Clinical performance of ormocer, nanofilled, and nanoceramic resin composites in Class I and Class II restorations: a three-year evaluation

The impact of Bis-GMA free and Bis-GMA containing resin composite as posterior restoration on marginal integrity: a randomized controlled clinical trial

BACKGROUND

There have been concerns surrounding the utilization of Bis-GMA, a type of bisphenol A (BPA) derivative, within the dental industry. The aim of this study was to compare the performance of bulk fill Bis-GMA-free resin composite class II restorations in respect of its marginal integrity in comparison to bulk fill Bis-GMA-containing resin composite class II restorations over a 12-month period in a parallel clinical trial utilizing a split-mouth, double-blind, randomized strategy.

METHODS

20 patients participated in this study. Each patient has received one pair of class II posterior restorations, Bis-GMA-free (Admira fusion x-tra), and Bis-GMA containing (x-tra fil) on each side of the mouth (split-mouth strategy), (n = 40). The restorations' marginal integrity was evaluated based on Ryge's criteria (modified USPHS) at baseline (after 1 week), as well as 1 month, 3 months, 6 months, 9 months, and after 12 months of follow-up by two calibrated examiners. The statistical analyses utilizing the Friedman and Wilcoxon tests, the significance level was adjusted to 0.05.

RESULTS

Following the 12-month period, all patients attended the recall visits to evaluate the restorations. The Wilcoxon signed-rank and Friedman tests, revealed that both types of bulk fill had 100% of Alpha (A) scores at baseline and after 1 month with no significant statistical differences. After 3, 6, 9, and 12 months, both tested bulk fill restorations showed Bravo (B) score with Bis-GMA free 10% and 5% for Bis-GMA containing with no statistically significant difference (p ≤ 0.05) for clinical marginal integrity parameter in USPHS criteria.

CONCLUSIONS

Bis-GMA-free resin composites demonstrated satisfactory, marginal integrity compared with Bis-GMA-containing resin composites within 12 months.

TRIAL REGISTRATION

The protocol of the current study was registered at www.

CLINICALTRIALS

gov , with the identification number NCT05480852 on 29/07/2022. All procedures involving human participants were performed in accordance with the ethical standards of the Research Ethics Committee of the Faculty of Dentistry, Minia University, Egypt, under the approval number 419 on 27/06/2020.

Micro shear bond strength of mineral trioxide aggregate to different innovative dental restorative materials

The objective of this in vitro study was to investigate the micro shear bond strength (µSBS) of mineral trioxide aggregate to four different restorative materials. Sixty mineral trioxide aggregate (MTA) samples were randomly assigned into four experimental groups based on the restorative materials used: nanohybrid resin composite as a control, giomer, alkasite and ormocer. µSBS samples were prepared for each group (n = 15). These samples were then submitted to a µSBS test (crosshead speed, 0.5 mm/min). The resulting data were statistically analyzed by one-way analysis of variance (ANOVA), Levene, and Bonferroni tests (α = 0.05). The bond strength of the alkasite group was statistically significantly higher than all the tested groups (p<0.05), while there were no significant differences between the nanohybrid resin composite, giomer, or ormocer groups (p > 0.05). Within the limitations of this study, alkasite restorative material could be a promising material when placed over MTA.

Effect of shelf-storage temperature on degree of conversion and microhardness of composite restorative materials

BACKGROUND

The pre-cure temperature is considered an important parameter that affects the polymerization kinetics and the properties of composite restoration. As dissension exists about the effect of storing composite restorative materials in refrigerator, this study aimed to assess the effect of shelf-storage temperature on degree of conversion (DC) and microhardness of three composite restorative materials with different matrix systems.

METHODS

Three commercially-available composite restorative materials were used in this study; an Ormocer-based composite (Admira Fusion, Voco GmbH), a nanoceramic composite, (Ceram.X SphereTEC One, Dentsply Sirona GmbH), and a nanohybrid composite (Tetric N-Ceram, Ivoclar Vivadent AG). Regarding DC and microhardness tests, 60 disc-shaped composite specimens for each test were randomly divided into 3 groups (n = 20) according to the restorative material used. Each group was divided into 2 subgroups (n = 10) according to the composite storage temperature; stored at room temperature or stored in the refrigerator at 4°-5 °C. DC was evaluated using a Fourier-transform infrared spectrometer coupled to an attenuated total reflectance accessory. Microhardness was evaluated using micro-Vickers hardness tester under a load of 50 g with a dwell time of 10 s. The results were analyzed by ANOVA, post-hoc LSD, and independent t-tests at a significance level of p < 0.05.

RESULTS

Regarding DC test all groups showed statistically significant differences at both storage temperature. The Ormocer-based composite had the highest mean values. There was a statistically significant difference between all room-stored groups and their corresponding groups stored at refrigerator (p < 0.05). For microhardness test, all groups exhibited also statistically significant differences at both storage temperatures with the Ormocer-based composite having the highest mean values. A statistically significant difference between both room-stored and refrigerator-stored groups has been observed also (p < 0.05).

CONCLUSIONS

Refrigeration of resin-composite might have a deleterious effect on DC and microhardness of the tested composite restorative materials with different matrix systems. Moreover, the differences in the formulations of composite matrix have a potential impact on DC and microhardness.

36-Month Randomized Clinical Trial Evaluation of Preheated and Room Temperature Resin Composite

OBJECTIVE

This study evaluated the effect of preheating resin composites (RCs) on the clinical performance of class I restorations during a 36-month period using a split-mouth, double-blinded randomized design.

METHODS AND MATERIALS

A total of 35 patients were selected. Every patient received one pair of class I nanofilled resin composite (RC, Filtek Z350 XT) posterior restorations (n=70). One side of the mouth received preheated composites; on the other side, the composite was placed in a nonheated state following the manufacturer's instructions. These restorations were evaluated at 1-week (baseline), 12-months, 24-months, and 36-months using the FDI World Dental Federation criteria. The statistical analyses were also performed using the Wilcoxon and Friedman tests with the level of significance set at 0.05.

RESULTS

After 36 months, 33 patients attended the recall visits, and 66 restorations were evaluated. The Friedman and Wilcoxon signed-rank tests revealed insignificant differences between both groups (p>0.05) for all FDI parameters. However, a significant difference was detected for staining as a criterion at 36 months (p=0.01). Moreover, a significant difference in the staining was detected when the baseline and 36 months were compared in the nonheated RC group (p=0.001). For esthetic, functional, and biological properties, the nonheated composite exhibited 93.9%, 100%, and 100% of the clinically accepted scores, respectively, and the preheated group presented 100% for all properties. Four restorations had postoperative sensitivity at baseline for nonheated (11.4%) and five for preheated (14.2%), but the postoperative sensitivity scores were considered highly acceptable at 12-, 24-, and 36-months.

CONCLUSIONS

After 36 months, preheated nanofilled RCs showed an acceptable clinical performance similar to that of the nonheated ones in class I restorations, but with better resistance to marginal staining.

Eighteen-month clinical performance of preheated nanoceramic resin-based composites in Class I occlusal cavities: A randomized clinical trial

Aims:

This study aimed to evaluate the effect of preheated nanoceramic resin-based composite (RBC) (Ceram-X-Mono) placed in Class I occlusal cavities over a period of 18 months.

Settings and Design:

This study involves split-mouth design, randomized controlled clinical trial (RCT)

Materials and Methods:

One operator restored 60 Class I occlusal cavities in 24 patients. Preheating of nanoceramic RBC to 60°C for 10 min was performed before insertion of the material into 30 prepared cavities, whereas 30 restorations in the nonpreheated group were placed according to the manufacturer's instructions. Two observers evaluated the restorations using Federation Dentaire Internationale (FDI) criteria at baseline, 6, 12, and 18 months.

Statistical Analysis:

Kappa index, Friedman and Wilcoxon matched pair test, and Krushal-Wallis and Mann-Whitney tests were used for statistical analysis.

Results:

100% retention rates were seen in both the groups. In nonpreheated group, significant difference was observed for surface staining (P = 0.0001), color stability (P = 0.0277), anatomic form (P = 0.0431), and marginal adaptation (P = 0.0051), whereas in preheated group, significant increase in surface staining (P = 0.0051) was recorded. There was a statistically significant difference observed between the preheated and nonpreheated groups at different time periods for the tested clinical parameters.

Conclusion:

Within the limitations of this RCT of 18 months, preheated nanoceramic RBC restorations showed better clinical performance compared to nonpreheated group.

Reliability of Class II Bulk-fill Composite Restorations With and Without Veneering: A Two-year Randomized Clinical Control Study

Bulk-fill composites are increasingly used in stress-bearing areas in posterior teeth, with a diversity of reports concerning their effectiveness and clinical reliability. The objective of this randomized clinical control study was to investigate the effectiveness of bulk-fill versus veneered bulk-fill Class II composite restorations. A double-blind split-mouth technique was employed in 80 subjects recruited for restoring Class II caries in one molar bilaterally in the same arch following respective inclusion and exclusion criteria and after obtaining written consent. While one molar was randomly restored with bulk-fill composite using the sealed-envelope technique, Tetric N-Ceram Bulk Fill (TBF), the contralateral was restored with a bulk-fill composite veneered with an increment of a heavy-body microhybrid composite-Tetric-Ceram HB (TBF/V). Box-only cavities were prepared and received etch-and-rinse adhesive bonding and Tetric N-Bond treatment before composite insertion. Restorations were assessed at 24 hours, 2 weeks, 6 months, 12 months, and 24 months for esthetic, functional, and biological quality employing the FDI ranking criteria. Friedman repeated-measures analysis of variance, the McNemar test, and the Cohen's kappa statistical test were used for statistical analysis. Over a 24-month interval, none of the test restorations were ranked as clinically unsatisfactory. In terms of functional criteria, clinically excellent restorations were significantly more prevalent in TBF/V than in TBF (p<0.05). For long-term satisfactory performance of Class II bulk-fill composites, an occlusal veneering increment of conventional heavy body microhybrid composite appears to be favorable.

Neurotic personality trait as a predictor in the prognosis of composite restorations: A 24-month clinical follow up study

The role of personality traits in modulating the incidence and progression of medical disease conditions are well documented, however, there is a paucity of information for its effects on dental health conditions and specifically on the prognosis of restorative dental materials. This study aims to evaluate the clinical performance of Micro-hybrid and Nano-ceramic composite restorations among patients with different personality traits. A total of 323 patients, indicated to receive operative treatment at a University Dental College Hospital, were invited to participate in this study. Consenting patients were requested to complete the Big Five Inventory (BFI-44 Item) personality questionnaire and were evaluated by a psychiatrist for categorizing the participants based on their personality traits. Out of the recruited patients, 124 patients falling in to the dominant trait of Agreeableness (n = 62) and Neuroticism (n = 62) were included in the study for further investigation. Next, patients from the Agreeableness (Group A) and the Neuroticism personality trait group (Group N) were randomly divided into two subgroups each—sub group Am (n = 44) and Nm (n = 48) for Micro-hybrid composite restorations and Sub group An (n = 42) and Nn (n = 47) for Nano-ceramic composite restorations. Two trained and calibrated dentists prepared the cavities according to previously published methodology. The restorations were evaluated at baseline (immediately after restoration), 6-months, 12-months and 24-months intervals by two blinded independent dental professionals for anatomical form, secondary caries, color match, retention, marginal adaptation, surface texture, marginal discoloration and post-operative sensitivity. There is no statistically significant difference noted in various parameters of restoration performance between Micro-hybrid composite and Nano-ceramic composite compared among ‘agreeableness’ personality group and among ‘neuroticism’ personality group after controlling the personality trait factor. Higher ‘Neuroticism’ individuals had higher restoration deterioration in color matching and surface texture when compared to higher ‘Agreeableness’ trait individuals. Regression analysis showed no effect of gender or cavity size on the outcome of results. Assessment of personality traits may serve as a useful tool during treatment planning which would aid clinicians in choosing suitable restorative dental material and prosthesis design according to individual patient’s physiological and functional needs, thereby overall improving the quality of treatment provided.

Indirect Resin Composite Inlays Cemented with a Self-adhesive, Self-etch or a Conventional Resin Cement Luting Agent: A 5 Years Prospective Clinical Evaluation

OBJECTIVE

The aim of this study was to clinically evaluate the 5-years clinical performance of indirect resin composite inlays luted with three different resin cement strategies in MOD Class II restorations.

MATERIALS AND METHODS

A randomized clinical trial was conducted following CONSORT guidelines. Forty patients with three large cavities indicated for indirect MOD Class II restorations were enrolled in the current study. Then, 120 indirect resin composite inlay restorations (SR Nexco) were placed and luted with three different resin cement strategies (n=40); an etch-and-rinse (Variolink N), self-etch (Panavia F2.0) and self-adhesive (RelyX Unicem). These restorations were evaluated to the periods of 1 week (baseline), 1, 3 and 5 years using modified USPHS criteria. Statistical analyses were performed with Wilcoxon and Friedman tests with level of significance set at 0.05.

RESULTS

The outcome of the clinical trial showed that, there was neither loss of restorations nor recurrent caries after 5 years for all luting cements groups. Both self-etch Panavia F2.0 and self-adhesive RelyX Unicem resin cements exhibited significant differences between the evaluation periods regarding to marginal discoloration and marginal adaptation (p=0.03). At baseline, only 8 cases of etch-and-rinse (Variolink N) resin cement group exhibited post-operative sensitivity which were relieved after short time (p=0.04).

CONCLUSION

All the three resin cement strategies tested, showed acceptable clinical performance after 5-years recall period. In time, etch-and-rinse resin cement group showed better clinical performance regarding marginal discoloration and marginal adaptation at 5-years recall period. Clinical Relevance statement:In vitro and in vivo studies reveal contradictory evidence of the clinical performance of indirect resin composite inlays luted with different resin cement strategies. Thus, this study revealed that etch-and-rinse resin cement still has the best prognosis for adhesive luting of indirect resin composite inlays.

Fabrication and characterization of low-shrinkage dental composites containing montmorillonite nanoclay

Dental composites are aesthetic materials widely used in Dentistry for replacing hard dental tissues lost due to caries or traumas. The aim of this study was to fabricate low-shrinkage dental composite charged with nanoclay fillers (montmorillonite Cloisite®-MMT) and evaluate their cytotoxicity and physicomechanical properties. Four dental composites were produced from the same organic matrix: Bis-GMA/TEGDMA (30 wt.%). The filler system was constituted of BaSi, SiO₂, and MMT in the following concentrations (wt.%): 93.8/6.2/0, 89.1/5.9/5, 86.7/5.8/7.5, and 84.4/5.6/10 (E₀: 0; E₅: 5%; E_7.5: 7.5%; E₁₀: 10% of MMT nanoclays). The following properties were tested: in vitro cytotoxicity, flexural strength, elastic modulus, volumetric shrinkage, water sorption, water solubility, and hygroscopic expansion. Scanning electron microscopy was used to characterize composites' topography. Data were analyzed by one-way ANOVA and Tukey's HSD post hoc test (p < 0.05). MMT nanoclays did not affect the cytotoxicity. E₅ and E_7.5 groups showed a significant decrease in polymerization shrinkage while maintained the overall physicomechanical properties. The inclusion of 5 and 7.5 wt.% of MMT nanoclays allowed the fabrication of dental composites with low cytotoxicity and low polymerization shrinkage, without jeopardizing the overall behaviour of their physicomechanical properties (flexural strength, elastic modulus, water sorption, water solubility, and hygroscopic expansion). These aspects suggest that the usage of MMT nanoclays could be an effective strategy to formulate new dental composites with clinical applicability.

Wear of monolithic zirconia against different CAD-CAM and indirect restorative materials

STATEMENT OF PROBLEM

The wear of monolithic zirconia against enamel has been widely studied, but how zirconia affects different opposing restorative materials is not clear.

PURPOSE

The purpose of this in vitro study was to investigate the depth of wear and volumetric loss of different restorative materials opposed by monolithic zirconia.

MATERIAL AND METHODS

Sixty-six Ø10×3-mm specimens (n=11) were fabricated from monolithic zirconia, zirconia reinforced ceramic, lithium disilicate ceramic, feldspathic ceramic, ORMOCER, and ceramic optimized polymer. A 2-body pin-on-disk wear test was performed by using monolithic zirconia pins. The specimens were scanned with a noncontact profilometer after the tests. The scan parameters were a frame size area of 1.5×1.5 mm, frequency of 400 Hz, and scan sensitivity of 2 μm. After the evaluation of depth and volume loss, the specimens were analyzed with a scanning electron microscope. The Kruskal-Wallis test was used to analyze the differences in wear values across the specimen groups, and pairwise comparison tests were performed with a post hoc test (α=.05).

RESULTS

Maximum depth of wear was 257.55 ±18.88 μm for lithium disilicate ceramic, 295.36 ±14.46 μm for zirconia reinforced ceramic, 421.82 ±214.49 μm for ORMOCER, 333.73 ±79.09 μm for ceramic optimized polymer, 146.27 ±22.86 μm for feldspathic ceramic, and 41.55 ±5.04 μm for monolithic zirconia. The depth of wear was not significantly different among lithium disilicate, zirconia-reinforced ceramic, ORMOCER, and ceramic optimized polymer (P<.05). However, the depth of wear of monolithic zirconia and feldspathic ceramic was less than that of other materials (P<.001). Volume loss of lithium disilicate was 1.68 ±0.25 mm³, 1.08 ±0.35 mm³ for zirconia reinforced ceramic, 4.29 ±2.91 mm³ for ORMOCER, 2.46 ±0.63 mm³ for resin ceramic, 1.07 ±0.09 mm³ for feldspathic ceramic, and 0.19 ±0.02 mm³ for monolithic zirconia. Feldspathic ceramic and monolithic zirconia had significantly less volume loss than the other groups (P<.001), and the difference between them for volume loss was statistically insignificant (P>.05).

CONCLUSIONS

The tested ceramic-based materials had favorable wear resistance compared with the tested composite resin-based ones. However, the ceramics tended to crack formation than the composite resins.

Cytotoxicity of Different Composite Resins on Human Gingival Fibroblast Cell Lines

The aim of the present study was to evaluate and compare the cytotoxic effects of eight composite resins on immortalized human gingival fibroblasts. Composite resins were eluted in cell culture medium for 48 or 72 h at 37 °C. Immortalized human gingival fibroblast-1 (HGF-1) cell lines were seeded in 96-well (1 × 10⁴) plates and incubated for 24 h at 37 °C with the obtained extraction medium. The percentage of viable cells in each well (MTT test) was calculated relative to control cells, which were set to 100%. Data observed were not normally distributed, and nonparametric statistical methods were used for statistical analysis. The Wilcoxon test was used for intragroup comparison, and the Kruskal–Wallis test was used for intergroup multiple comparisons. Significance value was set as p < 0.05. All materials tested showed cytotoxic effects on gingival fibroblasts, recordable as noncytotoxic, mildly cytotoxic or severely cytotoxic, depending on the percentage of cell viability. The Wilcoxon test for intragroup comparison showed that the percentage of viable cells decreased significantly for extracts, for all composite resins tested. The composite resins contained monomers that displayed cytotoxic properties. BisGMA, TEGDMA and UDMA had inhibitory effects and induced apoptotic proteins in pulp fibroblast. Composite resins that contained lower percentages of unbound free monomers—and that released less ions—possessed superior biocompatibility in vitro.

Influence of Neuroticism on the Prognosis of Nanoceramic and Microhybrid Composite Restoration: A Comparative 1-year Clinical Study

AIM

This study aimed to compare the clinical performance of nanoceramic and microhybrid-based composite restorations in adult patients with different personality traits.

MATERIALS AND METHODS

Patients in accordance with the inclusion and exclusion criteria were asked to complete the BFI (Big Five Inventory) questionnaire. Of a total of 323 patients, 124 (67 males and 57 females) patients were categorized into agreeableness and neuroticism traits and were included in the study. The patients were randomly divided into two subgroups: SG I A (n = 31) and II A (n = 31) for microhybrid composite (Spectrum TPH 3, Dentsply/DeTrey, Konstanz, Germany), SG I B (n = 31) and II B (n = 32) for nanoceramic composite restorations (Ceram X mono, Dentsply/DeTrey, Germany). At baseline, 6 and 12 months, the restorations were evaluated using the Modified USPHS (United States Public Health Service) evaluation criteria. The Pearson chi-square and the Fisher's exact test were used to assess the difference between the personality traits and restorative material groups where a probability value of P < 0.05 was considered to be statistically significant.

RESULT

Most of the restorations scored alfa (A), whereas very few scored bravo (B) in all the subgroups. However, there were no charlie (C) or delta (D) scores. Overall, Spectrum TPH and Ceram x mono displayed superior performances in retention and postoperative sensitivity than all the other clinical parameters. Furthermore, Ceram x mono restorations showed more surface roughness than Spectrum TPH. No statistical differences in the restoration performance were found between both personalities and restorative material types.

CONCLUSION

Although neuroticism has an effect on various health outcomes, its impact on the clinical performance of composite restorations during the follow-up period was not observed. In addition, there was no difference between the performance of nanohybrid and microhybrid composite.

RETROSPECTIVE ANALYSIS OF THE STATE OF DIRECT DENTAL RESTORATIONS AFTER ENDODONTIC TREATMENT

Endodontic treatment is accompanied by the loss of a significant amount of tooth crowns, which leads to a significant decrease in their strength characteristics. The restoration of endodontically treated teeth, as a rule, is carried out by the direct method, however, a unified approach regarding direct or indirect restoration has not yet been determined. The aim – retrospective analysis of the clinical condition of direct restorations of endodontically treated teeth. Materials and methods. 284 patients aged 25 to 60 years were examined; they studied the state of 888 previously performed direct restorations of the anterior and posterior teeth after endodontic treatment in a period of 2 to 10 years. Restorations were evaluated according to the adapted clinical criteria “integrity of the restoration”, “marginal fit of the material”, “marginal staining”, “anatomical shape”, “colour correspondence for the restoration”, “roughness of the surface of the material”, as well as the criterion “condition of the contact point” for located on the contact surfaces of the teeth of the restorations. Results. Of the 888 examined direct restorations, 760 restorations (85.6±1.18 %) were located in the posterior teeth, with 562 restorations in the molars (63.3±1.62 % of the total) and 198 in the premolars (22 , 3±1.40 %), and 128 restorations (14.4±1.18 %) were detected in the anterior teeth, while in the incisors - 80 restorations (9.0±0.96 %), in the fangs – 48 (3.5±0.76 %). 720 restorations (81.1±1.31 %) were made from photocomposite materials, 97 restorations (10.9±1.05 %) from chemical curing composites, 71 (8.0±0.91 %) from glass-ionomer cements . The most common violations were colour mismatch – in 511 restorations (57.5±1.66 %), marginal staining - in 470 restorations (52.9±1.68 %), surface roughness - in 357 restorations (40.2±1.0, 65 %). More often than others, in the reconstructions of their photocomposites and glass ionomers there was a colour mismatch, and surface roughness for chemical composites. Conclusions. For direct tooth restoration after endodontic treatment in 81.1±1.31 % of cases, photocomposite materials are used, less often chemical curing composites and glass ionomers. Of the violations of such restorations, the most frequent are colour mismatch, surface roughness and edge staining.

Nanofilled/nanohybrid and hybrid resin-based composite in patients with direct restorations in posterior teeth: A systematic review and meta-analysis

OBJECTIVE

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?

DATA

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.

SOURCES

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.

STUDY SELECTION

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.

RESULTS

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.

CONCLUSION

No evidence of difference was found between nanofilled/nanohybrid and hybrid composite in any of the clinical parameters evaluated.

Clinical Performance of a Glass Hybrid Restorative in Extended Size Class II Cavities

Objective:

To evaluate the clinical performance of a glass hybrid restorative compared with a resin composite in the restoration of large and deep Class II cavities after 24 months.

Methods and Materials:

A total of 108 extended size, with the width of the proximal box not interfering with the peak of the cusps and the proximal box in occlusion, Class II lesions in 37 patients were either restored with a glass hybrid restorative or with a micro-hybrid composite resin in combination with selective etching by two experienced operators according to the manufacturer's instructions. Two independent examiners evaluated the restorations at baseline and at the six-, 12-, 18-, and 24-month recalls according to the modified US Public Health Service criteria. Negative replicas at each recall were observed under scanning electron microscopy (SEM) to examine surface characteristics. Data were analyzed statistically.

Results:

After 24 months, 90 restorations were evaluated in 32 patients (recall rate: 86.5%). Four glass hybrid restorations were missing; three were due to bulk and one was due to proximal fracture at 12 months. Only six restorations were scored as bravo at baseline and at the six-, 12-, 18-, and 24-month recalls for color (p&lt;0.05). No significant differences were observed between the two restorative materials for the other criteria evaluated (p&gt;0.05). SEM observations exhibited acceptable surface and marginal adaptation characteristics for both restorative materials at 24 months.

Conclusions:

Although glass hybrid restorations showed significant mismatch in color, both restorative materials exhibited successful performance for the restoration of large Class II cavities after 24 months.

The differences between three performance measures on dental restorations, clinical success, survival and failure: A matter of perspective

OBJECTIVES

The aim of this retrospective methodology study was to investigate the influence of using different definitions for restoration failure and inclusion criteria on restoration longevity expressed in AFR.

METHODS

EPF from fifteen general dental practices were used for collecting the data for this study. From the EPF, 321,749 composite restorations placed in 52,245 patients by forty-seven GDPs between January 2000 and December 2011 were included. Kaplan-Meier statistics were applied and mean AFRs over 2, 5 and 10 years were calculated. The effect on the AFR of using different levels of failure: based on Claims data (CD), Success (SUC), Survival (SUR) and different inclusion criteria of tooth/restoration variables were reported.

RESULTS

Highest AFRs were found for level CD, in which every intervention was considered as failure, and the lowest AFRs for level SUR in which repairs and an endodontic treatments were not considered as a failure. AFRs increased when the observation period prolonged especially for SUR, followed by SUC and CD. An overview of long-term survival studies showed a wide variation in study design, performed clinical examination (USPHS criteria or GDP), number of restorations included, description of restoration failure and found AFRs for CD, SUC and SUR.

SIGNIFICANCE

Using failure criteria, Success and Survival, in future clinical studies would enable a better comparison of studies as well as demonstrate the impact of more conservative restorative intervention protocols on patient care.

Evaluation of the biocompatibility of resin composite-based dental materials with gingival mesenchymal stromal cells

Resin composite-based dental materials can leach certain components into the oral environment, causing potentially harmful gingival biological effect. Gingival tissue is a rich source of mesenchymal stem cells (MSCs) that is easily accessible, and can be used as a complementary approach for the investigation of dental material biocompatibility. Using gingival MSCs (gMSCs), the present study aimed to investigate the cytotoxicity of two classes of restorative dental materials (ormocers and resin composites) used to restore class II cavities close to the gingival margin, in addition to analyzing the leached compounds from these resin composite-based materials. Functionality assays (Colony-forming unit, migratory potential, and proliferation assays) and a viability assay (MTT) were employed. Cells' aspect was observed by scanning electron microscopy (SEM). Leached monomers were also quantitated using high-performance liquid chromatography (HPLC). The cytotoxicity of the biomaterials was highlighted by impaired functionality and diminished viability of gMSCs. Despite being variants of the same commercial material, the two ormocers behaved differently one material having a more negative impact on cell functionality than the other. Cells appeared to attach well to all materials. Main monomer molecules were mostly released by the tested materials. For all samples, an increased elution of monomers was recorded in artificial saliva as compared with culture medium. One composite material has released nearly eight times more urethane dimetacrylate in artificial saliva than in culture medium. Significantly lower gMSC viability scores were recorded for all the investigated samples in comparison with the control.

[The long-term results of teeth restoration with composite resin materials: a systematic literature review]

AIM

To evaluate by means of a systematic review the survival rate of composite resin restorations in the long-term period and the main factors, affecting the quality of restorations.

MATERIAL AND METHODS

An electronic search was performed in eLIBRARY.RU, PubMed/MEDLINE and Scopus. Restriction period was 2007-2017 years. The eligibility criteria included randomized controlled trials, controlled clinical trials and prospective and retrospective cohort studies with at least 3 years of follow-up.

RESULTS

The initial search resulted in 328 articles after an initial assessment and careful reading, 17 studies were included in this review. The overall survival rate of composite restorations was 90.7% after 3 years, 89.5% after 5 years, 89.3% after 7 years and 75.6% after 10 years. The highest loss rate was for class II restorations at molars. However there was not enough information about class III and IV restorations and direct veneers. According to majority of publications, type of composite resin material and adhesive system do not affect the survival rate of restorations. The main risk factors of failure are smoking, beverages consumption, bruxism, xerostomia and low level of caries resistance.

CONCLUSION

The results of this review suggest that composite resin restorations can demonstrate clinically acceptable results in the long-term period. In case of compliance with treatment protocol the longevity of composite resin restoration is more than 15 years.

Do Nanofilled/Nanohybrid Composites Allow for Better Clinical Performance of Direct Restorations Than Traditional Microhybrid Composites? A Systematic Review

This systematic review was carried out to assess the clinical effectiveness of nanofilled and nanohybrid composites used for direct restorations in comparison with microhybrid composites. The guidelines for the preferred reporting items for systematic reviews and meta-analyses were followed. A search of articles published from July 1996 to February 2017 was performed in PubMed, SciVerse Scopus, Latin American and Caribbean Health Sciences, the Scientific Electronic Library Online, and the Cochrane Library. The present review selected only randomized controlled trials comparing the clinical performance of a nanofilled or nanohybrid composite for direct restorations with that of a microhybrid composite. The research found 201 studies. Twenty-one articles fulfilled the criteria of the present review. However, the included studies were characterized by great methodological diversities. As a general trend, nanofilled and nanohybrid composites were found to be capable of clinical performance, marginal quality, and resistance to wear similar to that of traditional composites without showing improved surface characteristics. The risk of bias of included studies was judged unclear or high. The clinical performance of nanofilled/nanohybrid composites was found to be comparable to that of traditional composites in the posterior area. The data concerning anterior and cervical restorations were insufficient. With regard to the esthetic properties, there is a compelling need for studies on anterior teeth in which the operators are kept unaware of the restorative material. Nanofilled/nanohybrid composites seem to be a valid alternative to traditional microhybrid composites, and at the moment, there is low-level evidence attesting a lack of their superiority.

Nanofilled Resin Composite Properties and Clinical Performance: A Review

The aim of this review was to compile recent evidence related to nanofilled resin composite materials regarding the properties and clinical performance. Special attention was given to mechanical properties, such as strength, hardness, abrasive wear, water sorption, and solubility. The clinical performance of nanocomposite materials compared with hybrid resin composites was also addressed in terms of retention and success rates, marginal adaptation, color match, and surface roughness. A search of English peer-reviewed dental literature (2003-2017) from PubMed and MEDLINE databases was conducted using the terms "nanocomposites" or "nanofilled resin composite" and "clinical evaluation." The list was screened, and 82 papers that were relevant to the objectives of this work were included in the review. Mechanical properties of nanocomposites are generally comparable to those of hybrid composites but higher than microfilled composites. Nanocomposites presented lower abrasive wear than hybrids but higher sorption values. Their clinical performance was comparable to that of hybrid composites.

A Comparative Evaluation of Microleakage among Newer Composite Materials: An in vitro Study

Background:

Good adhesive bonding of restorative materials to cavity walls minimizing microleakage is an important criterion for the performance and longevity of a restoration in the oral cavity. The present study is aimed to compare the microleakage among newer composite materials.

Materials and Methods:

Forty-five extracted healthy premolars were collected; standard Class II cavities were prepared. They were randomly divided into three groups of 15 teeth each. The groups were made based on the different composite restorative materials used for restoration. Group A consisted of conventional microfilled composite resin restorations, and Group B was posterior nanocomposite resin. Group C was restored using ORMOCER – Admira. After completion of restorations, all teeth were subjected to thermocycling at 5° C, 37° C, and 55° C for 250 cycles. Later, all samples were immersed into 50% silver nitrate dye group wise for for 4 hours (h), and teeth were sectioned buccolingually. Sectioned teeth were observed under a stereomicroscope for the evaluation of microleakage. ANOVA and unpaired t-tests were used for statistical analysis. The significance level was at set P < 0.001.

Results:

The results of this study showed that Group C (ORMOCER – Admira) presented with the least microleakage followed by Group B (Tetric N-Ceram) followed by Group A (Tetric Ceram).

Conclusions:

Overall ORMOCER – Admira performed better than the other two composite materials with the least microleakage.

Fabrication of concave micromirrors for single cell imaging via controlled over-exposure of organically modified ceramics in single step lithography

This work describes the fabrication of concave micromirrors to improve the sensitivity of fluorescence imaging, for instance, in single cell analysis. A new approach to fabrication of tunable round (concave) cross-sectional shaped microchannels out of the inorganic-organic hybrid polymer, Ormocomp^®, via single step optical lithography was developed and validated. The concave micromirrors were implemented by depositing and patterning thin films of aluminum on top of the concave microchannels. The round cross-sectional shape was due to residual layer formation, which is inherent to Ormocomp^® upon UV exposure in the proximity mode. We show that it is possible to control the residual layer thickness and thus the curved shape of the microchannel cross-sectional profile and eventually the focal length of the micromirror, by simply adjusting the UV exposure dose and the distance of the proximity gap (to the photomask). In general, an increase in the exposure dose or in the distance of the proximity gap results in a thicker residual layer and thus an increase in the radius of the microchannel curvature. Under constant exposure conditions, the radius of curvature is almost linearly dependent on the microchannel aspect ratio, i.e., the width (here, 20-200 μm) and the depth (here, 15-45 μm). Depending on the focal length, up to 8-fold signal enhancement over uncoated, round Ormocomp^® microchannels was achieved in single cell imaging with the help of the converging micromirrors in an epifluorescence microscopy configuration.

Clinical performance of Class I nanohybrid composite restorations with resin-modified glass-ionomer liner and flowable composite liner: A randomized clinical trial

Background:

Liners play a vital role in minimizing polymerization shrinkage stress by elastic bonding concept and increase the longevity and favorable outcome for composite restorations.

Aims:

The aim of this study was to evaluate the clinical performance of nanohybrid composite restorations using resin-modified glass-ionomer and flowable composite liners.

Settings and Design:

A single-centered, double-blinded randomized clinical trial, with split-mouth design and equal allocation ratio that was conducted in the Department of Conservative Dentistry and Endodontics.

Materials and Methods:

In forty patients, a total of eighty Class I restorations were placed with resin-modified glass-ionomer cement (RMGIC) liner (FUJI II LC, GC America) in one group and flowable composite liner (smart dentin replacement/SDR, Dentsply Caulk, Milford, DE, USA) in another group. All restorations were clinically evaluated by two examiners, immediately (baseline), 3, 6, and 12 months using US Public Health Service modified criteria.

Statistical Analysis Used:

Statistical analysis was performed using McNemar's test (P < 0.05).

Results:

There was no significant difference in the color match, marginal discoloration, surface roughness, and marginal adaptation. Restorations with RMGIC liner group show 20% Bravo scores on anatomic form at 12 months but are still clinically acceptable.

Conclusion:

Nanohybrid composite restorations with RMGIC (Fuji II LC) and flowable composite liner (SDR) demonstrated clinically acceptable performance after 12 months.

One-year clinical evaluation of different types of bulk-fill composites

AIM

In the present study, we evaluated the 1-year clinical performance of a conventional posterior composite resin and three bulk-fill composite resins.

METHODS

Fifty patients with four class II restorations under occlusion were enrolled in the present study. A total of 200 restorations were placed in the cavity, 50 for each material (Clearfil Photo Posterior, Filtek Bulk-Fill Flowable and Filtek P60, Tetric EvoCeram Bulk-Fill, and SonicFill). One operator placed the restorations in the cavity, and 1 week later the patients were called for baseline examination. Two calibrated examiners evaluated the restorations once every 3 months for 1 year, according to United States Public Health Service criteria. The data were analyzed using SPSS. Non-parametric tests (Kruskal-Wallis, Mann-Whitney U-test, and Friedman) were used for the analysis at a confidence level of 95%.

RESULTS

The 1-year recall rate was 86%. All restorations showed minor modifications after 1 year. However, no statistically-significant differences were detected between the materials' performance at baseline and after 1 year for all criteria (P > 0.05).

CONCLUSIONS

The bulk-fill composite resin materials showed similar clinical performance when compared with a conventional posterior composite resin. Further evaluations are necessary for the long-term clinical performance of these materials.

Four-year Randomized Clinical Trial to Evaluate the Clinical Performance of a Glass Ionomer Restorative System

Objective

The aim of this study was to evaluate the clinical performance of a glass ionomer restorative system compared with a microfilled hybrid posterior composite in a four-year randomized clinical trial.

Methods

A total of 140 (80 Class 1 and 60 Class 2) lesions in 59 patients were either restored with a glass ionomer restorative system (Equia, GC, Tokyo, Japan), which was a combination of a packable glass ionomer (Equia Fil, GC) and a self-adhesive nanofilled coating (Equia Coat, GC), or with a microfilled hybrid composite (Gradia Direct Posterior, GC) in combination with a self-etch adhesive (G-Bond, GC) by two experienced operators according to the manufacturer's instructions. Two independent examiners evaluated the restorations at baseline and at one, two, three, and four years postrestoration according to the modified US Public Health Service criteria. Polyvinyl siloxane impression negative replicas at each recall were observed under scanning electron microscopy (SEM) to evaluate surface characteristics. The statistical analyses were carried out with McNemar, Pearson Chi-square, and Cochran Q- tests (p&lt;0.05).

Results

After four years, 126 (76 Class 1 and 50 Class 2) restorations were evaluated in 52 patients, with a recall rate of 88.1%. None of the restorations showed trends to downgrade in anatomical form, secondary caries, surface texture, postoperative sensitivity, and color match (p&gt;0.05). Significant differences in marginal adaptation and discoloration were found at four years compared to baseline for both restorative materials for Class 1 and Class 2 restorations (p&lt;0.05). Only one Class 2 Equia restoration was missing at three years (3.9%), and another one was missing at four years (7.7%) (p&gt;0.05). SEM evaluations were in accordance with the clinical findings.

Conclusions

The use of both materials for the restoration of posterior teeth exhibited a similar and clinically successful performance after four years.