Comparative Assessment of pH and Degree of Surface Roughness of Enamel When Etched with Five Commercially Available Etchants: An In Vitro Study.

AIM: To evaluate the pH and degree of surface roughness caused by five commercially and readily available etchants on tooth enamel. MATERIALS AND METHODS: Five different etchants were chosen. An electric pH meter was utilized to test the pH of the etchants employed. Fifteen maxillary bicuspids that had been extracted were cleansed and stored in thymol solution. The samples were sorted into five groups of three each. A noncontact profilometer was employed to assess the microsurface changes of the pre-etched enamel. The teeth were then etched for 30 seconds with respect to the group to which they belonged before being cleaned and dried. The surface roughness after etching was analyzed, measured and values were tabulated. Descriptive statistics and paired t-test were done. RESULTS: The pH of the etchants and surface roughness of the enamel are varied across the five groups, though they have the same composition of 37% orthophosphoric acid. Etchant from Group C was found to be most acidic while the one manufactured by Group E was least acidic. Ivoclar, DPI, and DTECH showed a statistically significant value in surface roughness parameter post-etching (p <0.05). A statistical difference that was significant was observed with the Kruskal-Wallis test for surface roughness parameter (p <0.05). CONCLUSION: All five etchants had varied pH and the amount of surface roughness was also varied though the composition was the same. Further elemental analysis of these etchants has to be done to validate the results obtained. CLINICAL SIGNIFICANCE: Etchants of the same composition should ideally produce the same effect on the tooth enamel surface, but etchants from different manufacturers produce different levels of surface roughness which could be due to differences in the composition of the prepared etchant. The study was conducted to assist in making an educated selection about the most cost-effective but efficient etchant for clinical application.

An experimental in vivo procedure for the standardised assessment of sealants retention over time.

AIM: The elaboration of an experimental system to obtain reproducible and comparable photographs of the occlusal surface to monitor sealants retention. MATERIALS AND METHODS: An intraoral camera connected to a computer was used to obtain photos of the occlusal surfaces. A specific software was utilized to perform measurements on archived pictures. An experimental two-part system, consisting of a dental arch support and a camera support, connected to each other through holes and pins, was made to obtain a standardised and reproducible placement of the camera in the mouth. In the first part, to test the degree of reliability of the procedure and the percentage of image distortion, 120 first molars were sealed and for each molar ten photographs were taken, using the intraoral camera connected with the dental arch support, the camera support and the dedicated software. In the second part, 165 first molars were sealed and photographed, as above described, immediately after sealing (T0), 6 months (T1) and 1 year later (T2). With the software, the sealed areas were measured. The comparison of the selected sealed areas between T0 and T1, T0 and T2, T1 and T2 determined the percentage of sealant loss. RESULTS: In the first part, the experimental procedure showed a reliability of 96.85%. In the second part, the difference in the rate of lost sealant between T0-T1 and T1-T2 was statistically significant (p <0.001). STATISTICS: ANOVA analysis was made. CONCLUSIONS: Photographs, obtained through the experimental two-part system, allowing a reproducible positioning of the intraoral camera in oral cavity, could represent a standardised and useful method to monitor sealants retention over time.

Fibre-reinforced composite (FRC) bridge--a minimally destructive approach.

Replacing missing teeth is an integral part of the clinical services of the dental practitioner. The fibre-reinforced composite (FRC) bridge is a relatively new method for replacing missing teeth. This article will explain and discuss this alternative treatment option. Practical instructions on how to construct a FRC bridge will be given, by means of a clinical case. Different technique options will be illustrated to provide the reader with a good understanding of the most practical way to use the FRC strips. The fibre-reinforced composite provides a non-destructive, aesthetically pleasing and cost-effective way to restore missing teeth. Clinical Relevance: Minimally invasive options should always be considered and destruction of healthy enamel and dentine during the preparation phase of a replacement treatment should be avoided as much as possible.

Effects of sandblasting before orthophosphoric acid etching on lingual enamel: in-vitro roughness assessment.

INTRODUCTION: In this study, we evaluated changes in lingual enamel roughness due to sandblasting with 27-, 50-, and 90-µm aluminum oxide particles followed by 37% orthophosphoric acid etching. METHODS: Twenty-four maxillary premolars were included in the study. The lingual enamel roughness of 20 teeth was evaluated using a laser confocal microscope before and after enamel conditioning. Group 1 (control) was etched with 37% orthophosphoric acid; groups 2, 3, and 4 were sandblasted with 27-, 50-, and 90-µm aluminum oxide particles, respectively, before acid etching. The lingual surfaces of the other 4 teeth were evaluated using scanning electron microscopy after they had received one of the conditioning methods under study. Paired t tests were used to compare the roughness parameters obtained before and after conditioning in each group, and 1-way analysis of variance was used to compare the surface roughness between groups. The significance level was set at 5% for all statistical analyses. RESULTS: The 4 conditioning methods significantly increased the roughness of the lingual enamel. However, the roughness increases in the groups that were sandblasted with 27-, 50-, and 90-µm aluminum oxide particles before orthophosphoric acid etching were statistically greater than was the increase in the group conditioned only with orthophosphoric acid. Scanning electron microscopy showed different conditioning patterns among specimens that were conditioned only with orthophosphoric acid and those sandblasted with aluminum oxide before acid etching. CONCLUSIONS: Lingual enamel conditioning with aluminum oxide sandblasting before acid etching results in greater roughness and produces a conditioning pattern different from that of acid etching alone.

Efficiency and effectiveness evaluation of three glass fiber post removal techniques using dental structure wear assessment method.

AIM: This study evaluated the efficiency and effectiveness of three glass fiber post removal techniques. MATERIALS AND METHODS: Forty-five extracted maxillary teeth were endodontically treated and cross-sectioned in thirds. Presence of cementing agent and dental structure wear were assessed by analyzing images taken before luting of glass fiber post and after removal procedure. Teeth were divided into 3 groups: Group 1 - diamond bur + Largo reamer; Group 2 - ultrasonic insert; Group 3 - carbide bur + ultrasonic insert. Time spent on removal procedures, dental structure wear and amount of remaining cement agent were recorded and results submitted to ANOVA, Kruskal Wallis and Tukey-Kramer tests. RESULTS: Group 1 - 16'46", 33.33% and 6.99%; Group 2 - 12'31", 40% and 7.86%; and Group 3 - 10'24", 80% and 8.14%. Group 3 presented the most effective removal of glass fiber posts. CONCLUSION: There was no significant difference in efficiency among the evaluated techniques.

Survival analysis of brackets and tubes: A twelve-month assessment.

OBJECTIVE: To compare the clinical performance of brackets bonded to anterior and posterior teeth, including second molars. MATERIALS AND METHODS: One operator, using the straight-wire technique, bonded metallic brackets to the teeth of 127 consecutive patients. All patients were observed for 12 months during their regular orthodontic appointments. Bracket failures were recorded and summarized for statistical analysis. The Cox proportional hazards regression analysis was performed to evaluate bracket failure rates. RESULTS: Statistically significant differences in survival rates were observed between molar tubes and anterior brackets (P < .05). Twelve-month failure rates of incisor, canine, premolar, and molar brackets were 3.6, 1.6, 4.8, and 11.6%, respectively. The first and second molar did not show significant difference in bond failure. Young patients (age <18 years) showed a higher failure rate than old patients (≥18 years). CONCLUSIONS: Brackets directly bonded to the buccal surfaces of molars failed significantly more often than those directly bonded to anterior teeth or premolars, but showed acceptable failure rate especially in adult patients. Bonding on second molars seems to be as reliable as bonding on the first molars.

Impact of intracoronal dentin treatment prior to bleaching on bond strength of restorative materials.

Surface treatment of dentin before the bleaching procedure may affect its permeability and influence the bond strength of restorative materials. This study evaluated the influence of surface treatment before the bleaching on shear bond strength (SBT) of restorative materials to intracoronal dentin. Dentin slabs were subjected to surface treatment: no bleaching (control - CON), no surface treatment + bleaching (HP), 37% phosphoric acid + bleaching (PA) and Er:YAG laser + bleaching (L). After the bleaching procedure, specimens (n=10) were restored with: microhybrid composite resin (MH), flowable composite resin (F), and resin-modified glass-ionomer cement (RMGIC). The shear test was carried out. ANOVA and Tukey's test (α=0.05) showed significant difference for surface treatment and restorative materials (p<0.05). CON presented higher STB and was statistically different from HP (p<0.05). PA and L showed intermediate values and were statistically similar to CON and HP (p>0.05). STB for MH and F were higher than RMGIC (p<0.05), and did not differ from each other (p>0.05). The surface treatments with phosphoric acid and Er:YAG laser before the bleaching procedure provided shear bond strength at the same level of unbleached dentin and the composite resins presented superior bond strength to the intracoronal dentin.

Microbial microleakage assessment of a new hydrophilic fissure sealant: a laboratory study.

PURPOSE: The purpose of this study was to compare microbial leakage of a new hydrophilic sealant with that of a conventional hydrophobic resin-based sealant. METHODS: One hundred extracted, caries-free, human maxillary premolars were randomly divided into five groups. Those in Groups 1, 2, and 3 had dry, wet, and artificial saliva-contaminated occlusal surfaces, respectively, and were sealed with a hydrophilic sealant, while those in Groups 4 and 5 had dry and wet occlusal surfaces, respectively, and were sealed with a hydrophobic sealant. A newly designed microbial penetration method utilizing Streptococcus mutans as an indicator was tested for leakage assessment. Data were analyzed using SPSS 15.0 software, and the significance level was set at α=0.05. RESULTS: The log rank test indicated a statistically significant difference in leakage rates among the five groups. Mantel-Cox log-rank test findings showed that Group 3 had the highest leakage rate, with Groups 2 and 4 having the lowest. There was no statistically significant difference in leakage rate between Groups 2 and 4. CONCLUSIONS: With respect to the limitations of an in vitro study, our findings suggest that hydrophilic sealants are an acceptable alternative to hydrophobic sealants.

Bonded functional esthetic prototype: an alternative pre-treatment mock-up technique and cost-effective medium-term esthetic solution.

As the economy has receded in recent years, many patients have been inclined to reject dental treatment beyond what they feel is the minimal amount necessary. Increasingly, there has been reluctance to take on the expense of full-mouth restorations and time-consuming procedures. Consequently, clinicians can benefit from innovative, conservative, interim solutions that enable them to provide segment treatment with long-term stability and esthetics, with lower initial cost. The bonded functional esthetic prototype (BFEP) allows fabrication of up to 14 teeth from composite in 1 hour, providing either a pre-treatment restoration or a long-term provisional solution until further treatment can be completed. As demonstrated herein, the BFEP enables superb function, stability, and esthetics in the interim while dispersing the cost of definitive treatment over time.

Bonded molar tubes: a survey of their use by specialist orthodontists.

OBJECTIVE: To investigate the use of bonded molar tubes (BMTs) by specialist orthodontists. DESIGN: Prospective postal questionnaire. SETTING: Ireland. PARTICIPANTS: Registered members of the Orthodontic Society of Ireland. METHODS: A questionnaire was posted to registered members of the Orthodontic Society of Ireland. It investigated demographics, pattern of use, reasons for use and techniques for placement of BMTs. RESULTS: A 74% response rate was obtained. In more than 80% of cases, BMTs were used on first and second permanent molars by 52% and 33% of orthodontists respectively. BMT usage was adopted by 97% of respondents in the previous decade. Direct bonding was used by all for BMT placement. Etch times for molars, compared to other teeth, increased from 15 to 30 seconds by 51% of orthodontists. Of the respondents, 97% used light-cured adhesives and 17% used self-etching primers. Molar tube holders were preferred by 54% for placement. Only with a history of epilepsy, were bands preferred to BMTs. BMTs were regarded as more cost-effective than molar bands by 66% of responding clinicians. CONCLUSIONS: Specialist orthodontists preferred BMTs to bands on first permenent molars. Direct bonding was favoured using a 30-second etch, a light-cured primer and adhesive with specialized molar tube holders. BMTs were perceived to be more cost-effective than molar bands.

Assessment of laminate technique using glass ionomer and resin composite for restoration of root filled teeth.

OBJECTIVE: To evaluate the open laminate technique using glass ionomer cements (GIC) in association with a low shrink composite for restoring root filled premolars. METHODS: Extensive MOD cavities plus endodontic access and root filling were performed in intact extracted maxillary premolars. Three restoration types were evaluated: (1) resin composite alone; (2) resin-modified GIC (RM-GIC) open laminate plus resin composite; (3) conventional GIC open laminate plus resin composite (n=8 for all groups and tests). Three tests were conducted to assess restorations: (A) inward cusp deflection during light curing, using DCDTs; (B) fracture strength using a ramped oblique load at 45° to the long axis in a servohydraulic testing machine in comparison with intact and unrestored teeth; (C) proximal marginal leakage using methylene blue dye and the effect of thermocycling. Data were analysed using 1-way ANOVA for cuspal deflection and fracture strength and Fisher's exact test for leakage. RESULTS: Laminate restorations resulted in significantly less cuspal deflection compared with resin composite (4.2±1.2 µm for RM-GIC and 5.1±2.3 µm for conventional GIC vs. 12.2±2.6 µm for composite, P<0.001). Fracture strength was not significantly different among all groups. Failure with all restorations was predominantly adhesive at the tooth-restoration interface. The two laminate groups showed significantly better marginal seal than composite alone, but sealing ability of conventional GIC deteriorated after thermocycling. CONCLUSIONS: Laminate restoration of root filled teeth had beneficial effects in terms of reducing cuspal deflection and marginal seal, with acceptable fracture strength.

Assessment of the quality of resin-dentin bonded interfaces: an AFM nano-indentation, µTBS and confocal ultramorphology study.

OBJECTIVE: The aim of this study was to assess by using confocal microscopy (CLSM), AFM nano-indentation and microtensile bond strength test (µTBS) the quality of the resin-dentin interfaces created with selected bonding parameters. METHODS: Dentin conditioned with H(3)PO(4) or EDTA was bonded in ethanol- or water-wet condition using a HEMA-free or HEMA-containing adhesive. The resin-bonded teeth were stored in distilled water (24h) and sectioned as match-sticks (0.9 mm(2)) for µTBS. Further resin-bonded teeth were sectioned and analyzed using CLSM, and AFM nano-indentation. The AFM imaging and nano-indentation processes were undertaken using a Berkovich diamond indenter. The modulus of elasticity (Ei) and hardness (Hi) across the interface were evaluated with the specimens in a fully hydrated status. The AFM imaging was performed both in dry and wet conditions for evaluating the shrinkage of the hybrid layer on dehydration. RESULTS: The HEMA-containing adhesive applied onto H(3)PO(4)-etched ethanol or water-wet dentin created hybrid layers with the lowest biomechanical nano-properties (p<0.05); no significant differences in µTBS were found between the two wet-bonding techniques (p>0.05). However, the ethanol-wet bonding reduced the dye penetration into the adhesive layer created with the HEMA-containing adhesive. Hybrid layers with high biomechanical properties, low micropermeability and no shrinkage were only possible when using HEMA-free adhesive applied in ethanol wet-dentin. In particular, a significant increase in Ei and Hi was achieved at the hybrid layer and underneath the resin-dentin interface of ethanol-wet EDTA-treated dentin. SIGNIFICANCE: The use of HEMA-free adhesives applied onto ethanol-wet dentin may be considered as an alternative and suitable bonding strategy to achieve high quality resin-dentin interfaces.

Micro-raman assessment of the ratio of carbon-carbon double bonds of two adhesive systems cured with LED or halogen light-curing units.

PURPOSE: the purpose of the study was to compare the ratio of carbon-carbon double bonds (RDB) of two adhesive systems cured by five different light-curing units (LCUs) using micro-Raman spectroscopy. materials and methods: ten samples of an etch-and-rinse (Excite), a two-step self-etching adhesive system (AdheSE) - ie, primer and bond mixed - and AdheSE Bond only were prepared and cured with one of the following LEDs: Elipar Freelight2; Bluephase; SmartLite; Coltolux, each for 10 s; or a conventional halogen Prismetics Lite for 10 s or 20 s. Micro-Raman spectra were obtained from uncured and cured samples of all three groups to calculate the RDB. Data were statistically analyzed using ANOVA. RESULTS: the mean RDB values were 62% to 76% (Excite), 36% to 50% (AdheSE Primer+Bond) and 58% to 63% (AdheSE Bond). At 20 s, Prismetics Lite produced significantly higher RDB in Excite than the other LCUs and Prismetics Lite at 10 s (p < 0.05). Prismetics Lite at 20 s and Elipar produced comparable RDB values of AdheSE Bond and AdheSE Primer+Bond (p > 0.05). Excite showed significantly higher RDB values than AdheSE (p < 0.05) whilst AdheSE Bond showed significantly higher RDB than AdheSE Primer+Bond (p < 0.05). CONCLUSION: the etch-and-rinse adhesive cured with the halogen LCU for 20 s gave higher conversion than LED LCUs or halogen for 10 s curing time. The highest intensity LED [Elipar] produced higher or comparable conversion compared to the lower intensity LED LCUs for the same curing time. The etch-and-rinse adhesive showed higher RDB than the self-etching adhesive system. The presence of the primer in the self-etching adhesive compromised polymerisation.

Microleakage assessment of a repaired, nano-filled, resin-based fissure sealant.

PURPOSE: The purpose of this study was to evaluate the effects of different repairing techniques of a fractured sealant on microleakage in vitro. METHODS: A nono-filled flowable composite (Filtek Z350) was placed on the occlusal surfaces of 112 intact extracted molars following cleoning by prophylaxis and acid etching. Sealant failure was produced on the entire sample. The teeth were then randomly allocated into 4 groups, each representing a different method of repair: group 1 (control)-prophylaxis brush followed by acid etching and 10 seconds of curing time; group 2-prophylaxis brush, acid etching, application of bonding agent, and 10 seconds of curing time; group 3-prophylaxis brush, acid etching, and 5 seconds of curing time; and group 4-prophylaxis brush, acid etching, and 20 seconds of curing time. Then, they were pointed with varnish and immersed in 1% methylene blue. The teeth were then sectioned, and a total of 648 surfaces were scored for microleakage. RESULTS: Statistical analysis did not demonstrate any one method of repair to be superior to the control method. There were no significant differences in microleakage between 10 and 20 seconds of curing time. CONCLUSION: Prophylaxis brush, acid etching, and light-emitting diode light curing for 10 seconds seems to be the simplest and the most appropriate method of repair and is, therefore, recommended.

Are one-step adhesives easier to use and better performing? Multifactorial assessment of contemporary one-step self-etching adhesives.

PURPOSE: The objective of this study was to examine whether one-step self-etching adhesives (1-SEAs) really have an advantage over multistep systems. MATERIALS AND METHODS: Nine one-step self-etching adhesives (Absolute, Adper Prompt L-Pop, Clearfil S3 Bond, G-Bond, Hybrid Bond, iBond, One-up Bond F Plus, Optibond All-in-one and Xeno III) were included in this study. One two-step self-etching adhesive (Clearfil SE Bond) and one three-step etch-and-rinse adhesive (Optibond FL) served as controls. Their microtensile bond strength to bur-cut enamel and dentin was determined using a standardized protocol and the respective adhesive/dentin interface of these adhesives was characterized by transmission electron microscopy. Statistical analysis was performed with the Kruskal-Wallis nonparametric test. RESULTS: Regarding bond strength, the control adhesives tended to perform superior to the one-step adhesives. However, a significant difference between the control adhesives and some one-step adhesives could not always be demonstrated, partly due to the statistical setup of this study. Interface analysis by electron microscopy showed wide variation among the one-step adhesives, depending on their composition and their acidity. 1-SEAs also exhibited two different kinds of droplets, depending on their hydrophilicity. Hydrophobic HEMA-free 1-SEAs such as G-Bond were prone to phase separation, while especially HEMA-containing hydrophilic 1-SEAs, such as Clearfil S3 Bond and Xeno III were predisposed to forming osmosis-induced droplets. Hybrid bond, Absolute, and iBond featured both phase separation as well as osmosis. Optibond All-in-one exhibited a clustering reaction of the filler particles upon solvent evaporation. All adhesives including the control adhesives showed signs of nanoleakage, indicating that all adhesives are to some extent permeable to water. A definitive conclusion with regard to quantitative assessment of nanoleakage was much hindered by inconsistencies in the silver deposition. The application procedure of some 1-SEAs sometimes proved as elaborate and time consuming as those of the two-step adhesive Clearfil SE Bond. CONCLUSION: Considering bond strength and application procedure, 1-SEAs are not always a better alternative to multistep adhesives.

An in vitro comparative assessment of different enamel contaminants during bracket bonding.

In orthodontics, adhesive failures can occur because of saliva contamination during bonding. However, most in vitro studies concerning bond strength of saliva-contaminated enamel disregard the influence of temperature changes in a wet environment. The aim of the present study was to compare the influence of saliva, blood and etching gel remnant contamination on shear bond strength (SBS) after thermocycling. After etching of extracted human third molars (n = 80), a conventional primer (Transbond XT) and a moisture-insensitive primer (Transbond MIP) were evaluated using the adhesive, Transbond XT, under dry conditions and after contamination with saliva, blood and etching gel remnants. To simulate temperature changes and the moisture of saliva in the oral cavity, all samples were thermocycled (6,000 x 5 degrees C/55 degrees C) in a mastication device before SBS testing. A Mann-Whitney U test was used to determine statistical differences. Under dry conditions Transbond XT and Transbond MIP showed no significant difference in SBS. However, clinically unacceptable (P = 0.005) bond strength was observed using Transbond XT after saliva and blood contamination. In wet conditions only Transbond MIP showed sufficient bond strength. If contamination during bonding is expected, a hydrophilic primer should be used. Under dry conditions hydrophilic or hydrophobic primers could be applied. Blood contamination seems to be a more serious problem for bond strength than saliva or etching gel contamination.

A comparative assessment of the failure rate of molar tubes bonded with a self-etching primer and conventional acid-etching.

OBJECTIVES: Comparative assessment of the failure rate of molar tubes bonded to first and second molars with a self-etching primer and conventional acid-etching. MATERIAL AND METHODS: Four hundred forty-four molar tubes (246 first molar tubes and 198 second molar tubes) were bonded, using a split-mouth design, on 62 patients (23 male, 39 female; mean age 13.7 years) with the 3M Transbond Plus self-etching primer combined with Transbond XT paste; or with conventional acid-etching, Orthosolo primer, and Enlight adhesive paste. First-time failures were recorded over a period of 15 months. RESULTS: Bond failure per adhesive system, arch (maxilla-mandible), quadrant (left, right) and tooth (first or second molar) were studied. Statistical analysis using logistic regression modeling (alpha = .05) showed that the overall failure rate for the first and second molar tubes was 11% (8% with self-etching primer and 13% with conventional acid-etching). No significant difference was found between the 2 bonding methods. Tooth location and type showed statistically significant associations. Mandibular tubes showed a 3:1 probability for failure compared to maxillary tubes. Right-sided tubes demonstrated 3 times more failures when compared to left-sided tubes, and second molar tubes showed a 3-fold increase in failure. CONCLUSION: Molar tube bonding with self-etching primer shows similar success rates to conventional acid-etching, whereas the mandibular right second molar presents the highest failure incidence.

A comparative in vivo assessment of the long-term failure rate of 2 self-etching primers.

INTRODUCTION: The purpose of this study was to comparatively assess the failure rate of brackets bonded with 2 self-etching adhesives after 14 months of treatment. METHODS: Twenty-two patients with complete permanent dentitions, and similar treatment plans and mechanotherapies, were selected for the study. Four hundred twenty-three brackets were bonded by using a split-mouth design, with Transbond Plus Self-Etching Primer (3M Unitek, Monrovia, Calif) or One-Step Self-Etching Primer (Reliance, Itasca, Ill). These self-etching primers were applied alternately so that they were equally distributed on the maxillary and mandibular right and left quadrants. RESULTS: Failure rates were recorded for 14 months and analyzed with the chi-square test at alpha = 0.05 level of significance. Overall total failure rates were 0.94%, for Transbond Plus and 8.10% for One-Step. Although significantly more failures were found for the mandibular arch, no difference was identified in failure rate between anterior and posterior teeth. The results of this study suggest that care should be taken in ensuring the compatibility of retainers with adhesives.