Method Of Cavity Preparation Research Articles

Bond strength comparison of a fiber-reinforced composite resin: Different dentin conditions and preparation techniques.

This study aimed to compare the bond strength of a fiber-reinforced composite resin with traditional and bulk-fill composite resins under different dentin conditions and preparation techniques. Eighty molar teeth, excluding the mesio-distal half of the occlusal dentin surfaces of each teeth, were isolated with acid-resistant nail varnish and stored in a demineralisation solution (pH 4.5). After mechanical removal of the varnish, the teeth were buried in acrylic resin blocks. In every composite resin group, one-half of the specimens were prepared with a diamond bur and another half with Er: YAG laser. Then, the specimens were divided into four groups of composite resins (Filtek Z250, G-aenial Posterior, SonicFill 2, Ever X Posterior) (n = 10). Shear bond strengths were measured using a universal testing device, and failure types were determined with stereomicroscope images. SEM images were obtained at 1000× magnification. Data were analyzed using a three-way analysis of variance (ANOVA), and Bonferroni correction was used for multiple comparisons (p = .05). Differences in the dentin surface affected the bond strength results (p < .05), whereas there was no significant difference between cavity preparation methods (p > .05). EverX Posterior showed the highest bond strength results. Within the limitations of this study, fiber-reinforced composite resin exhibited successful bond strength results in addition to improved mechanical properties. RESEARCH HIGHLIGHTS: Fiber-reinforced composite had successful bond strength values. Bond strength values of sound dentin groups were higher than those of caries-affected dentin groups. The use of an Er: YAG laser for preparation did not lead to insufficient bond strength results.

Factors Affecting the Outcome of Periapical Surgery; a Prospective Longitudinal Clinical Study

Wound healing following periapical surgery is influenced by age, gender, smoking, periapical lesion size, type of root-end filling, method of root-end cavity preparation and the use of microsurgical or conventional technique. This study aimed to evaluate the influence of various preoperative factors such as age, gender, smoking, preoperative pain, and preoperative periapical lesion size on the outcome of surgical endodontic treatment. A thorough history, examination, and investigation were performed to establish patient age, gender, smoking status, periapical lesion size, and the presence of preoperative pain. Forty patients aged between 15–57 years presented with persistent chronic apical periodontitis of single-rooted anterior teeth after conventional re-root canal treatment were enrolled for periapical surgery. Following periapical surgery, all patients were recalled for evaluation of periapical healing after 12 months based on clinical and periapical X-ray examination due to inaccessibility of an advanced imaging system (CBCT). Chi-squared and Fisher’s exact test were applied, which revealed a statistically significant association of periapical healing with age (p = 0.025), smoking (p = 0.029), and lesion size (p &lt; 0.001). Although, the success of periapical healing was higher in males 78.6% (22/28) compared to females 58.3% (7/12) however, no statistically significant relationship was found between gender and healing (p = 0.254). Patient age, smoking status, and size of the preoperative lesion had a strong influence on periapical healing after surgical endodontic treatment.

Evaluation of Microleakage in Resin Composites Bonded to an Er:YAG Laser and Bur-Prepared Root and Coronal Dentin Using Different Bonding Agents.

Introduction: This study was conducted to assess the microleakage in Er:YAG laser-ablated and bur-prepared root and coronal dentin cavities using self-etch and total-etch adhesive systems. Methods: Sixty extracted caries-free human third molars were sectioned for dentin exposure. Then, two standard class V cavities were prepared in the root and coronal dentin of each tooth and allocated to one of the following conditioning groups randomly (n=12/Group): G1: Diamond bur for cavity preparation and single bond (BESB) etch-and-rinse adhesive for bonding, G2: Er:YAG laser (160 mJ, 20 Hz, 29.88 J/cm2) and SB (LESB), G3: Er:YAG laser and SB without acid etching (LSB), G4: Diamond bur and Clearfil SE Bond (BCSE) self-etch system, and G5: Er:YAG laser and Clearfil SE Bond (LCSE). The cavities were filled with Z100 composite resin. Dye penetration was assessed after thermocycling. Data analysis was done by Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was set at P<0.05. Results: The results showed there were no statistically significant differences in microleakage between the two preparation methods (bur and laser) or the bonding agents applied (P>0.05). Regardless of the cavity preparation method, dye penetration was significantly higher in coronal dentin than in root dentin (P<0.05). Conclusion: The Er:YAG laser had the same efficacy as the conventional method for cavity preparation, and microleakage did not depend on the bonding agent. Microleakage was significantly higher in coronal restorations than in root restorations.

Evaluation of the Effect of Cavity Preparation Using Er,Cr:YSGG Laser on Microleakage of Class V Composite Restorations

Background: The application of laser in dentistry for medical purposes such as caries removal, preparation of restorative cavities, and dental surface treatment for more effective bonding of restorative materials to the tooth has been significant. The present experimental study aimed to evaluate the effect of cavity preparation on microleakage by using erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) lasers, and to compare it with the effect of bur on microleakage in class V composite restorations. Methods: In this experimental study, 20 intact human premolar teeth were randomly divided into 2 equal groups according to the cavity preparation technique: G1: laser cavity preparation (LCP) using a Er,Cr:YSGG laser (Bio Lase, USA), and G2: bur cavity preparation (BCP). Standard class V cavity was prepared on both lingual and buccal surfaces in two groups. The samples underwent thermocycling for 3000 times (5-55ºC) and were immersed in a methylene blue 2% solution for 24 hours. After buccolingual sectioning from the middle of the restoration, a stereomicroscope with 20 x magnification was used to measure the penetration rate of the dye and to determine the score for microleakage. Data were analyzed using SPSS (version 16) software and Mann-Whitney U test (α=5%). Results: According to the study results, the minimum and maximum microleakage values were observed in the occlusal and gingival margins, respectively, which were identically for both groups. Comparing two groups (BCP and LCP) revealed that there was no significant difference between them in terms of microleakage values at the occlusal and gingival margins (P&gt;0.05). Conclusions: It was concluded that cavity preparation using Er,cr:YSGG laser had microleakage values similar to those found with conventional cavity preparation (bur) method in class V composite restorations.

Effect of Hydro- abrasion versus Conventional Cavity Preparation on the Clinical Performance of Composite Resin Restoration

Aim: To evaluate the effect of hydro abrasion versus the conventional drill method of cavity preparation on the clinical performance of composite restoration over one year follow up period. Materials and methods: Twenty patients with occlusal carious lesions were selected and examined with DIAGNO cam and ICDAS visual criteria to select teeth having ICDAS Code 3 or 4. Forty lesions were randomly divided into two groups (n=20) according to the method of caries removal. Cavities were prepared by the conventional drill method in group I and by hydro-abrasion in group II. Cavities of both groups were restored by self-etch adhesive (Adper Easy Bond) and nano- filled composite (Filtek Z350XT). All restorations were evaluated after 24 hours, after 9 and 12 months according to (USPHS) criteria for retention, marginal adaptation, postoperative sensitivity, marginal discoloration, and secondary caries. Results: Mild, moderate - severe and very severe pain was recorded in group I While in group II, only mild pain was recorded in (40%) of cases. The st. analysis of the collected data related to the tested USPHS criteria revealed 100% Alpha scoring regarding retention, marginal adaptation and secondary caries in both groups throughout the study period. The gap width measured under SEM was found increased sig. by time in both groups. Marginal discoloration was observed in the two groups after nine and 12 months. Post-operative hypersensitivity was found only in group I in 100% of cases at the base line and was disappeared during the next follow up period.

Clinical Evaluation of Laser Versus Conventional Cavity Preparation Methods in Primary Teeth Restorations

Purpose: To compare between laser and conventional cavity preparation techniques in children, to assess clinical presentation of bulk fill composite and high viscous glass ionomer restoration. Materials and Method: In vivo study included 20 children aged from 4-8 years using split mouth technique (a total of 40 teeth was treated). Group I: 20 teeth treated by turbine. Group II: 20 teeth treated with laser. Each group was subdivided into two subgroups. The teeth were filled with Equia forte in groups IA and IIA or filled with REVEAL HD Bulk composite in groups IB and IIB. Results: Results of the study showed that conventional technique need less time than Laser. It also showed higher mean pain score than Laser although it was not significant. Tooth materials displayed excellent clinical evaluation. Conclusion: laser minimize the onset of pain during caries removal compared with drilling. A longer treatment time was the main disadvantage of this technique. Equia, and bulk fill composite, showed acceptable clinical performance.

Selected Spectroscopic Techniques for Surface Analysis of Dental Materials: A Narrative Review.

The presented work focuses on the application of spectroscopic methods, such as Infrared Spectroscopy (IR), Fourier Transform Infrared Spectroscopy (FT-IR), Raman spectroscopy, Ultraviolet and Visible Spectroscopy (UV-Vis), X-ray spectroscopy, and Mass Spectrometry (MS), which are widely employed in the investigation of the surface properties of dental materials. Examples of the research of materials used as tooth fillings, surface preparation in dental prosthetics, cavity preparation methods and fractographic studies of dental implants are also presented. The cited studies show that the above techniques can be valuable tools as they are expanding the research capabilities of materials used in dentistry.

Effect of different types of adhesive systems on the bond strength and marginal integrity of composite restorations in cavities prepared with the erbium laser-a systematic review.

There are inconclusive results regarding etching and bonding protocol to achieve optimal bond strength and marginal integrity of adhesive composite resin restorations in erbium laser prepared cavities. This systematic review aimed to consider which adhesive system protocol may be optimal in achieving the bond strength and marginal integrity in erbium laser-prepared cavities, comparable to that obtained with conventional method of cavity preparation. This review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement with literature search based on all publications during the period January1, 2000-October 10, 2020, in three databases: MEDLINE, Google Scholar and ScienceDirect. The necessary information was extracted by two independent authors. The search resulted in 139 articles from all databases, and a total of thirty-one articles met the inclusion criteria. The results indicated that the selection of adhesives depending on their pH and composition and the laser pulse duration and pulse energy used plays an important role in predicting the adhesion and marginal integrity. The 10-MDP containing moderate self-etch adhesives has demonstrated predictable outcomes. Longer pulse durations used for cavity preparations may indicate the use of etch-and-rinse (EnR) or moderate self-etch adhesives (SEA) to allow better resin infiltration in deep craters formed due to laser irradiation. However, further studies with more standardizations in relation to adhesives and laser parameters are needed.

Analysis of the Mechanical Properties of the Titanium Layer Obtained by the Mold Cavity Preparation Method

Analysis of the Mechanical Properties of the Titanium Layer Obtained by the Mold Cavity Preparation Method

The current state of the art in bond strength of laser-irradiated enamel and dentin (Nd: YAG, CO2 lasers) part 1: a literature review

The present study aimed to conduct a review of the literature about the current state of bond strength of laser-irradiated dental substrates to different adhesive systems. The bond strength between the adhesive materials and dental substrates is affected by many factors such as the tooth itself, adhesive system, and pretreatment procedure of tooth surface. With the introduction of the lasers in conservative dentistry, it has become possible to remove enamel and dentin in an effective way like the conventional cavity preparation and subsurface conditioning methods. This opens a new possibility of using the lasers as an alternative to these procedures. An electronic search to identify studies was performed in the PubMed, Google Scholar, Research gate, and LIVIVO online databases. The relevant studies were conducted from 2009 to 2018. Based on the literature, the collected data varied according to the type of adhesive and resin composite used, parameters (power, energy density, pulse duration, irradiation time, and distance, cooling system), substrates, and the bond strength test methodology used. Based on the limited information and low number of studies currently available, the superiority of laser surface treatment in comparison with conventional surface treatment on bond strength could not be identified.

Effect of cavity preparation and bone mineral density on bone-interface densification and bone-implant contact during press-fit implantation of hip stems.

Implant loosening and periprosthetic fracture are two major revision causes for uncemented hip stems. The chosen method of cavity preparation could play a key role for both failure mechanisms. The aim of this study was to determine the dependence of the broach type as well as patient bone mineral density (BMD) on densification and contact conditions at the bone-implant interface. Hip stems were implanted into cadaveric femora using compaction, blunt extraction or sharp extraction broaches with computed tomography scans performed prior to broaching, after broaching and after stem implantation. Proximal periprosthetic bone densification as well as press-fit, contact area and stem seating relative to the last broach were determined. Median bone densification was higher with the compaction and blunt extraction broaches compared to sharp extraction broaches (181% and 177%, respectively, p = 0.002). The bone densification of femora prepared with compaction broaching increased with higher BMD (R2 = 0.183, p = 0.037), while stem seating decreased with higher BMD for all broach types (R2 = 0.259, p = 0.001). Incomplete seated prostheses were associated with smaller press-fit and bone-implant contact area (R2 = 0.249, p = 0.001; R2 = 0.287, p < 0.001). Clinical Significance: The results suggest that compaction broaching maximizes bone densification in patients with higher bone density. However, there appears to be an increased risk of insufficient stem seating in high-density bone that could limit the benefits for primary stability. For lower quality bone, the broach type appears to play a lesser role, but care must be taken to limit extensive stem seating which might increase periprosthetic fracture risk. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1580-1589, 2019.

Modern methods of hard tissue cavity preparation – literature overview

Abstract Undeniably, adhesives play crucial role in modern dentistry. In order to deliver high bonding quality, profound removal of decayed hard tissues is indispensable, along with a healthy tissue preservation. There is a great variety of tools and agents, dentists can use in practice. The most popular among them are certainly dental drill units. However, air abrasion, ultrasonic generators and lasers are also relevant. While selecting the right approach, both advantages and limitations of a particular technique must be considered.

Technology of Alloy Layers on Surface of Castings

The paper presents a technology of layered castings based on the use of a method of mould cavity preparation via spatial skeleton insert. The insert was created as a result of application of 3D printing selective laser melting method. The studied spatial skeleton insert, made from CP2 Ti powder, was placed into the mould cavity directly before pouring grey cast iron. The scope of the conducted studies covered metallographic research using a light microscope and scanning electron microscope with EDS analysis, hardness measurements and abrasive wear resistance tests. The obtained results show that the interaction between the solid spatial skeleton insert and liquid alloy allowed for the production of a casting of pearlitic grey cast iron with flake graphite, containing a surface layer reinforced with titanium carbides. In consequence, a local increase in hardness was obtained and, moreover, an increase in abrasive wear resistance of the whole surface layer of the casting.

Evaluation of micro leakage of two direct esthetic restorations with different preparation techniques

ObjectivesIn recent times, the term “minimal intervention dentistry” has coined to describe a new approach to the treatment of the disease of caries. This study was carried out to evaluate the marginal integrity of class V cavity in permanent posterior teeth prepared with different air abrasion parameters compared with classical rotary cavity preparation. MethodsA total number of 150 sound caries for free human posterior teeth were used in this study. Teeth were extracted for periodontal disease or orthodontic reasons and the average age of patients between 20 and 35 years. Teeth were divided according to the type of restoration into two main groups: Group I (n = 75) restored with low shrinkable posterior composite (P90) and Group II (n = 75) restored with Ketac nano ionomer (N100). Each main group was divided into five groups (n = 15), then each group was further subdivided into three subgroups (n = 5) according to the storage time (immediately, three months, and six months). All teeth would be tested at both occlusal and gingival margins of prepared class V cavity according to the method of cavity preparation. ResultsA high significant difference was found in the mean ranks of micro-leakage at both occlusal enamel and gingival dentin walls among Groups 1–5 (p-value of <0.05). For main groups that restored with low shrinkable composite resin material (P90) and Ketac nano ionimer (N100), results revealed that scores of micro-leakage between (P90) or (N100) and both occlusal enamel or gingival dentin walls were significantly higher in group (AS1P1) than those in groups (B), (AS1P2), and (AS2P2) respectively. While no statistical significant difference was detected between groups (AS1P1) and (AS2P1). High scores of micro-leakage were detected at groups with six months, three months and immediately storage time respectively. ConclusionLow shrinkable silorane based composite yielded better results of micro-leakage scores along the occlusal enamel and gingival dentin walls when the cavity of class V was prepared with air abrasion technique with large size alumina particles under high pressure at immediate storage time as compared with Ketac N100.

Qualitative evaluation of hybrid layer formation using Er:YAG laser in QSP mode for tooth cavity preparations.

The purpose of this study was to evaluate the thickness and qualitative characteristics of the hybrid layer after two cavity preparation methods, using Er:YAG laser in QSP mode and conventional carbide burs. Additionally, two different adhesive techniques were investigated using etch-and-rinse and self-etch adhesive systems. Sixty sound human third molars were used and were randomly divided into four groups (n = 15). In the first two groups, large (4mm length, 3mm wide, and 3mm deep) class I cavities were prepared using Er:YAG laser (2.94μm) in QSP mode, while in the other two groups, the cavities were prepared using carbide burs. After cavity preparations, two different adhesive techniques with GLUMA® 2 Bond (etch-and-rinse) and Clearfil™ Universal Bond Quick (self-etch) were applied. For the qualitative evaluation of the formed hybrid layer, photomicrographs were taken using SEM, and elemental semi-quantitative analysis was performed using EDS to confirm the extent of the hybrid layer. One-way ANOVA was applied to verify the existence of statistically significant differences, followed by Tukey test for post hoc comparisons (Bonferroni corrected), and the level of significance was set at a = 0.05. The laser-treated groups exhibited higher hybrid layer thickness than bur-treated groups (p < 0.001). Between the laser-treated groups, etch-and-rinse technique presented higher hybrid layer thickness than self-etch technique (p < 0.001), while between the bur-treated groups, no significant differences were detected (p = 0.366). Er:YAG laser cavity preparations in QSP mode may be advantageous for adhesion of composite restorations, but more data are necessary to confirm its clinical effectiveness.

Marginal quality of ceramic inlays after three different instrumental cavity preparation methods of the proximal boxes

ObjectivesThe marginal quality of ceramic inlays was evaluated after the use of three different instrumental finishing methods in mesio-occluso-distal (mod) cavity boxes in vitro after hydrothermal loading (HTL).Materials and methodsCaries-free human molars were divided into three groups. Mod-cavities were conventionally prepared. Box finishing was performed in every group with rotating (RI), sonic (SI), or ultrasonic (USI) instruments. Surface roughness was examined. Twelve mod-cavities remained untreated. Continuous margin quality was evaluated with scanning electron microscopy (SEM). Ceramic inlays were cemented into cavities. After HTL microleakage, marginal and absolute marginal gaps were examined. All data were analyzed statistically.ResultsSignificant differences were found, between cavity surface roughness of RI and SI groups, the RI and USI groups, but not between microleakage, marginal, absolute marginal gaps after HTL and in proximal marginal quality. No correlations between microleakage and marginal gaps nor between microleakage and surface roughness were found.ConclusionMod-cavity proximal box finishing with SI or USI resulted in a higher surface roughness than the use of RI. The type of the finishing method did not influence the marginal quality of ceramic inlays. For the mod-cavity finishing, the use of SI and USI could be an alternative instrumental method to conventional RI methods with a lower risk of iatrogenic damage of the adjacent teeth.Clinical relevanceThis study allows the practitioner to better determine the proper indications and limitations of the sonic and ultrasonic instruments for mod-cavity proximal box finishing.

The effect of Er:YAG laser and bulk filled composite type on marginal adaptation of class II cavities: an SEM analysis study

Purpose: To evaluate the effect of cavity preparation method (Er:YAG laser or diamond bur) and bulk-filled composite material type on marginal adaptation mesial occlusal (MO) class II cavities. Materials and Methods: Two-surface box cavities (4-mm proximal depth and 5-mm occlusal width) were prepared on 60 human mandibular molar teeth. Cavities were prepared using Er:YAG laser or diamond burs in an air-turbine hand-piece. All cavities were applied Single Bond Universal dentin bonding agent. The cavities were further subdivided into three subgroups according to the restorative material used; two bulk-filled composites [Filtek Bulk Fill Posterior (3M ESPE) and SonicFill 2 (Kerr)] and one traditional composite material Filtek Ultimate Universal Restorative (3M ESPE). Restorations were evaluated using scanning electron microscopy at ×200 magnification for their adaptation to the approximal margins of the tooth. Results were analyzed using the two-way ANOVA and Tukey Post Hoc Test (p < 0.05). Results: A total of 900 SEM figures were obtained from all groups. Filtek Bulk Fill Posterior, SonicFill 2, and Filtek Ultimate Universal Restorative exhibited statistically similar gapped margins. However, the lowest scores of gapped margins were observed with SonicFill 2 (4.22%). Conclusions: Completely gap-free margins were not obtained with any of the tested materials. Bulk-fill composite materials showed similar marginal adapatation compared with standard composite. Marginal adaptation of Er:YAG laser prepared cavities was more irregular and had more gaps, but was statistically similar to diamond bur-prepared cavities.

Possibilities of using 3D printing for surface layers

This article describes how to improve the tribological properties of cast iron by local strengthening by titanium layer, directly in the casting process. The research comprised test molds with a titanium (composite) layer. The insert with titanium was made basing on proprietary development of geometric assumptions. The innovation relies on application the 3D printing insert obtaining in SLM (selective laser melting) method. The tests included measurement of resistance to abrasive wear and carried out metallographic, microhardness measurements as the presents detailed geometry of the insert as well. On the basis of obtaining results was stated that there is a possibility of reinforcing surface layer of the grey cast iron casting by using 3D printing scaffold insert in the method of mould cavity preparation. Moreover there was a local increase in hardness and abrasive wear resistance in spite of the precipitation of titanium carbides in surface layer of grey cast iron.

Clinical and Radiographic Comparison of Conventional and Minimal Invasive Method of Cavity Preparation in Mandibular Molars

Clinical and Radiographic Comparison of Conventional and Minimal Invasive Method of Cavity Preparation in Mandibular Molars

Comparison of marginal microleakage of flowable composite restorations in primary canine teeth prepared with high-speed diamond bur, Er:YAG laser and Er,Cr:YSGG laser.

Adhesive restorations have become highly popular in pediatric dentistry, and novel methods of cavity preparation with minimal patient discomfort including Er:YAG and Er,Cr:YSGG laser preparations have greatly advanced. This study aimed to compare the microleakage of composite restorations of class V cavities prepared in primary canine teeth with high-speed bur and Er:YAG and Er,Cr:YSGG lasers. This in vitro study was conducted on 30 class V cavities prepared on the buccal surfaces of primary canine teeth in three groups (n = 10) of bur preparation, Er:YAG laser and Er,Cr:YSGG laser. The cavities were etched, bonded and restored with Grandio flowable composite according to the manufacturer's instructions. After thermocycling, the teeth were immersed in 1% methylene blue dye for 24 hours to detect microleakage. The teeth were evaluated under a stereomicroscope at ×32 magnification to assess the depth of penetration of methylene blue. The data were analyzed using SPSS version 19 and non-parametric Kruskal-Wallis and Mann Whitney tests. Non-parametric Kruskal-Wallis test showed no significant difference in dye penetration among the three groups (P > 0.05). Pairwise comparisons of occlusal and gingival margins by nonparametric Mann Whitney test revealed no significant difference in microleakage either (P > 0.05). Use of Er:YAG and Er,Cr:YSGG lasers can decrease microleakage to the level of bur preparation. Bur and laser cavity preparations are not significantly different in terms of microleakage at the enamel or dentin margins. Thus, considering the advantages of laser, it may serve as a suitable alternative to bur preparation in pediatric dentistry.