30-Month randomised clinical trial to evaluate the clinical performance of a nanofill and a nanohybrid composite

doi:10.1016/j.jdent.2010.09.005

Journal of Dentistry

Volume 39, Issue 1, January 2011, Pages 8-15

https://doi.org/10.1016/j.jdent.2010.09.005 Get rights and content

Abstract

Objective

To evaluate the clinical performance of a nanofill and a nanohybrid composite in restorations in occlusal cavities of posterior teeth in a randomised trial over 30 months.

Methods

Forty-one adolescents participated in the study. The teeth were restored with a nanofill (Filtek Z350, 3M ESPE), a nanohybrid (Esthet-X, Dentsply); Filtek Z250 (3M ESPE) was used as a control. After 30 months, the restorations were evaluated in accordance with the US Public Health Service (USPHS) modified criteria. The McNemar and Friedman tests were used for statistical analysis, at a level of significance of 5%.

Results

There were significant differences in the roughness of Filtek Z250 (p = 0.008) and Filtek Z350 (p < 0.001) when the four time periods (baseline, 6 months, 12 months and 30 months) were compared. There were significant differences in the marginal adaptation of Filtek Z250 (p = 0.001), Filtek Z350 (p < 0.001) and Esthet-X (p = 0.011). Except for one of each composite restoration, all the modifications ranged from Alpha to Bravo. There were significant differences in the surface roughness (p = 0.005) when the three composites were compared after 30 months.

Conclusions

The materials investigated showed acceptable clinical performance after 30 months. Long-term re-evaluations are necessary for a more detailed analysis of these composites (CEP: #1252).

Introduction

Aesthetic considerations are playing a greater role in the treatment planning of dental care, even in the restoration of posterior teeth, stimulated by the popularity of aesthetics, patient demands for nonmetallic restorations and the controversy about the systemic and environmental effects of dental amalgam.1, 2 In addition, the minimally invasive approach is increasingly being emphasised in the dental literature.³ Those facts have stimulated the development of adhesive techniques.⁴ Adhesive dentistry became possible after the introduction of etching enamel with acid,⁵ the advent of resin composites,⁶ and the formation of the hybrid layer with adhesive systems first described by Nakabayashi et al.⁷

However, many changes have taken place in adhesive systems and restorative materials. One significant change was the introduction of the first restorative nanocomposite resin for dentistry. Nanotechnology, also known as molecular nanotechnology or molecular engineering, is the production of functional materials and structures in the range of 0.1–100 nm (the nanoscale) by various physical or chemical methods.⁸ Nanocomposites contain a unique combination of two types of nanofillers (5–75 nm) and nanoclusters. Nanoparticles are discrete non-agglomerated and non-aggregated particles, 20–75 nm in size. Nanocluster fillers are loosely bound agglomerates of nano-sized particles. The agglomerates act as a single unit enabling high-filler loading and high strength. As a result of the reduced dimensions of the particles and wide size distribution, increased filler load can be achieved, leading to reduction polymerisation shrinkage and increase in the mechanical properties such as tensile strength and compressive strength to fracture. These properties of nanocomposites seem to be equivalent or sometimes even higher than hybrid composites and significantly higher than microfilled composites. As a consequence, manufacturers now recommend the use of nanocomposites for both anterior and posterior restorations.9, 10, 11, 12

In addition, there are composites on the market that combine nanoparticles with other micrometric particles, and these provide even better performance. These materials are considered the precursors of nanoparticle composites and are sometimes referred to as nanohybrids.⁹

Clinical trials are important to verify the performance of these composites under real conditions of use. This study evaluated the clinical performance of a nanofill, a nanohybrid, and as a control, a conventional microhybrid composite, in restorations in occlusal cavities of posterior teeth over 30 months. The null hypotheses to be tested were (1) there was no difference in the clinical performance amongst the 3 composites after 30 months, and (2) there was no difference in the clinical performance of the composites with the passage of time.

Section snippets

Materials and methods

This was a clinical study, under a controlled and randomised design and followed the guidelines published by Consolidated Standards of Reporting Trials (CONSORT).13, 14

This research was approved by the Research Ethics Committee of the Health Science Center (CEP: #1252) of the Federal University of Paraíba (Brazil). The volunteers and their guardians were consulted to obtain authorisation for their participation in the research, and for the researchers to use the results, by means of signing a

Results

The characteristics of the samples are shown in Table 3. After performing the statistical tests to verify the homogeneity of the sample, it was found that the distribution of the variables was homogeneous in the three groups (p > 0.05). There was no association amongst the variables; that is, the groups were in the same conditions as they were before the restorations were made.

After 30 months, 37 patients were re-evaluated. The results are shown in Table 4. When the four time periods (baseline, 6

Discussion

A nanofill (Filtek Z350) and a nanohybrid composite (Esthet-X) were used in this study; a microhybrid composite (Filtek Z250) was used as the control. These composites are currently available on the market, and their manufacturers present them for restoring anterior and posterior teeth.

Filtek Supreme (3 M ESPE, St. Paul, MN, USA) was the first nanocomposite on the market that contains nanometric particles (nanomers) and nanoclusters (NCs). Nanomers are monodispersed, non-agglomerated, and

Conclusions

The materials investigated showed acceptable clinical performance in Class I restorations after 30 months. Long-term re-evaluations are necessary for a more detailed analysis of these composites. Further long-term clinical trials are necessary to confirm our results.

Acknowledgements

The authors thank 3M ESPE and Dentsply/Calk for the kind donation of materials for this investigation. The authors do not have any financial interests in the companies whose materials are included in this article.

References (32)

G.L. Adabo et al.
The volumetric fraction of inorganic particles and the flexural strength of composites for posterior teeth
Journal of Dentistry
(2003)
R.L. Bowen
Properties of a silica-reinforced polymer for dental restorations
The Journal of the American Dental Association
(1963)
S. Beun et al.
Characterization of nanofilled compared to universal and microfilled composites
Dental Materials
(2007)
J.R. Condon et al.
Reduced polymerization stress through non-bonded nanofiller particles
Biomaterials
(2002)
S.B. Mitra et al.
An application of nanotechnology in advanced dental materials
The Journal of the American Dental Association
(2003)
R.C. Spreafico et al.
Clinical performance and marginal adaptation of class II direct and semidirect composite restorations over 3.5 years in vivo
Journal of Dentistry
(2005)
S. Palaniappan et al.
Three-year randomized clinical trial to evaluate the clinical performance and wear of a nanocomposite versus a hybrid composite
Dental Materials
(2009)
L.S. Türkün et al.
Twenty-four-month clinical evaluation of different posterior composite resin materials
The Journal of the American Dental Association
(2001)
C.D. Mayworm et al.
Influence of artificial saliva on abrasive wear and microhardness of dental composites filled with nanoparticles
Journal of Dentistry
(2008)
A. Brunthaler et al.
Longevity of direct resin composite restorations in posterior teeth
Clinical Oral Investigations
(2003)

B.G. Efes et al.

Clinical evaluation of an ormocer, a nanofill composite and a hybrid composite at 2 years

American Journal of Dentistry

(2006)

A.D. Loguercio et al.

A 12-month clinical evaluation of composite resins in class III restorations

Journal of Adhesive Dentistry

(2007)

M.G. Buonocore

A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces

Journal of Dental Research

(1955)

N. Nakabayashi et al.

The promotion of adhesion by the infiltration of monomers into tooth substrates

Journal of Biomedical Materials Research

(1982)

M.-H. Chen

Update on dental nanocomposites

Journal of Dental Research

(2010)

A.U.J. Yap et al.

Comparison of surface finish of new aesthetic restorative materials

Operative Dentistry

(2004)

Cited by (35)

Clinical evaluation of posterior restorations over wet and dry dentin using an etch-and-rinse adhesive: A 36-month randomized clinical trial
2024, Dental Materials
To evaluate the clinical performance of posterior restorations over wet and dry dentin with an etch-and-rinse adhesive after 36 months of clinical service.
Forty-five participants were recruited, each one had at least two posterior teeth that needed restoration. Ninety restorations were placed on Class I or Class II cavities. For the restoration protocol, a simplified etch-and-rinse adhesive (Adper Single Bond 2) was applied over wet (WD) or dry dentin (DD) and later restored with a bulk-fill composite (Filtek Bulk Fill) under rubber dam isolation. Each restoration was evaluated using the World Dental Federation (FDI) criteria after 6, 12, and 36 months of clinical service, regarding the following principal restoration characteristics: postoperative sensitivity, marginal discoloration, marginal adaptation, fracture of material and retention, and recurrence of caries. Kruskal Wallis analysis of variance rank (α = 0.05) and Kaplan-Meier survival analysis were used for statistical analysis.
After 36 months of clinical evaluation, no significant difference between groups was observed in each FDI criterion (p > 0.05). Twenty restorations (WD=10, DD=10) showed minor marginal staining, and twenty-two restorations (WD=11, DD=11) presented small marginal adaptation defects (p > 0.05). Four restorations were lost (WD = 2, DD = 2) and the fracture rates (95% confidence interval) were 94.9% for each one, without significant difference between wet and dry dentin (p > 0.05).
The degree of dentin moisture does not seem to affect the clinical performance of a simplified etch-and-rinse adhesive in posterior restorations when the adhesive is applied vigorously over the dentine surface.
Nanofilled/nanohybrid and hybrid resin-based composite in patients with direct restorations in posterior teeth: A systematic review and meta-analysis
2020, Journal of Dentistry
Citation Excerpt :
Twelve studies reported that beveling of the enamel margins was not performed [41,42,45,47–54,57,58,61–63], while it was the case in two studies [55,56]. Etch-and-rinse adhesive systems had been used in fourteen studies [13,39,40,43–46,48–62], self-etch strategy adhesive systems in three studies [41,42,47,63], and two studies used both types of adhesive systems [14,15]. In three studies a glass ionomer cement was applied for the protection of the dentin-pulp complex [13,39,40,54,55], in two studies a calcium hydroxide cement [41–43], and in five both materials [14,44,53,56].
A systematic review and a meta-analysis were performed to answer the following research question: Are there differences in the color match and surface texture of nanofilled/nanohybrid and hybrid composite in patients with direct posterior restorations?
Randomized clinical trials that compared nanofilled/nanohybrid and hybrid composite in direct restoration in posterior teeth were included. For the analysis of the bias the risk of bias tool (RoB) was used. Meta-analyses of different pairs (nanofilled vs. hybrid and nanohybrid vs. hybrid composite) were conducted for surface texture and color match and other secondary outcomes at different follow-ups, using a random effects model. Heterogeneity was assessed with the Cochran Q test and I² statistics. GRADE was used to assess the quality of the evidence.
A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and SIGLE, without restrictions. IADR abstracts (2001–2019), unpublished and ongoing trials registries, dissertations and theses were also searched.
28 studies remained. No study was considered to be at low RoB; four studies were judged to have high RoB, and the remaining were judged to have unclear RoB.
For the primary and secondary outcomes variables no significant differences were detected between nanofilled/nanohybrid restorations and hybrid composite restorations in any of the study follow-ups (p > 0.08). The body of evidence for surface texture and color match was classified as moderate or low.
No evidence of difference was found between nanofilled/nanohybrid and hybrid composite in any of the clinical parameters evaluated.
Oral nanomedicine and the emergent process of clinical translation
2017, Nanostructures for Oral Medicine
Nanotechnologies have a wide spectrum of applications, and oral medicine has been benefited from several nanotechnological approaches. These strategies include, for instance, bleaching potential, improvement in mechanical proprieties of resin composites and implants, inhibition of biofilm growth, and the treatment of root canal. These new interventions proposed significant advances in this field over the past few years, but are still experimental. In this scenario, clinical trials are emerging. These studies are tools to translate basic research into standard clinical practice, attributing value and credibility to a line of research, guiding new research steps, and providing safety for clinical applications.
The history of clinical trials in a field speaks importantly for its relevance and short- and medium-term potential. To this point, we have seen a substantial movement of clinical translation of oral nanomedicine, starting less than a decade ago. Oral medicine is the third most clinically studied subject in nanomedicine overall. Studies include implants, bleaching, desensitizing, gingival invaginations, and other topics. The results of these trials and their potential for catalyzing posterior clinical studies are an important achievement to oral medicine, stimulating further research at all levels, and translating the high potential of the field.
Does the adhesive strategy influence the post-operative sensitivity in adult patients with posterior resin composite restorations?: A systematic review and meta-analysis
2015, Dental Materials
A systematic review and meta-analysis were performed on the risk and intensity of postoperative sensitivity (POS) in posterior resin composite restorations bonded with self-etch (SE) and etch-and-rinse (ER) adhesives.
A comprehensive search was performed in the MEDLINE via PubMeb, Scopus, Web of Science, LILACS, BBO and Cochrane Library and SIGLE without restrictions. The abstracts of the annual conference of the IADR (1990–2014), unpublished and ongoing trials registry were also searched. Dissertations and theses were searched using the ProQuest Dissertations and Periodicos Capes Theses databases.
We included randomized clinical trials that compared the clinical effectiveness of SE and ER used for direct resin composite restorations in permanent dentition of adult patients. The risk/intensity of POS was the primary outcome. The risk of bias tool of the Cochrane Collaboration was used. The meta-analysis was performed on the studies considered ‘low’ risk of bias.
After duplicates removal, 2600 articles were identified but only 29 remained in the qualitative synthesis. Five were considered to be ‘high’ risk of bias and eleven were considered to be ‘unclear’ in the key domains, yielding 13 studies for meta-analysis. The overall relative risk of the spontaneous POS was 0.63 (95% CI 0.35 to 1.15), while the stimuli-induced POS was 0.99 (95% CI 0.63 to 1.56). The overall standardized mean difference was 0.08 (95%CI −0.19 to 0.35). No overall effect was revealed in the meta-analyses, meaning that no influence of the ER or SE strategy on POS.
The type of adhesive strategy (ER or SE) for posterior resin composite restorations does not influence the risk and intensity of POS. CRD42014006617.
Microleakage study of a restorative material via radioisotope methods
2014, Revista Portuguesa de Estomatologia, Medicina Dentaria e Cirurgia Maxilofacial
To validate the quantitative method used in the evaluation of microleakage and to evaluate the microleakage of dental restorations using GCP Fill. The null hypothesis was that the restorative system doesn’t have any influence regarding microleakage.
Sixty noncarious extracted human molars were cut in two equal halves occlusogingivally and Class V cavities were prepared on the buccal or lingual surfaces of each tooth. The specimens were randomly divided into 4 groups. Two were restored with GCP Fill, while another was restored with Filtek Supreme. The control group was not restored. The specimens were stored in distilled water at 37 °C for 7 days before 500 cycles of thermocycling between 5 °C and 55 °C, dwell time of 30 s. The specimens were submersed in a solution of 99mTc-pertechnetate for 3 h and the radioactivity was determined. The nonparametric Kruskal–Wallis and Mann–Whitney test with Bonferroni correction at a significance level of 5% were used for statistical analyses.
There were statistically significant differences between experimental groups and control groups (p < 0.05). Apart from these differences, a significant difference was observed between negative and positive control groups (p < 0.001). In the control + group there was a large microleakage, and the control-group received minimum counts.
The GCP Fill and the Filtek Supreme XTE do not differ as regards microleakage; this technique proved to be simple, quick and fulfilled the objective of a quantitative method in the evaluation of microleakage. Long-term clinical studies need to be carried out to substantiate these results.
Validar um método quantitativo de medição da microinfiltração e avaliar a microinfiltração de restaurações dentárias realizadas com GCP Fill. Considerou-se como hipótese nula que o material de restauração não tem influência na microinfiltração.
Cortaram-se 60 molares humanos hígidos em duas partes iguais no sentido oclusogengival.e prepararam-se cavidades Classe V em cada metade. Os espécimes foram divididos aleatóriamente em 4 grupos. Em dois, foram restaurados com GCP Fill, noutro, com Filtek Supreme e no grupo controlo positivo não foram restaurados. Armazenaram-se os espécimes durante 7 dias em água destilada 37 °C antes de serem termociclados em 500 ciclos (5 °C e 55 °C, 30 segundos em cada imersão). Submergiram-se numa solução de 99mTc-Pertechnetate durante 3 horas e contou-se a radioatividade. A análise estatística realizou-se recorrendo aos testes não paramétricos Kruskal-Wallis e Mann-Whitney com correção de Bonferroni, considerando-se o intervalo de significância de 5%.
existe diferença estatisticamente significativa entre os grupos de estudo e os grupos controlo (p<0.05). Existe diferença estatisticamente significativa entre o grupo controlo positivo e o grupo controlo negativo (p<0.001). A maior microinfiltração verificou-se no grupo controlo positivo enquanto que o grupo controlo negativo apresenta menores valores de contagens.
Não existem diferenças na microinfiltração entre as restaurações com GCP Fill e Filtek Supreme XTE; esta técnica provou ser simples e rápida e permite a avaliação quantitativa da microinfiltração. São necessários mais estudos clínicos para suportar os resultados deste trabalho.
A split-mouth randomized clinical trial of conventional and heavy flowable composites in class II restorations
2014, Journal of Dentistry
The aim of this study was to evaluate the 2-year clinical performance of class II restorations made with a composite resin with two different viscosities.
47 patients received two class II restorations (n = 94), one made with GrandioSO (conventional viscosity – CV), and the other with GrandioSO Heavy Flow (flowable viscosity – FV), subjecting both materials to the same clinical conditions. The self-etching adhesive Futurabond M was used for all restorations. The composites were inserted using the incremental technique. The restorations were evaluated using the modified USPHS criteria according to the periods: baseline, 6 months, 1 year and 2 years after restorative procedures.
After 24 months, 40 patients attended the recall and 78 restorations were evaluated. In all periods, no secondary caries was observed. After 6 months, there were slightly overall changes of scores for most parameters. After 24 months, the higher number of changes from score Alfa to Bravo was observed for marginal discolouration (32.5% – CV and 39.5% – FV) and colour match (15% – CV and 31.6% – FV), followed by proximal contact (25% – CV and 23.7% – FV) and marginal adaptation (20% – CV and 21.1% – FV). For wear, surface texture and postoperative sensitivity the changes were very small. Just two restorations were lost during the 24-month follow up. Less than 5% of all restorations showed postoperative sensitivity. Chi-square test showed no significant differences between the two materials for all parameters analysed.
After 2 years of clinical service, no significant differences were observed between GrandioSO conventional and GrandioSO Heavy Flow for the parameters analysed. Both materials provided acceptable clinical behaviour in class II restorations.
This study presents the possibility of using a flowable composite with high filler content, for performing class II restorations.

View all citing articles on Scopus

View full text

30-Month randomised clinical trial to evaluate the clinical performance of a nanofill and a nanohybrid composite

Abstract

Objective

Methods

Results

Conclusions

Introduction

Section snippets

Materials and methods

Results

Discussion

Conclusions

Acknowledgements

Journal of Dentistry

The Journal of the American Dental Association

Dental Materials

Biomaterials

The Journal of the American Dental Association

Journal of Dentistry

Dental Materials

The Journal of the American Dental Association

Journal of Dentistry

Longevity of direct resin composite restorations in posterior teeth

Clinical Oral Investigations

Clinical evaluation of an ormocer, a nanofill composite and a hybrid composite at 2 years

American Journal of Dentistry

A 12-month clinical evaluation of composite resins in class III restorations

Journal of Adhesive Dentistry

A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces

Journal of Dental Research

The promotion of adhesion by the infiltration of monomers into tooth substrates

Journal of Biomedical Materials Research

Update on dental nanocomposites

Journal of Dental Research

Comparison of surface finish of new aesthetic restorative materials

Operative Dentistry