Managing the transition to a complex full mouth rehabilitation utilizing injectable composite.

OBJECTIVE: This article describes the use of flowable injectable composite resins to facilitate transitional treatment of a complex complete mouth rehabilitation. CLINICAL CONSIDERATIONS: Some patients require urgent and complex complete mouth rehabilitations that are time and cost intensive. Financial considerations can prevent some patients from pursuing treatment. This can result in the oral conditions worsening over time and compromising the long-term prognosis of the teeth. CONCLUSIONS: Injectable composite resins can be used as a transitional bonding material for complex cases using an injection molding technique utilizing clear indices obtained from a diagnostic waxing. This allows for a full mouth rehabilitation to be performed in a single appointment, producing instant results. CLINICAL SIGNIFICANCE: Transitioning with injectable composite as demonstrated in this case will immediately stabilize an otherwise deteriorating situation in a cost-effective way and allows patients to address the realities of financial or time constraints when transitioning to more durable porcelain restorations over a period of years.

Hard X-ray phase-contrast-enhanced micro-CT for quantifying interfaces within brittle dense root-filling-restored human teeth.

Bonding of resin composite fillings, for example following root-canal treatment, is a challenge because remaining gaps grow and lead to failure. Here, phase-contrast-enhanced micro-computed tomography (PCE-CT) is used to explore methods of non-destructive quantification of the problem, so that countermeasures can be devised. Five human central incisors with damaged crowns were root-filled followed by restoration with a dental post. Thereafter, the crowns were rebuilt with a resin composite that was bonded conventionally to the tooth with a dental adhesive system (Futurabond U). Each sample was imaged by PCE-CT in a synchrotron facility (ID19, European Synchrotron Radiation Facility) with a pixel size of 650 nm. The reconstructed datasets from each sample were segmented and analysed in a semi-automated manner using ImageJ. PCE-CT at sub-micrometre resolution provided images with an impressive increased contrast and detail when compared with laboratory micro-computed tomography. The interface between the dental adhesive and the tooth was often strongly disrupted by the presence of large debonded gaps (on average 34% ± 15% on all surfaces). The thickness of the gaps spanned 2 µm to 16 µm. There was a large variability in the distribution of gaps within the bonding area in each sample, with some regions around the canal exhibiting up to 100% discontinuity. Although only several micrometres thick, the extensive wide gaps may serve as gateways to biofilm leakage, leading to failure of the restorations. They can also act as stress-raising `cracks' that are likely to expand over time in response to cyclic mechanical loading as a consequence of mastication. The observations here show how PCE-CT can be used as a non-destructive quantitative tool for understanding and improving the performance of clinically used bonded dental restorations.

Comparison of Marginal Gap and Microleakage in Copy-Milled and Cad-Milled Zirconia Copings Bonded Using Light Cure and Chemical Cure Resin Bonding Systems.

This in vitro study assessed the marginal gap and marginal microleakage in zirconia copings fabricated using two computer aided techniques- CAD milling and Copy milling and cemented to respective tooth preparations using two resin bonding systems, light cure and self-cure resin bonding systems. 32 extracted premolars were prepared to receive zirconia copings fabricated using CAD/CAM and Copy milling techniques. Once the copings were fabricated, the samples were evaluated for marginal fit prior to cementation through microscopic observation. Evaluation of marginal gap was done again after cementation, in order to incorporate the influence of the resin bonding system on the marginal microgap. The specimens were evaluated under the stereomicroscope for micro-leakage using commercial software. A comparative statistical analysis was done following data collection using Mann-Whitney U test, Wilcoxon test and chi-square test. The data collected regarding marginal gap was well within 120 µ, which is in accordance with previous studies. However, Copy milled specimens showed statistically lesser marginal gap when compared to CAD milled specimens. While comparing microleakage, it was observed that the microleakage in Copy milled specimens bonded with light cure resin bonded cement was statistically lesser than that of specimens cemented with chemical cure resin cement.(P = 0.003). This in vitro study concluded that Copy milling technique fabricated zirconia restorations with lesser marginal gap and microleakage score in comparison to CAD milled samples. Light cure resin bonding system also proved to be more effective option compared to self cure resin bonding systems. However, the limitations of this study should be taken into concern and further research should be aimed at a larger sample size to validate the results.

Current Protocols for Resin-Bonded Dental Ceramics.

Resin-bonded ceramic restorations are common treatment options. Clinical longevity of resin-bonded ceramic restorations depends on the quality and durability of the resin-ceramic bond. The type and composition of the specific ceramic determines the selection of the most effective bonding protocol. Such protocol typically includes a surface pretreatment step followed by application of a priming agent. Understanding of fundamental ceramic properties and chemical compositions enables the clinician to make proper material selection decisions for clinically successful and long-lasting restorations. Based on research accrued over the past decades, this article reviews and discusses current resin-bonding protocols to most commonly used dental ceramics.

In-lab simulation of CAD/CAM grinding and intaglio surface treatments of 4YSZ monolithic restorations: Effect on its load-bearing capacity under fatigue.

OBJECTIVES: To evaluate the effect of in-lab simulation of CAD/CAM grinding and intaglio surface treatments on the surface characteristics (topography and roughness) and fatigue behavior of adhesively luted 4YSZ simplified restorations. METHODS: Ceramic discs (Ø = 10 mm, thickness = 1 mm) were randomly allocated into 6 groups considering: "In-lab simulation of CAD/CAM grinding" (ground or polished) and "intaglio surface treatments": Ctrl (without surface treatment), AlOx (aluminum oxide air abrasion) or GLZ (glaze spray application). The surface roughness of all samples was measured, the treated discs received a ceramic primer, were luted with resin cement onto a dentin analogue material (woven glass-reinforced epoxy resin) and tested under a cyclic fatigue test (step-stress approach, n = 15; 1.4 Hz, 10,000 cycles/step, step-size of 100N starting at 200N until failure). A complementary analysis was performed to corroborate the findings in the fatigue test that the glaze fill defects increase the mechanical properties of the ceramic. To do so, bars (n= 10; 1.0 × 1.0 × 12 mm; considering the groups: N-ID: non-indented; ID: indented; ID-GLZ: indented plus glaze spray application) were indented in a vickers hardness tester to produce a crack pattern, treated with glaze or not, and then submitted to flexural strength tests (FS). Fractographic and topographic analysis were performed. RESULTS: In-lab simulation of CAD/CAM grinding decreased the fatigue failure load of the 4YSZ ceramic when comparing polished and ground groups, regardless of surface treatment. GLZ induced better fatigue performance compared to the air abrasion, regardless of the grinding condition (ground or polished surface). The results of the flexural strength test corroborated the findings in the fatigue test, as the ID-GLZ group presented superior FS than the ID group, however both had inferior FS than N-ID. There is an inverse association between roughness and fatigue failure load, as the higher the surface roughness, the lower the fatigue failure load. Failures in the fatigue and flexural strength tests started from the face subjected to tensile stresses. CONCLUSION: In-lab simulation of CAD/CAM grinding had a detrimental effect on the fatigue behavior of 4YSZ and glaze spray induced better 4YSZ performance compared to the air abrasion. The intaglio surface treatments differently influenced the 4YSZ fatigue performance, however, only glaze spray can reverse the damage caused by the grinding.

Adhesion to Zirconia: A Systematic Review of Surface Pretreatments and Resin Cements.

This systematic review aims to evaluate the different pretreatments of the zirconia surface and resin cement in order to determine a valid operative protocol for adhesive cementation. Methodologies conducted for this study followed the Prisma (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. An electronic search was performed in four databases. The established focus question was: "What type of surface conditioning method is the one that obtains the best adhesion values to zirconia over time by applying a resin cement?" Forty-five relevant papers were found to qualify for final inclusion. In total, 260 different surface pretreatment methods, mainly combinations of air-abrasion protocols and adhesive promoters, were investigated. Altogether, the use of two artificial aging methods, three types of cement and four testing methods was reported. The results showed that mechanicochemical surface pretreatments offered the best adhesive results. Self-adhesive cement and those containing 10-MDP obtained the best results in adhesion to zirconia. Artificial aging reduced adhesion, so storage in water for 30 days or thermocycling for 5000 cycles is recommended. A standardized adhesive protocol has not been established due to a lack of evidence.

Influence of Sandblasting Particle Size and Pressure on Resin Bonding Durability to Zirconia: A Residual Stress Study.

The influence of residual stress induced by sandblasting the zirconia ceramic surface on the resin bonding to the ceramic is still unclear. The effect of four different sandblasting conditions (with 50 and 110 µm alumina at pressures of 0.2 and 0.4 MPa) on the bonding of adhesive resin cement (Panavia F 2.0) to zirconia (Cercon® ht) was investigated in terms of residual stress. The surface roughness and water contact angle of the zirconia surfaces were measured. The tetragonal-to-monoclinic (t-m) phase transformation and residual stresses (sin2ψ method) were studied by X-ray diffraction. The resin-bonded zirconia specimens were subjected to shear bond strength (SBS) tests before and after thermocycling (10,000 and 30,000 cycles) (n = 10). As the particle size and pressure increased, the roughness gradually and significantly increased (p = 0.023). However, there were no significant differences in roughness-corrected contact angle among all the sandblasted groups (p > 0.05). As the particle size and pressure increased, the m-phase/(t-phase + m-phase) ratios and compressive residual stresses gradually increased. After thermocycling, there were no significant differences in SBS among the sandblasted zirconia groups (p > 0.05). In conclusion, increased surface roughness and residual stress do not directly affect the resin bonding durability.

Closing open contacts adjacent to an implant-supported restoration.

Loss of interproximal contact between fixed implant-supported restorations and the adjacent teeth is one of the most common complications in implant dentistry. This article presents a clinical chairside technique for closing open contacts adjacent to an implant-supported restoration. A silicon model is perfused from a restoration-level impression using the open tray technique. Composite resin is bonded to the implant-supported ceramic restoration extraorally to restore the interproximal contact. The tooth and restoration contact is double confirmed on the silicon model and in the mouth. This chairside procedure may save time and improve patient comfort.

Silane reactivity and resin bond strength to lithium disilicate ceramic surfaces.

OBJECTIVE: To evaluate the silane status in commercially available products and their bonding capacity with polished glass-ceramic surfaces before and after hydrofluoric (HF) acid-etching. METHODS: The products tested were Calibra Silane Coupling Agent/CS, G-Multi Primer/GM, Kerr Silane Primer/KS, Monobond Plus/MB and Scotchbond Universal Adhesive/SB. The silane status was studied by 13C nuclear magnetic resonance spectroscopy (13C-NMR). The roughness parameters of polished (group A) and HF acid-etched (group B) lithium disilicate glass-ceramic surfaces were measured by optical profilometry (n = 5/group). The interaction of the products with group A and B ceramic surfaces was examined by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The shear strength (SBS) of a flowable composite bonded to the ceramic surfaces (groups A, B) was assessed before (NS) and after silane treatment (n = 20/group, product). RESULTS: The NMR analysis showed the presence of silanol monomers only in CS. Methoxylated-siloxane adducts were found in GM, silanol-siloxane adducts in MB, SB, and siloxane polymers in KS. Acid-etching greatly increased Sa, Sz, Sdr, Sc and Sv parameters (p < 0.001) and ATR-FTIR analysis demonstrated evidence of bonding with the substrate in CS. Weibull analysis of SBS revealed the following rankings in characteristic life (p < 0.05): CS > SB,KS,MB > GM > NS (group A) and CS > GM > SB,KS,MB,NS (group B). The most reliable treatment in both groups was CS. For the same silane treatment, the SBS of group B were significantly higher from group A. Failures were mainly of adhesive type, except of several partial resin cohesive failures found in group B. SIGNIFICANCE: The chemical bonding capacity of the silanes was highest in products with silanol monomers. Acid-etching increased bond strength to a level that neutralized the silane contribution in products with silanol-siloxane adducts and siloxane polymers, providing thus bond strength values similar to silane-free treatments.

Effect of Simplified Bonding on Shear Bond Strength between Ceramic Brackets and Dental Zirconia.

The aim of this study was to evaluate the long term stability of shear bond strength (SBS) when 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) containing universal adhesive was used in the ceramic bracket bonding on dental zirconia. Twenty human maxillary incisors were collected. The ceramic bracket was bonded on the buccal enamel surface after the acid-etching and orthodontic primer application (Group CON). Sixty zirconia specimens were sintered, sandblasted and divided into three experimental groups; group CP-ceramic primer followed by an orthodontic primer; group U-universal adhesive; group CU-ceramic primer followed by a universal adhesive. For each specimen, the bracket was bonded onto the treated surface with composite resin (Transbond XT, 3M ESPE). The SBS tested before (CON0, CP0, U0, CU0) and after the artificial aging (CON1, CP1, U1, CU1). The data were statistically analyzed with the Kruskal-Wallis test at a significance level of 0.05. The mean SBS of CON0, CP0, U0 and CU0 were within the clinically acceptable range without significant differences. After the aging process, SBS decreased in all groups. Among the aged groups, CP1 showed the highest SBS. Based on the results, when bonding ceramic brackets to a dental zirconia surface, we can conclude that ceramic primer used with an orthodontic primer, rather than using a universal adhesive, is recommended.

Influence of ageing on glass and resin bonding of dental glass-ceramic veneer adhesion to zirconia: A fracture mechanics analysis and interpretation.

Adhesion plays a major role in the bonding of dental materials. In this study the adhesion of two glass-ceramic systems (IPS e.max and VITABLOCS) to a zirconia sintered substrate using a glass (for IPS e.max) and resin (VITABLOCS) before and after exposure to ageing for 14 days in distilled water at 37 °C are compared using two interfacial fracture mechanics tests, the 3 point bend Schwickerath (Kosyfaki and Swain, 2014; Schneider and Swain, 2015) and 4 point bend (Charalambides et al., 1989) approaches. Both tests result in stable crack extension from which the strain energy release rate (G, N/m or J/m2) can be determined. In the case of the 3 PB test the Work of Fracture was also determined. In addition, the Schwickerath test enables determination of the critical stress for the onset of cracking to occur, which forms the basis of the ISO (ISO9693-2:2016) adhesion test for porcelain ceramic adhesion to zirconia. For the aged samples there was a significant reduction in the resin-bonded strengths (Schwickerath) and strain energy release rate (both 3 and 4 PB tests), which was not evident for the glass bonded specimens. Critical examination of the force-displacement curves showed that ageing of the resin resulted in a major change in the form of the curves, which may be interpreted in terms of a reduction in the critical stress to initiate cracking and also in the development of an R-curve. The extent of the reduction in strain energy release rate following ageing was greater for the Schwickerath test than the Charalambides test. The results are discussed in terms of; the basic mechanics of these two tests, the deterioration of the resin bonding following moisture exposure and the different dimensions of the specimens. These in-vitro results raise concerns regarding resin bonding to zirconia. STATEMENT OF SIGNIFICANCE: The present study uses a novel approach to investigate the role of ageing or environmental degradation on the adhesive bonding of two dental ceramics to zirconia. This continues to be a major clinical problem but current approaches, till now, have relied upon a myriad of strength based tests to quantify the extent of environmental degradation with time. In this paper we use two fracture mechanics approaches, based upon simple 3 and 4 point bend testing procedures that enable stable debonding crack extension to occur. The paper provides a more critical approach to evaluate the role of environmental degradation of adhesion for dental materials.

Comparison of three and four point bending evaluation of two adhesive bonding systems for glass-ceramic zirconia bi-layered ceramics.

OBJECTIVES: To quantify the adhesion of two bonding approaches of zirconia to more aesthetic glass-ceramic materials using the Schwickerath (ISO 9693-2:2016) three point bend (3PB) [1] test to determine the fracture initiation strength and strain energy release rate associated with stable crack extension with this test and the Charalamabides et al. (1989) [2] four point bend (4PB) test. METHODS: Two glass-ceramic materials (VITABLOCS Triluxe forte, Vita Zahnfabrik, Germany and IPS.emax CAD, Ivoclar Vivadent, Liechtenstein) were bonded to sintered zirconia (VITA InCeram YZ). The former was resin bonded using a dual-cure composite resin (Panavia F 2.0, Kuraray Medical Inc., Osaka, Japan) following etching and silane conditioning, while the IPS.emax CAD was glass bonded (IPS e.max CAD Crystall/Connect) during crystallization of the IPS.emax CAD. Specimens (30) of the appropriate dimensions were fabricated for the Schwickerath 3PB and 4PB tests. Strength values were determined from crack initiation while strain energy release rate values were determined from the minima in the force-displacement curves with the 3PB test (Schneider and Swain, 2015) [3] and for 4PB test from the plateau region of stable crack extension. RESULTS: Strength values for the resin and glass bonded glass ceramics to zirconia were 22.20±6.72MPa and 27.02±3.49MPa respectively. The strain energy release rates for the two methods used were very similar and for the glass bonding, (4PB) 15.14±5.06N/m (or J/m2) and (3PB) 16.83±3.91N/m and resin bonding (4PB) 8.34±1.93N/m and (3PB) 8.44±2.81N/m respectively. The differences in strength and strain energy release rate for the two bonding approaches were statistically significant (p<0.05). SEM observations showed fracture occurred adhesively for the resin bonding and cohesively for the glass bonding. SIGNIFICANCE: The present results indicate 3PB and 4PB tests have very similar values for the strain energy release rate determination. However while strength tests reveal minimal differences between resin and glass bonding, strain energy release rates for the latter are superior for bonding CAD/CAM milled glass-ceramics to zirconia.

Bonding to oxide ceramics­laboratory testing versus clinical outcome.

OBJECTIVES: Despite a huge number of published laboratory bonding studies on dental oxide ceramics clinical long-term studies on resin bonded oxide ceramic restorations are rare. The purpose of this review is to present the best available clinical evidence for successful bonding of dental oxide ceramic restorations. METHODS: Clinical trials with resin-bonded restorations that had no or only limited mechanical retention and were made from alumina or zirconia ceramic were identified using an electronic search in PubMed database. Overall 10 publications with clinical trials could be identified. Their clinical outcome was compared with that laboratory bond strength studies. RESULTS: Clinical data provide strong evidence that air-abrasion at a moderate pressure in combination with using phosphate monomer containing primers and/or luting resins provide long-term durable bonding to glass-infiltrated alumina and zirconia ceramic under the humid and stressful oral conditions. SIGNIFICANCE: As simple and clinically reliable bonding methods to oxide ceramics exist, the rationale for development of alternative bonding methods might be reconsidered especially when these methods are more time consuming or require rather complicated and/or technique sensitive procedures.

Diastema closure using direct bonding restorations combined with orthodontic treatment: a case report.

Closure of interdental spaces using proximal build-ups with resin composite is considered to be practical and conservative. However, a comprehensive approach combining two or more treatment modalities may be needed to improve esthetics. This case report describes the management of a patient with multiple diastemas, a peg-shaped lateral incisor and midline deviation in the maxillary anterior area. Direct resin bonding along with orthodontic movement of teeth allows space closure and midline correction, consequently, creating a better esthetic result.

Clinical evaluation of short fiber ribbon combined with resin bonding technology for the treatment of food impaction between posterior teeth / 实用口腔医学杂志

Objective:To evaluate the clinical effects of short fiber ribbon combined with resin bonding technology for the treatment of food impaction between posterior teeth. Methods:98 cases of vertical food impaction between posterior teeth( total of 135 vertical food impaction units) were included. 73 units were treated by short quartz fiber ribbon combined with resin bonding technology( SQFRB) and 63 by resin bonding(RB). 12, 24 and 36 months after restoration, clinical effects were evaluated referring to the Modified United States Public Health Service (USPHS) Criteria, data were statistically analyzed. Results:12, 24 and 36 months after treatment the cure rate of SQFRB was 97. 3%, 97. 3% and 95. 9%, inefficacy rate was 0, 0 and 0;the cure rate of RB was 85. 5%, 82. 2% and 82. 2%, the inefficacy rate was 4. 8%, 11. 3% and 12. 9%, respectively(between groups, P<0. 05). Conclusion:Minimally inva-sive restorations using short fiber ribbon combined with resin bonding technology is effective in the treatment of vertical food impaction between posterior teeth.

Diastema closure using direct bonding restorations combined with orthodontic treatment: a case report

Closure of interdental spaces using proximal build-ups with resin composite is considered to be practical and conservative. However, a comprehensive approach combining two or more treatment modalities may be needed to improve esthetics. This case report describes the management of a patient with multiple diastemas, a peg-shaped lateral incisor and midline deviation in the maxillary anterior area. Direct resin bonding along with orthodontic movement of teeth allows space closure and midline correction, consequently, creating a better esthetic result.