In-Vitro Evaluation of Dental Adhesive Bond Strength With Diode Laser Irradiation Before Photopolymerization.

AIM: In-vitro evaluation of shear bond strength, mode of failure, and adaptation of fifth-generation (etch-and-rinse), seventh-generation,and eighth-generation self-etch dental adhesives to human dentin with or without diode-laser irradiation before photopolymerization. MATERIALS AND METHODS: Seventy-two extracted human maxillary premolar teeth were collected. The buccal and lingual surfaces of teeth were grounded until dentin was exposed. Test areas of 4 mm diameter were created on both surfaces of teeth to standardize the area of treatment. The samples were then randomly allocated into three groups (n = 24): Group 1 Adper Single Bond 2 Etch-and-Rinse; Group 2 Tetric-N-Bond Universal Self-Etch; Group 3 Prime and Bond Universal Self-Etch dental adhesives were used. Buccal surfaces (sub-groups 'a') of all specimens were irradiated with diode laser before photopolymerization of the adhesive material, and palatal surfaces (sub-groups 'b') were directly photopolymerized without prior diode laser irradiation and restored with composite resin. All specimens were thermocycled. Four specimens from each group were then subjected to scanning electron microscopy (SEM) analysis to examine the adaptation of adhesive to dentin, and the remaining 60 specimens were evaluated for shear bond strength tests, modes of failure at the adhesive-dentin interface, and values were recorded, tabulated, and used for data analysis. A one-way ANOVA test and the Student's t-test were used for statistical analysis. A P value ≤ 0.05 was considered statistically significant. RESULTS: The mean shear bond strength for the groups was: Group 1a (13.96 MPa), 1b (14.95 MPa); Group 2a (10.06 MPa), 2b (10.30 MPa); Group 3a (12.03 MPa), and 3b (10.44 MPa). No statistically significant difference was seen among sub-groups 1a and 3a, 2a and 3a, 2b and 3b as P > 0.05. A significant difference was seen among sub-groups 1b and 3b (P<0.05), 1a and 2a, and 1b and 2b (P<0.01). CONCLUSION: Adper Single Bond 2 without diode-laser irradiation before photopolymerization showed the highest shear bond strength, followed by Adper Single Bond 2 irradiated with diode laser before photopolymerization, with the maximum adaptation of dental adhesive to dentin compared to other adhesives used either with or without diode-laser irradiation.

Evaluation of Radicular Dentin Thickness in Maxillary and Mandibular Central Incisor, Canine, and Premolar Teeth.

Background This study aimed to compare the radicular dentin thickness in single-rooted maxillary and mandibular anterior and premolar teeth by measuring on four different surfaces (buccal, lingual, mesial, and distal) at three different levels (apical, middle, and coronal). Methods A total of 150 single-rooted human anterior and premolar teeth were included in the present study. The teeth were sectioned at the cemento-enamel junction (CEJ; coronal), 4 mm away from the apex (apical), and the midpoint between these two distances (middle). First, the teeth were divided buccolingually into two parts, and the dentin thickness in the mesial/distal region was measured. Subsequently, both parts were divided again to measure the dentin thickness in the buccal/lingual region. All measurements were recorded, and statistical analysis was performed. Results Apical radicular dentin thickness was significantly less than CEJ (p < 0.001). The maxillary central incisor, maxillary, and mandibular canine exhibited the maximum radicular dentin thickness, whereas the mandibular premolars showed the minimum. Radicular dentin thicknesses on the lingual and buccal surfaces were significantly higher than those on other surfaces (p < 0.001). Conclusion The lowest radicular dentin thickness values were observed in the premolars, especially on mesial and distal surfaces. Considering these areas as danger zones and paying attention during dental procedures are essential to avoid possible complications.

Bonding to Fluorosed Teeth: A Review of the Literature.

Excessive fluoride availability during tooth formation can cause structural alterations in enamel and dentin. These alterations may negatively impact the adhesion of various dental materials to teeth with dental fluorosis. The aim of this review of literature is to identify updates in bonding to fluorosed teeth and summarize relevant recommendations. Findings from the available literature suggest that bonding procedures may be carried out reliably on most fluorosed teeth with consideration to the severity of fluorosis and the employment of additional bond-enhancing measures for the severely involved teeth.

Warm Air Delivery in Adhesive Application: Effect on Bonding Performance and Morphological Outcomes.

Solvent evaporation within an adhesive layer is a crucial step during a bonding process. The aim of this current research was to test whether the use of different air temperatures (20 °C, 40 °C, and 60 °C) for solvent evaporation improves the performance of four adhesive systems to dentin. Sixty non-carious human molar teeth were randomly prepared for micro-tensile bond strength (µTBS) tests. Four different adhesive systems, Prime&Bond Universal (PBU), OptiBond Universal (OBU), OptiBond FL (OBFL), and Clearfil SE (CSE), were applied following the manufacturer's instructions. Three groups based on the air-drying temperature were used: solvent evaporation was performed with either of warm (40 °C), (60 °C), and cold air as control group (20 °C) for 10 s at a distance of 5 cm. In all bonded surfaces, three resin composite (Reflectys, Itena Clinical, Paris, France) layers of 2 mm thickness were built up. The resin-dentin samples were kept in distilled water at 37 °C for 24 h and 6 months, respectively, before µTBS testing. Failure analysis, scanning electron microscopy of resin-dentin bonded interface, and solvent evaporation rate were tested as secondary variables. All analyses were conducted using a significance level of α = 0.05. Bond strength (BS) values were similar among all the adhesive systems used (p > 0.05). Also, the aging factor did not affect the BS (p > 0.05). Only the factor of temperature used for solvent evaporation resulted in a statistically significant effect (p < 0.05), with the temperature of 60 °C being the highest value (p < 0.05). A failure mode evaluation revealed mostly adhesive or mixed modes of failures in all the different temperatures of air used for the solvent evaporation of each adhesive system. The thickness of the adhesive layer and the creation of resin tags varied amongst the temperatures evaluated. For all adhesive systems tested, the use of 40 °C or 60 °C air for solvent evaporation led to an increased mass loss. Warmer temperatures for solvent evaporation contributed positively to bonding performance, enhancing both the quality of the adhesive layer and its interaction with the dentin tissue. Optimizing solvent evaporation with warmer air temperatures (40 °C and 60 °C) significantly improved µTBS, offering a practical means to enhance the quality and longevity of adhesive restorations in esthetic dentistry.

Dentin hypersensitivity and toothache among patients diagnosed with Molar-Incisor Hypomineralization: A systematic review and meta-analysis.

OBJECTIVES: To determine the prevalence of dentin hypersensitivity (DH) and toothache in patients with Molar-Incisor Hypomineralization (MIH); and evaluate whether patients with MIH have greater likelihood of presenting DH/toothache than controls. DATA: Studies evaluating DH/toothache in patients with MIH were included. Studies focusing on other enamel defects were excluded. SOURCES: Eight databases, including grey literature, were searched in January 2024. STUDY SELECTION: The methodological quality of studies was assessed using the Joanna Briggs Institute checklist for Cross-sectional studies. Proportion and association meta-analyses, subgrouped by diagnostic methods, were conducted. The certainty of evidence was assessed using GRADE approach. RESULTS: Fifteen studies were included in the qualitative analysis and fourteen in the meta-analyses. Two studies fulfilled all items of the methodological quality checklist. The overall prevalence of DH/toothache among patients with MIH was 45 %. Prevalence rates of 30 %, 47 %, and 55 % were estimated based on proxy reports, self-reports, and air stimulation, respectively. The overall prevalence of DH/toothache per tooth was 22 %, ranging from 16 % to 29 % according to the diagnostic method. Patients with MIH demonstrated higher likelihood of presenting proxy reports of DH/toothache compared to those without MIH (OR: 1.51, 95 % CI [1.23-1.85], P < 0.01, I2: 0 %). The certainty of evidence was very low, mainly due to the low methodological quality of included studies and high inconsistency. CONCLUSIONS: The global prevalence of DH/toothache was 22 %, per tooth, and 45 % per patient. Estimates vary according to diagnostic methods. Patients with MIH showed higher likelihood of presenting proxy reports of DH/toothache than controls. CLINICAL SIGNIFICANCE: This systematic review contributes valuable information to the dental literature by assessing the prevalence and associated factors of DH/toothache in patients with MIH. The findings can guide future research, inform clinical practices and public policy makers, and ultimately improve the management of oral health of patients with MIH. REGISTRATION: PROSPERO CRD42023432805.

Use of marine occurrent extracts to enhance the stability of dentin extracellular matrix.

Chitosan (CS) and phloroglucinol (PhG), two extracts abundantly found in marine life, were investigated for their ability to biomodify demineralized dentin by enhancing collagen crosslinks and improving dentin extracellular matrix (ECM) mechanical and biochemical stability. Dentin obtained from non-carious extracted human molars were demineralized with phosphoric acid. Baseline Fourier-transform infrared (FTIR) spectra, apparent flexural elastic modulus (AE) and dry mass (DM) of each specimen were independently acquired. Specimens were randomly incubated for 5 min into either ultrapure water (no-treatment), 1% glutaraldehyde (GA), 1% CS or 1% PhG. Water and GA were used, respectively, as a negative and positive control for collagen crosslinks. Specimens' post-treatment FTIR spectra, AE, and DM were obtained and compared with correspondent baseline measurements. Additionally, the host-derived proteolytic activity of dentin ECM was assessed using hydroxyproline assay (HYP) and spectrofluorometric analysis of a fluorescent-quenched substrate specific for matrix metalloproteinases (MMPs). Finally, the bond strength of an etch-and-rinse adhesive was evaluated after application of marine compounds as non-rinsing dentin primers. Dentin specimens FTIR spectral profile changed remarkably, and their AE increased significantly after treatment with marine compounds. DM variation, HYP assay and fluorogenic substrate analysis concurrently indicated the biodegradation of CS- and PhG-treated specimens was significantly lesser in comparison with untreated specimens. CS and PhG treatments enhanced biomechanical/biochemical stability of demineralized dentin. These novel results show that PhG is a primer with the capacity to biomodify demineralized dentin, hence rendering it less susceptible to biodegradation by host-proteases.

Evaluation of different mechanical cleaning protocols associated with 2.5% sodium hypochlorite in the removal of residues from the post space.

Aims: This study evaluated the effectiveness of different mechanical protocols using rotary brush (RB), ultrasonic tip, and oscillatory system (OS) associated with 2.5% sodium hypochlorite (NaOCl) in the removal of residues and dentin permeability in the cervical and apical segments of the post space. Settings and Design: Experimental in vitro study. Methods: Forty roots from human first molars were prepared and divided into four groups according to the cleaning protocols: Control (CO), NaOCl 2.5% conventional irrigation with a syringe; RB associated with NaOCl 2.5%; ultrasonic tip (US) associated with NaOCl 2.5%; OS associated with NaOCl 2.5%. Statistical Analysis Used: The persistence of residues was evaluated by scanning electron microscopy and data submitted to Kruskal-Wallis and Dunn tests, and dentin permeability evaluated by confocal microscopy and date submitted to ANOVA one-way and Tukey's tests (P = 0.05). Results: There were no differences in residue cleaning among the CO, RB, US, and OS groups, regardless of the analyzed root segment (P > 0.05). When comparing groups, dentin permeability in the CO group was significantly lower in the cervical segment (P < 0.05). Conclusions: The OS group promoted the highest permeability value in the apical segment. RB, US, and OS are similar in removing residues from the post space. However, OS results in higher dentin permeability in the apical segment.

Evaluation of Three Methods for the Treatment of Dentin Hypersensitivity: A Randomised Clinical Trial.

OBJECTIVES: In this study, we aimed to compare the effectiveness of Gluma and high-power 980-nm diode laser, alone or in combination, in the treatment of cervical dentin hypersensitivity. METHODS: A total of 20 patients (5 men and 15 women), aged 25 to 60 years, who met the inclusion criteria, were enrolled in this study. A total of 60 teeth were randomly divided into 4 groups: G1, 980 nm diode laser (in 2 sessions within a 1-week interval); G2, Gluma (in 2 sessions within a 1-week interval); G3, 980 nm diode laser plus Gluma; and G4: control. Thermal (cold spray) and air blast (air syringe of dental unit) stimuli were used to evaluate cervical dentin hypersensitivity in the patients. Their pain response was assessed using a visual analogue scale (VAS) before treatment (baseline), in the first treatment session (15 minutes after treatment), in the second treatment session (after 1 week), and in 2-week, 1-month, and 3-month follow-up sessions. The obtained data were analysed using non-parametric tests, including Kruskal-Wallis test, Friedman test, Mann-Whitney test, and Wilcoxon test, in SPSS Version 22 at a significance level of P < .05. RESULTS: Based on the results, there was a significant difference in the average VAS scores for cold and air blast stimuli between the 4 groups 1 month after the intervention (P < .05). Meanwhile, the laser group had the lowest VAS score for cold and air stimuli. On the contrary, no significant difference was found between the 4 groups 3 months after the intervention (P ˃ .05). CONCLUSION: The present results showed that 980-nm diode laser alone was more effective than the other 2 intervention methods for 1 month. TRIAL REGISTRATION: The study was registered in the Iranian Registry of Clinical Trials (IRCT20120901010703N5).

The effect of 2% chlorhexidine iontophoresis on dentin sealing ability of etch-and-rinse adhesive: An in vitro study.

Background/purpose: Iontophoresis could enhance the delivery of chlorhexidine into oral tissue. This study aimed to determine the effect of 2% chlorhexidine iontophoresis (CHI) on the sealing ability of etch-and-rinse adhesive in human dentin using hydraulic conductance (HD) measurement, scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM-EDS). Materials and methods: Thirty-nine sound dentin specimens were prepared from 39 extracted intact third molars. Thirty specimens were used for HD measurement and randomly divided into 3 equal-sized groups; (1) No chlorhexidine treatment (control), (2) passive chlorhexidine treatment (CHT) and (3) CHI on acid-etched dentin. Each dentin surface was treated with etch-and-rinse adhesive. HD of each specimen was measured before treatment, after immediate bonding and after 14 days. The other 9 specimens were subjected to SEM-EDS analysis of the acid-etched dentin and the dentin treated with CHT and CHI. ANOVA test and Student-Newman-Keuls method were used for statistical analysis. Results: After bonding, there was no significant difference in percentage decrease of HD among the treatment groups (P > 0.05). After 14 days, CHI and CHT groups had greater percentage decrease of HD than the control (P < 0.001 and P = 0.009, respectively). Under SEM-EDS analysis, acid-etched dentin with CHI presented opened dentinal tubule orifices and more chlorhexidine precipitates on dentin than the dentin with CHT, which strongly related to a higher percentage of chloride ions on the CHI dentin surface (P < 0.001). Conclusion: The use of CHI on acid-etched dentin had a positive effect on dentin sealing ability of etch-and-rinse adhesive.

Development of a zinc chloride-based chemo-mechanical system for potential minimally invasive dental caries removal system.

Background/purpose: The chemo-mechanical caries-removal technique is known to offer advantages of selective dentin caries treatment while leaving healthy dental tissues intact. However, current sodium hypochlorite based reagents usually excessively damage dentin collagen. Therefore, the purpose of this study was to develop a novel chemo-mechanical caries-removal system to preserve the collagen network for subsequent prosthetic restorations. Materials and methods: The calfskin-derived collagen was chosen as a model system to investigate the dissolution behavior of collagen under different operating conditions of chemical-ultrasonic treatment systems. The molecular weight, triple-helix structure, the morphology, and functional group of collagen after treatment were investigated. Results: Various concentrations of sodium hypochlorite or zinc chloride together with ultrasonic machinery were chosen to investigate. The outcomes of circular dichroism (CD) spectra demonstrated stability of the triple-helix structure after treatment of a zinc chloride solution. In addition, two apparent bands at molecular weights (MWs) of 130 and 121 kDa evidenced the stability of collagen network. The positive 222 nm and 195 nm negative CD absorption band indicated the existence of a triple-helix structure for type I collagen. The preservation of the morphology and functional group of the collagen network on the etched dentin surface were investigated by in vitro dentin decalcification model. Conclusion: Unlike NaOCl, the 5 wt% zinc chloride solution combined with ultra-sonication showed dissolution rather than denature as well as degradation of the dentin collagen network. Additional in vivo evaluations are needed to verify its usefulness in clinical applications.

The Synergistic Effect of Ozonated Oil and Desensitising Toothpaste on Dentinal Tubule Occlusion: An In Vitro Study.

Introduction Dentin hypersensitivity (DH) is the most common problem encountered by clinicians. It can be managed either by blocking neural activities or by occluding tubules. Ozonated oil facilitates the simple passage of desensitizing agents into dentinal tubules. Aim This study aimed to evaluate the effect of ozonated oil on dentinal tubule occlusion before and after the application of desensitizing toothpaste. Materials and methods The study was carried out in Kalinga Institute of Dental Sciences, KIIT (Deemed to be University), Bhubaneswar, India. The sample size of the study was 80. The first group contained specimens for control. The second group comprised specimens treated with ozonated oil. The third group comprised specimens being treated with a desensitizing agent. The fourth group contained specimens treated with both the desensitizing agent and ozonated oil. The specimens then received an acid challenge. The specimens were observed under a scanning electron microscope (SEM) before any therapy, after the application of the therapeutic agents and after the 37.5% ortho-phosphoric acid challenge. Results Inferential statistics to compare between the groups was calculated using one-way analysis of variance (ANOVA) statistics. Post-hoc Tukey's honestly significant difference (HSD) was performed to compare the groups. The mean scores of the partial tubular occlusion of Group 1, Group 2, Group 3 and Group 4 before the acid challenge were 0.035, 0.691, 0.564 and 0.368, respectively. The maximum score was obtained in the case of Group 2, which was statistically significant. The mean scores for partial tubule occlusion after the acid challenge for Group 1, Group 2, Group 3 and Group 4 were 0.055, 0.531, 0.733 and 0.142, respectively. There was evidence of maximum partial tubule occlusion after the acid treatment in the case of Group 3. The mean scores of Group 1, Group 2, Group 3 and Group 4 before the acid challenge were 0.019, 0.309, 0.442 and 0.609, respectively. The maximum score was obtained in the case of Group 4, implying a greater number of total tubular occlusions before the acid challenge. The mean scores of the total tubular occlusions after the acid challenge for Group 1, Group 2, Group 3 and Group 4 were 0.047, 0.465, 0.272 and 0.890, respectively. There was evidence of maximum tubule occlusion in the case of Group 4, which was statistically significant. Conclusion Overall, the application of a desensitizing toothpaste with ozonated oil holds promise as a potentially more effective treatment approach for DH. Further research and clinical studies may be needed to fully validate its efficacy and safety in dental practice.

Effect of the timing of primary endodontic treatment and dosage of radiation therapy on the filling material removal.

This study investigated the effect of the timing of primary endodontic treatment and dosage of radiotherapy on the remaining filling material (RFM) during endodontic reintervention. 60 single-rooted human mandibular premolars were distributed into five groups (n = 12), according to the timing and dosage of radiation (55Gy or 70Gy): NegativeCG-non-irradiated teeth; Endo-pre-RT55/70-obturation before irradiation (55Gy or 70Gy); Endo-post-RT55/70-obturation and reintervention after irradiation (55Gy or 70Gy). Roots were cleaved and analysed under stereomicroscope and Scanning Electron Microscope to quantify (%) the RFM. Experimental groups had a significantly greater amount (p < 0.05) of RFM in the middle and apical thirds than the control group, except for Endo-pre-RT55 in the middle third (p < 0.0001). The apical third had greater amount of RFM (p < 0.05). Radiation therapy, before and after primary endodontic treatment, increased the amount of RFM, regardless of the dose delivered. When necessary, reintervention preferably must be performed before radiation therapy.

The effects of re-irradiation on the chemical and morphological properties of permanent teeth.

This study aimed to assess the in vitro effects of re-irradiation on enamel and dentin properties, simulating head and neck cancer radiotherapy retreatment. Forty-five human permanent molars were classified into five groups: non-irradiated; irradiated 60 Gy, and re-irradiated with doses of 30, 40, and 50 Gy. Raman spectroscopy, scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were employed for analysis. Raman spectroscopy assessed intensity, spectral area, and specific peaks comparatively. Statistical analysis involved Kolmogorov-Smirnov and One-Way ANOVA tests, with Tukey's post-test (significance level set at 5%). Significant changes in irradiated, non-irradiated, and re-irradiated enamel peaks were observed, including phosphate (438 nm), hydroxyapatite (582 nm), phosphate (960 nm), and carbonate (1070 nm) (p < 0.05). Re-irradiation affected the entire tooth (p > 0.05), leading to interprismatic region degradation, enamel prism destruction, and hydroxyapatite crystal damage. Dentin exhibited tubule obliteration, crack formation, and progressive collagen fiber fragmentation. EDX revealed increased oxygen percentage and decreased phosphorus and calcium post-reirradiation. It is concluded that chemical and morphological changes in irradiated permanent teeth were dose-dependent, exacerbated by re-irradiation, causing substantial damage in enamel and dentin.

Influence of etching mode on bonding performance of self-adhesive flowable resin composites to bovine teeth.

This study aimed to evaluate the bonding performance of self-adhesive flowable resin composites (SARs) to bovine teeth. Three SARs, one experimental, and two commercially available products, were used. The study parameters were shear bond strength (SBS), microleakage, and scanning electron microscopy (SEM) evaluation of bonding interfaces. The SBS of the materials was 14.1-15.1 MPa to enamel, 22.2-23.2 MPa to etched enamel, and 7.4-10.7 MPa to dentin. Specimens with pre-etching showed lower microleakage scores than those without pre-etching. SEM images of the interfaces of the materials showed excellent adaptation regardless of the substrate or etching mode. The study results indicate that enamel pre-etching can improve the bonding performance of SARs.

Optical penetration models for practical prediction of femtosecond laser ablation of dental hard tissue.

OBJECTIVES: To develop and practically test high-precision femtosecond laser ablation models for dental hard tissue that are useful for detailed planning of automated laser dental restorative treatment. METHODS: Analytical models are proposed, derived, and demonstrated for practical calculation of ablation rates, ablation efficiency and ablated morphology of human dental enamel and dentin using femtosecond lasers. The models assume an effective optical attenuation coefficient for the irradiated material. To achieve ablation, it is necessary for the local energy density of the attenuated pulse in the hard tissue to surpass a predefined threshold that signifies the minimum energy density required for material ionization. A 1029 nm, 40 W carbide 275 fs laser was used to ablate sliced adult human teeth and generate the data necessary for testing the models. The volume of material removed, and the shape of the ablated channel were measured using optical profilometry. RESULTS: The models fit with the measured ablation efficiency curve against laser fluence for both enamel and dentin, correctly capturing the fluence for optimum ablation and the volume of ablated material per pulse. The detailed shapes of a 400-micrometer wide channel and a single-pulse width channel are accurately predicted using the superposition of the analytical result for a single pulse. CONCLUSIONS: The findings have value for planning automated dental restorative treatment using femtosecond lasers. The measurements and analysis give estimates of the optical properties of enamel and dentin irradiated with an infrared femtosecond laser at above-threshold fluence and the proposed models give insight into the physics of femtosecond laser processing of dental hard tissue.

Evaluation of Microbiological Susceptibility and Long-term Adhesive Properties to Dentin of Primers with Terminalia catappa Linn.

PURPOSE: To investigate the antibacterial effects of Terminalia catappa Linn (TCL) leaf extracts at different concentrations and the effects of these extracts used as primers on the long-term adhesive properties of two universal adhesives. MATERIALS AND METHODS: After extract preparation, the antimicrobial and antibacterial activities of TCL against Streptococcus mutans (UA 159) were assessed in microdilution assays to provide the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Additionally, to provide quantitative data on the ability of TCL extract to reduce cell viability, colony forming units (CFU) were counted. To examine adhesive properties, 288 human molars were randomly assigned to 32 experimental conditions (n = 9) according to the following variables: (1) treatment agent: negative control (untreated surface), and primers at concentrations of 1xMIC, 5xMIC, and 10xMIC; (2) adhesives: Scotchbond Universal (SBU) and Futurabond Universal (FBU); (3) adhesive strategy: etch-and-rinse (ER) or self-etch (SE); and (4) storage time: 24 h or after 2 years. Primers were applied for 60 s, upon which the teeth were incrementally restored and sectioned into adhesive-dentin bonded sticks. These were tested for microtensile bond strength (µTBS) and nanoleakage (NL) after 24-h and 2-year water storage, as well as in-situ degree of conversion (DC) at 24 h. The chemical profile of the hybrid layer was determined via micro-Raman spectroscopy. Biofilm assay data were analyzed using the Kruskal-Wallis test; the pH of culture media and the chemical profile were analyzed by one-way ANOVA. The adhesive properties (µTBS, NL, DC) were evaluated using a four-way ANOVA and Tukey's test. Significance was set at 5%. RESULTS: Similar values of MIC and MBC were observed (2 mg/ml), showing bactericidal potential. CFU analysis demonstrated that concentrations of 5xMIC and 10xMIC significantly inhibited biofilm formation (p < 0.001). The application of the TCL primer at all concentrations significantly increased the immediate µTBS and DC, and decreased the immediate NL values when compared to the control group (p < 0.05), regardless of the adhesive and adhesive strategies. Despite an increase in the NL values for all groups after 2 years (p > 0.05), in groups where the TCL primer was applied, the µTBS remained constant after 2 years for both adhesives, while a decrease in the µTBS was observed in the control groups (p < 0.05). Usually, 10xMIC showed better results than 1xMIC and 5xMIC (p < 0.05). The application of TCL promoted cross-linking; cross-linking rates increased proportionally to the concentration of TCL (p < 0.05). CONCLUSION: Primers containing TCL promoted bactericidal and bacteriostatic action, as well as cross-linking with dentin, while maintaining the adhesive properties of the adhesive-dentin interface after 2 years of water storage.

Short-Wavelength Infrared Imaging of Infected and Affected Dentin.

Stains produced by bacteria or those found in blood and food byproducts accumulate in highly porous caries lesions. They can interfere with accurate diagnosis and the selective removal of carious tissue during cavity preparations. Short-wavelength infrared (SWIR) imaging studies have shown that stain molecules do not absorb light beyond 1200 nm. The objective of this study was to image affected and infected dentin atSWIR wavelengths. Sections of 3 mm thickness were cut from the extracted teeth with deep dentinal lesions. The sound (normal), affected (stained), and infected (demineralized) dentin on each section were examined with reflected light at wavelengths from 400 to 1700 nm, red and green fluorescence, and with optical coherence tomography (OCT). Microcomputed tomography (microCT) was used to measure the mineral density at each location investigated. Significant (p < 0.05) differences were observed in the reflected light intensity at 400-850 nm and for fluorescence between the sound, affected, and infected dentin. SWIR imaging did not show significant reductions in reflectivity for the affected and infected dentin. SWIR images may be valuable for monitoring the lateral spread of dentinal lesions on the occlusal surfaces of teeth.

Protective effect of various toothpastes and mouthwashes against erosive and abrasive challenge on eroded dentin: an in vitro study.

The study aimed to compare various toothpastes and mouthwashes on permanent tooth dentin after erosive and abrasive challenges. 130 sound premolars dentin were randomly submitted to an initial erosive challenge and a cycle of erosive and abrasive challenges for five days. The five experimental groups (n = 26) were: (1) Control group (artificial saliva), (2) Elmex erosion protection toothpaste and mouthwash, (3) Vitis anticaries biorepair toothpaste and mouthwash, (4) Oral B Pro-expert toothpaste and Oral B Fluorinse mouthwash, and (5) MI Paste ONE toothpaste and Caphosol mouthwash. Microhardness, surface roughness values, and the topographical characteristics of the dentin surface were assessed. The highest percentage of recovered dentin microhardness (%RDMH) value was observed in groups 2 and 4, followed by groups 5 and 3, respectively. The %RDMH values in groups 2 and 4 did not demonstrate a significant difference (p = 0.855). The highest percentage of improvement in surface roughness was recorded in groups 2 and 4, with no significant differences (p = 0.989). The atomic force microscopy (AFM) findings were consistent with the surface roughness data. The best recovery of dentin microhardness and roughness were measured with the Elmex and Oral B toothpaste and mouthwash, followed by MI Paste ONE toothpaste and Caphosol mouthwash and Vitis anticaries biorepair toothpaste and mouthwash.

FEA Comparison of the Mechanical Behavior of Three Dental Crown Materials: Enamel, Ceramic, and Zirconia.

The restoration of endodontically treated teeth is one of the main challenges of restorative dentistry. The structure of the tooth is a complex assembly in which the materials that make it up, enamel and dentin, have very different mechanical behaviors. Therefore, finding alternative replacement materials for dental crowns in the area of restorative care isa highly significant challenge, since materials such as ceramic and zirconia have very different stress load resistance values. The aim of this study is to assess which material, either ceramic or zirconia, optimizes the behavior of a restored tooth under various typical clinical conditions and the masticatory load. A finite element analysis (FEA) framework is developed for this purpose. The 3D model of the restored tooth is input into the FEA software (Ansys Workbench R23)and meshed into tetrahedral elements. The presence of masticatory forces is considered: in particular, vertical, 45° inclined, and horizontal resultant forces of 280 N are applied on five contact points of the occlusal surface. The numerical results show that the maximum stress developed in the restored tooth including a ceramic crown and subject to axial load is about 39.381 MPa, which is rather close to the 62.32 MPa stress computed for the natural tooth; stresses of about 18 MPa are localized at the roots of both crown materials. In the case of the zirconia crown, the stresses are much higher than those in the ceramic crown, except for the 45° load direction, while, for the horizontal loads, the stress peak in the zirconia crown is almost three times as large as its counterpart in the ceramic crown (i.e., 163.24 MPa vs. 56.114 MPa, respectively). Therefore, the zirconia crown exhibits higher stresses than enamel and ceramic that could increase in the case of parafunctions, such as bruxism. The clinician's choice between the two materials should be evaluated based on the patient's medical condition.

Comportamiento clínico, radiográfico e histomorfométrico del diente autólogo como biomaterial en elevación de seno maxilar de acceso lateral. Caso clínico con seis mese de seguimiento post-carga protésica / Clinical, radiographic and histomorphometric behaviour of the autologous tooth as a biomaterial in lateral access maxillary sinus elevation. Case report with six months of post-prosthetic loading follow-up

Introducción: la pérdida ósea tras las extracciones puede requerir en el maxilar posterior la realización de una elevación de seno para la correcta colocación de implantes. El hueso autólogo se considera el gold estándar, pero tiene una alta tasa de reabsorción y morbilidad, haciendo que haya otras alternativas como el diente autólogo, con buenos resultados en procedimientos regenerativos. Este caso clínico evalúa a nivel clínico, radiográfico e histomorfométrico el empleo del diente autólogo en elevación de seno maxilar y el comportamiento de dos implantes colocados de manera diferida. Caso clínico: se presenta el caso de una mujer de 48 años, que acudió a consulta para reponer el sector posterior derecho. Se realizó la exodoncia del 4.8 como diente donante para utilizarlo como biomaterial en una elevación de seno de acceso lateral, colocando dos implantes seis meses tras la intervención, y evaluándolos seis meses tras su carga protésica. Discusión: el diente autólogo en el presente caso clínico presentó un 30,56% de hueso neoformado tras seis meses de espera, con mejores resultados que al emplear aloinjertos y xenoinjertos. Además, diferentes aspectos culturales y étnicos respaldan la aceptación del diente autólogo por parte de los pacientes, aunque se necesitan más estudios a largo plazo para evaluar la estabilidad de este tipo de injerto en elevación de seno maxilar. Conclusiones: el diente autólogo en la elevación de seno ofrece biocompatibilidad, baja incidencia de complicaciones y buena aceptación por parte del paciente, con un buen comportamiento clínico y radiográfico de los implantes, a pesar del poco tiempo transcurrido en este caso tras la carga. (AU)

Introduction: Bone loss after extractions may require a sinus elevation to be performed in the posterior maxilla for the correct placement of implants. Autologous bone is considered the gold standard, but has a high rate of resorption and morbidity, leading to other alternatives such as autologous tooth, with good results in regenerative procedures. This case report evaluates at the clinical, radiographic and histomorphometric level the use of the autologous tooth in maxillary sinus elevation and the behaviour of two implants placed in a delayed manner. Case report: The case is presented of a 48-year-old woman who came for consultation to replace the right posterior sector. The extraction of 4.8 as a donor tooth was performed to use it as a biomaterial in a lateral access sinus elevation, placing two implants six months after the intervention, and evaluating them six months after their prosthetic loading. Discussion: The autologous tooth in this case report showed 30.56% of newly formed bone following a six-month wait, with better results than when allografts and xenografts were used. In addition, different cultural and ethnic aspects support the acceptance of the autologous tooth by patients. However, more longterm studies are needed to evaluate the stability of this type of graft in maxillary sinus elevation. Conclusions: The autologous tooth in the sinus elevation offers biocompatibility, low incidence of complications and good patient acceptance, with good clinical and radiographic behaviour of the implants, despite the short time elapsed in this case after loading.(AU)