Marginal Integrity Of Restorations Research Articles

Marginal integrity of classical and bulk-fill composite restorations in permanent and primary molars

Bulk-fill composites enable timesaving and less technical-sensitive application of restorations. This study investigated and compared the marginal integrity of classical and bulk-fill composite restorations in primary and permanent molars before and after thermo-mechanical loading (TML). Two Class II cavities were prepared in each of 20 primary and 20 permanent molars. The molars were randomised in four groups for each molar type. Groups 1 and 5 were restored with a high-viscous bulk-fill composite (Tetric PowerFill), groups 2 and 6 were restored with a flowable bulk-fill composite (Tetric PowerFlow), groups 3 and 7 were restored with a high-viscous classical composite (Tetric Prime), and groups 4 and 8 were restored with a flowable classical composite (Tetric EvoFlow). In permanent molars, the flowable composites were covered with a 2-mm layer of high-viscous composite (groups 6 and 8). The restorations were subjected to TML in a custom-made chewing machine (5–50 °C, 2 min dwelling time, × 1000; 400 ,000 loading cycles, 1.7 Hz, 49 N), and quantitative marginal analysis was conducted using scanning electron microscopy. Marginal integrity of each restoration was calculated as a percentage of continuous margins before and after TML. The tested high-viscous bulk-fill restoration showed similarly high marginal integrity in primary and permanent molars as the classical restoration. The tested flowable bulk-fill restoration showed the lowest marginal integrity compared to all other restorations after TML. In contrast to flowable bulk-fill restorations, high-viscous bulk-fill restorations show similar marginal integrity as classical hybrid composite restorations after TML, in both primary and permanent molars.

Comparative Evaluation and Correlation of Marginal Fit and Retention of Metal Copings Fabricated Using Two Different Designs of Die Spacerandndash; An In Vitro Study

Introduction: The art and science of fixed prosthodontics is predicted on accomplishing precise and clinically accurate operative techniques based on sound biological and mechanical principles. Many factors have been demonstrated to influence the marginal seating and retention of crowns, such as size and shape of the prepared teeth, manipulation of the cement, retentive properties of the cement, cement film thickness, relieving space or venting for cement, cement application, and roughness of the dentinal surface. Optimum retention form is considered to be one of the most important principles of tooth preparation. The longevity of fixed prosthesis depends on the retention and marginal integrity of restoration. This study was done to evaluate, compare and correlate the marginal fit and retention for two different designs of die spacer. Materials and Method: The samples to be studied were divided into 2 groups of 15 each. Each having a different die spacer design. Results: The results showed no significant difference in marginal fit of group Ia and group IIa and retention was better in group IIb compared to group Ib. But no statistically significant differences were seen when correlating the marginal fit and retention between group Ia, group Ib and group IIa and group IIb.

Clinical evaluation of carious cavity restorations using Vertise Flow – 2-year observations

Introduction. The introduction of self-adhesive materials in dentistry has significantly reduced the duration of filling carious cavities. This group includes a light-curing, semi-liquid composite material from Kerr, called Vertise Flow. Aim. The aim of the study was clinical evaluation of restorations made using Vertise Flow in class I cavities in permanent teeth. Material and methods. In children aged 8-17 years, 154 cavities were filled with Vertise Flow. After 2 years, 49 fillings were clinically evaluated according to the modified Ryge’s criteria. The anatomical shape, colour, smoothness, marginal integrity of restorations and the evidence of secondary caries were assessed. Parents or legal guardians of the children consented to the medical procedures. Results. All the evaluated restorations were found retained, with acceptable anatomical shape and smoothness. One restoration slightly changed the colour, and unacceptable marginal integrity was seen in 2 cases. Secondary caries involved 2 teeth. Conclusions. In this 2-year observation, Vertise Flow meets the requirements for materials used for filling minimally prepared class I carious cavities in permanent teeth of young patients.

Effect of Base Metal Alloys Recasting on Marginal Integrity of Castable Crowns

Base metals have a wide use in casting methods. Sometimes they are reused in laboratories which may have an adverse effect on the restoration marginal integrity. This study aimed to investigate the effect of recasting of alloys on marginal integrity of restorations. Models with two types of finishing lines shoulder bevel 45° and shoulder 135° were produced and 15 wax copings were formed on each one of them. Each group containing 15 copings was divided into three subgroups A, B and C. Group A was casted with 100% new alloy, group B with 50% new and 50% recasted alloy and group C with 100% recasted alloy. Obtained metal copings were placed on dies and marginal gap size between restoration margin and the dies finishing line was measured using metric microscope and Moticam camera in four points, buccal, lingual, mesial and distal. A significant difference in mean marginal gap size exists among three types of alloys used (p-value = 0.036). A significant difference is observed between mean marginal gap size of two types of finishing lines for different alloys (p-value = 0.001). Using 100% recasted alloy is not recommended for any of the two types of finishing lines.

Marginal integrity: clinical significance.

The marginal integrity of restorations is an important parameter as marginal gap formation is associated with recurrent caries and pulpal disease. Testing of marginal integrity in vitro is viewed with uncertainty due to interactions and interpretation problems. The clinical evaluation of marginal behaviour is also questionable due to the lack of reliable diagnostic skills of the clinician. The scientific community must recognize that in vitro and in vivo testing have severe limitations and accept that materials will be misjudged during evaluation processes.

The effects of mechanical loading on marginal integrity of composite restorations.

Utilization of composite restorations in high stress areas requires a re-evaluation of this factor in relationship to marginal integrity. Sixty Class V cavity preparations were prepared in the buccal surfaces of premolars and restored by conventional methods using a bonding agent and large particle composite resin. These restorations were subjected to repetitive mechanical loading with and without thermal cycling. The effect on the composite-enamel bond was evaluated by autoradiography. The induced stresses resulted in no statistical change in the marginal integrity of the restorations.

Correlation of laboratory testing to three-year clinical behavior of silicate cements

A study was carried out to evaluate the correlation between the results of laboratory tests and clinical behavior of silicate cement restorations. Three techniques for placing silicate cement restorations were used. These techniques brought different results when tested for strength and solubility. Changes in surface and marginal integrity of restorations were observed at evaluations made after one and three years of service. At both time intervals, clinically observed changes could not be related to the differences demonstrated by laboratory tests. When considering the specific silicate cement and the specific techniques used in this study, it can be concluded that the differences demonstrated in the laboratory tests of transverse strength and solubility did not predict clinical performance.