Why do composite restorations fail

Journal of Dental restoration 65 5 All rights reserved. Article Tools Print this article. Indexing metadata. How to cite item. Finding References. Email this article Login required. Email the author Login required. Characteristics of the clinical operators, particularly their decision making when it comes to observing or approaching an existing restoration, are decisive for longevity. Cavity features such as the number of restored walls, composite volume, and presence of endodontic treatment are of major importance and may dictate the service time of the restorative approach.

The choice of restorative composite seems to have a minor effect on longevity provided that appropriate technical procedures are used. Composite resin restorations can be considered a reliable treatment as long as both the professional and the patient are aware of the factors involved in restoration failures.

These genetic variants were selected due to their known functional activity, gene location, and allele frequency 16 — Genotyping data for the 92 individuals selected as cases and 92 individuals used as comparison were commensurate with genotyping data obtained previously from distinct individuals from the Pittsburgh area drawn for studies of different phenotypes [formation of periapical lesion related to deep caries lesions in dentin 16 ; chronic periodontitis 18 ] and we concluded these samples we selected were not under the influence of undetected population substructure.

The PLINK software package 20 was used to analyze the distribution of alleles and genotypes between individuals with direct composite resins that failed versus controls that had the same restorations without any failures.

To assure, we obtained a satisfactory matching for our case—control analysis, we used age, sex, ethnicity, smoking tobacco, drinking alcohol, diabetes, and periodontal health as covariates and performed both linear and logistic analyses and found that there were no differential influence of the covariates in the results.

Therefore, we present here the results of the genotypic two degrees of freedom test as implemented in PLINK. From those 6, amalgam and 2, composite restorations, 2, amalgam and composite restorations could not be monitored, since the patients discontinued treatment.

A total of amalgam 9. These figures show lower rates than those found in the literature 4 and show small differences between up to 5-year failure rates of amalgam in comparison to composite restorations. The differences in failure rates of 0. It is worth noting that these restorations were performed by students dentists in training. A total of individuals who had direct composite resin restorations were studied.

Failures were five times more common in the maxilla in patients who did not smoke tobacco; however, smoking tobacco changed the maxilla—mandible ratio to All genotypes were in Hardy—Weinberg equilibrium.

One variant in MMP3 rs had a p -value borderline of the nominal alpha of 0. The distribution of all other genetic variants was not statistically and significantly different.

Mineralized dentin contains MMP2, MMP3, MMP8, and MMP9 and acidic resin components incorporated into etch-and-rinse adhesives and self-etch adhesives increase collagenolytic and gelatinolytic activities of demineralized collagen matrices. We show for the first time that genetic variation potentially affecting degradation of collagen is associated with failures of more extensive composite restorations.

These results support the suggestion that patient-related factors rather than the restorative material are the most important determinants of secondary caries and restoration failures It is remarkable that the association we found between MMP2 rs and failure of extensive composite restorations is evident with only 92 cases.

While concerned about multiple testing, we did not apply the strict Bonferroni correction as it would increase type II errors and a major focus of this study was to identify putative associations with having a failure composite resin for further studies. For example, under the Bonferroni correction, we would have lowered the alpha to 0. We have demonstrated before 24 that known true associations are missed when correction for multiple testing is implemented.

It is also important to note that a larger discussion on the interpretation of p -values is currently underway and we should move to the near future to an interpretation that takes into account the biological relevance of an observation beyond the blind consideration of the arbitrary alpha threshold to determine significance The results of our work should be considered with caution and serve to generate hypothesis to be directly tested in larger and more homogeneous samples.

On the other hand, simply disregarding the nominal associations presented here may delay discovery by misleading the field to believe no true biological relationships exist.

Whereas the p -value of 0. We also simplified our analyses bivariate instead of multivariate since we paired our sample by a number of covariates and each individual included was not related to anyone else in the cohort. The justification of using amalgam due to its lower costs alone in contrast to the potential of eliminating an environmental hazard has become harder to support now that direct composite resins can perform at acceptable levels. Our data come from a large clinic where dentists working are in the beginning of their professional careers.

Also, the population treated has some of the worst oral health and overall health indicators in the country We also showed that smoking tobacco and alcohol drinking increase the chance of anterior extensive direct composite resin restoration failure.

Based on these data, we argue that the mechanism underlying this result relates to the fact that smoking tobacco alters salivation 27 , since we found that the higher failure rates of anterior maxillary restorations in the cases when individuals did not smoke equalized with anterior mandibular restoration failures when the patient smoked tobacco.

Matrix metalloproteinase 2, also known as gelatinase A, is a membrane-bound protein that is important for extracellular matrix turnover, preferentially cleaving collagen types IV, V, VII, and XI and gelatin The MMP2 variant rs was found to be associated with formation of a periapical lesion when there is deep carious lesions in dentin The underlying mechanism for this finding is possibly the same that explains the association of this genetic variant in MMP2 and failures of direct resin composite restorations of the present study.

MMP2 gelatinolytic activity probably occurs both in partially demineralized dentin at the bottom of caries lesions and at the surface treated with either etch-and-rinse or self-etch adhesives.

Overtime, this gelatinolytic activity weakens the bond between the material and the remaining dentin structure leading to failure of the restoration. This result is compatible with the findings that showed significantly higher risk of failure of composite restorations in individuals with a higher number of restored surfaces 3. Altered expression and activity levels of MMP2 is known to be associated with pathological states.

For instance, in colorectal cancer, MMP2 mRNA is detected in higher levels in unaffected tissue surrounding metastatic tumors Inactivating mutations in MMP2 in humans lead to connective tissue underlying issues as seem in Torg—Winchester syndrome 31 , multicentric osteolysis, arthritis syndrome 32 , and possibly influence the formation of keloids MMP2 encodes an enzyme that degrades type IV collagen.

This role is particularly important in endometrial menstrual breakdown, vascular regulation, and inflammatory responses In teeth, type IV collagen is located along the dental—enamel junction Therefore, knowing the roles of MMP2 in other tissues and pathologies, we believe the mechanism underlying the genetic influence of MMP2 in failure of extensive composite resin restorations involves degradation of type IV collagen in individuals who have higher MMP2 activity for carrying particular genetic variants in the gene, which is located along of the dentin—enamel junction.

Although MMP2 rs may not have any function, it may be a surrogate for individuals at higher risk for extensive composite resin restorations failure since it may be in linkage disequilibrium to genetic variants that alter MMP2 activity. Since MMP activity has been associated with severity of chronic airway diseases 36 , it would be interesting to investigate if patients with conditions such as idiopathic interstitial pneumonia or bronchiectasis have a history of more often replacing direct composite resins or forming periapical lesions in comparison to individuals not affected by chronic airway diseases.

Similarly, since MMP2 activity has been linked to poor prognosis of multiple forms of cancer 37 , including colorectal, melanoma, breast, lung, ovarian, and prostate, it would be interesting to interrogate if patients that more often have direct composite resin failures or develop periapical lesions, when affected by cancer, have a worse prognosis.

In summary, our studies of cases with extensive direct composite resin restoration failures suggest that composite resins can fully substitute dental amalgams in routine dental practice. Smoking tobacco and alcohol drinking increase the chance of failure in anterior complex direct composite resin restorations. Finally, MMP2 may have a role in the cases that composite restorations fail and genotyping rs may be useful to determine follow-ups of extensive direct composite resin restorations.

This study was carried out in accordance with the recommendations of the Belmont Report, University of Pittsburgh institutional Review Board with written informed consent from all subjects. All subjects gave written informed consent in accordance with the Declaration of Helsinki. AV designed the studies, obtained support, analyzed and interpreted data, and wrote the first draft of the manuscript.

AR and AM obtained support, interpreted data, and critically revised the manuscript. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Alexandre Richter and Roshan Padodara revised the text for grammar and style. National Center for Biotechnology Information , U. Journal List Front Med Lausanne v. Front Med Lausanne. Published online Nov 6. Alexandre R. Silva , 1 Kesia K. Filho , 3 Aronita Rosenblatt , 3 and Adriana Modesto 2. Kesia K. Author information Article notes Copyright and License information Disclaimer.

Vieira, ude.