Clinical performance and wear resistance of milled resin composite material versus direct nanohybrid bulk-fill resin composite in the restoration of endodontically treated posterior teeth over 1 year: Randomized clinical trial

Context

The restorative complexities associated with endodontically treated teeth surpass those encountered with vital ones. The field of adhesive dentistry experienced a significant advancement that led to a shift in treatment approach toward bonded restorations.

Aim

The aim of the study was to assess the clinical performance of using indirect Milled composite or direct bulk-fill resin composite restorations for endo-treated teeth, as well as to measure the amount of wear on the occlusal tables of both restorations using a digital scanner.

Subjects and Methods

Participants were divided into two groups, where R1 represents the endodontically treated teeth restored with Milled composite, R2 represents the endodontically treated teeth restored with direct bulk-fill composite where 13 patients in each group were treated with a total number of 26 restorations in all patients. Where each restoration was assessed immediately at baseline (T0), 6 months (T6), and 12 months (T12) using the modified United States Public Health Service criteria. Moreover, wear was measured immediately at (T0) and (T12) intraorally and extraorally using intraoral scanners and three-dimensional surface-based superimposition software.

Statistical Analysis Used

Chi-squared test, Mann-Whitney U-test, Friedman's test, Nemenyi post hoc test, Shapiro-Wilk test, paired t-tests, intraclass correlation coefficient.

Results

At all intervals, the majority of the cases in both groups had an alpha score. Some cases exhibited bravo scores in both groups at T6 and T12 regarding the color match, marginal adaptation, marginal discoloration, and marginal integrity without statistically significant difference (P > 0.05). Direct nanohybrid bulk-fill resin composite showed a greater amount of wear without a statistically significant difference (P > 0.05). Extraoral measurement was significantly higher than intraoral measurement (P < 0.001). There was no significant reliability/agreement between both methods.

Conclusions

Both milled composite and direct bulk-fill resin composite restorations in endodontically treated teeth demonstrated appropriate clinical performance and minimal wear over an 1-year follow-up period.

Effect of contamination and decontamination methods on the bond strength of adhesive systems to dentin: A systematic review

INTRODUCTION

In a suitable condition, it is important to perform any dental restorative procedure using an operatory field isolated. Then, the aim of this study was to compare the bond strength of composite restorations to dentin affected by any contamination agent through a systematic review.

METHODS

This systematic review was performed following the PRISMA 2020 guidelines. The literature search was conducted until September 2022 by scanning the following databases: Embase, PubMed, Scielo, Scopus, and Web of Science. Manuscripts evaluated the bond strength of resin-based materials to permanent human dentin contaminated with blood or saliva were selected for full-text review. The risk of bias was assessed by the RoBDEMAT tool.

RESULTS

A total of 3750 papers resulted from the search from all databases. After the full-text reading, a total of 62 articles remained for the qualitative analysis. The contamination agents used were blood, saliva, and hemostatic agents. A great variety of protocols were used to contaminate the dentin surface, and the contamination process occurred in several steps of the bonding process, including before and after the etching process, after the primer application and after the adhesive application. Also, several decontamination procedures were tested, including reapplication of the etching material, rinsing with water, chlorhexidine or sodium hypochlorite and reapplication of the adhesive system.

CONCLUSION

Any contamination with blood or saliva impaired the bond strength of resin-based materials to dentin. Decontamination procedures including water-spray and reapplication of the bonding system could revert the impairment produced by the saliva or blood contamination. The use of hemostatic agents as a method of blood decontamination is not recommended.

CLINICAL SIGNIFICANCE

Clinicians should avoid contamination during a bonding procedure, otherwise, a reduction in the bond quality is expected.

Bonding Protocols to Reverse the Bond Strength of a Universal Adhesive to Hemostatic Agent-contaminated Dentin

OBJECTIVE

To evaluate the effect of different bonding protocols on the microtensile bond strength (μTBS) of a universal adhesive to dentin contaminated with a hemostatic agent.

METHODS AND MATERIALS

Ninety-five extracted premolars were used in this study. For the μTBS test, 80 teeth were cut to expose mid-coronal dentin and randomly divided into two groups (uncontaminated dentin and hemostatic agent-contaminated dentin). Each group was further divided into five subgroups (n=8/group): 1) SE: no additional treatment, 2) ER: etching with 32% phosphoric acid, 3) CHX: rinsing with 0.2% chlorhexidine, 4) EDTA: rinsing with 17% EDTA, and 5) T40: application of universal adhesive for 40 seconds. A universal adhesive was applied followed by resin composite build-up. μTBS test was performed after 24 hours of water storage. Two-way analysis of variance (ANOVA) was calculated followed by the Duncan testing (α=0.05). The failure mode was analyzed using light microscopy. Additional teeth were prepared for energy-dispersive X-ray (EDX) analysis (n=1/group) and resin-dentin interface observation (n=2/group) using scanning electron microscopy.

RESULTS

Adverse effects of hemostatic agent contamination on the bonding performance of a universal adhesive was found in the SE, CHX, and T40 groups (p<0.05). Fewer and shorter resin tags were observed in the SE, CHX, and T40 groups. A higher percentage of adhesive failure and mixed failure was found in contaminated dentin. All bonding protocols revealed lower amounts of Al and Cl after dentin contamination, except for the SE group.

CONCLUSIONS

Hemostatic agent contamination adversely affected dentin bond strength. However, this bond strength could be reversed using the etch-and-rinse technique or rinsing with EDTA prior to adhesive application.

The effect of different tooth preparation finishing procedures and immediate dentin sealing on the scanning accuracy of different intraoral scanners

PURPOSE

To measure the effect of different tooth preparation finishing procedures (super-coarse grit, fine grit, and air-particle abrasion) and immediate dentin sealing (IDS) on the scanning accuracy of 4 intraoral scanners (IOSs).

MATERIAL AND METHODS

A tooth preparation for a full-coverage restoration was performed on an extracted mandibular molar using super-coarse diamond burs. Four groups were created depending on the tooth preparation finishing procedure: super-coarse grit (bur with a grit size of 150 µm) (SCG group), fine grit (bur with a grit size of 30 µm) (FG), air-particle abrasion with 27-µm aluminum oxide particles (APA group), and IDS (IDS group). Each group was divided into 5 subgroups according to the scanning system used to digitize the tooth preparation: laboratory scanner (control subgroup) (T710; Medit), Trios 4 (Trios subgroup), CS 3800 (CS subgroup), i700 wireless (i700 subgroup), and iTero Element 5D Plus (iTero subgroup) (n=20). For each subgroup, the control file was aligned with each experimental scan using the best-fit algorithm and an engineering program (Geomagic Control X). The discrepancy between the control and experimental files of each subgroup was computed by measuring the root mean square (RMS) error. Two-way ANOVA and Tukey tests were used to analyze the data (α=.05).

RESULTS

Tooth preparation finishing procedures (P<.001) and the IOS assessed (P<.001) were significant predictors of the trueness and precision values obtained. The highest trueness and precision values were measured in the APA group, while the IDS group had the lowest trueness and precision. Additionally, the i700 subgroup obtained the highest trueness and precision values, while the CS and Trios subgroups had the lowest trueness and precision values.

CONCLUSIONS

The different tooth preparations finishing procedures tested influenced on the scanning accuracy of the 4 IOSs considered. The air-particle abrasion procedure obtained the best accuracy values. The trueness discrepancies measured among all the subgroups was 19µm and the precision discrepancies measured among all the subgroups was 4.69 µm.

CLINICAL SIGNIFICANCE

The tooth preparation finishing procedure used can reduce the intraoral scanning accuracy of any of the intraoral scanners tested. The air-particle abrasion finishing procedure might be recommended for maximizing the scanning accuracy of the IOSs tested.

Noncarious cervical lesions: Morphology and progression, prevalence, etiology, pathophysiology, and clinical guidelines for restoration

PURPOSE

To synthesize the literature regarding noncarious cervical lesions (NCCLs) and propose clinical guidelines when lesion restoration is indicated.

MATERIAL AND METHODS

A PubMed search was performed related to NCCL morphology, progression, prevalence, etiology, pathophysiology, and restoration.

RESULTS

NCCLs form as either rounded (saucerlike) depressions with smooth, featureless surfaces that progress mainly in height or as V-shaped indentations that increase in both height and depth. Prevalence ranges from less than 10% to over 90% and increases with age. Common locations are the facial surfaces of maxillary premolars. They have a multifactorial etiology due to personal habits such as excessive horizontal toothbrushing and consumption of acidic foods and drinks. Occlusal factors have been identified as contributing to the prevalence of NCCLs in some studies, whereas other studies indicate there is no relationship. The concept of abfraction has been proposed whereby mechanical stress from occlusal loading plays a role in the development and progression of NCCLs with publications supporting the concept and others indicating it lacks the required clinical documentation. Regardless of the development mechanism, demineralization occurs and they are one of the most common demineralization diseases in the body. Treatment should be managed conservatively through preventive intervention with restorative treatment delayed until it becomes necessary due to factors such as lesion progression, impact on patient's quality of life, sensitivity, poor esthetics, and food collection may necessitate restoration. Composite resins are commonly used to restore NCCLs although other materials such as glass ionomer and resin-modified glass ionomer are also used. Sclerotic dentin does not etch like normal dentin and therefore it has been recommended to texture the dentin surface with a fine rotary diamond instrument to improve restoration retention. Some clinicians use mechanical retention to increase retention. Beveling of enamel is used to increase the bonding area and retention as well as enhance the esthetic result by gradually creating a color change between the restoration and tooth. Both multistep and single-step adhesives have been used. Dentin etching should be increased to 30 seconds due to the sclerotic dentin with the adhesive agent applied using a light scrubbing motion for 20 seconds but without excessive force that induces substantial bending of a disposable applicator. Both flowable and sculptable composite resins have been successfully used with some clinicians applying and polymerizing a layer of flowable composite resin and then adding an external layer of sculptable composite resin to provide enhanced resistance to wear. When caries is present, silver diamine fluoride has been used to arrest the caries rather than restore the lesion.

CONCLUSIONS

Noncarious cervical lesions (NCCLs) form as smooth saucerlike depressions or as V-shaped notches. Prevalence values as high as 90% and as low as 10% have been reported due to habits such as excessive toothbrushing and an acidic diet. Occlusal factors have been proposed as contributing to their presence but it remains controversial. Publications have both supported and challenged the concept of abfraction. They are one of the most common demineralization diseases in the body. Conservative treatment through prevention is recommended with restorative treatment delayed as long as possible. When treatment is needed, composite resins are commonly used with proposed restorative guidelines including texturing the sclerotic dentin, beveling the enamel, potential use of mechanical retention, 30 seconds of acid etching, and use of either multistep or single-step adhesives in conjunction with a light scrubbing motion for 20 seconds without excessive force placed on disposable applicators.

Status of decontamination methods after using dentin adhesion inhibitors on indirect restorations: An integrative review of 19 publications

The purpose of this review was to assess the literature regarding the decontamination of resin cement before the luting procedure in order to provide clinicians with a comparative overview of decontamination effects. A total of 19 articles were selected for inclusion in this review. The results indicated that bonding effectiveness is reduced due to residual adhesion inhibitors such as saliva, blood, hemostatic agents, and temporary/provisional cement. Self-etching and self-adhesive systems tend to be more negatively affected by adhesion inhibitors than do etch and rinse systems. Cleaning with an ultrasonic scaler or rotating brush have demonstrated conflicting effects in several studies. Some studies have reported that phosphoric acid has negative effects and recommend mild acid for decontamination. The application of phosphoric acid followed by sodium hypochlorite has been shown to help avoid negative effects. Alumina blasting has been investigated as a mechanical cleaning method in a relatively large number of experiments, most of which have confirmed its effectiveness. An intraoral cleaner containing functional monomers that has become commercially available in recent years is a promising method in clinical practice because it can easily and effectively remove temporary adhesive material. In addition, adhesion inhibitors can be easily removed from resin-coated dentin surfaces.

The Influence of Hemostatic Agents and Cordless Gingival Retraction Materials on Smear Layer: An Ex vivo Scanning Electron Microscope Analysis

Context:

Cordless gingival retraction materials are now routinely used method for gingival retraction. Although evidence-based information is available on the effect of gingival displacement cord and cordless system on the effectiveness of displacement and the periodontal health, there is a lack of literature regarding the effect of cordless retraction agents on enamel and dentin substrates.

Aim:

The purpose of this investigation was to analyze the changes on the smear layer induced by the hemostatic agent and cordless retraction material at scanning electron microscopic level.

Materials and Methods:

Ferric sulfate (15.5% m/v), expasyl, and magic foam cord were evaluated. Buccal surfaces of 16 recently extracted mandibular premolars were prepared for metal-ceramic crowns, and four teeth each were exposed to ferric sulfate solution, expasyl, and magic foam cord, respectively, for 5 min. Teeth in the control group were exposed to distilled water. The assessment of changes was performed using a scanning electron microscope (SEM).

Results:

SEM exhibited smear layer covering the dentin and occluding the dentinal tubules in the control group. Exposure to ferric sulfate caused the opening of few of the dentinal tubules whereas expasyl caused the partial removal of smear layer with dentinal plugs partially occluding the openings of most of the dentinal tubules. The specimens treated with magic foam exhibited a smear layer similar to the control group.

Conclusions:

The smear layer was affected most with ferric sulfate solution, followed by expasyl and magic foam cord. Magic foam cord did not affect the smear layer.

The Effects of Various Hemostatic Agents on Shear-bond Strength in Primary Teeth: An In Vitro Study

Aims and objectives:

The aim of this study was to determine the effects of chitosan, Ankaferd Blood Stopper® (ABS, Ankaferd Health Products Ltd, Turkey), and ferric sulfate (FS) on the shear-bond strength of the self-etch adhesive to primary tooth dentin.

Materials and methods:

The occlusal surfaces of 80 extracted human primary teeth (stored in a 0.5% chloramine-T solution at 4oC) were ground flat, exposing the dentin. The teeth were divided into 4 groups: chitosan, ABS, FS, and control. Hemostatic agents were applied to the teeth, and then they were rinsed with distilled water and air dried. In the control group, the teeth were only rinsed with distilled water and slightly air dried. A self-etch adhesive was applied, and the composite cylinder was created on all the samples. Shear-bond strength was tested with a universal testing machine. Failure mode analysis was performed using scanning electron microscopy.

Results:

The study revealed no statistically significant difference between the hemostatic agent and control groups in terms of bond strength ( P >.05). The highest bond strength was observed in the chitosan group. In this group, a statistically significant difference between chitosan and ABS was observed ( P <.05). The adhesive failure was the predominant failure mode in all the groups.

Conclusions:

These findings suggest that chitosan, ABS, and FS have no adverse effects on the bonding of the self-etch adhesive to primary teeth dentin.

Effect of dentin contamination with two hemostatic agents on bond strength of resin-modified glass ionomer cement with different conditioning

This study evaluated the effect of two hemostatic agents on bond strength of resin-modified glass ionomer cement (RMGIC) to root dentin after using different pretreatment solutions compared to resin composite with a 2-step self-etch adhesive. Dentin specimens were either uncontaminated or contaminated with a ferric sulphate or aluminum chloride astringent, RMGIC was applied after conditioning with; Cavity Conditioner, Self Conditioner or Clearfil SE Primer, while a resin composite was bonded using Clearfil SE Bond. Microtensile bond strength (μTBS) values and failure modes were determined. Two-way ANOVA revealed that hemostatic agents did not significantly affect the RMGIC bond strength with any conditioning material (p>0.05). SE Primer pretreatment provided the highest μTBS values among RMGIC groups. For the resin composite, ferric sulphate astringent significantly reduced μTBS value (p≤0.001). Scanning electron micrographs of representative dentin surfaces contaminated with the hemostatic agents showed effects on smear layer removal and dentinal tubule occlusion.

The Effect of Hemostatic Agents on the Retention Strength of Zirconia Crowns Luted to Dentin Abutments

The purpose of this study was to investigate whether hemostatic agents (HA) show an effect on the retention strength (RS) of zirconia crowns luted to dentin abutments after cleaning with an air/water spray. Human molars (N = 60/n = 12) were prepared and zirconia crowns were milled. Prior to luting (Scotchbond Universal/RelyX Ultimate), molars were pretreated using HA: i. 25% AlCl₃ (VSC), ii. 20% Fe₂(SO₄)₃ (VS), iii. 15.5% Fe₂(SO₄)₃ (AS), iv. 12.7% iron ion solution (ASX) and v. no pretreatment (control). Mastication simulation and pull-out tests were performed. Failure types were defined: cohesive 1-tooth root; cohesive 2-tooth crown; adhesive 1-cement on tooth; adhesive 2-cement on tooth and crown; mixed-adhesive/cohesive. Data were analyzed using 1-way ANOVA, post-hoc Scheffé, Pearson's chi-square-test and Ciba⁻Geigy table (p = 0.05). No RS differences between the tested groups were observed (p = 0.200). ASX fractured more cohesive 2 than the control group. VSC showed more cohesive 2 than adhesive 1 fractures. VS showed more adhesive 2 than mixed fractures. AS showed more cohesive 2 than adhesive 1 and more adhesive 2 than mixed fractures. ASX showed predominantly cohesive 2 fractures. RS was not affected when HA were cleaned off by 30 s of air/water spray prior to luting. HA still seem to weaken the dentin abutment, making it prone to cohesive fractures.

Hydro air abrasion on dental glass-ceramics: A direct 3D analysis by stylus profilometry

Air abrasion is used in dentistry for cavity opening, post-endodontic cavity cleaning, and removal of hard deposits or stains. Different applications may require different settings. We aimed to gain better understanding of the effect of some operating parameters on the efficiency of air abrasion on a model dental material. We abraded lithium disilicate glass-ceramic blocks (IPS e.max CAD, Ivoclar Vivadent) with Prepstart H2O device (Danville) and 27-µm-size aluminium oxide abrasive (Danville). At 5 bar constant pressure, we varied incidence direction, treatment time, distance, powder consumption, and supporting medium, in separate experiments addressing individual aspects. The abraded surfaces were characterized by stylus profilometer XP-2 (Ambios). Laboratory condition of normal incidence at fixed direction showed threefold increased volume abrasion vs 45° incidence and oscillating direction. Working in air, 2 mm distance was more efficient than 1 and 5 mm, likely due to its influence on the abrading particles speed. Maximum vs medium powder consumption decreased the abraded volume, while increasing the treated area. Using water restricted the treated surface. To minimize the risk of dental material damage, the best conditions should be 45° direction and 5 mm distance, which both increase the treated area. To counteract this, water may be used. The most abrasive condition is instead 90°, at intermediate 2 mm distance. In most cases, abraded volume scales linearly with time. The present combination of device and abrasive can be effective even on enamel-like ceramic material. Tuning air abrasion settings to the specific dental application appears to be necessary.

Effect of the time-point of acid etching on the persistence of sealer residues after using different dental cleaning protocols

Endodontic sealer residues remaining within the pulp chamber dentin after root canal obturation and cleaning with various solvents may compromise the appearance and the durability of dental restorations. Acid etching is routinely performed prior to application of dentine adhesive systems, but is effect on residual sealer material and the optimal time-point for performing etching, are unknown. Here, we evaluated the effect of acid etching on the dentin surface when performed either immediately or 7 days after removal of the endodontic sealer with two solvents, i.e., 95% ethanol or xylol. Forty crowns fragments from bovine incisors were impregnated with sealer and divided into 4 groups (n = 10 each), according to the dentin cleaning protocol and to the acid etching time-point: G1, 95.0% ethanol and immediate acid etching; G2, xylol and immediate acid etching; G3, 95.0% ethanol and acid etching after 7 days; and G4, xylol and acid etching after 7 days. Scanning electron microscopy (SEM) images (2000 ×) were obtained from each specimen and the number of open dentinal tubules counted and compared. Another 40 fragments were similarly prepared, and SEM images were obtained (500 ×) to score and compare the persistence of sealer residues on the dentin. G4 showed the most open dentinal tubules and the least epoxy resin-based sealer residues on the dentin surface (p < 0.05). The least epoxy resin-based sealer residues was obtained when acid etching, using 37% phosphoric acid, was performed after 7 days after cleaning the dentin with xylol.

Effects of Contamination by Hemostatic Agents and Use of Cleaning Agent on Etch-and-Rinse Dentin Bond Strength

Abstract The aim of this study was to evaluate the influence of contamination by hemostatic agents and rinsing with chlorhexidine on bond strength between dentin and resin composite. Ninety-six bovine teeth were sectioned to expose a flat dentin surface area. A standardized cavity with 2.0 mm in thickness, superficial diameter of 4.0 mm and bottom diameter of 3.0 mm was prepared with a diamond bur in each dentin specimen. The teeth were divided into four groups according to the hemostatic employed: G1: control; G2: use of ViscoStat, Ultradent; G3: Hemosthasegel, FGM; and G4: Hemostop, Dentsply. The groups were divided into two subgroups according to the cleaning protocol method (n=12): A: without any further cleaning; and B: cleaning with chlorhexidine at 0.2%. All cavities were filled using a dentin adhesive and a resin composite, following the manufacturer's instructions. After 24 h, the specimens were aged by thermal and mechanical cycling. The bond strength was determined by the push out bond test (MPa), Statistical analysis was performed using two-way ANOVA and Tukey test (p<0.05). Statistically significant differences were detected among all groups treated with hemostatic agents and the control group. The post-hoc test showed that cleaning the cavity with chlorhexidine significantly improves the bond strength between dentin and resin composite. Our results suggested that the use of chlorhexidine can reestablish the bond strength between dentin and resin composite when a hemostatic agent was applied.

Marginal integrity of low-shrinkage and methacrylate-based composite resins: Effect of three different hemostatic agents

Background

Moisture control is very important in restorative procedures in dentistry. Use of hemostatic agents helps control moisture; however, they might result in changes on enamel and dentin surfaces, affecting composite resin bond quality. The aim of this in vitro study was to evaluate the marginal microleakage of two different composite resins with the use of three different hemostatic agents.

Material and Methods

Standardized Class V cavities were prepared on the buccal and lingual surfaces of 48 premolars with cervical margins 1 mm apical to the cementoenamel junction (CEJ). The samples were randomly divided into 8 groups. In groups 1 to 4, an etch-and-rinse adhesive (Adper Single Bond) was applied as the bonding system, followed by exposure to different hemostatic agent: group 1: no hemostatic agent (control); group 2: ViscoStat; group 3: ViscoStat Clear; and group 4: trichloracetic acid, as hemostatic agents. The cavities were restored with Z-250 composite resin. In group 5 to 8 Silorane System Adhesive (Filtek P90 Adhesive) was applied as a bonding agent, followed by exposure to different hemostatic agents in a manner similar to that in groups 1to 4. The cavities were restored with Filtek P90, a low-shrinkage composite resin. The samples in each group were evaluated for dye penetration under a stereomicroscope at ×36 after 24 hours and a 500-round thermocycling procedure at enamel and dentin margins. Statistical analysis was carried out using Kruskal-Wallis and Mann-Whitney tests (α=0.05).

Results

Z-250 composite resin exhibited significantly higher dentin microleakage scores compared to Filtek P90 (P = 0.004). Trichloracetic acid increased dentin microleakage with Filtek P90 (P=0.033).

Conclusions

Under the limitations of this in vitro study, application of hemostatic agents did not affect microleakage of the two tested composite resins except for trichloracetic acid that increased marginal microleakage when used with Filtek P90.

Key words:Composite resin, dental leakage, hemostatics, silorane system adhesive.

Haemostatic agents on the shear bond strength of self-adhesive resin

Background

Dentin surface contaminated with haemostatic agents can interfere with the bonding of self-adhesive resin cement. Therefore the purpose of this study was to evaluate the effect of various haemostatic agents such as Aluminium chloride, Ferric sulphate and Tannic acid on the shear bond strength of self-adhesive resin luting agent.

Material and Methods

The buccal surfaces of extracted premolars were flattened to expose the dentine. The teeth were then randomly divided into four groups. In Group I Aluminium Chloride was applied on the flattened dentinal surface, in Group II Ferric Sulphate was applied to exposed dentin surface, in Group III tannic acid was applied on to the dentinal surface, and the control group, i.e. Group IV was rinsed with saline. After the surface treatment, all the teeth were air dried. Then a predetermined dimension of RelyX™ U200 self-adhesive resin cement was bonded to the pretreated dentin surfaces. The samples were then stored under 370C in distilled water for 24 hours under 100 % humidity. Following this each sample was tested for shear bond strength with an Instron testing machine at a crosshead speed of 1mm/min.

Results

There was significant difference in the shear bond strength of control and tannic acid contaminated group (p<0.05), whereas there was no significant differences between the shear bond strength between control and aluminium chloride and ferric sulphate groups (p>0.05).

Conclusions

The usage of haemostatic agent can negatively affect the bond strength of self-adhesive resin cement (Rely X) on to the dentin surface. As per the study Tannic acid significantly weakened the bond between the self-adhesive resin and dentin.

Key words:Aluminium chloride, Ferric sulphate, haemostatic agent, self-adhesive resin cement, shear bond strength, Tannic acid.

Comprehensive Risk-Based Diagnostically Driven Treatment Planning: Developing Sequentially Generated Treatment

The clinical example presented in this article demonstrates a risk-based, diagnostically driven treatment planning approach by focusing on 4 key categories: periodontal, biomechanical, functional, dentofacial. In addition, our unique approach allowed the comprehensive clinical management of a patient with complex restorative needs. A full-mouth rehabilitation was completed sequentially without sacrificing the amount of dentistry necessary to restore health, comfort, function, and esthetics. The result exceeded the patient's expectation and was made financially possible by extending treatment over numerous years.

Effect of different surface-cleaning techniques on the bond strength of composite resin restorations

STATEMENT OF PROBLEM

Different techniques have been suggested for cleaning dentin surfaces after the removal of an interim prosthesis and before the application of a bonding agent. How different surface-cleaning techniques affect the bond strength of the composite resin restorations is not clear.

PURPOSE

The purpose of this study was to investigate the effects of different surface-cleaning techniques on the bond strength of composite resin restorations and the surface topography of the prepared tooth surfaces.

MATERIAL AND METHODS

The occlusal surfaces of 25 molars were ground until the dentin was exposed. A bonding agent and interim cement were applied on the teeth. The teeth were divided into 5 groups (n=5) according to the method used for surface-cleaning (microairborne-particle abrasion, alcohol, rubber-rotary instrument, desiccating agent, and control). Once the surfaces of the teeth had been cleaned, the same bonding material was applied to the teeth. A 5-mm-thick composite resin layer was built up. Each specimen was sectioned to microbars, and 6 centrally located beams were selected for microtensile testing (n=30) (1.10 ±0.10 mm). The data were statistically analyzed with 1-way ANOVA (1-sample Kolmogorov-Smirnov test). The Bonferroni test was used for significantly different groups (α=.05). One specimen from each group was observed under a scanning electron microscope and an atomic force microscope. Energy dispersive x-ray analysis also was performed.

RESULTS

Bond strength values were in the following descending order: microairborne-particle abrasion, desiccating agent, alcohol, rubber-rotary instrument, control. Differences between the microairborne-particle abrasion group and the remainder of the groups, desiccating agent--rubber-rotary instrument, desiccating agent-control, alcohol--rubber-rotary instrument, and alcohol-control groups, were statistically significant (P<.05). The microairborne-particle abrasion group displayed the roughest surface and a different surface topography from the remainder of the groups. Increased aluminum was observed in the microairborne-particle abrasion group.

CONCLUSIONS

Surface-cleaning techniques, except for the rubber-rotary instrument, increased the bond strength of composite resin. The roughest dentin surfaces and highest bond strength were achieved with the microairborne-particle abrasion technique.

Influence of different conditioning methods on immediate and delayed dentin sealing

STATEMENT OF PROBLEM

Data are needed to evaluate the effect of various conditioning methods on immediate and delayed dentin sealing.

PURPOSE

The purpose of this study was to test bond strength and surface configuration of immediate and delayed dentin sealing surfaces after applying different surface conditioning methods.

MATERIAL AND METHODS

A total of 96 premolars were allocated to the immediate and delayed groups. The groups differed in the timing of dentin sealing. The immediate-group specimens were sealed with a self-etching adhesive immediately after preparation. The delayed-group specimens were sealed before the final ceramic restoration bonding. Provisional restorations were cemented on immediate-group and delayed-group specimens for 1 week. Four conditioning methods were used: polishing with fluoride-free pumice paste, airborne-particle abrasion with silicoated aluminum oxide, glycin, or calcium carbonate. After 24-hour storage, the shear bond strength was tested. The fractured specimens were optically inspected with a stereomicroscope. An optical 3-dimensional surface analysis was performed for quantitative and qualitative evaluation. A 2-way ANOVA with post hoc Tukey honestly significant difference tests for significant effects was performed to investigate effects of the 2 factors, sealing and conditioning, and their interaction (α=.05).

RESULTS

Two-way ANOVA found significant differences between the sealing and conditioning groups. The immediate group had significantly lower bond strengths than the delayed group. In all groups, surface polishing produced the highest bond strengths, and airborne-particle abrasion with calcium carbonate produced the lowest. Fracture analysis found more failures in the adhesive layers in the immediate groups and a prevalence of mixed failures in the delayed groups. The surface analysis found significant abrasion and roughness when airborne-particle abrasion with silicoated aluminum oxide was used for immediate and delayed dentin sealing surfaces.

CONCLUSIONS

Polishing and airborne-particle abrasion with silicoated aluminum oxide or glycin are efficient methods in conditioning immediate and delayed dentin sealing surfaces. Airborne-particle abrasion with silicoated aluminum oxide leaves significant surface alterations on both types of surfaces.

Persistence of epoxy-based sealer residues in dentin treated with different chemical removal protocols

The presence of residual endodontic sealer in the pulp chamber may cause discoloration of the dental crown and interfere with the adhesion of restorative materials. The aim of this study was to compare the efficacy of different solvents in removing residues of an epoxy resin-based sealer (AH Plus) from the dentin walls of the pulp chamber, by scanning electron microscopy (SEM). Forty-four bovine incisor dental crown fragments were treated with 17% EDTA and 2.5% NaOCl. Specimens received a coating of AH Plus and were left undisturbed for 5 min. Then, specimens were divided in four groups (n = 10) and cleaned with one of the following solutions: isopropyl alcohol, 95% ethanol, acetone solution, or amyl acetate solution. Negative controls (n = 2) did not receive AH Plus, while in positive controls (n = 2) the sealer was not removed. AH Plus removal was evaluated by SEM, and a score system was applied. Data were analyzed by Kruskal-Wallis and Dunn tests. None of the solutions tested was able to completely remove AH Plus from the dentin of the pulp chamber. Amyl acetate performed better than 95% ethanol and isopropyl alcohol (p < 0.05), but not better than acetone (p > 0.05) in removing the sealer from dentin. No significant differences were observed between acetone, 95% ethanol, and isopropyl alcohol (p > 0.05). It was concluded that amyl acetate and acetone may be good options for cleaning the pulp chamber after obturation with AH Plus.

The effect of various surface contaminants on the microleakage of two different generation bonding agents: A stereomicroscopic study

Aim:

The aim of this in vitro study was to evaluate the microleakage of two different generation bonding agents in the presence of various surface contaminants.

Materials and Methods:

Class V cavities were prepared on 150 extracted human permanent molars. The samples were randomly divided into two main groups of 75 teeth each. Group I: Fifth generation bonding system (Single Bond, 3M). Group II: Seventh generation bonding system (iBond, Kulzer). Subgroups were formed according to exposure to different surface contaminants (saliva, blood, caries disclosing agent and haemostatic agent). Cavities were restored with hybrid composite (Z-100, 3M) and evaluated for microleakage. The scores were subjected to ‘t’ test and analysis of variance (ANOVA) test.

Results:

Single Bond and iBond did not provide complete resistance to microleakage when there was no contamination. Microleakage was minimum in the no contamination subgroup and maximum with the haemostatic agent subgroup for both the groups.

Conclusion:

Single bond showed lesser micro leakage in contaminated conditions.