In vitro antibacterial and remineralizing effect of adhesive containing triazine and niobium pentoxide phosphate inverted glass

Effect of the addition of silver nanoparticles on the mechanical properties of an orthodontic adhesive

Objectives

This study evaluated the effects of adding silver nanoparticles on the shear bond strength, microhardness, and surface roughness of orthodontic adhesives.

Material and Methods

Fifty upper premolars were randomly allocated to five groups (n = 10). Orthodontic brackets were bonded with silver nanoparticle (AgNP)-modified adhesives (1 %, 0.5 %, 0.1 %, 0.05 %), and conventional adhesive was used as a control. The shear bond strength was recorded using a universal testing machine, and the adhesive remnant index was evaluated using a stereomicroscope. Ten discs of each adhesive were subjected to the microhardness and surface roughness tests. The Vickers microhardness values were measured under a constant load of 100 g for 30 s using a microhardness tester. The samples were analyzed using a surface profilometer, and the arithmetic average roughness was used as the measurement parameter. Data were analyzed using one-way analysis of variance and chi-square tests. A significance level of 5 % was considered significant.

Results

AgNP concentration > 0.1 % significantly reduced the shear bond strength (p < 0.05). At higher AgNP concentration, the bonding failure pattern occurred mainly at the bracket-resin interface. The Vickers microhardness increased with increasing concentration, and significant differences were observed between the group with 1 % AgNP and the other groups (p < 0.05). The average roughness values were similar between the groups with AgNP concentrations > 0.1 % (p > 0.05).

Conclusion

The incorporation of AgNP into an orthodontic adhesive has the potential to decrease the shear bond strength while increasing the microhardness and surface roughness.

Bioceramic micro-fillers reinforce antibiofilm and remineralization properties of clear aligner attachment materials

Introduction: Clear aligners, while offering a more hygienic alternative to fixed appliances, are still associated with challenges including plaque accumulation and enamel demineralization. The aim of the present study was to investigate the antibiofilm and remineralization effectiveness of innovative flowable composite attachments containing bioceramic micro-fillers. Methods: Four experimental attachments were formulated and bonded to human enamel specimens: 3M Filtek Supreme flowable composite (Filtek SF) + 10% bioactive glass 45S5 (BAG), Filtek SF + 30% BAG, Filtek SF + 10% Bredigite (BRT), Filtek SF + 30% BRT. Plaque biofilms were grown on the bonded enamel using a standardized protocol and the biofilm-killing effect was assessed by confocal laser scanning microscopy and scanning electron microscopy. Vickers microhardness was measured to evaluate the remineralization effect of the attachments containing bioceramic fillers after acid challenge. Shear bond test was performed to assess the bonding strength. Results: Attachments with bioceramic fillers significantly inhibited plaque biofilm growth in 3 weeks on enamel, contributing over 20% bacterial cell killing in 10% filler groups and over 30% killing in 30% filler groups. All four experimental groups demonstrated significantly higher microhardness values than the control group without fillers on the attachment side. The shear bonding strength was not compromised in the attachments with micro-fillers. Discussion: Proper incorporation of bioceramic micro-fillers in attachments provides an innovative approach for clear aligner therapy with reinforced antibiofilm and remineralization effects without weakening shear bonding strength.

Extensive Investigation on the Effect of Niobium Insertion on the Physical and Biological Properties of 45S5 Bioactive Glass for Dental Implant

Dental implants have emerged as one of the most consistent and predictable treatments in the oral surgery field. However, the placement of the implant is sometimes associated with bacterial infection leading to its loss. In this work, we intend to solve this problem through the development of a biomaterial for implant coatings based on 45S5 Bioglass® modified with different amounts of niobium pentoxide (Nb2O5). The structural feature of the glasses, assessed by XRD and FTIR, did not change in spite of Nb2O5 incorporation. The Raman spectra reveal the Nb2O5 incorporation related to the appearance of NbO4 and NbO6 structural units. Since the electrical characteristics of these biomaterials influence their osseointegration ability, AC and DC electrical conductivity were studied by impedance spectroscopy, in the frequency range of 102–106 Hz and temperature range of 200–400 K. The cytotoxicity of glasses was evaluated using the osteosarcoma Saos-2 cells line. The in vitro bioactivity studies and the antibacterial tests against Gram-positive and Gram-negative bacteria revealed that the samples loaded with 2 mol% Nb2O5 had the highest bioactivity and greatest antibacterial effect. Overall, the results showed that the modified 45S5 bioactive glasses can be used as an antibacterial coating material for implants, with high bioactivity, being also non-cytotoxic to mammalian cells.

Bioactive glasses incorporating less-common ions to improve biological and physical properties

Bioactive glasses (BGs) have been a focus of research for over five decades for several biomedical applications. Although their use in bone substitution and bone tissue regeneration has gained important attention, recent developments have also seen the expansion of BG applications to the field of soft tissue engineering. Hard and soft tissue repair therapies can benefit from the biological activity of metallic ions released from BGs. These metallic ions are incorporated in the BG network not only for their biological therapeutic effects but also in many cases for influencing the structure and processability of the glass and to impart extra functional properties. The "classical" elements in silicate BG compositions are silicon (Si), phosphorous (P), calcium (Ca), sodium (Na), and potassium (K). In addition, other well-recognized biologically active ions have been incorporated in BGs to provide osteogenic, angiogenic, anti-inflammatory, and antibacterial effects such as zinc (Zn), magnesium (Mg), silver (Ag), strontium (Sr), gallium (Ga), fluorine (F), iron (Fe), cobalt (Co), boron (B), lithium (Li), titanium (Ti), and copper (Cu). More recently, rare earth and other elements considered less common or, some of them, even "exotic" for biomedical applications, have found room as doping elements in BGs to enhance their biological and physical properties. For example, barium (Ba), bismuth (Bi), chlorine (Cl), chromium (Cr), dysprosium (Dy), europium (Eu), gadolinium (Gd), ytterbium (Yb), thulium (Tm), germanium (Ge), gold (Au), holmium (Ho), iodine (I), lanthanum (La), manganese (Mn), molybdenum (Mo), nickel (Ni), niobium (Nb), nitrogen (N), palladium (Pd), rubidium (Rb), samarium (Sm), selenium (Se), tantalum (Ta), tellurium (Te), terbium (Tb), erbium (Er), tin (Sn), tungsten (W), vanadium (V), yttrium (Y) as well as zirconium (Zr) have been included in BGs. These ions have been found to be particularly interesting for enhancing the biological performance of doped BGs in novel compositions for tissue repair (both hard and soft tissue) and for providing, in some cases, extra functionalities to the BG, for example fluorescence, luminescence, radiation shielding, anti-inflammatory, and antibacterial properties. This review summarizes the influence of incorporating such less-common elements in BGs with focus on tissue engineering applications, usually exploiting the bioactivity of the BG in combination with other functional properties imparted by the presence of the added elements.

Physicochemical and biological evaluation of a triazine-methacrylate monomer into a dental resin

OBJECTIVES

This study aimed to (1) formulate blend resins with 2.5 or 5 wt.% of the methacrylate monomer 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAT), and (2) to evaluate the blend resins regarding the physicochemical and biological properties.

METHODS

The base resin was formulated mixing 60 wt.% of bisphenol A glycol dimethacrylate and 40 wt.% of triethylene glycol dimethacrylate with photoinitiator/co/initiator system. TAT was added at 2.5 (G_2.5%) or 5 (G_5%) wt.%, and a group without TAT was used as control (G_ctrl). The resins were analyzed for degree of conversion (DC), Knoop hardness (KHN), softening in solvent (ΔKHN), ultimate tensile strength (UTS), contact angle, surface free energy (SFE), antibacterial activity against Streptococcus mutans biofilm formation, and cytotoxicity against human keratinocytes.

RESULTS

There was no difference for the DC (p = 0.676). The addition of TAT at 5 wt.% induced higher KHN (p<0.001), higher resistance against softening in solvent (p<0.001), and higher UTS (p = 0.04). There were no statistically significant differences for contact angle with water (p = 0.106), α-bromonaphtalene (p = 0.454), and SFE (p = 0.172). The higher the TAT concentration, the higher the antibacterial activity (p<0.001). G_2.5% showed no cytotoxicity compared to G_ctrl (p>0.05), and G_5% induced lower cell viability (p<0.05).

CONCLUSIONS

The addition of 2.5 wt.% of TAT is suitable for conveying antibacterial activity for dental resins without changing the physicochemical properties or impairing the cytotoxic effect.

CLINICAL RELEVANCE

Methacrylate monomers that decrease bacterial viability and copolymerize with the resin matrix are exciting approaches to developing therapeutic materials. TAT showed promising properties to may hamper and prevent carious lesions when incorporated into dental materials. Further evaluations with higher cariogenic challenges will be carried to analyze the formulated materials.

Physicochemical properties and biological effects of quaternary ammonium methacrylates in an experimental adhesive resin for bonding orthodontic brackets

METHODOLOGY

Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes.

RESULTS

The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p<0.05). None of the groups presented any differences for SBS (p>0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05).

CONCLUSION

Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.

Titanium dioxide nanotubes with triazine-methacrylate monomer to improve physicochemical and biological properties of adhesives

OBJECTIVE

Formulate experimental adhesives containing titanium dioxide nanotubes (nt-TiO₂) or titanium dioxide nanotubes with a triazine-methacrylate monomer (nt-TiO₂:TAT) and evaluate the effect of these fillers on the physical, chemical, and biological properties of the adhesives.

METHODS

First, nt-TiO₂ were synthesized via a hydrothermal method. The nt-TiO₂ were mixed with a triazine-methacrylate monomer (TAT) to formulate nt-TiO₂:TAT, which were characterized by transmission electron microscopy (TEM). The nt-TiO₂, TAT, and nt-TiO₂:TAT were evaluated via Fourier Transform Infrared, Ultraviolet-visible, and micro-Raman spectroscopies. An experimental adhesive resin was formulated with bisphenol A glycerolate dimethacrylates, 2-hydroxyethyl methacrylate, and photoinitiator/co-initiator system. nt-TiO₂ or nt-TiO₂:TAT were incorporated at 2.5 wt.% and 5 wt.% in the adhesive. The base resin without nt-TiO₂ or nt-TiO₂:TAT was used as a control group. The adhesives were evaluated for antibacterial activity, cytotoxicity, polymerization kinetics, degree of conversion (DC), Knoop hardness, softening in solvent (ΔKHN%), ultimate tensile strength (UTS), 24 h- and 1 year- microtensile bond strength (μ-TBS).

RESULTS

TEM confirmed the nanotubular morphology of TiO₂. FTIR, UV-vis, and micro-Raman analyses showed the characteristic peaks of each material, indicating the impregnation of TAT in the nt-TiO₂. Adhesives with nt-TiO₂:TAT showed antimicrobial activity against biofilm formation compared to control (p < 0.05), without differences in the viability of planktonic bacteria (p > 0.05). All groups showed high percentages of pulp cell viability. The polymerization kinetics varied among groups, but all presented DC above 50%. The addition of 5 wt.% of nt-TiO₂ and both groups containing nt-TiO₂:TAT showed higher values ​​of Knoop hardness compared to the control (p < 0.05). The groups with nt-TiO₂:TAT presented lower ΔKHN% (p < 0.05) and higher UTS (p < 0.05) than the control group. After one year, the group with 5 wt.% of nt-TiO₂, as well as both groups containing nt-TiO₂:TAT, showed higher μ-TBS than the control (p < 0.05).

SIGNIFICANCE

The mixing of a triazine-methacrylate monomer with the nt-TiO₂ generated a filler that improved the physicochemical properties of the adhesive resins and provided antibacterial activity, which could assist in preventing carious lesions around tooth-resin interfaces. The set of physical, chemical, and biological properties of the formulated polymer, together with the greater stability of the bond strength over time, make nt-TiO₂:TAT a promising filler for dental adhesive resins.

Niobium silicate particles promote in vitro mineral deposition on dental adhesive resins

OBJECTIVE

This study aims to analyze the addition of niobium silicate particles to dental adhesive resins and evaluate its physicomechanical and biological properties.

METHODS

The SiNb particles were produced by the sol-gel route and presented a mean particle size of 2.1 μm and a specific surface area of 616,96m2/g. An experimental adhesive resin was formulated with 66 wt% Bisphenol A-Glycidyl Methacrylate and 33 wt% Hydroxyethyl methacrylate with diphenyl(2,4,6-trimethyl benzoyl)phosphine oxide as the photoinitiator. The SiNb particles were incorporated into the adhesive resins in 1 wt% (SiNb1%) and 2 wt% (SiNb2%) concentration. A control group (SiNb0%) without the addition of particles was used. The developed adhesives were evaluated by their polymerization kinetics, refractive index, softening in solvent, cytotoxicity, mineral deposition, ultimate tensile strength, and micro shear bond strength.

RESULTS

The refractive index range was increased by the addition of niobium silicate particles. No statistically significant difference was found between groups in the degree of conversion,.softening in solvent analysis, cytotoxicity and ultimate tensile strength. The deposition of minerals increased after immersion of specimens in SBF after 14 days on the SiNb2%. The SiNb2% group showed high micro shear bond strength values, reaching 33.87 MPa.

CONCLUSION

In the present study, the addition of 2 wt% of niobium silicate into dental adhesive resins promoted the mineral deposition with increased bond strength without affecting other material properties.

CLINICAL SIGNIFICANCE

Bioactive fillers must maintain the physical-chemical properties of dental adhesives, guaranteeing their clinical performance. Niobium silicate particles could promote the remineralization of dentin hard tissues without compromising the physico-mechanical properties on these materials.

Dental Sealant Empowered by 1,3,5-Tri Acryloyl Hexahydro-1,3,5-Triazine and α-Tricalcium Phosphate for Anti-Caries Application

Quaternary ammonium compounds and calcium phosphates have been incorporated into dental materials to enhance their biointeractivity and preventive effects. This study aimed at evaluating the physical and chemical properties and effects against Streptococcus mutans of a dental sealant containing 1,3,5-tri acryloyl hexahydro-1,3,5-triazine (TAT) and α-tricalcium phosphate (α-TCP). A methacrylate-based dental sealant was initially formulated. α-TCP and TAT (G_α-TCPTAT) were added to the experimental sealant at 2 wt.% each. One group was formulated without α-TCP and TAT and used as control (G_CTRL). All tested resins were analyzed for polymerization kinetics and degree of conversion (DC %), Knoop hardness (KHN), softening in solvent (∆KHN%), ultimate tensile strength (UTS), the contact angle with water or with α-bromonaphthalene, surface free energy (SFE) and antibacterial activity against Streptococcus mutans in biofilm and in planktonic cells. The polymerization kinetic was different between groups, but without statistical differences in the DC % (p < 0.05). KHN and ΔKHN% did not change between groups (p > 0.05), but G_α-TCPTAT presented greater UTS compared to G_CTRL (p < 0.05). No differences were found for contact angle (p > 0.05) or SFE (p > 0.05). G_α-TCPTAT showed greater antibacterial activity in comparison to G_CTRL (p < 0.05). The formulation of dental sealants containing TAT and α-TCP can be characterized by improved mechanical and antibacterial properties.

Ionic liquid as antibacterial agent for an experimental orthodontic adhesive

OBJECTIVE

The aim of this study was to formulate and evaluate experimental orthodontic adhesives with different concentrations of 1-n-butyl-3-methylimidazoilium bis(trifluoromethanesulfonyl)imide (BMIM.NTf₂).

METHODS

The experimental orthodontic adhesives were formulated with methacrylate monomers, photoinitiators and silica colloidal. The ionic liquid BMIM.NTf₂ was synthesized and characterized. BMIM.NTf₂ was added at 5 (G_5%), 10 (G_10%) and 15 (G_15%) wt.%. One group contained no BMIM.NTf₂ to function as control (G_Ctrl). The adhesives were evaluated for polymerization kinetics, degree of conversion (DC), Knoop hardness and softening in solvent, ultimate tensile strength (UTS), shear bond strength (SBS), thermogravimetric analysis (TGA), antibacterial activity and cytotoxicity.

RESULTS

BMI.NTf₂ showed the characteristic chemical peaks. The polymerization kinetics were different among the groups. G_10% and G_15% showed higher DC (p < 0.05). G_5% and G_Ctrl had no differences for softening in solvent (p > 0.05). There were no differences for UTS (p > 0.05) and SBS (p > 0.05). TGA showed one different peak for G_15%. All groups with BMIM.NTf₂ showed antibacterial activity compared to G_Ctrl (p < 0.05) without cytotoxicity (p > 0.05).

SIGNIFICANCE

To reduce biofilm formation around brackets and to prevent demineralization at susceptible sites, materials have been developed with antibacterial properties. In this study, a new experimental orthodontic adhesive was formulated with an imidazolium ionic liquid (BMIM.NTf₂) as antibacterial agent. The incorporation of 5 wt.% of ionic liquid decreased biofilm formation without affecting the physico-chemical properties and cytotoxicity of an experimental orthodontic resin.

Antibacterial, chemical and physical properties of sealants with polyhexamethylene guanidine hydrochloride

The aim of this study was to evaluate the influence of polyhexamethylene guanidine hydrochloride (PHMGH) in the physico-chemical properties and antibacterial activity of an experimental resin sealant. An experimental resin sealant was formulated with 60 wt.% of bisphenol A glycol dimethacrylate and 40 wt.% of triethylene glycol dimethacrylate with a photoinitiator/co-initiator system. PHMGH was added at 0.5 (G0.5%), 1 (G1%), and 2 (G2%) wt.% and one group remained without PHMGH, used as control (GCTRL). The resin sealants were analyzed for degree of conversion (DC), Knoop hardness (KHN), and softening in solvent (ΔKHN), ultimate tensile strength (UTS), contact angle (θ) with water or α-bromonaphthalene, surface free energy (SFE), and antibacterial activity against Streptococcus mutans for biofilm formation and planktonic bacteria. There was no significant difference for DC (p > 0.05). The initial Knoop hardness ranged from 17.30 (±0.50) to 19.50 (± 0.45), with lower value for GCTRL (p < 0.05). All groups presented lower KHN after immersion in solvent (p < 0.05). The ΔKHN ranged from 47.22 (± 4.30) to 57.22 (± 5.42)%, without significant difference (p > 0.05). The UTS ranged from 54.72 (± 11.05) MPa to 60.46 (± 6.50) MPa, with lower value for G2% (p < 0.05). PHMGH groups presented no significant difference compared to GCTRL in θ (p > 0.05). G2% showed no difference in SFE compared to GCTRL (p > 0.05). The groups with PHMGH presented antibacterial activity against biofilm and planktonic bacteria, with higher antibacterial activity for higher PHMGH incorporation (p < 0.05). PHMGH provided antibacterial activity for all resin sealant groups and the addition up to 1 wt.% showed reliable physico-chemical properties, maintaining the caries-protective effect of the resin sealant over time.

Antibacterial and Remineralizing Fillers in Experimental Orthodontic Adhesives

Orthodontic adhesives with antimicrobial and remineralizing properties may be an alternative to control white spot lesions around brackets. The aim of this study is to develop an experimental orthodontic adhesive containing boron nitride nanotubes (BNNT) and alkyl trimethyl ammonium bromide (ATAB). Methacrylate (BisGMA and TEGDMA) monomers were used to formulate the adhesives. Four experimental groups were produced with the addition of 0.1 wt.% BNNT (G_BNNT); 0.1 wt.% ATAB (G_ATAB); and 0.2 wt.% BNNT with ATAB (G_BNNT/ATAB); in the control group, no fillers were added (G_Ctrl). The degree of conversion, cytotoxicity, softening in solvent, contact angle and free surface energy, antibacterial activity, shear bond strength, and mineral deposition were evaluated. Adhesives achieved degree of conversion higher than 50% and cell viability higher than 90%. G_BNNT and G_ATAB adhesives exhibited reduced softening in solvent. Mean free surface energy was decreased in the G_BNNT adhesive. Significant reduction in bacterial growth was observed in the G_BNNT/ATAB. No statistical difference was found for shear bond strength. Mineral deposition was found in G_BNNT, G_ATAB, and G_BNNT/ATAB groups after 14 and 28 days. The addition of 0.2% BNNT/ATAB to an experimental orthodontic adhesive inhibited bacterial growth and induced mineral deposition without affecting the properties of the material.

Bond Strength of an Orthodontic Adhesive Containing an Antibiofilm Agent (Octafluoropentyl Methacrylate)

Objective

The objective of this study was to determine whether an adhesive containing antibiofilm agent octafluoropentyl methacrylate (OFPA) has an acceptable bond strength as an orthodontic adhesive.

Methods

Sixty human premolars were divided into four groups. In Groups 1 and 2, brackets were bonded to the teeth using experimental nanohybrid adhesive containing OFPA (ENH-OFPA) and Transbond XT (TXT) was used in Groups 3 and 4. In Groups 1 and 3, the samples were stored in water at 37°C for 24 h and in Groups 2 and 4 thermocycled between 5°C and 55°C. The entire samples were debonded utilizing a universal testing machine. Two-way ANOVA test employed to compare the shear bond strength (SBS) between two adhesives. Independent Student's t-test was utilized to compare the SBS at 24 h and followed thermocycling in each adhesive group. Adhesive remnant index (ARI) evaluated in different groups using Chi-square test.

Results

The mean value for SBS in ENH and TXT groups were 8.13 MPa and 8.10 MPa, respectively. The inference of P = 0.260 was observed and concluded to be nonsignificant for adhesives in terms of SBS. Statistically, differences that observed in SBS at 24 h and following thermocycling in TXT (P = 0.288) and ENH-OFPA (P = 0.145) groups did not consider to be significant. Comparing ARI scores with bracket failure mode resulted in no significant difference (P = 1) between two adhesives in both 24 h and following thermocycling.

Conclusion

Adding OFPA does not compromise SBS of the experimented orthodontic adhesive.

Bioactivity and properties of an adhesive system functionalized with an experimental niobium-based glass

OBJECTIVE

This study evaluated the incorporation of niobophosphate bioactive glass (NbG) fillers into a commercial adhesive resin.

MATERIALS AND METHODS

The silanized (NbGs) or non-silanized (NbG) NbG was added to the commercial adhesive system One Step (OS) at 30% by weight; unfilled adhesive served as control. The bioactivity of adhesives was analyzed by SEM and FTIR/ATR after 28 days in PBS. The adhesives were evaluated as regards microtensile bond strength immediately and after six months (n = 6); degree of conversion (n = 3), microhardness (n = 5); and radiopacity (n = 3). Data from each test were submitted to ANOVA and Tukey tests (P <0.05).

RESULTS

FTIR/ATR analysis showed phosphate and carbonate precipitates on the NbG adhesive specimen surface. Statistical analysis of microtensile bond strength values showed that material x time interaction was not significant, but NbG group values were similar to those of unfilled adhesive (p <0.05). Addition of NbG did not alter the degree of conversion, but did increase microhardness and radiopacity values of the adhesive systems compared with those of the control group (OS). Incorporation of NbG into the adhesive system did not compromise the properties of the adhesive.

CONCLUSION

A smart adhesive system with bioactive properties, high radiopacity, microhardness, and similar bond strength and degree of conversion was obtained by incorporating 30% by weight of NbG.

Niobium pentoxide phosphate invert glass as a mineralizing agent in an experimental orthodontic adhesive

OBJECTIVE

The aim of this study was to develop an experimental orthodontic adhesive and evaluate how adding phosphate invert glass containing niobium pentoxide (PIG-Nb) affected the adhesive's properties.

MATERIAL AND METHODS

PIG-Nb was added at 1, 2.5, and 5 wt% to experimental adhesive (75 wt% bisphenol A methacrylate [BisGMA], 25 wt% triethylene glycol dimethacrylate [TEGDMA], 5 wt% colloidal silica and photoinitiator system). The adhesives were evaluated for mineral deposition, degree of conversion (DC), softening solvent by Knoop microhardness (KNH) variation, pH changes, and shear bond strength (SBS). One-way analysis of variance (ANOVA) (DC and ΔKHN%), two-way ANOVA (SBS), repeated measures ANOVA (pH), and paired test (KNH1 and KNH2) were used at a significance level of P < .05.

RESULTS

Adding PIG-Nb to orthodontic adhesives induced deposition on its surface associated with a constant neutral pH. The SBS increased after immersion in artificial saliva, and the PIG-Nb5 exhibited less softening.

CONCLUSION

The addition of PIG-Nb into orthodontic adhesives induced mineral deposition. Experimental orthodontic adhesive containing 5% wt of PIG-Nb exhibited increased mineral deposition and suitable properties for orthodontic applications.