Maneger (version 5.2.8; The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark, 2014).
3- RESULTS
3.1 Search process
The initial search resulted in 938 titles in PubMed / MEDLINE, 89 titles in the Cochrane Central Register of Controlled Trials and 172 in Web of Science. After the first evaluation, 21 full papers were selected. After careful reading, 13 studies were excluded because they do not fit the eligibility criteria of this review. Thus, 8 studies 14-21 published between the years 1992 to 2013 were included in this review. The reasons for exclusion of studies and the selection process can be accompanied by figure 01.
The K value of agreement between reviewers for potential articles to include (titles and abstracts) was 0.97 and for the selected articles was 0.85, demonstrating an agreement "almost perfect" according to the criteria proposed by Landis & Koch13.
3.2 Characteristics of studies
The characteristics of the included studies are presented in Table 02. Two randomized18,19 clinical trials, five prospectives14-17 cohort studies, 20 and a retrospective cohort study, 21 were included. The number of participants in the studies ranged from 2714 to 472, 19, mean age 21.6 years. The follow-up ranged from 1218.20 to 12017.21 months with a mean of 64.5 months of follow-up. Three thousand nine hundred ninety-five cavities class I and II Black were restored with amalgam (1852) and composite (2143). All studies used amalgam alloys with high copper content and dispersed phase and hybrid resins or micro-hybrid composite. The adhesive used for the adhesion of technical systems have two or three steps to enamel and dentin.
Only four studies 14,16,17,19 reported the technique for insertion of composite resin and control of polymerization shrinkage. No job explaining the mechanisms used for rubber dam.
3.3 Quality Analysis
All studies achieved a score ≥ 6 stars, classified as high quality. The scores of each study are summarized in Table 03.
3.4 Meta-analysis
The average survival of the amalgam and composite ranged 57.614 to 100%21 and 35.514 to 100%21, having an annual average of 10 and 30% faults , respectively. The random effect model was used for analysis of failures between the two restorations type analyzed due to considerable heterogeneity found (I2 = 83%; P <0.00001). The meta-analysis showed RR 0.44 (95% CI: 0:27 to 0.72), demonstrating a statistically significant difference (P = 0.001) in favor of amalgam restorations (Figure 02). For the evaluation of the risk of secondary caries, the fixed effect model was used due to low evidence of heterogeneity (I2 = 1%; P = 00:39), with RR 0.23 (95% CI: 018 to 0.30), with statistically significant difference (P <0.00001) in favor of the amalgam (Figure 03). In relation to the fracture risk, the fixed effect model was used due to the absence of heterogeneity (I2 = 0%; P = 0.77), no statistically significant difference (P = 00:46) between the two types of restoration, with RR 1:24 (95% CI: 0.71 to 2.16) (Figure 04).
3.5 Publication bias
The funnel plot showed no asymmetry when the failure of the restorations was analyzed, showing the possibility of no publication bias (Figure 05).
4- DISCUSSION
This systematic review aimed studies comparing the longevity of amalgam and composite resin restorations. After the search process, only two RCTs were within the inclusion criteria of this review, and other prospective and retrospective cohort studies. Despite the inclusion of cohort studies, systematic reviews increase the amount of information and enable the consolidation of the results of clinical questions 22 to the absence or a reduced number of TCRs can increase the risk of bias.10,23 Thus, the data this systematic review should be analyzed and interpreted with caution.
The quality of analysis, based on the NOS, characterized the studies included as high quality. However, some studies did not report important information in their methodologies, such as information of the study participants, 14,15,17,19-21 complete description of the operator technique and used materials 15,20,21. These absences causes difficulty in interpreting data and methodological analysis of these studies.
This systematic review found that the posterior restorations black class I and II amalgam have greater clinical longevity compared the composite resin restorations. All amalgam alloys used by the included studies had a high copper content, which provides better clinical performance of the restorations by inhibiting phase range 2:24 However, the latest study included in this review, 21 was published in 2012, this may have influenced the quality of used composite, as the constant improvement in physical and mechanical performance of composite resins. Other factors may also influence the performance and longevity of the restoration, such as operator skill, material used, operative technique, isolation of the field, patient cooperation and oral conditions. None of the RCTs included opted for a split-mouth design, which would be ideal to match the oral health conditions of patients such as occlusion, diet and parafunctional habits.
The results of this meta-analysis were expressed as relative risk (RR), a statistical analysis often used in binary outcomes, defined as the probability that an event occurs. Regarding the failure of the restorations, the present meta-analysis showed a RR of 0.44 (95% CI: 0.72 to 0:27), ie, the composite resin restorations have a chance to fail 44% more when purchased the amalgam restorations .
The study 21 that had the highest number of failures of the restorations, did not report the brands or characteristics of the materials used, making it difficult to interpret the data. However, this study used the USPHS25 index as success criteria, which is characterized as an absolute failure restorations that could suffer repairs or adjustments, as in the case of small fractures or marginal misfits, which could explain the high number of failures reported by article.
This systematic review had an average survival rate for the amalgam of 90.5% and the composites of 81.1%. These data are similar to the one reported by a recent systematic review 26 also compared the longevity of amalgam vs. composite resin, with an average survival rate of 92.5 and 85.8%, respectively. However, the cited review included only RCTs, performing meta-analysis of only two studies.
The main causes of failures reported in the included studies were secondary caries and fractures of the restorations or teeth, which had already been reported by other previous studies.26-28 The presence of secondary caries was significantly higher (P <0.00001) in composite resin restorations. The formats oxides in the tooth interface vs. amalgam help seal the margins, which may explain the lower incidence of caries.29 By contrast, factors such as adhesion technique, adhesive system, polymerization shrinkage and the type of tooth substrate can act critically to adhesive failure in composites, increasing the risk of recurrent decay. Regarding fractures, there was no statistically significant difference (P = 00:46) between the two materials, as this also observed in another study, 26 showing a lower sensitivity of posterior restorations will fracture when compared to recurrent caries.
In summary, based on meta-analysis of the eight included studies, amalgam restorations showed a better performance of relative longevity when compared to composite resin restorations. All the studies selected for this review found a greater longevity of amalgam restorations for posterior teeth.
5- CONCLUSION
The results of this review suggest that the composite resin restorations for posterior teeth still have less longevity and a greater number of secondary caries when compared to amalgam restorations. Regarding fractures, there was no statistically significant difference between the two restorative materials in relation to the observation period. The data from this review should be interpreted with caution by the inclusion of only two RCTs. The achievement of a greater number of RCTs based on CONSORT-statement30 and preferably with split-mouth design is key to a better understanding and monitoring the performance of the restorations in a long term.
6- TABLES AND FIGURES
Table 01. Search strategy ( PEAKS strategy )
Population 1) MeSH Terms: dental caries, dental restoration failures, dental restorations (permanent), posterior teeth, molar, premolar.
Text word: class I, class II, class I cavities, class II cavities.
Intervention 2) MeSH Terms: dental restoration OR amalgam restoration OR composite restoration OR dental amalgam OR dental composite OR dental composite restoration OR restoration posterior teeth OR composite posterior teeth. Text words: direct class I, direct class II, class I restoration, class II restoration.
Comparisons Amalgam vs. composite resin
Outcomes 3) MeSH Terms: survival OR success OR failure OR longevity OR amalgam longevity OR resin longevity OR composite resin longevity OR long-term OR follow-up OR prospective study OR retrospective study OR randomized controlled trial OR controlled trial.
Study design Randomized controlled trials, controlled clinical trials, prospective and retrospective cohort studies
Search combination 1 AND 2 AND 3
Database search
Language No restriction
Eletronic databases PubMed/MEDLINE, Cochrane Central Register of Controlled Trials and Web of Science
Figure 01 - Flowchart ( PRISMA format ) of the process of search and selection Records identified through database searching (n = 381) Scr ee nin g Eli gibi lity Ide ntifi cati on
Studies included in the present meta-analysis (n = 8) Incl ud ed Medline/PubMed Records identified through database searching (n = 938) Cochrane (CENTRAL) Records identified through database searching (n = 89) Records excluded (n = 1178) Full-text articles assessed
for eligibility (n = 21)
Full-text articles excluded (n = 13)
13 full-text articles excluded: 2 review paper
1 in vitro study 5 resin-modified
1 complex amalgam restoration 4 not reported survival rates Web of Science
Records identified through database
searching (n = 172)
Table 02. Key features of the included studies Author (year) Study design Observation period (years) No. of subjects Dropouts (%) Age Range Mean Age Black class Cavity size Tooth type No. of Restorations Adhesive system
Johnson et al. (1992) Prospective 3 27 15 NR NR Cl I and II Small, medium, large Premolar and molar 40 (AM) 88 (CR) Scotchbond L/C
Mjor and Mokstad (1993) Prospective 3 142 37 NR 13 CL II Small Premolar and molar 88 (AM) 91 (CR) NR
Collins et al. (1998) Prospective 8 72 36 13-32 16.8 Cl I and II Medium Premolar and molar 52 (AM) 161 (CR) Ketac Bond
Mair et al. (1998) Prospective 10 NR NR NR NR Cl II NR Premolar and molar 60 (AM) 90 (CR) Clearfil Bonding Agent, Occlusion Bond, Scotchbond Wilson et al. (2002) RCT 1 49 2 18-75 35 Cl I and II Medium Premolar and molar 52 (AM) 52 (CR) Singlebond Bernardo et al. (2007) RCT 7 472 35 8-12 NR Cl I and II Small, medium, large 856 (AM) 892 (CR) Scotchbond Multi-Purpose
Premolar and molar
Levin et al. (2007) Prospective 1 459 NR 18-19 NR Cl II NR Premolar and molar 557 (AM) 93 (CR) NR
Kim et al. (2013) Retrospective 10 232 0 NR NR Cl I, II and V NR Premolar and molar 147 (AM) 676 (CR) NR Continuation
Author (year) Resin
restorative technique Amalgam / Composite resin brand Amalgam survival (%) Composite Resin survival (%) Failed / total restorations Secundary caries (%) Fracture (tooth or restoration) (%) Johnson et al. (1992) Incremental Dispersalloy /
Bisfil-P, P-30 100 100 0 / 40 (AM) 0 / 88 (CR) AM = 0 / CR = 0 AM = 0 / CR = 0
Mjor and Mokstad (1993) NR Dispersalloy / P-10 95.4 90.1 4 / 88 (AM)
9 / 91 (CR)
AM = 0 / CR = 4.39 AM = 3.41 / CR = 2.19
Collins et al. (1998) Incremental Dispersalloy / Heliomolar, Herculite XR, P-30 94.2 86.4 3 / 52 (AM) 22 / 161 (CR) AM = 1.92 / CR = 4.34 AM = 3.84 / CR = 3.72
Mair et al. (1998) Incremental New True Dentalloy, Solola Nova / Clearfil Posterior, Occlusin, P-30 96.6 95.5 2 / 60 (AM) 4 / 90 (CR) NR AM = 0 / CR = 0
Wilson et al. (2002) NR Dispersalloy / Z250 98 100 1 / 52 (AM)
0 / 52 (CR)
AM = 0 / CR = 0 AM = 1.92 / CR = 0
Bernardo et al. (2007) Incremental Dispersalloy / Z100 94.4 85.6 48 / 856 (AM) 129 / 892 (CR)
AM = 3.7 / CR = 12.7 AM = 1.9 / CR = 1.8
Levin et al. (2007) NR NR / NR 88 56 67 / 557 (AM)
47 / 93 (CR)
AM = 8 / CR = 43 AM = 4 / CR = 1
Kim et al. (2012) NR NR 57.6 35.5 63 / 147 (AM)
436 / 676 (CR)
Table 03. Quality analysis of the included studies ( Newcastle -Ottawa scale )
Authors (year) Selection Comparability Outcome
Representative ness of the exposed cohort Selection of external control Ascertaiment of exposure Outcome of interest not present at start Comparability of cohorts on the basis of the design or analysisa Assessment of outcome Was follow-up long enough for outcomes occurb Adequacy of follow-up of cohorts Total 9/9 Johnson et al. (1992) 0 ★ ★ ★ ★0 ★ ★ ★ 7/9 Mjor and Mokstad (1993) 0 ★ ★ ★ ★0 ★ ★ ★ 7/9 Collins et al. (1998) 0 ★ ★ ★ ★0 ★ ★ ★ 7/9 Mair et al. (1998) 0 ★ ★ ★ ★0 ★ 0 ★ 6/9 Wilson et al. (2002) 0 ★ ★ ★ ★0 ★ ★ 0 6/9 Bernardo et al. (2007) 0 ★ ★ ★ ★0 ★ ★ ★ 7/9 Levin et al. (2007) 0 ★ ★ ★ ★0 ★ ★ 0 6/9
Kim et al. (2012) 0 ★ ★ ★ ★★ ★ ★ ★ 7/9 a A study can be awarded a maximum of one star for each item within the selection and outcome categories. A maximum of two star can be given for comparability.
Figura 05. Funnel Plot para os estudos reportando "taxa de falhas das restaurações".
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