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At least 19 recordsLinked to original sources
PubMedDate not supplied

Marginal adaptation of dental composites containing prepolymerized filler.

Marginal adaptation to cylindrical dentin preparations of five commercially available dental composites--Charisma, Estelite, Herculite, Pertac, and Silux Plus--and seven experimental dental composites containing prepolymerized filler was evaluated by measurement of the wall-to-wall polymerization contraction gaps. The experimental composites were prepared with varying amounts of spherical inorganic filler particles, irregularly shaped prepolymerized filler particles, and a base resin matrix composed of BIS-GMA and TEGDMA. Cylindrical dentin preparations, approximately 3.0 mm in diameter and 1.5 mm deep, were prepared in the exposed approximal dentin surfaces of extracted human molars. These cavity preparations were pretreated with an experimental dentin bonding system consisting of 0.5 mol/L EDTA, 35% glyceryl methacrylate, and Clearfil Photo Bond, then restored with each composite. Complete marginal adaptation was observed in two composites (Silux Plux and Estelite). Wall-to-wall contraction gaps were significantly related to the amount of ashed inorganic component in the composites (0.01 < P < 0.05) and to the spherical inorganic filler content by volume (P < 0.01).

Bisphenol A-Glycidyl Methacrylate↗
PubMed1984

Early prediction of long-term margin adaptation of dental amalgam restorations.

The present study assessed the predictive value of an indirect metric method for the early detection of margin defects of amalgam restorations, relative to results using a direct clinical method. The material consisted of plaster casts of amalgam restorations taken at 1- and 2-yr examinations of four different amalgam-treatment combinations. The widest margin defect of each restoration was measured in a dissection microscope equipped with a metric scale in the ocular. The ranking order obtained from the metric measurements of the different amalgam-treatment combinations after 1 and 2 yr was compared with that obtained from the direct clinical evaluation after 2 yr. Finally, the rank order of those restorations rated Alfa (no visible evidence, along the margin, of a crevice (ditch) into which an explorer will penetrate) at the 2-yr clinical examination was studied in relation to the 1-yr metric measurements. For the total material, the rank order based on the metric measurements of the margin defects of the four amalgam-treatment combinations agreed with that obtained with the clinical rating. In the 1-yr data, where the metric technique was applied only on the restorations rated Alfa at the 2-yr clinical evaluation, the order of two neighboring combinations was reversed; otherwise the same rank order was obtained. It is recommended that the clinical performance of new brands of amalgam alloy are tested in short-term, small-scale studies using the metric evaluation technique, before more extensive field studies over longer periods are instituted, in order to sort out unsatisfactory materials and treatment techniques at an early stage.

Child↗
PubMed2003

The effect of different power densities and method of exposure on the marginal adaptation of four light-cured dental restorative materials.

PURPOSE: To determine whether marginal adhesion is sensitive to different irradiation parameters, we investigated the in vitro adhesion values of four dental resins on metal surfaces. METHODS: Four groups of eight specimens each of Z250, Filtek flow, Dyract AP and Dyract flow were placed in pre-treated stainless steel cavities and irradiated using different methods of exposure. The curing lights used were a Spectrum 800 halogen curing light at settings of 800 and 450 mW/cm(2) and an Optilux 501 ramping light. The maximum amount of push-out force required to displace the resin from the metal cavity was equated with adhesive value (shear bond strength). Comparisons (ANOVA, p<0.0001) were made within the same material and between the different materials when using different curing protocols. RESULTS: Significant lower bond strengths were recorded when curing was done by gradually increasing the intensity (ramping method) compared to curing with the fixed intensities (p>0.0001) Comparing the fixed intensities, significant lower bond strength values were obtained at 800 mW/cm(2) compared to 450 mW/cm(2) (p<0.0001). For all exposures, the two flowable materials demonstrated weaker values when compared to the higher filled materials. CLINICAL SIGNIFICANCE: The advantage of initial slow polymerization (more elasticity and less tension) obtained by the so-called "soft start" method, was offset by a rise in total polymerization shrinkage, when final curing was completed at 1130 mW/cm(2). These tests demonstrated that using halogen units, exposure for 40s with an intensity of 450 mW/cm(2) appeared to be the most promising for light-curing dental resin composites.

Dental Marginal Adaptation↗
PubMed2003

[Gingivo-dental sparing strategy of orthodontic treatment (fitting with permanent dentures)].

Development of inflammatory process in the marginal part of the mucosa is caused not only by epithelial injury during tooth preparation and dental plaque accumulation, but by irregular contour and position of the artificial crown edge as well. Clinical, x-ray, and cytoenzymological studies showed that orthodontic treatment with cermet and polyceramic dentures with fixation of the supporting elements at the level of the gingival edge in tissues adjacent to the tooth causes the slightest pathological changes. The compensatory adaptive processes in this area of the buccal mucosa are the most pronounced if preparation of hard dental tissues is combined with closed currettage of periodontal pouches, which was confirmed by remote clinical results and laboratory findings in patients with slight and medium-severe periodontitis.

Adaptation, Physiological↗
PubMedDate not supplied

Use of CAD/CAM system to fabricate dental prostheses. Part 1: CAD for a clinical crown restoration.

The development of a computer-aided design system for a clinical crown restoration is reported. Initially, the shape of the standard crown was deformed and adapted on the die depending on the shape of the margin. Then, the measured occlusal record data were taken in the computer graphics, and the adapted crown was adjusted with these data to obtain the centric occlusion. The occlusal data were replaced with data obtained using a functionally generated path record and the occlusal interferences eliminated. The ends of the adapted crown were connected with the margin. Thus, the entire crown was efficiently designed using the computer program developed.

Computer-Aided Design↗
PubMed2001

[In vitro study of marginal quality of small approximal composite fillings].

The aim of the study was to compare different preparation methods and filling techniques for class II microcavities in vitro. The following methods were evaluated: Sonicsys halftorpedo, Sonicsys halfsphere, Sonicsys approx, Siplus, Piezo cavity system and rotating finishing bur. Every cavity type was obturated with a flowable (Tetric flow) and with a hybrid composite (Tetric ceram). One group consisted of prefabricated ceramic inlays (Sonicsys approx) and one group was filled with a three-site light curing technique. This resulted in 128 composite fillings. The evaluation of the quality of the margins under the SEM demonstrated a statistically significant higher percentage of perfect margins for Siplus compared with the PCS-System (88% versus 58% perfect margins). Marginal adaptation before and after thermocycling demonstrated the following results: Bewelled margins showed in general better adaptation than box-shaped cavities. Similar results were found for normal and flowable composites. Microcavities with occlusal access prepared with the sonicsys halfsphere showed in general better marginal adaptation in comparison to the other methods tested. It was concluded that simple obturation techniques can lead to a stable adaptation of the margins.

Composite Resins↗
PubMedDate not supplied

Marginal adaptation of stainless steel crowns.

The chief goal of full coronal restoration using preformed stainless steel crowns (SSC) is replication of normal crown form and function. Marginal adaptation of SSCs involves appropriate crown size selection, trimming the crown form to achieve proper length, crimping crown edges to proximate the prepared tooth, and finishing and polishing the crown form. This report about SSC restoration focuses on the procedure of adapting, finishing, and polishing crown margins.

Crowns↗
PubMed1997

[Influence of smear layer and adhesive resin on the adaptation of amalgam restoration to cavity walls].

This in vitro study evaluated the effect of removing smear layer and applying adhesive on the marginal adaptation of amalgam fillings to cavity walls. Three groups were established, cavities in group 1 were exposed to 10% EDTA (pH7.4) for 1 minute to remove smear layer before amalgam condensation; cavities in group 2 were also subjected to EDTA, then Miradapt adhesive was applied on the walls, finally amalgam condensed into cavities before the adhesive set; cavities in group 3 received no special treatment before amalgam condensation. After thermocycling, all teeth were subjected to SEM and image analyser. Results showed: Space between restorations and tooth structure in group 1 was 6.31 microns, space in group 2 with adhesive was 3.49 microns and micromechanical interlocking was observed while space in control group was 14.22 microns. Difference among the three groups was statistical significant. It was indicated that removing smear layer and using adhesive resin significantly improved the adaptation of amalgam to cavity walls.

Composite Resins↗
PubMed2026

Clinical Performance of Bulk-Fill Versus Incremental Composite Placement Approaches in Vital Posterior Teeth: A 24&#x2009;Months Randomized Controlled Trial.

BACKGROUND: Composite resin placement technique may influence marginal integrity, polymerization stress distribution, and long-term clinical performance of posterior restorations. This randomized controlled clinical trial evaluated the 24-month clinical performance of four different placement techniques in Class I posterior composite restorations. METHODS: Fifty patients aged 20-35&#x2009;years presenting with four occlusal carious lesions each were enrolled, resulting in 200 restorations. Cavities (4-5&#x2009;mm depth) were prepared according to caries extension. Restorations were randomly allocated into four equal groups (n&#x2009;=&#x2009;50) according to placement technique: stamp technique, snowplow technique, modified incremental "pizza" technique, and bulk-fill technique. All materials were applied following manufacturers' instructions. Clinical evaluation was performed at baseline and after 6, 12, and 24&#x2009;months using FDI criteria. Functional (fracture/retention, marginal adaptation), esthetic (marginal staining, anatomical form), and biological (postoperative sensitivity, secondary caries) properties were assessed by two calibrated evaluators. Statistical analysis was performed at a significance level of &#x3b1;&#x2009;=&#x2009;0.05. RESULTS: Thirty-eight patients with a total of 152 restorations were evaluated at the end of the 24&#x2009;months in line with FDI at the end of the study with 76% recall rates. No statistically significant differences were observed among groups regarding fracture/retention or secondary caries (p&#x2009;>&#x2009;0.05). Marginal adaptation and marginal staining demonstrated minor deterioration over time across all groups, with statistically significant intergroup differences found (p&#x2009;<&#x2009;0.05). Postoperative sensitivity was minimal and transient in all groups with no significant difference (p&#x2009;=&#x2009;0.181). CONCLUSIONS: Within the limitations of this 24-month follow-up, the four placement techniques demonstrated comparable clinical performance in Class I posterior composite restorations. Selection of technique may therefore be guided by clinical preference and procedural efficiency rather than differences in short-term clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT07415317.

Humans↗
PubMed2006

Two-year clinical evaluation of repair versus replacement of composite restorations.

PURPOSE: To investigate the effectiveness of alternative treatments to the replacement of resin-based composite (RBC) restorations through a prospective longitudinal cohort clinical study. MATERIALS AND METHODS: Forty patients aged 27 to 77 years (mean=55) with 88 RBC restorations, with one or more features that deviated from ideal, participated in the study. They were assigned to five treatment groups: repair (N=25), sealing of defective margins (N=13), resurfacing (N=18), replacement (N=16), and the no-treatment group (N=16). The replacement and no-treatment groups served as comparison groups and received random assignment. Two clinicians examined the quality of the restorations (N=88) prior to the assigned treatment, and at subsequent recalls (1 and 2 years) using a modified Ryge criteria (Alfa, Bravo, and Charlie, meaning clinically excellent, clinically acceptable with one or more features that deviated from ideal, and clinically unacceptable, respectively) that observed (1) color, (2) marginal adaptation, (3) anatomic form, (4) surface roughness, (5) marginal staining, (6) bulk discoloration, (7) contact, (8) secondary caries, (9) postoperative sensitivity, and (10) luster. RESULTS: At 1- and 2-year recalls, 66 (75%) and 58 (66%) restorations were examined. Kruskal-Wallis Test showed significant differences for marginal adaptation and marginal staining for both 1- and 2-year recall exams (p < .05). The repair, sealant, and replacement groups presented significant improvement when compared with the no-treatment group for marginal adaptation. The repair and replacement groups showed superior results when compared with the no-treatment group for marginal staining. CONCLUSION: RBC restorations that present less-than-ideal marginal adaptation and stained margins are better off being repaired. CLINICAL SIGNIFICANCE: Repair of resin-based composite (RBC) restorations is a conservative option for treatment of RBC restorations with inadequate marginal adaptation and marginal staining.

Adult↗
PubMedDate not supplied

Marginal and internal adaptation of class II restorations after immediate or delayed composite placement.

Direct class II composite restorations still represent a challenge, particularly when proximal limits extend below the CEJ. The aim of this in vitro study was to evaluate the influence of the type of adhesive and the delay between adhesive placement and composite insertion on restoration adaptation. Direct class II MOD box-shaped composite restorations (n=8 per group) were placed on intact human third molars, with proximal margins 1mm above or under CEJ. All cavities were filled with a horizontal layering technique, immediately after adhesive placement (IP) or after a 24h delay (DP). A filled three-component adhesive (OptiBond FL: OB) and a single-bottle, unfilled one (Prime & Bond 2.1: PB) were tested. Marginal adaptation was assessed before and after each phase of mechanical loading (250000 cycles at 50 N, 250000 cycles at 75 N and 500000 cycles at 100 N); internal adaptation was evaluated after test completion. Gold-plated resin replicas were observed in the SEM and restoration quality evaluated in percentages of continuity (C) at the margins and within the internal interface, after sample section. Adaptation to beveled enamel proved satisfactory in all groups. After loading, adaptation to gingival dentin degraded more in PB-IP (C=55.1%) than PB-DP (C=86.9%) or OB-DP (C=89%). More internal defects were observed in PB samples (IP: C=79.2% and DP: C=86.3%) compared to OB samples (IP: C=97.4% and DP: C=98.3%). The filled adhesive (OB) produced a better adaptation than the 'one-bottle' brand (PB), hypothetically by forming a stress-absorbing layer, limiting the development of adhesive failures. Postponing occlusal loading (such as the indirect approach) improved also restoration adaptation.

Acetone↗
PubMed1997

[Marginal fit of CAD/CAM ceramic inlays].

The purpose of this in vitro study was to investigate the marginal and internal fit of Cerec-2 inlays before and after adhesion. The test showed: 1. Before luting, the axial marginal space was 67 +/- 18 microns, cervical marginal space was 84 +/- 22 microns and the mean occlusal marginal space was 58 microns. 2. After luting, the thickness of the luting composite was 118 +/- 37 microns at axial margin, and 123 +/- 17 microns at cervical margin, the mean occlusal margin space was 80 microns. This study demonstrated the marginal adaptation of Cerec-2 inlays satisfied the clinical demand, especially at occlusal margin.

Computer-Aided Design↗
PubMed1994

Two-year clinical evaluation of preventive resin restorations.

A three-year clinical study is being conducted at the University of Tennessee, Memphis, college of Dentistry, comparing occlusal wear of Class I amalgam restorations with preventive resin restorations. This paper will concentrate on the two-year results of the preventive resin restoration with regards to placement technique, wear as evaluated by the USPHS system, marginal adaptation, recurrent caries, marginal discoloration, and address problems encountered.

Adolescent↗
PubMedDate not supplied

Effect of cavity form and setting expansion of refractory dies on adaptability of fired ceramic inlays.

The purpose of this study was to investigate the effect of cavity form and setting expansion of refractory die materials on the adaptability of fired ceramic inlays. Standardized Class I cavities with three kinds of lateral wall divergences (10 degrees, 20 degrees, and 30 degrees) and three kinds of surface roughness were prepared in epoxy resin blocks. A refractory die was prepared from an impression of the epoxy resin cavity, whose setting expansion ranged from 0.01 to 1.13%. A ceramic inlay was fired on each die. The fabricated inlay was inserted into the epoxy resin cavity, and the interfacial distance between the ceramic inlay and the cavity wall at the margin was measured using a reflecting microscope at X100 magnification. The internal fit was measured after sectioning the specimen longitudinally. The results were analyzed by ANOVA and Sheffé's F test. Good adaptation was achieved with the smooth-surface cavity. The adaptability depended on the angle of the cavity divergence, and small gaps were observed in 20 degrees and 30 degrees cavities (P < 0.05). The inlays fabricated on the refractory dies with a small setting expansion demonstrated small internal gaps. Significantly good adaptation was achieved when the setting expansion was less than 0.2% (P < 0.05). The results indicated that the cavity form and the setting expansion of the refractory die material had significant effects on the adaptability of fired ceramic inlays.

Analysis of Variance↗
PubMedDate not supplied

Quantitative measurement of marginal disintegration of ceramic inlays.

The objectives of this study include establishing a method for quantitative measurement of marginal change in ceramic inlays and clarifying their marginal disintegration in vivo. An accurate CCD optical laser scanner system was used for morphological measurement of the marginal change of ceramic inlays. The accuracy of the CCD measurement was assessed by comparing it with microscopic measurement. Replicas of 15 premolars restored with Class II ceramic inlays at the time of placement and eight years after restoration were used for morphological measurement by means of the CCD laser scanner system. Occlusal surfaces of the restored teeth were scanned and cross-sections of marginal areas were computed with software. Marginal change was defined as the area enclosed by two profiles obtained by superimposing two cross-sections of the same location at two different times and expressing the maximum depth and mean area of the area enclosed. The accuracy of this method of measurement was 4.3 +/- 3.2 microm in distance and 2.0 +/- 0.6% in area. Quantitative marginal changes for the eight-year period were 10 x 10 microm in depth and 50 x 10(3) microm2 in area at the functional cusp area and 7 x 10 microm in depth and 28 x 10(3) microm2 in area at the non-functional cusp area. Marginal disintegration at the functional cusp area was significantly greater than at the non-functional cusp area (Wilcoxon signed-ranks test, p < 0.05). This study constitutes a quantitative measurement of in vivo deterioration in marginal adaptation of ceramic inlays and indicates that occlusal force may accelerate marginal disintegration.

Aluminum Silicates↗
PubMed2005

In vivo interfacial adaptation of class II resin composite restorations with and without a flowable resin composite liner.

The aim of this study was to evaluate in vivo the interfacial adaptation of class II resin composite restorations with and without a flowable liner. In 24 premolars scheduled to be extracted after 1 month, 48 box-shaped, enamel-bordered class II cavities were prepared and restored with a flowable liner (FRC, Tetric Flow/Tetric Ceram/Syntac Single-Component) or without (TRC), cured with three different curing modes: soft start and 500- or 700-mW/cm2 continuous irradiation. Interfacial adaptation was evaluated by quantitative scanning electron microscopic analysis using replica method. Gap-free adaptation in the cervical enamel (CE) was observed for FRC and TRC in 96.2 and 90.2%, for the dentin (D) in 63.6 and 64.9%, and for occlusal enamel (OE) in 99.7 and 99.5%, respectively. The difference between the two restorations was not statistically significant (ns). Significant better adaptation was observed for OE than CE and D (p<0.01), and for CE than D (p<0.01). Gap-free adaptation with the soft-start and 500- and 700-mW/cm2 continuous-curing modes was observed for CE: 88.7%, 92.7%, 97.9% (ns); OE: 99.8%, 98.7%, 100% (ns); and D: 64.0%, 63.9%, and 64.6% (ns), respectively. It can be concluded that neither the use of flowable resin composite liner nor the curing mode used influenced the interfacial adaptation.

Adolescent↗
PubMed2002

Modified Class II open sandwich restorations: evaluation of interfacial adaptation and influence of different restorative techniques.

The sandwich technique with resin-modified glass ionomer cement (RMGIC) has been proposed to relieve the contraction stresses of direct resin composite (RC) restorations. The aim of this study was to evaluate the interfacial adaptation to enamel and dentin of modified Class II open RMGIC/RC sandwich restorations and the influence of different light curing techniques and matrix bands. Forty box-shaped Class II fillings were placed in vivo in premolars scheduled for extraction after one month. In groups I and II, a metal matrix was used; RC was inserted with horizontal (group I) and diagonal (group II) increments and cured with indirect/direct light. Group III was performed as group II, but a transparent matrix was used. Group IV was as group II, but with a separating liner between RMGIC and RC. Group V was a closed sandwich restoration. Interfacial quality was studied using SEM replica technique. Gap-free interfacial adaptation to enamel was observed for RMGIC in 70%, for RC in 70% and to dentin for RMGIC in 81%, for RC in 56%. No significant differences were seen between the experimental groups. At the cervical margins, RMGIC showed significantly better adaptation to enamel than RC, 74% and 42%, respectively. In conclusion, the investigated restorations showed a high percentage of gap-free interfacial adaptation in vivo. Interfacial adaptation to dentin and to cervical enamel was significantly better for RMGIC than for RC.

Adolescent↗