Dentin Of Primary Teeth Research Articles

Influence of different cavity disinfectants on composite adhesion to dentin of primary teeth: an in vitro study

Influence of different cavity disinfectants on composite adhesion to dentin of primary teeth: an in vitro study

The Potential of Silver Diamine Fluoride in Non-Operative Management of Dental Caries in Primary Teeth: A Systematic Review

Background and Objectives: Dental caries has seen an increase in untreated cases, leading to significant health and quality-of-life impacts, necessitating innovative approaches like the promising non-operative management with silver diamine fluoride. This study aimed to evaluate the mechanisms of action of silver diamine fluoride on arresting dental caries in primary teeth. Materials and Methods: A systematic search was conducted across MEDLINE (PubMed), Google Scholar, and Wiley Online Library, including both in vivo and in vitro studies published from 1 January 2017 to 16 October 2022. The Cochrane Risk of Bias Tool assessed bias in in vivo studies, while the Quality Assessment Tool for In Vitro Studies evaluated the methodological quality of in vitro studies. Results: Nineteen publications met the inclusion criteria. Two studies indicated that silver diamine fluoride application significantly alters oral microflora, contributing to caries arrest. Additionally, two studies reported increased mineral density and mineral content in demineralised primary teeth, emphasising silver diamine fluoride’s role in promoting remineralisation. Three studies demonstrated significant improvements in surface microhardness, enhancing tooth resistance. However, no significant qualitative changes in bacterial species composition were noted. Modified silver diamine fluoride application techniques, including light curing or laser irradiation, enhanced efficacy, with light curing notably increasing surface microhardness. Based on a limited number of studies, no statistically significant differences in clinical effectiveness were observed with higher silver diamine fluoride concentrations or extended application durations. Conclusions: Silver diamine fluoride effectively induces quantitative changes in oral microflora and enhances the microhardness and mineral density of enamel and dentine in primary teeth, with modified application methods showing potential for improved outcomes.

Comparing the Effect of two different deproteinizing agents on shear bond strength and resin dentin interface in dentin of primary teeth (In-vitro study)

Comparing the Effect of two different deproteinizing agents on shear bond strength and resin dentin interface in dentin of primary teeth (In-vitro study)

Influence of Different Application Modes of a Universal Adhesive System on the Bond Strength of Bulk-Fill Composite Resin to Enamel and Dentin in Primary Teeth.

The objective of this study was to assess how the application mode of a universal adhesive system affects the microshear bond strength (μSBS) of bulk-fill and conventional composite resins to enamel and dentin in primary teeth. A total of 80 caries-free primary second molars were randomly assigned to eight experimental groups (n = 10) based on the bonding substrate (enamel or dentin), the application mode of the universal adhesive system (etch and rinse [E&R], or self-etch [SE]), and the type of composite resin used (bulk-fill or conventional). After bonding the composite resin to enamel or dentin, the μSBS of the bonded composite resins was measured. The mean μSBS value of bulk-fill composite resin was significantly higher than that of conventional composite resin for both enamel and dentin substrates, regardless of the application mode (p < 0.001). An interaction effect between the bonding substrate and the application mode of the adhesive system was observed, indicating a significant relationship (p < 0.001). The highest μSBS values for primary teeth enamel were achieved using the E&R mode with bulk-fill composite resin, while for dentin specimens, the SE mode with bulk-fill composite resin yielded the highest μSBS values. The μSBS of the E&R group was significantly higher than that of the SE group for enamel specimens (p < 0.001), whereas the μSBS of the SE group was significantly higher than that of the E&R group for dentin specimens (p < 0.001). Bulk-fill composite resin demonstrated higher μSBS in comparison to conventional composite resin. The universal adhesive system exhibited superior performance in the SE mode compared to the E&R mode on primary dentin. Pre-etching the enamel before the application of the universal adhesive enhanced the μSBS to primary teeth enamel, highlighting the importance of selectively acid etching the enamel of primary teeth.

Effect of silver diamine fluoride application on the microtensile bond strength of three commonly used restorative materials in primary teeth: An ultrastructural study.

Caries in primary teeth rapidly advances owing to its thin structure, thereby requiring restoration. However, restorations often fail due to various causes such as secondary caries and reduced microtensile bond strength (μTBS), which calls for the use of antimicrobial agents such as silver diamine fluoride (SDF). This study aims to measure and analyse the effect of SDF application on the μTBS of three regularly used restorative materials to dentin of primary teeth as well as compare the types of bond failure interfaces under SEM. The study comprised 60 samples equally divided into six groups among three restorative materials, namely, glass ionomer cement (GIC, Groups I and II), resin-modified glass ionomer cement (RMGIC, Groups III and IV), and composite resin (Groups V and VI) with subdivisions of A and B, where A represented samples with SDF application and B represented samples without SDF application. It was observed that μTBS of RMGIC to sound and carious dentin irrespective of SDF application was found to be statistically significant (P < 0.05), and when GIC, RMGIC, and composite resins were compared to both sound and carious dentin irrespective of SDF application, it was statistically significant (P < 0.05). SEM analysis revealed predominantly cohesive failures among all the groups. Based on the results, it was concluded that SDF has no adverse effect on the μTBS of GIC, RMGIC, and composite resin to both carious and sound dentin of primary teeth.

In-Vitro Evaluation of Shear Bond Strength of Glass Ionomer Cement to Primary Teeth Dentin Pretreated with Silver Diamine Fluoride and Sodium Fluoride Varnish

Aim: To evaluate and compare the shear bond strength (SBS) of glass ionomer cement (GIC) to primary teeth dentin pretreated with silver diamine fluoride (SDF) and sodium fluoride (NaF) varnish. Materials and Methods: A total of 50 non carious human primary molars were used in this study. The teeth were prepared to expose a flat dentin surface, ensuring comparability across samples. The samples were then randomly divided into two groups. Group I: The dentin surface of the primary teeth was pretreated with 38% SDF. Group II: The dentin surface of the primary teeth was pretreated with 5% NaF varnish. Following pretreatment, all samples were restored using GIC. The SBS was evaluated using a universal testing machine, which measures the force required to detach the GIC from the dentin surface. Results: The study found that the mean SBS of Group I (SDF 38%) was significantly higher at 10.11 ± 2.34 MPa compared to Group II (NaF 5%), which had a mean SBS of 6.34 ± 2.56 MPa. This represented a mean difference of 3.77 MPa in favor of the SDF pretreatment group. Conclusion: The primary teeth dentin pretreated with 38% SDF demonstrated a significant increase in SBS to GIC compared to the teeth pretreated with 5% NaF varnish. This suggests that SDF not only acts as a caries-preventive agent but also enhances the bond strength of restorative materials adhered to dentin surfaces. Clinical Significance: The findings hold considerable clinical significance, especially for pediatric dentistry. The use of SDF as a dentin pretreatment can improve the adhesion of GIC to the dentin of primary teeth. This is particularly beneficial given the minimally invasive nature of the procedure, making it an optimal choice for young patients who may find conventional dental procedures distressing. In summary, this study supports the use of SDF over NaF varnish for pretreating primary teeth dentin before GIC restoration, due to the superior bond strength observed. Implementing this can improve the longevity and effectiveness of restorative treatments in primary teeth, offering a viable, simple method that aligns well with pediatric dental care standards.

Evaluation of adhesive bond strength of restorative materials to hard tissues of deciduous teeth based on adhesion technique

Relevance. Treating caries in deciduous teeth remains one of the most complex challenges in pediatric dentistry. The bond strength between the enamel and dentin of deciduous teeth and restorative materials is crucial for the durability of hard tissue restorations in these teeth. This article evaluates the adhesive strength of restorative materials to the enamel and dentin of deciduous teeth using a universal adhesive system, both with and without prior etching with orthophosphoric acid.Purpose. To assess the adhesive bond strength of dental filling materials to the hard tissues of deciduous teeth, contingent upon the enamel and dentin etching techniques used with a universal adhesive system.Materials and methods. This study measured the adhesive strength of a composite filling material to the enamel and dentin of deciduous teeth using a universal adhesive system. The methods included both the absence of preliminary etching with 37% orthophosphoric acid (self-etch technique) and the application of preliminary etching of enamel and dentin with 37% orthophosphoric acid (total-etch technique). Sixty extracted deciduous teeth from children aged 6-8 years were used. Adhesive strength was assessed using the shear test of the filling material in cylinder form against the substrate surface.Results. Significant differences were observed in the adhesive bond strength of the composite material to the hard tissues of deciduous teeth when using 37% orthophosphoric acid before applying the adhesive system (total-etch technique) compared to no preliminary etching (self-etch technique). When filling carious lesions in deciduous teeth, if the defect is within the enamel, etching the surface with 37% orthophosphoric acid significantly (by two-fold) enhances the adhesive strength of the bond with the composite material using a universal adhesive. However, when repairing defects located deeper than the enamel layer in deciduous teeth, no statistically significant differences were observed in the adhesive strength with or without dentin etching. The optimal adhesive bond strength of composite materials to the hard tissues of deciduous teeth under laboratory conditions was attained by selectively etching the enamel with 37% orthophosphoric acid, followed by the application of a universal adhesive system to both the enamel and dentin.

Micro-shear Bond Strength of an Alternative Self-etch Application of "No Wait" Universal Adhesive to Caries-affected and Sound Dentin in Permanent and Primary Teeth.

This study aimed to compare the micro-shear bond strength (μSBS) of caries-affected dentin (CAD) and sound dentin (SoD) in primary and permanent teeth using an alternative self-etch application of "no wait" universal adhesive. Flat midcoronal dentin surfaces from 72 permanent third molars and 72 second primary molars were distributed randomly into 12 groups according to the substrate SoD and artificially-created CAD (pH cycling for 14 days) and the adhesive system (GLUMA Bond5, a two-step etch & rinse adhesive, GLUMA Bond, a one-step self-etch adhesive, and Tokuyama Universal Bond, a one-step self-etch adhesive) (n=12). Bonded dentin resin discs were put through micro-shear bond strength testing after 10,000 thermocycles. The results were evaluated using two-way ANOVA and the Bonferroni test with a significance level of α = 0.05. When compared to SoD, the etch & rinse system's test results on artificially created CAD showed a statistically significant poorer bonding performance in both permanent and primary teeth in all groups (p<0.05). While the bond strengths of permanent teeth using total-etch adhesive on sound dentin were statistically significantly higher than those using Tokuyama Universal Bond adhesive (p<0.05), there was no significant difference in sound dentin in primary teeth (p>0.05). The etch & rinse system performed the poorest of all adhesive systems on CAD. The Tokuyama Universal Bond's adhesive strength was similar in SoD and CAD on primary teeth. The use of Tokuyama Universal Adhesives can speed up restorative treatment in pediatric dentistry.

The effect of different intracanal irrigants on the push-out bond strength of dentin in damaged anterior primary teeth.

This experimental study investigated the effect of different intracanal irrigants on the push-out bond strength of dentin in damaged anterior primary teeth. The crowns of 90 anterior primary teeth were sectioned horizontally, 1 mm above the cementoenamel junction (CEJ). Following canal preparation with K-files, all groups except the negative control received normal saline irrigation. Canals were then irrigated with either 3% or 5.25% sodium hypochlorite (NaOCl), 2% or 0.2% chlorhexidine (CHX) solution (except negative and positive controls). The roots were filled with Metapex material and covered with a calcium hydroxide liner. In root canals, the bond was applied by self-etching and then light-cured for 20 seconds before canals were restored incrementally with composite. Stereomicroscopes were used to assess failure patterns. Push-out bond strengths (MPa ± SD) were: 3% NaOCl (16.92 ± 5.78), 5.25% NaOCl (8.96 ± 3.55), 2% CHX (14.76 ± 5.56), and 0.2% CHX (7.76 ± 2.93). Significant differences were seen across the irrigants regarding the push-out bond strength of dentin sections (P <0.001). The most frequent failures were adhesive and cohesive. NaOCl and CHX irrigants increased the push-out bond strength compared to controls. Compared to controls, both 3% NaOCl and 2% CHX irrigants significantly increased the push-out bond strength of dentin in non-vital anterior primary teeth.

Fishing for the evidence on community water fluoridation: a commentary on the CATFISH study.

Goodwin M, Emsley R, Kelly M P et al. Evaluation of water fluoridation scheme in Cumbria: the CATFISH prospective longitudinal cohort study. Southampton: National Institute for Health and Care Research, 2022. This longitudinal, prospective cohort study, recruited two populations - a birth cohort and older school cohort - assessing the effects of community water fluoridation (CWF) over a five-year period. The control group received non-fluoridated drinking water in the East of Cumbria, while the intervention group received fluoridated drinking water in the West of Cumbria. The primary outcome measures were the presence or absence of decay into dentine in primary and permanent teeth. Cost effectiveness was assessed by quality-adjusted life-years. Birth Cohort: Modest beneficial effect (17.4% with decay, 21.4% in control). Adjusted Odd Ratios (AOR): 0.74 (95% CI: 0.56 to 0.98). Older Cohort: Insufficient evidence of difference (19.1% with decay and 21.9% in control). AOR: 0.80 (95% CI: 0.58 to 1.09). The authors concluded that CWF was effective in the birth cohort and that the modest absolute reduction in caries should be considered in the context of other preventive measures. A longer follow-up period was recommended to fully understand the benefits and risks of CWF in contemporary low-prevalence populations.

Shear Bond Strength of Resin-modified Glass Ionomer Cement to Primary Teeth Dentin Pretreated with Silver Diamine Fluoride and Sodium Fluoride Varnish: An In Vitro Study

Shear Bond Strength of Resin-modified Glass Ionomer Cement to Primary Teeth Dentin Pretreated with Silver Diamine Fluoride and Sodium Fluoride Varnish: An In Vitro Study

Evaluation of the Dentinal Shear Bond Strength and Resin Interface in Primary Molars after Pre-Treatment with Various Dentin Bio-Modifiers: An In Vitro Study.

Dentine adhesives have demonstrated great success with permanent teeth. Though the results in primary teeth are not well documented, some studies have demonstrated lower values of bond strength in primary teeth than those found in permanent teeth. The aim of this study was to compare and evaluate the effect of grape seed extract (6.5%) (Herbal Bio Solutions, Delhi, India), glutaraldehyde (5%) (Loba Chemie PVT. LTD., Mumbai), hesperidin (0.5%) (Herbal Bio Solutions, Delhi, India), and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) (GC Corporation, Alsip, IL, USA) on the shear bond strength of dentine of primary teeth and to evaluate the resin tags at the resin tooth interface. Seventy-five caries-free human primary molars were collected, and their occlusal surfaces were ground flat. Dentin surfaces were etched using phosphoric acid. Then teeth were randomly assigned in sequential order to five groups according to the dentinal treatment method: Group I (Control group) (no treatment), Group II (5% glutaraldehyde), Group III (6.5% grape seed extract), Group IV (0.5% hesperidin), and Group V (CPP-ACP). Ten teeth from each group were assigned for Shear Bond Strength and five for SEM analysis. ANOVA and a post hoc least significant difference test (p < 0.05) were used for statistical analysis of the collected data. The grape seed extract group showed significantly increased shear bond strength than the control group (p < 0.05), and the mean length of resin tags in different dentine bio modifiers groups was also statistically significant (p < 0.05). The use of dentin bio modifiers such as 5% glutaraldehyde, 6.5% grape seed extract, 0.5% hesperidin, and CPP-ACP in the bonding process for primary teeth did not improve the dentinal bond strength.

Evaluation of Carisolv in the Chemico-Mechanical Removal of Carious Dentine in Primary Molars (In vivo study)

Caries removal by the Chemo-mechanical technique involves the application of chemical agents, to cause a selective softening of the carious dentine and facilitate removal by gentle excavation. Carisolv is one such new chemical agent used in this minimal invasive technique of carious dentine removal. The aims of this study was to evaluate the efficacy of Carisolv in the chemo-mechanical removal of carious dentine in primary teeth, the time taken for caries removal and to evaluate the restorations radiographically. Forty primary 1st and 2nd molars with dentinal carious lesions were excavated using this technique of caries removal. After isolation of the involved tooth, the Carisolv " new gel" marketed by Mediteam Dental AB (Goteborg, Sweden) was applied then the superficial softened carious dentine was gently excavated and scraped using a spoon excavator, the procedure repeated until the cavity was free from caries and the cavity was checked for remaining caries using an explorer. The time taken for the removal of carious dentine, beginning from the application of the gel until the completion of the procedure was evaluated using a stopwatch. After the placement of the restoration an intra-oral periapical radiograph was taken for immediate evaluation and after a period of six months, the longevity of the restorations and the presence of secondary caries at the restoration- dentine interface were evaluated radiographically. The statistical analysis of the results showed that the soft carious dentine was removed more effectively than the hard carious dentine and the removal of the soft carious dentine required a shorter period of time (4.96±0.99) minutes when compared to the removal of hard carious dentine (6.09±1.04) minutes and on radiographic evaluation of the restoration, none of the treated lesions showed the presence of secondary caries. In conclusion, the chemico-mechanical caries removal technique using Carisolv proved to be an effective atraumatic treatment modality with potential interest for use in clinical pediatric dentistry.

Comparative Efficacy of Smart Burs vs Conventional Burs in Removing Infected Dentin and Preserving Affected Dentin in Primary Teeth: A Randomised Control Study

Introduction: With the advent of time, the removal of caries has shifted from hand instruments to rotary instruments. A disadvantage of conventional burs is that they non selectively lead to over-preparation. A new polymer bur can be substituted to eliminate these undesirable effects. Aim: To compare and evaluate the efficacy of smart burs and conventional burs in removing infected dentine while preserving affected dentin in carious lesions in primary teeth. Materials and Methods: This was a double-blinded randomised controlled trial conducted in the Department of Paediatric and Preventive Dentistry at Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur, Maharashtra, India over a period of three months, from August 2023 to October 2023. A total of 40 children aged 6-12 years were selected and evaluated for caries removal efficacy using visual and tactile criteria, which were further confirmed by dye application and numerically scored. Group 1 included 20 children who underwent caries excavation with smart burs, while Group 2 included 20 children who underwent the procedure with diamond points. Statistical analysis was conducted using descriptive and inferential statistics, specifically the Chi-square test. Results: A total of 40 children aged 6-12 years were divided into two groups: Group 1 comprised 11 boys and 9 girls, whereas Group 2 included 10 boys and 10 girls. Of these, 12 cases (60%) showed complete caries removal after the first application of dye, regardless of which burs was used. However, 4 cases (20%) showed some residual caries when using smart burs, while 6 cases (30%) exhibited residual caries with diamond points at the base of the cavity preparation. Additionally, there were 4 cases (20%) with caries present at the base and/or in one wall of the cavity preparation when using smart burs, compared to 2 cases (10%) with conventional burs. Nonetheless, there was no statistically significant difference between the smart burs and the conventional diamond points regarding caries removal. Conclusion: It can be concluded that smart burs are equally effective in removing soft caries compared to conventional methods. Although the results were statistically insignificant, polymer burs were found to be more convenient and can be considered a viable alternative to conventional caries removal techniques.

Silver Diamine Fluoride: Clinical Tips

Caries continues to be a public health problem worldwide, and the prevention and conventional treatment of carious lesions may present challenges. Caries into dentine in primary teeth is common, with 30% of five-year-olds having dental caries in Ireland.1 In young children, there can be barriers to using some of the evidence-based recommended techniques to restore carious teeth. Reasons for this include access, co-operation and age. Similarly, root caries, commonly found in older adults, can be challenging to manage conventionally, particularly where the caries rate is high and there are access barriers or medical comorbidities. Silver diamine fluoride (SDF) is an alternative option to treat such cases where conventional methods are not appropriate or achievable for the patient.

SEM/EDS Analysis of Tubules and Mineral Deposition in the Dentin of Children with Osteogenesis Imperfecta

The aim is to quantitatively analyze the diameter and tubular density and semi-quantitatively analyze the elemental composition (Calcium and Phosphorus) in the dentin of primary teeth of children with Osteogenesis Imperfecta (OI) in comparison with a control group. Material and methods: A microstructural (in vitro) analysis of primary teeth of children with OI was performed with SEM and EDS. The variables measured were the tubule count (tubule/mm2) and diameter (µm) at 2000 times magnification at four points of the dentin of different depths. A semiquantitative analysis of the elemental composition of the dentin was performed with EDS of Calcium and Phosphorus (cps). Descriptive and inferential analysis (Fisher’s exact test, the Mann–Whitney U test, the Kruskal–Wallis test, the Bonferroni post hoc test, the ANOVA test of repeated measures, a test of inter- and intra-subject effects, and the Geisser–Greenhouse test) were carried out. Data were analyzed with a 95% confidence level (p-value &lt; 0.05). Results: A total of 25 deciduous teeth from 17 patients with OI and 30 teeth from healthy children were studied. There were differences in the count and tubular diameter for the control group with OI; in addition, the behavior curve changed when the systemic disease was severe. While there were no differences in the amount of dentinal Calcium, the OI tooth showed a significantly lower amount of Phosphorus (p &lt; 0.05), except in the pulpal dentin (p &gt; 0.05). Conclusion: The alterations of the dentinal tubules (density and diameter) were more pronounced in the most severe phenotypes of systemic disease. The amount of Phosphorus was decreased in the dentin of the primary teeth of children with OI compared to the control group.

Evaluation of the Effects of Different Types of Resin Cement Systems on the Push-Out Bond Strength of the Fiber Post to Intracanal Dentin in Anterior Primary Teeth.

This study aimed to evaluate the effects of using three different resin cements on push-out bond strength (PBS) of fiber posts to root canal dentin of primary teeth. Fifty primary canines were randomly divided into five experimental groups according to the type of the luting agent used for fiber post cementation after endodontic treatment and post space preparation as the following: Group 1: glass ionomer cement (GIC), Group 2: flowable resin composite, Group 3: etch and rinse (E&R) resin cement, Group 4: self-etch (SE) resin cement, Group 5: self-adhesive (SA) resin cement. The PBS values of the cemented fiber posts to root canals were measured. The data were statistically analyzed using a one-way analysis of variance, followed by Tukey's post hoc test. The highest mean PBS value was observed in Group 4 (SE resin cement), followed by Group 3 (E&R resin cement), and the lowest PBS value belonged to Group 1 (GIC), followed by Group 5 (p-values < 0.05). The mean PBS of Group 3 (E&R resin cement) was significantly higher than those of Groups 1 (GIC), 2 (flowable resin composite), and 5 (SA resin cement) (p-values < 0.05). However, no significant difference was found between the mean PBS of GIC and SA resin cement (p-value >0/05). Using SE resin cement for fiber post cementation in primary anterior teeth showed the best results, followed by E&R resin cement. The lowest PBS was observed for GIC, followed by SA resin cement.

Nano silver fluoride versus silver diamine fluoride with potassium iodide on carious dentine of primary teeth

Background Dental caries is one of the most prevalent diseases, and treating carious lesions remains a major concern, especially in pediatric dentistry. Minimally invasive interventions have been proposed as a promising treatment modality for caries control. Aim This study evaluated nano silver fluoride versus silver diamine fluoride with potassium iodide for the treatment of carious dentine in primary teeth. Material and methods This in vivo study was performed on 30 children presented with 60 primary molars with soft dentinal lesions. Carious teeth were assigned into two equal groups: group I received silver diamine fluoride with potassium iodide, while group II received nano silver fluoride. Teeth were diagnosed and treated at the baseline visit and followed up for clinical evaluation at 3, 6, and 9 months. Also, dentine samples were obtained from the initial carious teeth and after 9 months of applying the treatments for microbiological evaluation. Results Both groups had comparable clinical values at 3, 6, and 9 months, with no statistically significant difference. While after 9 months, there was a highly significant increase in the number of teeth showing dentine color change in group I compared with group II. Microbiological results showed no significant difference in the reduction of Lactobacillus count between both groups. While there was a significant difference between both groups in terms of Streptococcus mutans count. Conclusion Silver diamine fluoride with potassium iodide and nano silver fluoride provides simple and effective dentinal caries management.

Dentin Bonding Performance of Universal Adhesives in Primary Teeth In Vitro.

(1) Background: The aim of this in vitro study was to evaluate the micro-tensile bond strength (µ-TBS) of universal adhesives to primary tooth dentin after different storage periods. (2) Methods: Dentin of 100 extracted primary molars was exposed. Dentin surfaces were bonded with six universal adhesives (Adhese®Universal [AU], All-Bond Universal® [ABU], G-Premio Bond [GPB], iBond®Universal [IBU], Prime&Bond active™ [PBa], and Prime&Bond®NT as control [PBN]) and restored with a resin composite build-up (Filtek™ Z250). After 24 h, 6 months, and 12 months of water storage, specimens were cut into sticks, and µ-TBS was measured and analyzed using one-way ANOVA (p < 0.05) for normal distributions and the Mann-Whitney U-test (p < 0.05) for non-normal distribution. Pretesting failures were recorded as 0 MPa. Fracture modes were analyzed under a fluorescence microscope; interfaces were visualized with SEM/TEM. (3) Results: Compared with the reference group (PBN: 32.5/31.2 MPa after 6/12 months), two adhesives showed a significantly higher bond strength after 6 months (AU: 44.1 MPa, ABU: 40.9 MPa; p < 0.05) and one adhesive after 12 months (AU: 42.9 MPa, p < 0.05). GPB revealed significantly lower bond strengths in all storage groups (16.9/15.5/10.9 MPa after 24 h/6 months/12 months; p < 0.05). AU and IBU did not suffer pre-test-failures [PTF]. (4) Conclusions: After 12 months, PBN, IBU, AU, and GPB showed significantly lower results compared ithw initial µ-TBS, whereas AU revealed the highest µ-TBS and no PTF.

Temperature Changes in Primary and Permanent Teeth Dentine of Varying Thicknesses Following Irradiation by Two Light Curing Units.

This study was performed to determine the temperature rise under human dentin discs of different thicknesses from primary and permanent teeth during the photo-curing process using quartz tungsten halogen (QTH) or light-emitting diode (LED). The current experimental study sample consisted of 160 dentin discs of different thicknesses (0.5, 1, 1.5, and 2 mm), of which 80 dentin discs were prepared from sound lower second primary molars, and the remaining 80 dentin discs were prepared from sound lower third permanent molars extracted surgically for various reasons. A "K" type of thermal tentacle was placed in the center of an acrylic resin base, followed by the placement of a dentin disc. Then, the thermal changes were measured during the photo-curing of the composite using a second LED or QTH light curing unit for 20 s. Statistical evaluation was performed using the IBM SPSS Statistics® Version 20.0 software system (SPSS Inc., Chicago, IL, USA). The current study found that the temperature rise in primary teeth (1.17-2.96°C) is significantly lower compared to the rise in permanent teeth (1.55-3.33°C), regardless of the dentin disc thickness or light curing unit used. The temperature rise decreases significantly when the thickness of dentin discs increases, regardless of the type of teeth or light curing unit used (P<0.05). Furthermore, QTHcauses less temperature rise (1.17-2.65°C) compared to LED (1.61-3.33°C). The temperature rise during polymerization of the resin composite with the second-generation LED appeared to be below 5.5°C. Hence, it appears to be safe for use during the restoration of primary teeth. Primary teeth dentin might be more effective than permanent teeth dentin in protecting the dental pulp.