scholarly journals Evaluation of Newly Introduced Bioactive Materials in Terms of Cavity Floor Adaptation: OCT Study

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7668
Author(s):  
Heba B. Abdel-Maksoud ◽  
Aziza W. Bahanan ◽  
Lujain J. Alkattabi ◽  
Turki A. Bakhsh

Objective. The aim of the present study was to evaluate the adaptation of newly introduced bioactive restorative materials to the cavity floor using cross-polarization optical coherence tomography (CP-OCT). Materials and Methods. Round class V cavities were prepared on the proximal surfaces of sixty non-carious human anterior teeth (0.5 mm depth × 4 mm diameter), which were divided into groups according to the restorative material (n = 15). In the VF group, Vertise flow composite (Kerr, Orange, CA, USA) was used, in the BF group, Beautifil II composite (Shofu, Koyoto, Japan) was used, and in the AB group, ACTIVA BioACTIVE composite (Pulpdent, Watertown, NY, USA) was used. Cavities were restored using the bulk filling technique and cured according to the manufacturers’ instructions. Then, the specimens were immersed in a contrasting agent, and image acquisitions were taken by CP-OCT to calculate the adaptation percentage by using an image analysis software. Results. B-scans showed a diffuse bright band of white pixels at the tooth-resin interface that was interpreted as a micro-gap present between the cavity floor and restorative material. The Kruskal-Wallis test showed a statistically significant difference between all tested groups with the AB group representing the least gap formation, followed by the BF group, and then the VF group, which demonstrated the highest gap formation. Conclusions. In class V cavities, better adaptation to the cavity floor can be obtained when using ACTIVA BioACTIVE more than Vertise flow and Beautifil II composites. In addition, CP-OCT is considered a non-destructive imaging tool that helps in evaluating the quality of the tooth-restoration interface when bioactive composites are used.

2020 ◽  
Vol 45 (4) ◽  
pp. E207-E216 ◽  
Author(s):  
AMO Correia ◽  
MR Andrade ◽  
JPM Tribst ◽  
ALS Borges ◽  
TMF Caneppele

Clinical Relevance Restoring Class V cavities with a regular bulk-fill composite presents a more favorable biomechanical behavior than restoring with a regular nano-filled composite. SUMMARY Purpose: This study evaluated the influence of Class V cavity extension and restorative material on the marginal gap formation, before and after aging, and the theoretical polymerization shrinkage stress distribution in a tooth restoration. Methods and Materials: Class V cavities with the depth of 2 mm, cervical/incisal distance of 4 mm, and margins located in the enamel 1 mm above the cementoenamel junction were prepared in 60 bovine incisors in two mesiodistal dimensions (n=30): 2.9-mm large extension cavities (LE) or 1.4-mm small extension cavities (SE). The cavities' depths were validated using a periodontal probe, while the mesiodistal and cervical/incisal distances were measured using a stereomicroscope. After adhesive application (Clearfil SE Bond), each group was randomly divided into two groups (n=15) according to the restorative material: Filtek Z350 XT (N) or Filtek Bulk Fill Posterior (BF). The marginal gap formation between the tooth structure and the restorative material was evaluated using a stereomicroscope before and after thermocycling for 15,000 cycles (5°C and 55°C). Data were analyzed using repeated-measures analysis of variance (ANOVA) and Tukey test for multiple comparisons (α=0.05). A three-dimensional geometric model with the same dimensions as the experimental test was created for each cavity, and the restorations were modeled for each restorative material. In the analysis software, the finite element mesh was created with tetrahedral quadratic elements, and the polymerization shrinkage was simulated by thermal analogy. The maximum principal stress was used to express the tensile stress in the adhesive interface through colorimetric graphs. Results: For the marginal gap, the repeated-measures ANOVA revealed a significant effect only for the factors composite resin (df=1, F=4.09, p=0.04) and thermal aging (df=1, F=44.35, p<0.001). For all numerical simulations, higher stress concentration occurred at the enamel margin, and the stress peak decreased in the following sequence: LE-N (17.0 MPa) > SE-N (15.0 MPa) > LE-BF (9.1 MPa) > SE-BF (8.2 MPa). Conclusion: Marginal gaps in the specimens fell between approximately 12 and 17 μm; however, the regular bulk-fill composite showed less gap formation and better stress distribution around the cavity margin than the regular nano-filled composite, regardless of the cavity extension.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2661
Author(s):  
Kiche Shim ◽  
Young-Eun Jang ◽  
Yemi Kim

Background: This clinical trial aimed to compare the effects of bioceramic sealer and resin-based sealer on the incidence and intensity of postoperative pain. Methods: Patients with anterior teeth or premolars requiring root canal treatment were assigned to group 1 (n = 51). Those with molars requiring treatment were assigned to group 2 (n = 57). In groups 1En and 2En, root canals were obturated with Endoseal MTA using the single-cone technique. In groups 1AH and 2AH, the sealer used was AH Plus with the continuous wave technique. On the day of canal filling, each patient was instructed to indicate their pain intensity over the 7 day postoperative period, at rest and, while biting, using a visual analog scale. Results: There was no significant difference in the incidence or intensity of postoperative pain between the Endoseal MTA and AH Plus groups during the 7 day postoperative period (p > 0.05). Less time was needed to seal the root canals with Endoseal MTA, especially in group 2 (p < 0.05). Conclusions: Endoseal MTA and AH Plus had similar effects on the incidence and intensity of postoperative pain. The obturation time was shorter when using Endoseal MTA compared to AH Plus.


Author(s):  
Maame Esi Hammond ◽  
Radek Pokorný ◽  
Daniel Okae-Anti ◽  
Augustine Gyedu ◽  
Irene Otwuwa Obeng

AbstractThe positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration < 350 cm height were gathered. The results show that the intensity of disturbance was disproportional to gap size. Species diversity differed significantly between undisturbed and disturbed sites and, also between intermittently disturbed and disturbed sites for Simpson’s (1-D), Equitability (J), and Berger–Parker (B–P) indices. However, there was no significant difference among forest sites for Shannon diversity (H) and Margalef richness (MI) indices. Tree species composition on the sites differed. Regeneration density on the disturbed site was significantly higher than on the two other sites. Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers. Pioneer species giving way to shade tolerant species is a natural process, thus make them worst variant in gap regeneration.


2014 ◽  
Vol 39 (1) ◽  
pp. 30-34 ◽  
Author(s):  
SG Tulsani ◽  
N Chikkanarasaiah ◽  
S Bethur

Objectives: Biopure MTAD™, a new root canal irrigant has shown promising results against the most common resistant microorganism, E. faecalis, in permanent teeth. However, there is lack of studies comparing its antimicrobial effectiveness with NaOCl in primary teeth. The purpose of this study was to compare the in vivo antimicrobial efficacy of NaOCl 2.5% and Biopure MTAD™ against E. faecalis in primary teeth. Study design: Forty non vital single rooted primary maxillary anterior teeth of children aged 4-8 years, were irrigated either with NaOCl 2.5% (n=15), Biopure MTAD™ (n=15) and 0.9% Saline (n=10, control group). Paper point samples were collected at baseline (S1) and after chemomechanical preparation (S2) during the pulpectomy procedure. The presence of E. faecalis in S1 & S2 was evaluated using Real time Polymerase Chain Reaction. Results: Statistical significant difference was found in the antimicrobial efficacy of NaOCl 2.5 % and BioPure MTAD™ when compared to saline (p&gt;0.05). However, no statistical significant difference was found between the efficacies of both the irrigants. Conclusions: NaOCl 2.5% and BioPure MTAD™, both irrigants are equally efficient against E. faecalis in necrotic primary anterior teeth. MTAD is a promising irrigant, however clinical studies are required to establish it as ideal root canal irrigant in clinical practice.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3055-3055
Author(s):  
Yuntao Song ◽  
Jie Liu ◽  
Weiran Wang ◽  
Tonghui Ma

3055 Background: Ultrasound and ultrasound-guided fine needle aspiration (US-FNA) are the first choice for judging benign and malignant thyroid nodules. This study will report on the differences of US-FNA BSRTC class, postoperative pathology and mutation landscape of thyroid nodules between China and other countries. Methods: We conducted a prospective study containing 383 FNA samples of thyroid nodules. For most of these FNA samples, genomic DNA and RNA were extracted and sequenced with FSZ-Thyroid NGS Panel V1, and postoperative pathology were followed up. Moreover, we also compared results of this study with those of West China Hospital in China, Yamashita Thyroid Hospital in Japan, and Cleveland Clinic in the United States. Results: Among the 383 FNA samples, the proportions of BSRTC class I to VI were 10.7%, 6.3%, 18.8%, 3.7%, 12.3%, and 48.3% respectively. Compared with study in other countries, the proportion of class II was significantly lower than that in Japan and the United States. Meanwhile, the proportion of class V and VI were significantly higher than the above two countries. Subsequently, 232 thyroid nodules were surgically removed. Postoperative pathology showed that the proportion of malignant tumors (85.3%) was also significantly higher than reported in Japan and the United States. But compared with other studies in China, there was no significant difference. Most of the malignant tumors were papillary thyroid cancer (PTC, 96%), accompanied with 2 follicular thyroid cancer (FTC), 3 medullary cancer (MTC) and 3 anaplastic thyroid cancer (ATC). Compared with study in the United States, the proportion of PTC and FTC were elevated (96% vs. 85.3%) and reduced (1% vs. 9.3%) respectively. At last, we also analysis the mutation landscape of 180 malignant tumors. Compared with TCGA study, the frequency of BRAF V600E in PTC in our study was significantly higher than that of TCGA (73.3% vs. 58%), and the frequency of RAS mutation was significantly lower (1.2% vs. 12.6%). And compared with an institutional experience of ThyroSeq v3 for Bethesda III and IV at the University of Pittsburgh Medical Center, the frequency of BRAF V600E and RAS mutation in Bethesda III-IV malignant tumors was also significantly higher (45.8% vs. 1.4%) and lower (8.3% vs. 47.1%). Conclusions: There were significant differences in BSRTC class and postoperative pathology between China and other countries, such as Japan and the United States. The possible reasons included that the indications for FNA in China were different. For example, most of patients who underwent FNA in this study had suspicious clinical/ultrasound features. So the proportion of BSRTC class V and VI as well as the malignant rate were elevated. On the other hand, more BRAF V600E and less RAS mutations were detected in malignant tumors in this study which might result from racial differentiation and discrepancy in proportion of PTC and FTC.


2017 ◽  
Vol 07 (01) ◽  
pp. 025-028
Author(s):  
Lakshmi Nidhi Rao ◽  
Mithra N. Hegde ◽  
Aditya Shetty

AbstractComposite resins represent a class of material widely used in restorative dentistry, not only for anterior aesthetics but also as the first choice to restore posterior teeth. However the key limitation in the use of composite resins as a restorative material is related to shrinkage during polymerization which leads to poor marginal seal, marginal staining, restoration displacement, tooth fracture and recurring caries [1].Polymerization shrinkage may affect negatively the clinical outcome of the restoration. Hence the present study evaluates the Polymerization shrinkage of 2 different posterior composites; Filtek Z350(3M) and everX Posterior(GC), using a pycnometer.Independent Sample T-Test was used to determine statistically significant difference in volumetric shrinkage among the tested composite resins. everX Posterior showed comparatively less shrinkage than Filtek Z350; which can be attributed to the presence of silanated e-glass fibres.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Katarzyna Olczak ◽  
Halina Pawlicka

The aim of this study was to evaluate the sealing ability of three different canal filling techniques. Sixty-four roots of extracted human maxillary anterior teeth were prepared using ProTaper® rotary instruments. The specimens were then randomly divided into 3 experimental groups (n=16) and 2 control groups (n=8). The root canals were filled using cold lateral compaction (CLC group), continuous wave condensation technique using the Elements Obturation Unit® (EOU group), and ProTaper obturators (PT group). For the negative control group, 8 roots were filled using lateral compaction as in the CLC group, and the teeth were covered twice with a layer of nail varnish (NCG group). Another 8 roots were filled using lateral compaction, but without sealer, and these were used as the positive control (PCG group). A glucose leakage model was used for quantitative evaluation of microleakage for 24 hours and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 weeks. No significant difference in the cumulative amount of leakage was found between the three experimental groups at all observation times. The lateral condensation of cold gutta-percha can guarantee a similar seal of canal fillings as can be achieved by using thermal methods, in the round canals.


2017 ◽  
Vol 16 ◽  
pp. 1-11
Author(s):  
Shahin Kasraei ◽  
Ebrahim Yarmohammadi ◽  
Maryam Farhadian ◽  
Mona Malek

Objective: this study aimed to assess the effect of treatment of phosphoric acid etched dentin surface with 5% bromelain enzyme and Nd:YAG laser prior to the use of etch and rinse adhesive systems on microleakage margins of class V composite restorations. Materials and Methods: sixty sound premolar teeth were selected. Standard class V cavities were prepared in the buccal and lingual surfaces of each teeth. Preparation in that way 1 mm of the cavity was above and 1 mm of it was below the cementoenamel junction. The teeth were then randomly divided into three groups including 20 teeth(40cavities  in each gorup). Two ethanol base etch and rinse system (Adper Single Bond and OptiBond Solo) was applied in each group. In the control group, cavities were etched with 37% phosphoric acid. Adper Single Bond was applied to 20 and OptiBond Solo was applied to the remaining 20 cavities and they were restored with Z250 composite (n=40). The same procedures were performed in bromelain and Nd:YAG laser groups with the difference that prior to the application of adhesive, aqueous 5% bromelain was applied in bromelain group while Nd:YAG laser was irradiated in laser group. All teeth were thermocycled and their apices were sealed with sticky wax. The tooth surfaces were coated with nail varnish except for 1 mm around the restoration margins, and the teeth were then immersed in fuchsine and sectioned by a diamond disc into mesial and distal halves. Marginal microleakage at both sides was determined and scored under a stereomicroscope at x40 magnification. Then data were analyzed using the Kruskal Wallis and Mann Whitney tests (α=0.05). Results: according the result of Mann Whitney test, Cervical margins showed significantly higher microleakage than the occlusal margins (P=0.000) but no significant difference was noted in microleakage of occlusal (P=0.362) or gingival (P=0.147) margins among the three groups by Kruskal Wallis test. Conclusion: in conclusion, application of proteolytic agents(5% bromelain solution and Nd:YAG laser)  on acid-etched dentin surface prior to the application of adhesive has no significant effect on marginal microleakage of class V composite restorations. 


2020 ◽  
Author(s):  
Sumer M Alaki ◽  
Bashaer S Abdulhadi ◽  
Medhat A AbdelBaki ◽  
Najla M Al-Alamoudi

Abstract Background: Providing restorations to anterior teeth in children is a challenging task due to the need for high esthetics, strength, and durability. This study was done to compare prefabricated primary zirconia with resin composite strip crowns on primary maxillary central and lateral incisors with regards to gingival health, plaque accumulation, recurrent caries, restoration failure, and opposing teeth wear over a period of 3, 6 and 12 months. Methods: Children attending the King Abdulaziz University, Faculty of Dentistry (KAUFD) clinics who needed restorations were screened for inclusion criteria. A total of 120 teeth were treated; 60 with zirconia and 60 with strip crowns. Randomization was done by simple random allocation using SPSS software version 20.0 (Armonk, NY; IBM Corp.). A simple descriptive statistic was used for analysis by Wilcoxon Signed-Rank test and Chi-square test. Level of significance was set at (α = 0.05) and level of confidence at (95%). The presented research was registered retrospectively at ClinicalTrials.gov in 6th of August 2017, under registration number NCT03184012.Results: Zirconia crowns showed significantly less gingival bleeding at the 3- and 6-months follow up periods (p<0.006, p<0.001; respectively), less plaque accumulation at all follow up visits (p<0.001), no restoration failure (p<0.001), but more wear to opposing teeth (p<0.02). No significant difference was found between the two crowns with regards to recurrent caries (p<0.135).Conclusion: Based on our data we conclude that overtime teeth covered with zirconia crowns show better gingival health and less bleeding, plaque accumulation as well as less loss of material. On the other hand, zirconia can cause more loss of opposing tooth structure.


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