Significant Differences In Marginal Adaptation Research Articles

What is the Impact of Impression Techniques on the Marginal Adaptation of Metal-Ceramic Crowns Fabricated by Direct Metal Laser-Sintering

Introduction: Studies on Marginal adaptation of restorations fabricated by direct metal laser-sintering DMLS are limited. This study to evaluate the effect of two impression techniques on the marginal adaptation of metal ceramic crowns fabricated by DMLS. Materials and Methods: Twenty intact maxillary premolars extracted for orthodontics reasons were received metal-ceramic crowns. After preparation according to the preparation guidelines for metal-ceramic crowns, the teeth were divided into two groups according to impression techniques (n=10): (1) group A IOS impression, (2) group B conventional impression. Group A specimens were scanned using IOS (I 500, MEDIT, Korea). Whereas, a custom-made tray used to make putty-wash impression to the specimens of group B. Group B casts were scanned using extraoral scanner (Identica T300, META, Korea). The metal coping designs were transferred to a direct metal laser-sintering (MYSINT100, SISMA, Italy), and they were made from Co-Cr blocks. The marginal adaptation was measured at labial, palatal, misael, and distal surfaces using microscope (Olympus, Japan). Student’s paired t test was used to assess the marginal adaptation between the groups. The cutoff value for statistical significance was set at α = 0.05. Results: A statistically significant differences in marginal adaptation was found between the impression techniques for all evaluations (labial, palatal, misael, and distal) (P<0.05). The lowest values were recorded with IOS impression in all surfaces. Conclusions: the marginal adaptation values of IOS impression exhibited an acceptable marginal fit of less than 120 μm

Micro-CT analysis of the marginal adaptation and porosity associated with ultrasonic activation of coronally placed tricalcium silicate-based cements.

This study aimed to evaluate the effect of ultrasonic activation on coronal marginal adaptation and microporosity of tricalcium silicate-based materials. Sixty freshly extracted human maxillary lateral incisor teeth were instrumented with ProTaper Next X2 files followed by Peeso-Reamer burs, sizes 1 to 5. The specimens were randomly divided into six groups (n=10): Group 1, Biodentine+hand condensation; Group 2, Biodentine+ultrasonic activation; Group 3, NeoMTA Plus+hand condensation; Group 4, NeoMTA Plus+ultrasonic activation; Group 5, ProRoot WMTA+hand condensation; and Group 6, ProRoot WMTA+ultrasonic activation. All tested materials were mixed mechanically and placed 2mm underneath the cement-enamel junction by hand condensation or indirect ultrasonic activation. Volumetric analysis of the voids between the dentine wall and coronal barrier material and the porosity within the material was evaluated with micro-CT. There was no significant difference in marginal adaptation among the six groups (P>0.05). Ultrasonic activation favoured a reduced microporosity in Biodentine Group (P<0.001).

Comparison of marginal adaptation of Class II cavities restored with bulk-fill and conventional composite resins using different universal bonding agent application strategies

This in vitro study was conducted to compare the effect of universal bonding application strategy (i.e., self-etch and etch-and-rinse) on marginal adaptation of bulk-fill and conventional composite resins in Class II restorations. In this in vitro study sixty sound premolars extracted for orthodontic reasons were selected. The samples were allocated to four groups based on the universal bonding application strategy (self-etch and etch and rinse) and type of composite (bulk-fill and conventional). In each group, boxes were prepared with a depth of 4 mm on the mesial surfaces. Finally, the marginal adaptation of the samples was evaluated under a stereomicroscope. Two-way ANOVA was used to compare the marginal adaptation data in the study. Statistical significance was set at P < 0.05. Considering the type of universal bonding application strategy, there was a statistically significant difference in marginal adaptation. Etch-and-rinse strategy showed better marginal adaptation compared to self-etch strategy (P < 0.001). However, there was no statistically significant difference in marginal adaptation between the two composite resins (P = 0.829). Furthermore, the interaction between the two factors (type of universal bonding application strategy and type of composite resin) was not statistically significant (P = 0.629). Etch-and-rinse bonding application strategy in both the bulk-fill and conventional composite resins exhibited better marginal adaptation compared to self-etch bonding application strategy. However, the difference of marginal adaptation between the two types of composite resins (bulk and conventional) was not significant.

Clinical Performance and Epidemiologic Aspects of Fractured Anterior Teeth Restored with a Composite Resin: A Two-Year Clinical Study.

To investigate the etiologic factors, effect of age and gender on dental trauma, and to evaluate the performance of composite resin on the fractured crown of permanent anterior teeth. Over a 2-year period, 73 permanent teeth from 51 patients with dental trauma were treated with direct composite resin restoration. Informed consent and standardized trauma forms were completed by the patient; teeth were restored with a submicron hybrid composite resin (Spectrum TPH) and respective adhesive system (Prime&Bond NT). Sixty-nine teeth were directly restored without fiber posts, while four were treated with fiber posts. Two experienced clinicians, besides the operator, evaluated each restoration at 6-, 12-, and 24-month follow-ups according to US Public Health Service (USPHS) criteria for the following characteristics: anatomical form, marginal adaptation, color match, marginal discoloration, surface roughness, and caries. Data were analyzed using the Wilcoxon Signed Rank, Kruskal-Wallis, Mann-Whitney U, and Siegel and Castellan tests. A total of 73 traumatized teeth in 51 patients aged from 14 to 64 years (mean age 25.47 ± 14.058 years) were assessed according to the Ellis classification and restored over a 2-year period. Crown fractures were more common in the maxilla (84.9%) and caused by falls (58.8%). At the end of 24 months, a total of ten restorations were lost. The survival rate after 24 months was 82.14%. There were statistically significant differences in marginal adaptation between the 6-, 12-, and 24-month follow-ups. Although changes in marginal discoloration over time were not significant (p = 0.194), changes in color match were significant (p = 0.029). Within the limitations of this study, direct composite restorations were accepted as clinically satisfactory.

Clinical evaluation of microhybrid composites in noncarious cervical lesions: 24-month results.

To evaluate the clinical performance of two different microhybrid resin composites in noncarious cervical lesions (NCCLs) after 24 months. Ninety-seven NCCLs were restored with either TPH Spectrum (n = 48) or Filtek Z250 (n = 49) using an etch-and-rinse adhesive in 20 patients. The restorations were clinically evaluated using modified United States Public Health Service criteria for retention, color match, marginal discoloration, marginal adaptation, surface texture, anatomic form, postoperative sensitivity, and secondary caries. The restorations were assessed 1 week after placement (baseline) and after 6, 12, and 24 months. Restoration survival rates were calculated using the Kaplan-Meier procedure estimator, and a log-rank test was used to compare the survival distributions (P < 0.05). Statistical analysis was undertaken using Pearson's Chi-square test and Fisher's exact test to assess differences among the restorative materials (P < 0.05). Cochran's Q-test was employed for evaluating differences in the same restorative material between recall periods. The retention rates were 100% at 6 months, 89.6% and 91.8% at 12 months, and 85.4% and 89.8% at 24 months for TPH and Z250, respectively. TPH showed a statistically significant difference in marginal discoloration between the baseline and 24 months results (P < 0.05). Both TPH and Z250 showed statistically significant differences in marginal adaptation between the baseline and 24 months results (P < 0.05). Over the 24-month period, both microhybrid resin composites demonstrated acceptable clinical results in NCCLs.

Comparative Analysis of Calcium Silicate–based Root Filling Materials Using an Open Apex Model

IntroductionMany new calcium silicate–based root filling materials have emerged in the market; however, their performance in the orthograde obturation of an open apex has not been evaluated. The purpose of this study was to compare the marginal adaptation of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), NeoMTA Plus (Avalon Biomed Inc, Bradenton, FL), and Endosequence BC RRM-Fast Set Putty (BC RRM-FS; Brasseler USA, Savannah, GA) after orthograde placement in roots with open apices. MethodsPalatal roots of maxillary molars were instrumented to create divergent open apices and divided into 4 groups for orthograde obturation: ProRoot MTA, NeoMTA Plus, BC RRM-FS, and BC RRM-FS + BC Sealer. Using a scanning electron microscope, the quality of material adaptation at the anatomic apex was evaluated by 5 blinded examiners; 3 mm of the root end was sectioned, and gap distance was measured at the material-dentin interface. Statistical analyses were performed using the Kruskal-Wallis test. ResultsThere were no significant differences in marginal adaptation among the 4 groups at the level of the anatomic apex (P = .175). BC RRM-FS + BC Sealer had a significantly smaller gap size after 3-mm root end resection compared with the other 3 groups (P < .01). No differences were observed among the other 3 materials. ConclusionsAll materials showed comparable marginal adaptation at the anatomic apex when used for orthograde obturation of open apices. Application of BC Sealer before the delivery of BC RRM-FS Putty enhanced the quality of adaptation coronal to the apex.

Comparative evaluation of effects of bleaching on color stability and marginal adaptation of discolored direct and indirect composite laminate veneers under in vivo conditions.

Statement of Problem:Change in color and loss of marginal adaptation of tooth colored restorative materials is not acceptable. Bleaching is commonly used for treating discolored teeth. However, the literature is scanty regarding its effect on color and marginal adaptation of direct and indirect composite laminate veneers (CLVs) under in vivo conditions.Purpose:Purpose of the study was to determine the effect of bleaching on color change and marginal adaptation of direct and indirect CLVs over a period of time when exposed to the oral environment.Materials and Methods:For this purpose, a total of 14 subjects irrespective of age and sex indicated for CLV restorations on maxillary anterior teeth were selected following the inclusion and exclusion criteria. For each subject, indirect CLVs were fabricated and looted in the first quadrant (Group 1) and direct CLV's (Group 2), were given in the second quadrant. Color change was assessed clinically using intra-oral digital spectrophotometer and marginal adaptation was assessed on epoxy resin replica of the tooth-restoration interface under scanning electron microscope. After 6 months, the subjects underwent a home bleaching regimen for 14 days using 10% carbamide peroxide. The assessment of color change and marginal adaptation was done at 6 months after veneering (0–180 days), immediately after the bleaching regimen (0–194 days) and 3 months after the bleaching regimen (0–284 days).Results:The difference in median color change (ΔE) between the groups was tested using Wilcoxon rank sum test while the median color change with time within the groups was tested using Wilcoxon signed rank test. The difference in the rates of marginal adaptation was tested between the groups using Chi-square/Fisher's exact test.Bleaching led to statistically significant color change at cervical (CE), middle and incisal (IE) regions when direct and indirect composites were compared (P < 0.05). During intra-group comparison, direct CLV's showed significant color change at CE and IE regions when ΔE was compared at 180 days and 284 days (CE 10 vs. CE 30, P = 0.008, IE 10 vs. IE 30, P = 0.003). No significant differences were found when within group comparison was made for indirect laminates. Intergroup comparison between the groups showed significant difference in marginal adaptation at CE margin at all.time points (at baseline, P = 0.005; at 180 days, P = 0.007; 194 days, P = 0.025; at 284 days, P = 0.067).Conclusion:After bleaching, indirect CLVs performed better in terms of color stability whereas direct CLVs performed better in terms of marginal adaptation.Clinical Significance:Indirect composites should be preferred to direct composites as veneering materials as they have better color stability. Special attention should be given to their marginal adaptation especially in the CE region. Bleaching should be avoided in patients with composite restorations in the mouth.

Four-year randomized clinical trial to evaluate the clinical performance of a glass ionomer restorative system.

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. 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<0.05). 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>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<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>0.05). SEM evaluations were in accordance with the clinical findings. The use of both materials for the restoration of posterior teeth exhibited a similar and clinically successful performance after four years.

Luting of ceramic crowns with a self-adhesive cement: Effect of contamination on marginal adaptation and fracture strength

Objectives: This study evaluated the percentages of continuous margins (%CM) and fracture strength (FS) of crowns made out from blocs of leucite-reinforced ceramic (IPS Empress CAD) and luted with a representative self-adhesive cement (RelyX Unicem) under four contaminating agents: saliva, water, blood, a haemostatic solution containing aluminium chloride (pH= 0.8) and a control group with no contamination. Study Design: %CM at both tooth-cement (TC) and cement-crown (CC) interfaces were determined before and after a fatigue test consisting of 600’000 chewing loads and 1’500 temperature cycles changing from 5º C to 50º C. Load to fracture was recorded on fatigued specimens. Kruskal-Wallis test was used to compare %CM and FS between the five groups with a level of confidence of 95%. Results: At the TC interface, no significant differences in marginal adaptation before loading could be detected between groups. After loading, a significant marginal degradation was observed in the group contaminated with aluminium chloride (52 ± 22 %CM) in respect to the other groups. No significant differences in %CM could be detected between the groups contaminated with saliva, water, blood and the control. At the CC interface, no significant differences in marginal adaptation were observed between the groups. The FS on loaded specimens was around 1637N, with no significant differences between groups as well. Conclusions: An adverse interaction of the highly acidic haemostatic agent with either dentin or the self-adhesive cement could explain the specimens’ marginal degradation. The self-adhesive cement tested in this study was no sensitive to moisture contamination either with saliva, water or blood. Key words:Marginal adaptation, RelyX Unicem, contamination, all-ceramic crowns.

Marginal Adaptation of Nanofilled, Packable and Hybrid Dental Composite Resins Stored in Artificial Saliva

Resin based composites are possibly the most universal material available in dentistry as they are used in a huge variety of clinical applications, ranging from filling material, luting agent, indirect restorations and metal facing for endodontic posts and cores. The growth of bacteria on the composite resin surfaces, secondary caries and pulp damage or marginal imperfections may occur at the site of gap formation. In this study, marginal adaptation of three composites were measured and compared. A total of sixty human mandibular first molars were used. The teeth were divided into three main groups (20 teeth each) according to the composite resins that were used. In group I, Surefil (packable composite) was used as the restorative material. In group II, Esthet-X-improved (nanofilled composite) was used, while in group III Glacier (hybrid composite) was used. Each group was subdivided into four subgroups (five teeth each) according to the storage intervals (24 hours, one week, two weeks, and three weeks). In each group, occlusomesial cavities were prepared with diamond burs and restored with the composite, according to manufacturer's instructions. In all specimens, composite was applied to the cavity using incremental technique. All the restored teeth were subjected to in vitro thermal cycling and mechanical loading simulating a total of six months in vivo function. Marginal adaptation was evaluated using Measurescope-10 and the results were confirmed with scanning electron microscope. These specimens were dried, sputter coated with gold-palladium and then photographed with SEM at 1500x. A highly significant difference in marginal adaptation was found between the used composites. After specimen storage in artificial saliva, there was a gradual improvement in the marginal adaptability of the specimens. It can be concluded that the marginal adaptation of the nanofilled composite was the best when compared to the other composites.

Minimal Invasive Treatment for Defective Restorations: Five-Year Results Using Sealants

Replacement of dental restorations has been the traditional treatment for restorations that are defective. In this five-year randomized clinical trial, restorations with localized marginal defects were treated with sealants. Thirty-two patients (mean age, 26.8 years) with 126 Class I and Class II restorations with defective margins (amalgam n=69 and resin-based composite n=57) were recruited. Treatment was seal with pit and fissure sealant on localized marginal defects (group A: n=43) and was compared with total restoration replacement (group B: n=40) and untreated restorations (group C: n=43) as negative and positive controls. Restorations were assessed by two examiners using the modified US Public Health Service criteria, observing five clinical parameters: marginal adaptation, roughness, marginal stain, teeth sensitivity, and secondary caries at baseline and at five years after treatment. At the five-year recall examination, 23 patients with 90 restorations (71.4% recall rate) were examined. A significant improvement was observed in the marginal adaptation of the restorations in group A compared with group B. None of the treated group showed trends to downgrade in any parameter. Tooth sensitivity and secondary caries showed a low frequency in all groups. No significant difference in marginal adaptation of the restorations was found between amalgam and resin-based composite restorations (p=0.191). This study demonstrated that marginal sealing of restorations is a minimally invasive treatment that may be used instead of the replacement of restorations with localized marginal defects.

Clinical Evaluation of Bonded Amalgam Restorations in Endodontically Treated Premolar Teeth: A One-Year Evaluation

The aim of this clinical study was to compare the fracture resistance, marginal adaptation, and rate of recurrent caries of bonded and nonbonded amalgam restorations in endodontically treated premolar teeth. A total of 36 patients with endodontically treated maxillary first or second premolars were selected and divided into three groups. The treatments in all groups consisted of lingual cusp coverage and cementation of a prefabricated intracanal post (No. 2 long, Dentatus USA, New York, NY, USA). One type of cavity liner was used for each group as follows: copal varnish (Group A), Amalgambond Plus (Group B), and Scotchbond Multi-Purpose (Group C). The teeth were then restored with Cinalux high-copper spherical amalgam (Cinalux, Sh. Dr Faghihi Dental Co., Tehran, Iran). After one year, fracture resistance, marginal adaptation, and secondary caries were evaluated. Fischer's exact test was used for statistical analysis using a 0.05 percent significance level. There was no significant difference among groups with respect to fracture resistance (p=0.49). However, significant differences in marginal adaptation existed among the three groups (p=0.02) and no recurrent caries were found in any of the restored teeth. Bonding amalgam restorations using Amalgambond Plus and Scotchbond Multi-Purpose Plus did not improve the fracture resistance or affect the resistance to secondary caries in endodontically treated premolar teeth. However, the teeth in both these bonded groups showed significant improvement in marginal adaptation compared with restorations placed with copal varnish (p=0.02). Amalgambond Plus or Scotchbond Multi-Purpose adhesive resins significantly improved marginal adaptation of amalgam compared with copal varnish, but did not enhance fracture resistance or affect the prevention of secondary caries.

Comparison of the Marginal Fit of Pressable Ceramic to Metal Ceramic Restorations

The aim of this in vitro study was to compare the marginal adaptation of a pressed ceramic material, when used with and without a metal substructure, to a traditional feldspathic porcelain-fused-to-metal restoration with a porcelain butt margin. A maxillary central incisor typodont tooth was prepared with a 1.5 mm 360 degrees shoulder with rounded internal line angle, and 30 polyether impressions were made. Dies were poured in type IV dental stone, and 30 restorations were fabricated: 10 metal ceramic restorations (MCR) with porcelain butt joints, 10 pressed to metal restorations (PTM), and 10 all-ceramic restorations (PCR). All restorations were evaluated on their respective dies at 45x magnification using an Olympus SZX-12, measurements of the marginal openings were made, and ANOVA and Scheffé post hoc tests were used to evaluate the data. The mean marginal opening was 72.2 +/- 5.9 microm for MCR, 49.0 +/- 5.9 microm for PTM, and 55.8 +/- 5.9 microm for PCR. The post hoc tests showed that there was a statistical difference between the marginal adaptation of the PTM and MCR groups (p < 0.05). There was no significant difference in marginal adaptation between the PTM and the PCR groups, or the PCR and the MCR groups. The PTM group demonstrated a smaller mean marginal opening than the MCR group. The mean marginal openings of all three groups were within a clinically acceptable range.

Influence of core material on fracture resistance and marginal adaptation of restored root filled teeth

To investigate ex vivo the influence of direct placement core materials on the fracture strength and marginal adaptation of root filled maxillary central incisors restored with glass fibre-reinforced posts, various core materials and all-ceramic crowns. Forty-eight human maxillary incisors were root filled. Posts were placed and teeth restored with composite cores and crowns (n = 8). Six core materials were examined after thermal cyclic and mechanical loading (TCML). Fracture force was determined under static loading. The marginal adaptation at the interfaces between cement-tooth and cement-crown were categorized as 'intact margin' or 'marginal gap' using scanning electron microscopy. Statistical analysis was undertaken with the Mann-Whitney U-test (alpha = P < or = 0.05). Median fracture strength varied between 204 N (low viscous experimental core) and 1094 N (Multicore). No difference in fracture resistance was found with varying viscosity of the core material. The layering technique improved the fracture performance (P = 0.059) to a minor degree. Crowns with dedicated core materials (Rebilda 1063 N; Multicore 1094 N) had a significantly higher fracture resistance than crowns with a conventional restorative material (Tetric Ceram 509 N). Significantly poorer marginal adaptation before TCML was found for the layering technique at the tooth-cement interface and for all experimental cores after TCML. At the crown-cement interface significant differences in marginal adaptation could be determined between Multicore-layered core (P = 0.002) and Multicore-Rebilda (P = 0.001) after TCML. The fracture strength of post and core restorations was dependent on the core material and bonding system. Marginal adaptation was influenced by the method of application of the core material and by TCML.