Clinical Evaluation of Direct Cuspal Coverage with Posterior Composite Resin Restorations

A 23-Year Observational Follow-Up Clinical Evaluation of Direct Posterior Composite Restorations

The purpose of this observational follow-up clinical study was to observe the quality of posterior composite restorations more than 23 years after application. A total of 22 patients, 13 male and 9 female (mean age 66.1 years, range 50–84), with a total of 42 restorations attended the first and second follow-up examinations. The restorations were examined by one operator using modified FDI criteria. Statistical analysis was performed with the Wilcoxon Mann–Whitney U test and Wilcoxon exact matched-pairs test with a significance level of p = 0.05. Bonferroni–Holm with an adjusted significance level of alpha = 0.05 was applied. With the exception of approximal anatomical form, significantly worse scores were seen for six out of seven criteria at the second follow-up evaluation. There was no significant difference in the first and second follow-up evaluations in the grades of the restorations with regard to having been placed in the maxilla or mandible, as well as for one-surface or multiple-surface restorations. The approximal anatomical form showed significantly worse grades at the second follow-up when having been placed in molars. In conclusion, the study results show that significant differences regarding FDI criteria in posterior composite restorations occur after more than 23 years of service. Further studies with extended follow-up time and at regular and short time intervals are recommended.

Clinical longevity of extensive direct resin composite restorations after amalgam replacement with a mean follow-up of 15 years

OBJECTIVES

The aim of this retrospective clinical study was to determine the survival of extensive direct resin composite restorations after amalgam replacement on vital molars and premolars after a mean observation period of 15 years.

METHODS

Between January 2007 and September 2013, a total of 117 extensive cusp replacing direct resin composite restorations were placed in 88 patients in a general dental practice. These were indicated for replacement of existing amalgam restorations. Tooth vitality, the absence of at least one cusp in premolars, and at least two cusps in molars were considered for inclusion. The long-term follow-up of the restorations, re-evaluated after up to 17 years using the original evaluation criteria is reported.

RESULTS

81 of 88 patients (92.1%) and 106 of 117 restorations (90.6%) were available for follow-up. The cumulative success rate was 62.0% (95% CI: 47.3-76.2, AFR 2.79%) after a mean observation time of 163.4 months, the cumulative survival rate was 74.7% (95% CI: 59.8-89.6%, AFR: 1.70%) after a mean observation time of 179.1 months. The number of cusps replaced in premolars had a statistically significant influence on the success and survival rate of the restorations (HR of respectively, 2.974 and 3.175, p = <0.0005). Premolars with two cusps replaced had 297% more chance of failure than premolars with one cusp replaced.

CONCLUSIONS

Extensive direct resin composite restorations placed after amalgam replacement showed good survival after a mean observation period of 15 years. The number of cusps involved had a statistically significant influence on the longevity of the restorations in premolars.

CLINICAL SIGNIFICANCE

With good survival and low annual failure rates, direct resin composite restorations are a suitable treatment for repairing extensive defects in posterior teeth involving multiple cusps and surfaces, provided that they are placed by a dentist who has long experience and is skilled in the placement of direct composite materials.

Crack propagation and toughening mechanism of bilayered short-fiber reinforced resin composite structure -Evaluation up to six months storage in water

Clinically relevant parameters, such as stress intensity factor of bilayered resin composite structure with short fiber base and its stability over time, has yet to be investigated. This study investigated the stress intensity factor of pre-cracked bilayered specimens composed of short fiber resin composite base (SFC) and particulate filler resin composite (PFC) as veneering layer, with a crack located in the PFC layer, 0.5 mm away from the PFC-SFC interface. Monolayered specimens served as controls. All specimens were stored in water at 37°C either for 1 week, 1 month or 6 months before testing. Two-way ANOVA (p=0.05) was used to determine the differences among the groups. Results indicated that SFC base improve the brittleness of the PFC. The type of short fibers affected the crack propagation; fiber bridging in millimeter-scale SFC was the main crack arresting mechanism, whereas fiber pulling observed in micrometer-scale SFC mainly deviated the crack path.

Microbial contamination of resin composites inside their dispensers: An increased risk of cross-infection?

OBJECTIVES

To evaluate the effects of microorganisms' contamination inside the dispensing syringes of different types of resin-based composites (RBCs).

METHODS

This study encompassed two sections. First, an anonymous electronic survey was submitted via Google forms to Italian dentists to acquire information about composite handling during clinical procedures. Then, a bench test was performed on nanohybrid RBCs differing in matrix chemistry and fillers [FiltekTM Supreme XTE (3MTM); Venus Pearl (Kulzer GmbH); Admira Fusion x-tra (Voco)] to evaluate the microbial viability on their surfaces with/out photocuring. Uncured RBCs were exposed to standardized inocula of Streptococcus Mutans, Candida Albicans, Lactobacillus Rhamnosus, or mixt plaque in an in vitro model reproducing clinical restorative procedures. Half of the RBC specimens were cured after exposure. Microbial viability was assessed using an MTT-based test. Statistical analysis included three-way ANOVA and Tukey's tests (p<0.05).

RESULTS

Among 300 dentists completing the survey, the majority declared to use the spatula to carry the RBCs from the syringe to the dental cavity (50% same spatula; 35% two spatulas). However, 80% of respondents had personal feelings that using one spatula could be a source of cross-contamination. In vitro results using one spatula showed microbial contamination of all RBCs after one hour of storage. The contamination levels depended on the used strain and RBC type (p<0.0001), but photocuring did not reduce contamination (p = 0.2992).

CONCLUSIONS

Microbial species' viability on uncured RBCs and after photocuring shows the existence of a considerable risk of cross-infection. Clinical procedures in Restorative Dentistry need to acknowledge and to reduce such risk during RBCs handling.

CLINICAL SIGNIFICANCE

Dentists must be aware of the possibility of cross-infection during restorative procedures, especially when the same spatula is repeatedly used for placing RBC in the cavity.

Direct and indirect monomer elution from an RBC product family

OBJECTIVE

To develop a model for quantitative comparison of elutable substances by direct elution from resin-bonded composite (RBC) test specimens versus indirect elutability of substances from RBC-restored teeth. Furthermore, it was to be investigated whether the different composites of the Tetric® RBC product family release different types and amounts of substances.

METHODS

Four different composite materials from the Tetric® product family were studied. For each material subgroup ten human third molar teeth were prepared with standard Class-I occlusal cavities. These 'tooth group' specimens were provided with a three-step adhesive system (incorporating TEGDMA) and the respective composite restoration. Same sized control specimens, of each RBC restorative material, were prepared ('direct RBC' groups). All specimens were placed in individual elution chambers such that the elution media (ethanol/water, 3:1) only came into contact with either the tooth root or ¾ height of the 'direct RBC' materials. They were incubated at 37 °C for up to 7 d. Samples of the eluant were taken after 1, 2, 4 and 7 d and were analysed by high-temperature gas chromatography/mass spectrometry.

RESULTS

Bisphenol A ethoxylate dimethacrylate (bisEMA), bisphenol A glycidyldimethacrylate (bisGMA), tetraethylene glycol dimethacrylate (TEEGDMA), decan-1,10-diol dimethacrylate (DDDMA) were mostly found in the eluates of the 'direct RBC' groups in statistically significantly greater amounts than in the eluates of the 'tooth groups'. Such quantitative differences were also the case with eluates containing bisphenol A (BPA), dicyclohexyl phthalate (DCHP) and drometrizole, which are common in the environment. In contrast to the behavior found with all the other monomers, up to 3 orders of magnitude more triethylene glycol dimethacrylate (TEGDMA) was found in the 'tooth groups' compared to the 'direct RBC' groups, evidently released by the adhesive system.

SIGNIFICANCE

The release of most of the substances was clearly delayed in the 'tooth groups' indicative of their chronic, rather than acute, elution to the oral environment. A barrier function of the residual dentin layer and the adhesion layer can be inferred. The different release patterns of substances from the various composites of the RBC product family is a manifestation of their different and indication-specific compositions. Consideration of an overall restorative care (RBC plus adhesive) system, when assessing the total amount of released substances, is emphasized.

Micro-computed tomography evaluation of microleakage of Class II composite restorations: An in vitro study

Objective:

The aim of this study is to investigate the microleakage attained with three resin-based material used to restore deep Class II cavities. A null hypothesis was chosen: there is no difference in microleakage among the tested materials.

Materials and Methods:

A total of 30 Class II cavities were prepared in freshly extracted molars with the proximal mesial and distal margins located, respectively, 1.5 mm apically and 1.5 mm coronally to the cementum-enamel junction. Restorations were completed using a three-step enamel-dentin adhesive system “Etch and Rinse,” margins were relocated using a micro-hybrid, preheated, or flowable composite and restorations were then completed using a conventional composite. All samples were coated with nail varnish with the exception of an area along the margins and apex was sealed using epoxide cement and then thermocycled (30-s dwell time, 5°C/55°C, 1000 cycles). A 50% ammoniac AgNO3 solution was used as tracer according to Tay's protocol. The microleakage analysis was performed using a microtomography system Sky-scan 1072 (SKYSCAN, Kartuizersweg 3B 2550, Konitch, Belgium).

Results:

The mean microleakage of all the tested materials showed greater leakage in the cementum margins; flowable composite exhibit greater leakage among the groups. Significant differences (P < 5%) within groups in both enamel and dentin margins were present. None of the tested materials eliminated marginal microleakage. Preheated composite showed significantly lesser microleakage.

Conclusion:

Tested materials showed statistical differences in microleakage; thus, the null hypothesis has been rejected. Within the limitations of the present experimental procedure, it can be concluded that flowable resin composite should be avoided at the dentin/cementum margin.

Wear Characteristics of Dental Ceramic CAD/CAM Materials Opposing Various Dental Composite Resins

The aim of this study was to evaluate the wear properties of opposed dental ceramic restorative CAD/CAM materials and several posterior direct restorative composite resins. Three kinds of dental ceramics CAD/CAM materials (monolithic zirconia, lithium disilicate, leucite) and four dental composite resins—that is, MI Gracefil, Gradia Direct P, Estelite Σ Quick, and Filtek Supreme Ultra—were used in this study. For each of the 12 groups (three ceramics × four composite resins), five each of a canine-shaped ceramic specimen and a cuboidal shape opposing composite resin were prepared. All of the specimens were tested in a thermomechanical loading machine (50 N, 100,000 cycles, 5/55 °C). Wear losses of ceramic specimens and composite resin specimens were evaluated using a three-dimensional profiling system and an electronic scale, respectively. Statistical analyses were performed using the Kruskal–Wallis test and Mann–Whitney U test with Bonferroni’s correction. Zirconia showed significantly less volumetric loss than lithium disilicate or leucite regardless of composite resin type (p > 0.05/3 = 0.017), and that Estelite Σ Quick showed significantly more weight loss than Filtek Supreme Ultra, MI Gracefil, or Gradia Direct P regardless of ceramic type (p > 0.05/6 = 0.083). Zirconia showed less volumetric loss than lithium disilicate or leucite. Some composite resins opposing ceramics showed considerable weight loss.

Effect of cusp coverage and water storage on compressive strength of composite restorations of premolars

Background

The aim of this study was to assess the effect of cusp coverage and water storage on compressive strength of composite restorations.

Material and Methods

This in vitro experimental study was conducted on 40 extracted human maxillary premolar teeth, which were randomly divided into four groups of 10. Mesio-occluso-distal (MOD) cavities were prepared in all teeth. The thickness of composite for cusp coverage was 1.5 mm in groups 1 and 3 and 2.5 mm in groups 2 and 4. Compressive strength (CS) was measured after 24 hours in groups 1 and 2 and after six months of water storage in groups 3 and 4. Two-way ANOVA was used to statistically analyze the data.

Results

The mean and standard error (SE) of compressive strength was 795.23 ± 35.18N in Group 1, 1232.52 ± 78.01N in Group 2, 617.18 ± 40.19N in Group 3 and 963.22 ± 50.05N in Group 4.

Conclusions

Statistical analysis showed a significant difference in compressive strength measured after 24 hours (groups 1 and 3) and after six months of water storage (groups 2 and 4). The compressive strength of groups with 2.5 mm cusp coverage was significantly greater than that of groups with 1.5 mm cusp coverage.

Key words:Fracture strength, cusp coverage, water absorption, composite resin, compressive strength.

Stress-reduced Direct Composites for the Restoration of Structurally Compromised Teeth: Fiber Design According to the "Wallpapering" Technique

PURPOSE

The purpose of this work was to present a restoration technique based on an understanding of the biomechanical properties of the dentinoenamel complex (DEC) and the physical-mechanical properties of the resin-based composite including the stress generated from both polymerization shrinkage and occlusal forces. Technique Summary: The DEC is a functional interphase that provides crack tip shielding; the DEC should be preserved during restorative procedures. Dentists can design the strategic placement of restorative materials into the cavity to both resist the mode of failure and mimic the performance characteristics of the intact natural tooth. The term "wallpapering" describes a concept of covering the cavity walls with overlapping closely adapted pieces of Leno weaved ultra-high-molecular-weight polyethylene (LWUHMWPE) ribbons. The key for success is that the ribbons are adapted and polymerized as closely as possible against the contours of residual tooth substrate. The resulting thin bond line between the fibers and the tooth structure creates a "bond zone" that is more resistant to failing due to the intrinsic stress and energy absorbing mechanism of the LWUHMWPE ribbons. The formation of defects and voids, from which crack propagation may start, is also reduced. The fibers' tight adaptation to tooth structure allows a dramatic decrease of the composite volume between the tooth structure and the fiber, thus protecting the residual weakened walls from both the stress from polymerization shrinkage and the occlusal load.

CONCLUSION

By using a similar approach, fiber-reinforced stress-reduced direct composite restorations may be performed in the restoration of structurally compromised vital and nonvital teeth.

Quality and Survival of Direct Light-Activated Composite Resin Restorations in Posterior Teeth: A 5- to 20-Year Retrospective Longitudinal Study

PURPOSE

To analyze the clinical success of direct light-activated composite resin restorations in posterior teeth. The quality of the margins and occlusal surfaces were evaluated, as well as their survival, according to their extensions and locations. The clinical performance of posterior composite resin restorations with different compositions were compared. All restorations were performed by the first author in his private practice, in a 5- to 20-year period.

MATERIALS AND METHODS

Several types of composite resins, provided by different manufacturers, were placed in posterior teeth, after isolation with rubber dams. To be included in the study, the restorations had to have been in function for at least 5 years and had to have been placed between October 1993 and October 2008 by the first author. The established failure criteria were: tooth and/or restoration fracture, secondary caries, endodontic treatment, or tooth loss. Included patients must have been treated in the first author's office for at least 7 years and still in the practice through 2013; all patients had complete dental arches. Patients with removable dental prostheses or disabilities, who had moved, or who had died were excluded. Of 210 patients who fulfilled the inclusion criteria, 138 randomly selected subjects were clinically examined between November 2013 and April 2014. Of these 138 patients, 61 had received 105 direct-light-activated composite resin restorations in posterior teeth, which met the inclusion criteria. Twenty-nine patients (47.5%) underwent annual maintenance therapy. The patient-based data collected from clinical exams and personal records were recorded on a specially designed form. Age, gender, period of clinical attendance, tooth preparation, location, size, quality and longevity of the restorations, restorative materials, adhesive systems, parafunctional habits, secondary caries, and maintenance therapy were the variables evaluated. Authors were blinded to the clinical assessments. Cohen's Kappa coefficient of the quality analysis of the margins and occlusal surfaces of the restorations ranged from 0.78 to 1. Data processing was performed using Epidat software, v3.1, developed by the Consellería de Sanidade de la Xunta de Galicia with the support of PAHO-WHO and SPSS software v13.0. If the number of complete values was too small, a Kaplan-Meier curve could not be used. Therefore the Fisher's exact test, Chi-square test, Kruskal-Wallis test, and Mann-Whitney non-parametric test were indicated to analyze significant differences.

RESULTS

At the time of the examinations, 103 (98%) restorations were in function, and 98 (95.1%) were rated as clinically successful. Two restorations failed (2%). The observed mean survival time of restorations that remained functional was 11 years and 7 months.

CONCLUSIONS

In the present report, direct light-activated composite resin restorations in posterior teeth showed a high clinical success rate and long-term mean survival time. These composite resins might be considered the material of choice to restore medium, extended, and in some clinical situations, large preparations in posterior teeth.

Clinical evaluation of fiber-reinforced composite crowns in pulp-treated primary molars: 12-month results

Objective:

The aim of this study was to evaluate the clinical performance of tooth-colored fiber-reinforced composite (FRC) crowns in pulp-treated second primary mandibular teeth.

Materials and Methods:

This split-mouth randomized, clinical trial performed on 67 children between 3 and 6 years with two primary mandibular second molars requiring pulp treatment. After pulp therapy, the teeth were randomly assigned to stainless steel crown (SSC) or FRC crown groups. Modified United States Public Health Service criteria were used to evaluate marginal integrity, marginal discoloration, and secondary caries in FRC crowns at intervals of 3, 6, and 12 months. Retention rate and gingival health were also compared between the two groups. The data were analyzed using Friedman, Cochran, and McNemar's tests at a significance level of 0.05.

Results:

Intact marginal integrity in FRC crowns at 3, 6, and 12 months were 93.2%, 94.8%, and 94.2%, respectively. Marginal discoloration and secondary caries were not found at any of the FRC crowns. The retention rates of the FRC crowns were 100%, 98.3%, and 89.7% at 3, 6 and 12 months, respectively, whereas all the SSCs were found to be present and intact after 12 months (P = 0.016). There was no statistically significant difference between the two groups in gingival health.

Conclusion:

According to the results of this study, it seems that when esthetics is a concern, in cooperative patients with good oral hygiene, FRC crowns can be considered as a valuable procedure.

Fracture resistance of endodontically treated molars restored with horizontal fiberglass posts or indirect techniques

BACKGROUND

Because of the many possibilities for endodontically restoring the posterior teeth and the high prevalence of restoration failures, this topic continues to be of major concern. A composite resin (CR) restoration reinforced by a horizontal fiberglass post may improve the fracture resistance of endodontically treated teeth. The authors investigated this possibility by comparing the fracture resistance of molars restored with direct techniques with that of molars restored with indirect techniques.

METHODS

The authors divided 50 extracted sound third molars into 5 groups: sound teeth, onlay (ON), inlay (IN), direct CR, and transfixed fiberglass post (TFP) plus direct CR. The authors performed standardized mesio-occlusodistal cavity preparations and endodontic treatments. The authors cemented indirect restorations of Lava Ultimate (3M ESPE) adhesively in the ON and IN groups. The authors restored CR group teeth directly with Filtek Z230 XT (3M ESPE). In the TFP group, the authors transfixed 2 fiberglass posts horizontally and restored the teeth directly with CR. Thereafter, the authors submitted the teeth to cyclic fatigue loading with 500,000 cycles at 200 newtons. The authors tested fracture resistance in newtons in a universal testing machine. The authors analyzed data with 1-way analysis of variance and a Tukey test (P < .05).

RESULTS

Sound teeth had the highest fracture resistance. ON had the highest recovery of resistance, followed by TFP. CR had the lowest recovery, which was similar to that of IN.

CONCLUSIONS

Endodontically treated molars restored with TFP plus CR had fracture resistance similar to those restored with ON, which was higher than that for IN or CR only.

PRACTICAL IMPLICATIONS

Horizontal TFPs placed inside a composite restoration had the same performance as did ON restorations.

Effects of different cusp coverage restorations on the fracture resistance of endodontically treated maxillary premolars

STATEMENT OF PROBLEM

Cusp coverage restorations for the restoration of endodontically treated teeth represent a conservative approach in terms of function and esthetics. However, limited scientific data are available regarding the optimum reduction design and thicknesses.

PURPOSE

The purpose of this in vitro study was to evaluate the fracture resistance and fracture patterns of cusp coverage restorations with different cusp reduction designs and reduction thicknesses on endodontically treated maxillary premolars (ETMPs) with mesio-occluso-distal (MOD) cavities.

MATERIAL AND METHODS

One hundred sixty-five extracted intact human maxillary premolars were divided into 11 groups: G1-10 (test groups) and G11 (intact group). In the test groups, all of the teeth were restored with composite resin after canal treatments with MOD cavities. However, the cusps of the G1-9 teeth were reduced with combinations of different thicknesses (1.5, 2.5, and 3.5 mm) and designs (beveled, horizontal, and anatomic). The specimens were subjected to 10(5) cycles of 50 N mechanical loading. Next, the specimens were subjected to a compressive load at a crosshead speed of 0.5 mm/min until fracture. The fractured specimens were analyzed to determine the fracture pattern. Two-way ANOVA followed by the Fisher least significant difference (LSD) test was used to analyze the interaction between groups.

RESULTS

The fracture resistance values increased with increases in the cusp reductions. The fracture resistance values of the G6 (2.5 mm, anatomic) and G9 (3.5 mm, anatomic) groups were significantly greater than that of the MOD group. However, the G6, G8 (3.5 mm, horizontal), and G9 groups were comparable with G11. The highest restorable fracture rates were observed in G6 and G9.

CONCLUSIONS

Cusp reduction design and thickness influenced the fracture resistance and fracture patterns of cusp coverage restorations of ETMPs with MOD cavities. The teeth restored with anatomic cusp reduction designs with reduction thicknesses of at least 2.5 mm exhibited greater fracture resistance and more frequent restorable fractures.

Restoration of Severely Compromised Teeth With Modern Operative Techniques

This case report illustrates how to restore severely compromised teeth with direct composite restorations. The size of the restorations presented is often considered by dentists as being a contraindication for direct composites. Hence, the technique is explained step by step, addressing the crucial points.

Survival of direct resin restorations in posterior teeth within a 19-year period (1996-2015): A meta-analysis of prospective studies

OBJECTIVES

The aim of this study is to analyze the survival of posterior composite restorations published within the last 19 years (1996-2015).

METHODS

In this study only prospective, clinical trials with specification of the failure rate according to Class I/II composite fillings were included. Studies were analyzed according to the observation period (all studies vs. short-term vs. long-term studies). Retrospective studies and/or open laminate studies, tunnel restorations and Class V restorations were excluded. The following variables possibly influencing the failure rate were extracted from the studies: observation period, recall rate, average age of patients, number of patients, ratio of Class I/II fillings, number of restorations, ratio of premolars/molars, operator, method of isolation, bonding generation and filler size.

RESULTS

A total of 88 studies were included for statistical analysis. The observation period of the studies varied between 1 and 17 years, while most of the studies did not last longer than 5 years. Fracture of the restorations, secondary caries and marginal gap are the main causes for failure in the first 5 years (in descending order), while fracture and secondary caries are similarly distributed in long-term studies. Variables of investigation differed greatly in significance according to the respective observation period. The observation period, the recall rate, the ratio of Class I/II fillings and the number of restorations and patients had a significant influence on the overall failure rate when including all studies (short- and long-term). A linear correlation between the observation period and the failure rate was observed. In long-term studies these variables were not significant any longer. No significant difference in the failure rates between the materials per study was observed. The most common commercial composites investigated were: Tetric Ceram, Surefil, Filtek Supreme (incl. XT), Filtek Z250. The mean annual failure rate was 1.46% (±1.74%) for short-term studies and 1.97% (±1.53) for long-term studies. There is still a big need for clinical studies lasting longer than 5 years, as failure rates of composite restorations in posterior teeth increases with longer observation periods.

SIGNIFICANCE

A decreasing failure rate with an increasing recall rate as observed in our study suggests a patient selection in regard to availability and dental awareness. Internationally standardized evaluation criteria are mandatory in order to allow comparisons of the outcomes of clinical studies.

Impact of erosive conditions on tooth-colored restorative materials

OBJECTIVES

To give an overview of the impact of erosive conditions on the behavior of tooth-colored restoratives and performance of dental adhesives.

METHODS

Acid-induced erosive lesions of enamel and dentin often need restorative procedures for rehabilitation. Nowadays, mostly tooth-colored restoratives (ceramics or resin composites), which are adhesively fixed to the dental substrate are used for this purpose. In some cases it might be necessary to seal the exposed dentin before achieving this goal in order to combat hypersensitivities and to protect those teeth from further erosive and abrasive loss. Moreover, it is conceivable that patients will fall back into their old "erosive behavior" after the application of restoratives. The following overview describes in how far intra-oral erosive conditions might affect the integrity of restorative materials, such as composite resins and ceramics, or of dentin sealants. Additionally, the use of erosively altered enamel and dentin as substrate for adhesive technologies is elucidated.

RESULTS

In the literature, information of the behavior of tooth-colored restoratives under still persisting erosive conditions are limited and mostly based on in vitro-studies. There is information that the adhesion of dental adhesives to eroded dentin is compromised as compared to regular dentin. The impact of erosive conditions relevant for the oral cavity on ceramics and resin composites seems to be rather low, although only few clinical studies are available.

SIGNIFICANCE

The review showed that erosive conditions might have only little impact on behavior of tooth-colored restorative materials, such as composites and ceramics. Dentin sealants also seem to be rather resistant against erosive conditions and might therefore serve as an intermediary treatment option for exposed dentin surfaces. The adhesion of dentin adhesives to eroded dentin might be increased by mechanical pre-treatment of the substrate, but needs further investigation.

Interventions for the restorative care of amelogenesis imperfecta in children and adolescents

BACKGROUND

Amelogenesis imperfecta (AI) is a tooth development disorder in which the teeth are covered with thin, abnormally formed enamel. This enamel is easily fractured and damaged, which affects the appearance of the teeth, especially if left untreated. Negative psychological outcomes, due to compromised appearance and function, in patients with AI, have been found to compromise a person's attractiveness and reduce social interaction. The treatment used depends on the severity of the problem.

OBJECTIVES

To compare the success rates of different restorative materials and techniques used for the restoration of anterior and posterior teeth with AI in terms of patient satisfaction (aesthetics and sensitivity) and function.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 18 April 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 3), MEDLINE via OVID (1946 to 18 April 2013), EMBASE via OVID (1980 to 18 April 2013), CINAHL via EBSCO (1980 to 18 April 2013), Abstracts of the Conference Proceedings of the International Association for Dental Research (2001 to 18 April 2013) and reference lists of relevant articles. There were no restrictions on language or date of publication in the electronic searches.

SELECTION CRITERIA

Randomised controlled trials where children and adolescents with AI who required restoration of teeth were allocated to different restoration techniques would have been selected. Outcomes which would have been evaluated were patient satisfaction, aesthetics, masticatory function and longevity of restorations.

DATA COLLECTION AND ANALYSIS

Two review authors would have extracted data and assessed the risk of bias in included studies independently. Disagreement between the two authors would have been resolved by consulting a third review author. First authors were contacted for additional information and unpublished data.

MAIN RESULTS

No studies met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We found no randomised controlled trials of restorative treatments for children and adolescents with AI, and therefore there is no evidence as to which is the best restoration. Well defined randomised controlled trials which recruit children and adolescents and focus on the type and severity of the disorder should be undertaken to determine the best intervention for restoring teeth affected by AI.

Functional and Aesthetic Guidelines for Stress-Reduced Direct Posterior Composite Restorations

Amalgam has been used in the restoration of structurally compromised posterior teeth for many years. When placing large amalgam restorations, replacement of weak cusps with restorative material is recommended to prevent tooth fracture. This recommendation can be modified with new guidelines using modern adhesive techniques. Semidirect and indirect inlay/onlay composite restorations have progressively replaced amalgam restorations over the past 20 years. Lately, single visit direct resin-bonded composite (RBC) restorations have also been used as a viable alternative to conventional indirect restorations. This paper is intended to introduce a step-by-step protocol for the direct restoration of structurally compromised posterior teeth using RBCs with stress-reducing protocols.

Extensive composite molar restorations: 3 years clinical evaluation

Abstract Objective. To evaluate the clinical performance of extensive direct composite restorations in molars after 1 and 3 years and to find out the importance of extent of the restorations and other factors related to their performance. Materials and methods. Seventy-four patients with a molar tooth in need of a restoration covering at least three surfaces and one cusp were selected. Patient-related factors were registered and the tooth was prepared and restored by using a nano-filled composite. A topographic system for classification of extensive posterior restorations was developed. At baseline, the operator recorded a clinical evaluation, using modified USPHS-criteria. After 1 and 3 years, an independent observer evaluated the restorations. Post-operative problems arising during the observation period were registered. Results. A change in clinical score from baseline to the 1 and 3 year recall was recorded for all clinical criteria. A total of nine restorations were graded as unacceptable after 3 years (3-year survival rate of 87.7% and a mean annual failure rate of 4.2%). Except for gender (p = 0.022), none of the patient-related factors investigated (age, caries risk, extension of the restoration and presence of cervical enamel) had a significant influence on the survival of the restorations. Conclusions. Extensive direct posterior composite restorations showed an acceptable clinical performance after 3 years. Men had a significantly greater restoration failure rate than women.

Implementation and experience of a new method for posterior vertical bite reconstruction using direct resin composite restorations in the private practice--a survey

OBJECTIVE

The purpose of the present survey was to evaluate the implementation and experience of a new method for posterior vertical bite reconstruction using direct resin composite restorations by private practitioners who attended a hands-on continuing education course on this technique.

MATERIALS AND METHODS

In the years 2007 and 2008, 17 1-day continuing education courses on vertical bite reconstruction in the worn dentition by using direct resin composite restorations were attended by 310 participants. A 13-item questionnaire was posted to all course participants in April 2009 seeking information on the acceptance, implementation and experience of the presented technique in the private practice.

RESULTS

A total of 97 (31%) questionnaires were returned, whereas 67% of the respondents had used the presented technique. Analysis of the overall experience and satisfaction with the placed resin composite restorations using visual analog scale (VAS) revealed a mean VAS score of 7.2 ± 1.7 (0 = maximal unsatisfied, 10 = maximal satisfied). The direct resin composite restorations were predominantly rated 'good' within the assessed criteria surface texture, anatomical form, marginal integrity, marginal discoloration and color match. Ninety-eight percent of the private practitioners stated that they would continue to carry out vertical bite reconstructions according to this technique. The three most frequently observed clinical problems were related to marginal discolorations, bulk fractures and adhesive failures.

CONCLUSION

The presented restoration method was well accepted by private practitioners who used this treatment approach at least once after course participation, even though some clinical problems were observed.

Clinical Evaluation of Stress-reducing Direct Composite Restorations in Structurally Compromised Molars: A 2-year Report

Objective

To evaluate the clinical performance of class II large-size direct composite restorations.

Materials and Methods

Fifty (50) patients 18 years or older were included in this clinical trial restoring 75 vital molar teeth with large-size cavities.

Inclusion Criteria

Occlusal extension greater than two-thirds the intercuspal distance and proximal extension greater than half the distance between line angles. Teeth with residual cavity walls less than 1 mm and with one or more cusps involved were excluded. Teeth were randomly divided in three groups. Group 1: Opti-Bond FL; group 2: Scotchbond 1 XT; group 3: PQ1. Total-etching was performed using 35% phosphoric acid followed by the application of 2% chlorhexidine gluconate in the three groups. All teeth were restored using Vit-l-escence microhybrid composite resin. The proximal surface was built up first, followed by dentin and enamel occlusal surface stratification; wedge-shaped increments of composite resin were placed and cured using the UltraLume V curing light through a combination of pulse and progressive curing techniques.

Results

Restorations were evaluated at six-month intervals during the two-year period using a modified US Public Health Service criteria by two independent evaluators precalibrated at 85% reliability. No failures were reported and α scores were recorded for all parameters. Statistical analysis was performed using a χ2 test and the Fisher exact test (χ2=10.6; p=0.001). No teeth exhibited sensitivity in the three groups both at the two-week recall and two-year follow-up.

Composite vertical bite reconstructions in eroded dentitions after 5·5 years: a case series

In the following case series, we report on six cases of erosive worn dentitions (75 posterior teeth), which have been reconstructed using a template-based technique with direct composite resin restorations and already examined after 3 years in service. In all patients either one or both tooth arches were completely restored using direct resin composite restorations. A wax-up-based template was used to avoid freehand build-up techniques and to ensure optimal anatomy and function. All patients were re-assessed after a mean service time of 5·5 years (mean 67 ± 4 months) using United States Public Health Service criteria. The overall quality of the restorations was good with predominantly 'alpha' and 'bravo' scores, respectively. However, the restorations showed some deterioration with respect to marginal quality, marginal discoloration, surface texture and anatomy as compared to the 3-year investigation. The marginal impairments could be resolved by polishing. It is concluded that this non-invasive technique provides a possible treatment option at least for the displayed observation period of 5·5 years.

A new approach to compare the esthetic properties of different composite materials

STATEMENT OF THE PROBLEM

Modern composite systems are either very simple with few shades or very complex with an array of shades. Which approach gives the best esthetic results?

PURPOSE

The study aims to use a new approach to compare the esthetic properties of different composite materials and evaluate the ability of four different composite systems to imitate the natural shade of teeth.

MATERIALS AND METHODS

Seventeen extracted teeth were restored using four different composite materials (Filtek Supreme XT [3M ESPE, Glostrup, Denmark], Ceram-X Duo [Dentsply-Friadent, Roskilde, Denmark], Tetric EvoCeram [Ivoclar Vivadent AB, Solna, Sweden], Enamel Plus HRI [Micerium, Avegno, Italy]). In total, 68 restorations were fabricated using the 17 teeth as their own control. This was made possible utilizing a device designed to remove exactly the same piece of tooth/composite every time. The time for placement and shades used were recorded. Two dentists evaluated the esthetic match of the restorations using slightly modified Extended Visual Rating Scale for Appearance Match criteria.

RESULTS

There was a statistically significant difference (p ≤ 0.05) between Filtek Supreme XT and Tetric EvoCeram and between Enamel Plus HRI and Tetric EvoCeram regarding the esthetic match. However, this was not deemed clinically relevant in most cases. Filtek Supreme XT required the most time, whereas Ceram-X Duo required the least time. There was a high intra- and interobserver agreement regarding ratings.

CONCLUSION

The study concluded that: (1) it was possible with all four composite systems to make restorations that were judged clinically acceptable in 91 to 96% of the cases; (2) more time was needed when using the more "advanced systems"; and (3) the new standardized, simple, and clinically relevant evaluation method was capable of comparing different composite systems' ability to imitate natural teeth.

Influence of cusp coverage on the fracture resistance of premolars with endodontic access cavities

AIM

To assess the influence of cusp reduction and coverage with composite resin on the fracture resistance of premolars with prepared access cavities.

METHODOLOGY

Endodontic access cavities were prepared in 60 premolar teeth that were divided into four test groups: R1, R2, R3 and NR (n=15). In all test groups, MOD cavities were prepared and extended towards one of the cusps. The remaining cusp-wall thickness was: 1-1.5 mm in R1, 1.5-2 mm in R2 and 2-3 mm in both R3 and NR groups. In addition, in group R1, R2 and R3 the same cusp was reduced in height to 3.5 mm. Cuspal coverage and MOD restorations were performed using composite resin. Ten intact premolars served as positive controls and another ten MOD-prepared unrestored premolars as negative controls. Teeth were submitted to cyclic fatigue of 1.2 million cycles. A compressive load was applied 30° to the long axis of the teeth until fracture. Fracture loads were recorded and the means and the Confidence Intervals were compared.

RESULTS

The mean fracture resistance of each of the cusp-reduced groups R1, R2 and R3 (603, 712 and 697 N, respectively) was significantly higher than the non-reduced cusp group (305 N) and was comparable to the intact-premolar group (653 N).

CONCLUSIONS

Cusp reduction and coverage with composite resin significantly increased the fracture resistance of premolar teeth with MOD and endodontic access cavities.

Fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage

Objectives:

This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal) restored with condensable resin composite with and without cusp coverage.

Material and Methods:

Thirty human maxillary premolars were divided into three groups: Group A (control), sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min.

Results:

The mean fracture resistance values ± standart deviation (kgf) were: group A: 151.40 ± 55.32, group B: 60.54 ± 12.61, group C: 141.90 ± 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05). The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage.

Conclusion:

The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth.

Three-year Evaluation of Posterior Vertical Bite Reconstruction Using Direct Resin Composite–A Case Series

The occlusion of extensively worn teeth can be restored using direct resin composite materials. The quality over a mean observation period of three years is good. The proposed method, using a wax-up-based template, can help the clinician to restore the occlusal anatomy and function.

Modified matrix band design for ultra-conservative posterior restorations

Conventional box preparations, tunnel cavities and slot preparations have been recommended for the treatment of proximal carious lesions over the years. If the adjacent tooth is missing or the proximal surface becomes accessible at the time of cavity preparation of the adjacent tooth, a direct proximal access to the decay process can be performed. A similar procedure is supported by the use of adhesive composite restorations reinforcing the remaining sound tooth structure. The increasing patient and clinician's desire for ultraconservative treatment justifies this minimally invasive tooth preparation approach; however, appropriate materials and techniques need to be selected to achieve adequate bonding of the cavity walls and marginal adaptation of the composite.

Direct fiber-reinforced composite restoration in an endodontically-treated molar: a three-year case report

The reconstruction of structurally compromised non-vital posterior teeth may represent one of the most challenging adhesive-based restorative procedures. Several factors may influence the longevity of direct fiber-reinforced resin composite restorations: endodontic procedures prior to post cementation, dentin and/or post surface treatments, selection of the appropriate post design and architecture, resin composite polymerization and layering techniques. Thus, different specialties, such as endodontics and restorative dentistry, should work as a team to improve the longevity of restorations. This article presents three-year clinical results following reconstruction of a severely damaged endodontically-treated molar using direct fiber reinforced resin composite systems.