Mesenchymal stem cells derived from human teeth and bone marrow have been characterized by many research groups, but demonstrate inconsistent cellular phenotypes or functions, partly because of differences in culture methodology. Therefore, our aims were to resolve these inconsistencies and discuss the potential uses of these cells in research/clinical applications. We isolated and characterized dental stem cells (DSCs) from the dental pulp, periodontal ligament, apical papilla (APSCs) and dental follicle (DFSCs) of mature and immature teeth, along with bone marrow-derived stem cells (BMSCs) from the iliac crest. We compared the clonogenic and proliferative potentials of these cells in terms of colony-forming efficiency, proliferation potential, population doubling time and cell cycle. All DSCs, particularly APSCs and DFSCs, possessed greater proliferative potential than BMSCs. All stem cells expressed typical mesenchymal and embryonic markers, and developed alizarin red-positive mineralization nodules and Oil red O-positive lipid droplets when cultured in osteogenic and adipogenic media, respectively. Immunocytochemistry revealed that all stem cells developed neuronal markers when cultured in a control medium without neural inductive supplements. After 7 days of neurogenic culture, the differentiated cells showed a transition from fibroblast-like to neuron-like cell bodies with long processes, suggesting that the stem cells differentiated into mature neurons. Karyotyping confirmed that the stem cells maintained a normal karyotype and were chromosomally stable. Our results provide new insights into the physiological properties of stem cells with a normal karyotype and indicate that DSCs are appropriate for basic research and clinical applications.
Over the past decade, platelet-rich plasma (PRP), a platelet-concentrated plasma fraction, has been widely investigated and applied to regenerative medicine. The clinical utility of PRP is supported by evidence that PRP contains high concentrations of platelet-related growth factors and normal concentrations of plasma-derived fibrinogen, both of which contribute synergistically to the regenerative process. Additionally, its superior cost-efficacy versus conventional therapies is attractive to many clinicians. However, current disadvantages of PRP include a relatively complicated preparation procedure and variable operator-dependent efficacy. An additional disadvantage is the use of bovine thrombin, an animal-derived biological, as a coagulant. Many of these disadvantages are overcome by recent advances in preparation procedures and devices; for example, Joseph Choukroun simplified the platelet-rich fibrin preparation procedure and improved handling efficiency without the aid of animal-derived factors. With advancements in cell processing technology, there has been a general shift in cell therapy from autologous to allogeneic treatment; however, autologous PRP therapy will not easily be replaced by allogeneic treatment in the near future. Therefore, to provide more predictable regenerative therapy outcomes using autologous PRP, further investigations should address developing a standardized procedure for PRP preparation to augment its efficacy and potency, independent of donor variability. We would then propose that operators and clinicians prepare PRP according to the standardized protocol and to carefully evaluate the clinical scenario (i.e., recipient factors comprising skeletal defects) to determine which factor(s) should be added to PRP preparations. This careful approach will lead to improved clinical outcomes for patients.
Certain cell populations within periodontal tissues possess the ability to induce regeneration, provided they have the opportunity to populate the wound or defect. Guided regeneration techniques have been investigated for regenerating periodontal tissues and such therapies usually utilize barrier membranes. Various natural and synthetic barrier membranes have been fabricated and tested to prevent epithelial and connective tissue cells from invading while allowing periodontal cells to selectively migrate into the defect. This paper focuses on the literature relevant to the use and potential of resorbable collagen membranes in GBR procedures, sites of periodontal and intrabony defects, in cases of socket and alveolar ridge preservation and at implant sites. The results of their use in GBR procedures has shown them to be effective and comparable with non-resorbable membranes with regards to clinical attachment gain, probing depth reduction and defect bone filling. They have also shown to prevent epithelial ingrowth into the defect space during the initial wound healing phase postsurgically. Collagen membranes have also been used for root coverage and GBR procedures and have shown good success rates comparable to subepithelial connective tissue grafts and expanded-polytetrafluoroethylene (e-PTFE) membranes. The future for periodontal tissue engineering is very exciting with the use of barrier membranes expected to continue playing a critical role. However, long-term clinical trials are required to further evaluate and confirm the efficacy of the available collagen barrier membranes for periodontal and bone regeneration use.
For decades, physicians and dentists have paid close attention to their own respective fields, specializing in medicine pertaining to the body and the oral cavity, respectively. However, recent findings have strongly suggested that oral health may be indicative of systemic health. Currently, this gap between allopathic medicine and dental medicine is quickly closing, due to significant findings supporting the association between periodontal disease and systemic conditions such as cardiovascular disease, type 2 diabetes mellitus, adverse pregnancy outcomes, and osteoporosis. Significant effort has brought numerous advances in revealing the etiological and pathological links between this chronic inflammatory dental disease and these other conditions. Therefore, there is reason to hope that the strong evidence from these studies may guide researchers towards greatly improved treatment of periodontal infection that would also ameliorate these systemic illnesses. Hence, researchers must continue not only to uncover more information about the correlations between periodontal and systemic diseases but also to focus on positive associations that may result from treating periodontal disease as a means of ameliorating systemic diseases.
The aim of the present study was to compare the cyclic fatigue resistances of HyFlex EDM (HEDM), WaveOne Gold (WOG), Reciproc Blue (RB), and 2Shape (TS) NiTi systems having different metallurgic properties. HEDM, WOG, RB, and TS instruments were rotated in artificial canals which were made of stainless steel with an inner diameter of 1.5mm, 45 degrees, and 90 degrees angles of curvatures and a radius of curvature of 5mm until fracture occurred, and the time to fracture (TTF) was recorded in seconds. Also, number of cycles to fracture was calculated (NCF). Data were statistically analyzed using Kruskal-Wallis and t test. The statistical significance level was set at P0.05). When the NCF values were taken into consideration, HEDM reported a significantly higher cyclic fatigue resistance than TS in both canal curvatures analyzed (P<0.05). Within the limitations of the present study, RB NiTi files showed statistically higher cyclic fatigue resistance in artificial canals with 45 degrees and 90 degrees than the other NiTi files tested.
The aim was to evaluate the influence of different irrigation solutions on the push-out bond strength (POBS) of three different sealers (AH Plus, BioRoot RCS, GuttaFlow2). Root canals of 180 single-rooted human teeth were instrumented with F360 up to size 45.04. All canals were irrigated with 5 ml NaOCl 3% and 5 ml EDTA 17%. The canals were finally irrigated with either 5 ml NaOCl 3%, CHX 2%, EDTA 17%, citric acid 20% or NaCl 0.9% (n = 36) with a contact time of 5 min and obturated using matching gutta-percha cones according to the single-cone technique in combination with one of the sealers (n = 12). After 8 weeks of incubation, the roots were embedded in resin. Two slices of 1 mm thickness were obtained representing the middle third of the root. Dislodgement resistance was measured and POBS was calculated. Specimens were examined under 4× magnification to determine the mode of bond failure. Statistical analysis was performed using two-way ANOVA and Student–Newman–Keuls test for POBS and Chi-square test for the mode of failure. POBS was significantly affected by the factor “sealer” (P 0.05). The POBS of AH Plus was positively influenced by EDTA and NaOCl. EDTA had a negative effect on the POBS of BioRoot RCS. The POBS of GuttaFlow2 was not influenced by the irrigation solutions.
Porphyromonas gingivalis (P. gingivalis) and nicotine have been implicated as a major pathogen in the development and progression of periodontitis. One of the possible mechanism is via the oxidative stress of human periodontal ligament fibroblasts (PDLF) which lead to the damage of cell viability and function. This study aimed to investigate oxidative stress (OS) levels in the cultured media of human PDLF under the induction of P. gingivalis lysate and nicotine. Primary PDLF was cultured in growth media under P. gingivalis or/and nicotine treatment in different concentrations for 2 and 24 h. Following incubation, oxidative stress molecules malondialdehyde (MDA) and oxidized guanine species (Ox-GS) from the cell cultured supernatant were determined by spectrophotometric assay and ELISA, respectively. DCFDA and superoxide assays were performed to verify the production of ROS and intracellular superoxide radical under various stimuli. As a result, at both 2 and 24 h, Ox-GS and MDA levels in the medium of cells treated with different concentrations of P. gingivalis lysate and nicotine, either separately or in combination, were significantly different from the negative controls in a dose- and time-dependent manner. Interestingly, except MDA levels in P. gingivalis lysate at 20 µg/ml, MDA levels in all other tested conditions were found as same as one in the positive controls after 24 h. ROS and superoxide production were enhanced under P. gingivalis and/or nicotine stimulation. Therefore, OS biomarkers were generated by PDLF upon treatment with periodontal pathogens and nicotine which could elucidate a potential local mechanism of periodontal disease etiology via superoxide mediation.
Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a chronic, systemic, inflammatory condition of unknown etiology. Histopathologic examination is the key to diagnosis of IgG4-RD. The histopathologic features of IgG4-RD are lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis. As for fewer than 15 years, IgG4-RD has been recognized as a unified diagnostic entity. CD4+ T and B cells, which likely cause organ damage and disabling tissue fibrosis, constitute the major inflammatory cell population in patients with IgG4-RD. Affected patients with active, untreated disease have a marked expansion of IgG4-secreting plasmablasts in the blood. Important mechanistic insights regarding the pathogenesis of IgG4-RD have been gradually disclosed in recent years. Exploring the role of interactions between these CD4+ T and B cells in patients with IgG4-RD is a highly promising field of investigation. In this review, we focus on CD4+ T cell subsets and the T-cell clones that are involved in the pathogenesis of IgG4-RD.
This study aims to evaluate the effects of etching with sulfuric acid (SA) and vinyl sulfonic acid (VSA) on the bond strength between a light-curing indirect resin composite and polyetherketoneketones (PEKK). PEKK specimens were ground with 600 silicon carbide papers, etched with 90% SA for 5 s (90-5 SA) or 95% VSA for 30 s (95-30 VSA), and then modified with a phosphate primer; afterward, a light-curing resin composite was veneered on the specimens. Two control groups were also prepared without etching (unetched/unprimed and unetched/primed). After 20,000 thermocycles in water at 4 and 60 °C, the shear bond strengths of the specimens were determined and subjected to a nonparametric (Steel–Dwass) test (α = 0.05, n = 8). The etched surfaces were observed by scanning electron microscopy (SEM) at 2000× magnification. Higher bond strengths were obtained when the PEKK surface was etched with 90-5 SA or 95-30 VSA (90-5 SA/unprimed 24.3 ± 4.3 MPa, 90-5 SA/primed 26.2 ± 3.2 MPa, 95-30 VSA/unprimed 23.7 ± 2.5 MPa, 95-30 VSA/primed 24.3 ± 4.1 MPa), and these values were not statistically different, whereas the two control groups exhibited significantly lower bond strengths (unetched/unprimed 12.2 ± 1.7 MPa, unetched/primed 9.5 ± 2.7 MPa). SEM observations revealed that 95-30 VSA led to a microporous (felt-like) surface, which was different from the surface structure etched with 90-5 SA. Etching the PEKK surface with SA or VSA significantly improved the bond strength between resin composite and PEKK in contrast with the application of the phosphate primer. Appropriate chemical etching could be a useful option when fabricating prostheses using PEKK-based materials and indirect resin composites.
The aim of the present study was to evaluate the difference in cyclic fatigue resistance between OneCurve (OC) and OneShape (OS) endodontic single-file NiTi systems in a severely curved artificial canal. After sample size calculation (α = 0.01; β = 0.20; σ = 20.0; δ = 20.0), 25 OC and 25 OS files were used. An artificial canal with 60° angle and 5-mm radius of curvature was milled in a stainless-steel block reproducing the size and taper of the files used. The test device was electrically heated to maintain the environmental temperature at 37 °C. All files were rotated until fracture; the time to failure was recorded and the number of cycles to fracture (NCF) calculated. The length of the fractured fragments was measured too. Fractographic examination and cross-sectional area calculation were performed by scanning electron microscopy analysis (SEM). Data were statistically analyzed using an independent sample t test. The significance level was set at 0.01. Statistical analysis showed that OC files exhibited significantly greater cyclic fatigue resistance than OS (p 0.01). SEM fractographic analysis confirmed that all the scanned samples separated due to cyclic fatigue. Within the limitations of the present study, OC endodontic instruments resisted to cyclic fatigue better than OS. The improved mechanical resistance of OC could be related to new NiTi alloy used for their manufacturing.
The aim was to compare the canal straightening of M-wire [Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland)] and gold- and blue-wire heat-treated [Reciproc blue (VDW) and WaveOne Gold (Dentsply Maillefer)] instruments in severely curved root canals. A total of 80 root canals in extracted human teeth with angles of curvatures ranging between 25° and 35° and radii ranging between 3.1 and 8.5 mm were divided into four groups (n = 20). Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature (P = 1.0 and P = 1.0, respectively). All canals were prepared to an apical size 25 according to the manufacturers’ instructions. Pre- and post-instrumentation radiographs were superimposed and canal straightening was analysed using a computer imaging programme. Preparation time and instrument failure were also recorded. Data were analysed statistically using ANOVA and Student–Newman–Keuls test. During preparation no instrument fractured. All instruments maintained the original canal curvature well with no significant differences between the instruments (P = 0.278). Regarding preparation time, no significant differences between the four instruments were obtained (P > 0.05). Under the conditions of this study, all instruments respected the original canal curvature well. Instruments were safe to use. The use of the gold- and blue-wire heat-treated instruments was not associated with an improved shaping ability.
This study aimed to evaluate color longevity after 2 years of whitening gel (6% hydrogen peroxide (HP), blue LED/infrared laser activation system) in comparison to a control 35% concentration in a split-mouth study and investigate the long-term effect on quality of life (QOL).Thirty-one patients were treated. Whitening using 6% or 35% HP gel was performed on half of the upper jaw in each patient. The color was measured at baseline and 1 week, 1 month, 1 and 2 years after treatment using the Easyshade Vita spectrophotometer and the Vita Bleached and Vita Classical Shade Guides organized by value. During 2 years of follow-up, color was evaluated before and after dental prophylaxis. Oral Health of Impact Profile (OHIP 14) and Psychosocial Impact Dental Aesthetics Questionnaire (PIDAQ) surveys measured QOL. Nineteen patients were evaluated at the 2-year follow-up. Significant differences in ΔE were measured between the two groups at all time points (p 0.05). The positive effect of bleaching on QOL was maintained in patients treated with a low concentration of the whitening gel. The two compounds remained effective after 2 years. An objective color difference was found between the groups, but no difference was observed in subjective reports. The positive effect on QOL remained after 2 years of follow-up in this cohort of patients. ClinicalTrials.gov identifier NCT02353611.
This study evaluated characteristics of light transmission, degree of monomer conversion and surface microhardness of bulk fill, conventional and fiber-reinforced resin based composites (RBCs) through different incremental thicknesses of resin composite. Working hypotheses was that there are differences in transmission of blue light through RBCs of different kinds and that the thickness of the increments influence the degree of monomer conversion of RBCs. Six bulk fill, three conventional nanohybrid, one short fiber reinforced and one flowable RBCs were evaluated. For each material, four different incremental thicknesses (1, 2, 3 and 4 mm) were considered (n = 5). The specimens were prepared in cylindrical Teflon molds that are open at the top and the bottom sides and cured for 40 s by applying the curing unit. After curing process, the specimens were ground with a silicon carbide paper with a grit size of 1200 and 4000, and then stored dry at 37 A degrees C for 24 h. Light transmission, degree of monomer conversion, surface microhardness were measured and data were analyzed using ANOVA (p = 0.05). There were differences in light transmission of resin composites of various types and brands. Low-viscous bulk fill and short fiber-reinforced RBCs presented higher light transmission compared to resin composites of higher viscosity. Reduced light transmission and lower surface microhardness and DC % at bottom side of the specimen suggests that more attention needs to be paid to ensure proper curing of the resin composite in deep cavities.
To evaluate the stain susceptibility of CAD/CAM blocks and direct composite after long term exposure to various staining agents. 40 disk-shaped samples were fabricated from each of nine materials; six CAD/CAM (Vitablocs Mark II, Paradigm MZ100, Experimental Vita Hybrid Ceramic, Vita Enamic, Experimental Kerr and Lava Ultimate) and three direct composites (Filtek Supreme, Venus Diamond and Filtek Silorane). Samples were randomly divided into five groups (n = 8) according to different staining solutions (distilled water, tea, red wine, coffee and artificial saliva). Initial L*a*b* values were assessed using a calibrated digital spectrophotometer. Specimens were immersed in staining solutions and stored in an incubator at 37 °C for 120 days. L*a*b* values were assessed again and color change (∆E) was calculated as difference between recorded L*a*b* values. ANOVA, and Duncan test were used to identify differences between groups (α = 0.05). Significant differences in ∆E values were detected between materials (p = 0.000). Among all staining solutions, the highest ∆E value was observed with red wine. The new CAD/CAM blocks (Vita Enamic, Vita Hybrid Ceramic and Lava Ultimate) showed the highest resistance to staining compared to the MZ100 composite resin blocks. Filtek Silorane, a direct composite, showed high stain resistance values compared to CAD/CAM materials and other direct composites. Ceramic and composite CAD/CAM blocks had lower staining susceptibility than methacrylate based direct composite. Staining susceptibility of the new resin based CAD/CAM materials Vita Enamic and Lava Ultimate was comparable to feldspathic ceramic blocks (Vitablocs Mark II). Filtek Silorane showed promising results that were comparable to some CAD/CAM blocks.
Curcumin, a yellow phytochemical found in the rhizomes of Curcuma longa, has various biological effects, including anti-oxidant and anti-inflammatory activities. In the present study, we examined the effect of curcumin on the expression of inflammatory cytokines in human gingival epithelial progenitor cells (HGEPs) stimulated for a prolonged period with lipopolysaccharide (LPS) derived from Porphyromonas gingivalis. The cells were alternately cultured with LPS and/or curcumin every 3 days for 18 days. The expression levels of TNF-α, IL-1β, IL-6, TIMP-1, and MMP-9 in the HGEPs were evaluated by quantitative real-time polymerase chain reaction. Enzyme-linked immunosorbent assay was used to measure the concentrations of these five proteins in the supernatant and nuclear factor (NF)-κB in the nuclear extracts. Curcumin inhibited the mRNA expression levels of TNF-α, IL-1β, IL-6, and MMP-9 in HGEPs treated with curcumin over a prolonged period. Similarly, the expression levels of IL-1β, IL-6, and MMP-9 were decreased in the culture supernatants. NF-κB activity was also inhibited in the cells cultured with curcumin. In conclusion, these findings indicate that curcumin inhibits the expression of inflammatory cytokines and MMP-9 in primary gingival epithelial cells stimulated with P. gingivalis-derived LPS via NF-κB activation.
The purpose of this study was to examine the influence of thickeners with different levels of thickness on the sizes of particles in food boluses. In medical and nursing care, thickeners are used to make food safe for patients with dysphagia. However, the effect of thickeners on the foods they are added to, especially during swallowing, is still unclear. The bolus particles of 20 healthy volunteers were photographed, and the digital images were used to estimate the sizes of particles in them. Eight test samples with thickeners with different levels of thickness were tested: six grades of thickened carrot juice with raw carrots in it, raw carrot with banana, and raw carrot alone. The particle homogeneity index (HI) and particle size index (SI) just before swallowing were calculated. The viscosities of the liquid part of the test samples were also measured. The number of mastication cycles across the test samples was not significantly different. However, significant differences were found in SI and HI across the test samples: the absolute values of SI and HI tended to rise as the thickness of the test sample increased. The viscosity of the liquid part of the test sample also increased as the thickness increased. The differences in the thickness of food had an influence on the bolus particle sizes just before swallowing.
Several growth factors and their receptors, such as epidermal growth factor receptor, have been studied as prognostic biomarkers for many epithelial malignancies. The signal transduction cascade of those receptors includes RAS/RAF/ERK, PI3K/Akt/mTOR, and STAT3 pathways. The aim of this study was to investigate the expression levels of several key proteins of those pathways in patients with oral squamous cell carcinoma (OSCC) and oral epithelial precursor lesions (OEPLs), and to correlate the expressions of these proteins with clinicopathologic features and prognosis. Fifteen leukoplakia (LP), 15 low-grade epithelial dysplasia, 15 high-grade epithelial dysplasia (HD), and 132 OSCC specimens were immunohistochemically examined for KRAS, HRAS, NRAS, BRAF, pERK1/2, pAkt, pmTOR, and pSTAT3 expression. Immunoreactivity for these molecules predominantly occurred in regions OEPL basal to prickle layers and in most OSCC cells. KRAS and NRAS expression was significantly lower in OSCC than in OEPLs, while pAkt and pmTOR showed higher expression in OSCC than in OEPLs. pERK1/2 expression was significantly higher in HD than in LP. In OSCC, KRAS and NRAS immunoreactivity was significantly higher in advanced age and male gender. In addition, higher immunoreactivity was shown in pERK1/2 in female gender and advanced TNM stage, pAkt in advanced T classification and cases without postoperative metastasis, pmTOR in advanced mode of invasion, and pSTAT3 in invasion depth. Correlations between these markers and clinicopathological variables were also noted. MAPK, Akt, and STAT3 pathways might play diverse roles in oral carcinogenesis.
Dysphagia prevalence has increased with increasing elderly population worldwide. Therefore, early detection of dysphagia has become increasingly important. Repetitive saliva swallowing test (RSST), modified water swallowing test (MWST), and cervical auscultation, which are convenient for non-experts to assess eating and swallowing and have been frequently used in Japan since 20 years. Using aspiration and pharyngeal residues, the objective of this study was to elucidate the efficacy of the three screening tests performed by non-experts in patients who had swallowing disorders. In total, 102 patients with cerebrovascular diseases who were suspected of having dysphagia were assessed. A swallowing team assessed their swallowing capabilities; videofluoroscopy and screening tests were performed. RSST, MWST, and cervical auscultation were performed by junior dentists who were non-experts in dysphagia. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio in each examination were evaluated using results of aspiration in videofluoroscopy and pharyngeal residues. For aspiration, the highest sensitivity with cervical auscultation (VES) was 93.7%. For pharyngeal residue, the highest sensitivity with cervical auscultation (VES) was 84.3%. For piriform sinus residue, the highest sensitivity with cervical auscultation (VES) was 86.4%. Despite being evaluated by a non-expert, the sensitivity of cervical auscultation (VES) and MWST was ≥ 80%, suggesting their effectiveness as prescreening tests, although the range of specificity was 25.5–68.4% in all examinations. These tests are easy to perform and useful to screen for aspiration or pharyngeal residues before precision tests.
The aim of this study was to evaluate self-reported periodontitis (PD) prevalence in migraineurs as well as to investigate the association between both diseases. A cross-sectional survey was carried out including patients diagnosed with migraine attending 12 Spanish Headache Units. We determined diagnosis of PD administering a validated self-reported questionnaire. Socio-demographic, clinical and medical information, comorbidities, daily habits, migraine characteristics and medication were collected using a questionnaire. Of the 651 consecutive migraineurs included in the study, 393 suffered from chronic migraine (CM). Self-reported PD was detected in 327 patients with migraine (50.2%). Migraineurs with self-reported PD were significantly older and had a previous history of fibromyalgia, stress, anxiety, depression, and allodynia (all P < 0.001). Additionally, this group of patients consumed more topiramate (P = 0.008) and simple analgesics (P < 0.001) than patients with migraine and without self-reported PD. Also, they were less active physically and belonged to a low education level (both P < 0.001). Prevalence of self-reported PD was significantly higher in chronic migraineurs compared to those diagnosed with episodic migraine (EM) (53.9% vs. 44.6%, P = 0.019). Logistic regression analyses showed that self-reported PD was associated with CM (OR 1.456; 95% CI 1.062-1.997, P = 0.020). However, after adjusting for significant confounders, the association was attenuated (OR 1.100; 95% CI 0.784-1.543, P = 0.581). We concluded that self-reported PD was significantly more frequent in CM compared to EM. Self-reported PD was associated with the presence of CM, although some comorbidities shared by both diseases could have an effect on this association.
Glass ionomer cement is a widely used luting agent for indirect restorations but presents inferior mechanical properties compared to resin cement due to its low elastic modulus. This study evaluated the mechanical and adhesion properties of glass ionomer luting cements reinforced with nano-sized hydroxyapatite particles (HA). The nano-sized HA particles were synthesized using the co-precipitation technique and the resulting precipitate was characterized using X-ray diffraction analysis (XRD), field emission scanning electron (FESEM) and transmission electron microscopy (TEM). HA particles were incorporated into the glass powder (FUJI I, GC) and the luting agent was manipulated in a liquid to powder ratio of 3:1 into 6% by weight after determining the best ratio. The flexural strength of the luting agent and shear bond strength of dentin were analyzed and compared to other luting agents namely, (a) glass ionomer (FUJI I), (b) resin-modified glass ionomer (RelyX Luting Plus) and (c) adhesive resin cement (RelyX U200). Failure types after debonding from dentin were evaluated under SEM. Flexural strength and bond strength data were analyzed using one-way ANOVA and Tukey's tests (alpha = 0.001). Addition of 6 w % HA particles in the range of 80-150 nm enhanced the flexural strength (30.97 ± 5.9 versus 11.65 ± 5.63) and shear bond strength (0.97 ± 0.41 versus 0.39 ± 0.16) of a conventional glass ionomer luting agent significantly compared to the non-reinforced ones when manipulated at a liquid to powder ratio of 3:1 (P < 0.001). While conventional glass ionomer, HA-reinforced glass ionomer and resin-modified glass ionomer specimens showed exclusively mixed type of failures, adhesive resin cement showed cohesive failures within the resin cement. Increased mechanical and adhesion potential of the experimental glass ionomer luting agent after incorporation of HA particles could expand the scope of application of this cement.