The use of intermediary resins when bonding glass polyalkenoate (ionomer) cement to composite resin

This study was designed to examine the effects of three different types of glass polyalkenoate lining cement combined with three different types of bonding resin and varying surface treatments on the seal between the lining cement and the composite resin as used in the so called 'laminate' technique. The seal was assessed using a radioisotope and autoradiographic technique.
Results showed that all the cements behaved in a manner specific to them. The seal of all systems examined could be improved, or at least, not compromised, by modification of the surface of the cement prior to attachment of the resin. Only one type of intermediate resin gave a reliable seal when applied to an unmodified surface of any of the cements under investigation.
It is concluded that all the glass polyalkenoate cements tested behave differently when used beneath composite resin. Recommendations about the laminate restoration technique must be related to the specific combinations of materials used.     

Bond strength of glass ionomer cement to composite resin.

This report assesses the effect of acid etching, acid etching plus bonding adhesive and bonding adhesive only, on the bond strength of one light curing and two chemical curing glass ionomer cements (GICs) to composite resin. Bonded specimens were fractured using a three point flexural jig. The only bond obtained with the chemically curing cements was after acid etching and bonding adhesive application. The light curing cements produced a bond with all treatments but a true cohesive fracture was only obtained after application of the dentine primer and bonding adhesive of the particular bonding system employed. It is recommended that a bonding adhesive be applied after acid etching chemically curing GICs in order to achieve a bond to composite resin. The light curing GIC should not be etched with phosphoric acid and is the material of choice as it is both stronger and less technique sensitive than the chemically curing GICs. Manufacturers' instructions may not always give the best results.     

Amalgam, composite resin and glass ionomer cement in Class II restorations in primary molars--a three year clinical evaluation.

Amalgam (ANA 2000), composite resin (Occlusin), and glass ionomer cement (ChemFil) were compared in conventional Class II restorations in second primary molars. Twenty-five restorations of each material were placed by two dentists in 50 patients. The restorations were evaluated during a three year period using the USPHS criteria. Great differences could be found between the materials. The failure rate (USPHS ratings Charlie) was after three years 8 per cent for the amalgam, 16 per cent for the composite resin and 60 per cent for the glass ionomer cement restorations.     

Repairability of type II glass polyalkenoate (ionomer) cements.

Two Type II glass polyalkenoate (ionomer) cements were evaluated for their repairability by measuring tensile bond strength of new material added to previously placed cement. Variables included time of repair (20 min vs. 24 h) and surface condition prior to repair (smooth and unetched, smooth and etched, rough and unetched, rough and etched). Failures were evaluated using light microscopy and categorized as cohesive, adhesive, or mixed. Scanning electron microscopy was employed to view the cement surfaces following each of the four pretreatments. Surface pretreatment was found to significantly affect both materials when repaired at 20 min (P less than 0.05). The highest bond strength was achieved when bonding to the smooth, unetched surface. Surface pretreatment did not significantly affect bond strength when the cements were repaired at 24 h (P greater than 0.05). Tensile bond strengths were greater for repairs made at 20 min than for those made at 24 h, but the differences were not always statistically significant.     

Adhesion of composite resin to etched glass ionomer cement

A laboratory study was undertaken to determine the tensile bond strengths of three glass ionomer cements to dentine and the tensile bond strengths of composite to the three glass ionomers after etching. The tensile bond strength to untreated dentine was in the range of 4.47–5.52 MPa, being approximately twice that of a glass ionomer restorative material. After etching the glass ionomer, the bond strength to composite resin ranged from 1.83 MPa to 6.17 MPa, depending on the ionomer and on the time after mixing at which it was etched. In the majority of clinical situations, retention of a composite restoration via etched glass ionomer cement would probably need to be supplemented by additional mechanical retention.     

The 5-year results of a clinical trial comparing a glass polyalkenoate (ionomer) cement restoration with an amalgam restoration

A clinical trial comparing the efficacy of a glass polyalkenoate cement (GPC) restoration with an amalgam cement restoration (ACR) in the management of caries in the deciduous molar dentition was undertaken. Two hundred and thirty-eight restorations, that is 119 pairs, were placed in 76 patients with an age range of 5 to 11 years. The durability of these restorations was assessed during a 5-year follow-up period, using modified United States Public Health Service criteria. The glass polyalkenoate cement restorations occupied 16% of the occlusal surface of the tooth compared to 28% for the amalgam restorations, had a lower median survival time (33.4 [SE 2.26] months compared to 41.4 [SE 2.24] months) and underwent greater loss of anatomical form and marginal integrity than the paired amalgam controls.     

玻璃离子夹层对光固化复合树脂修复楔形缺损疗效的影响

目的 :探讨玻璃离子夹层在光固化复合树脂修复楔形缺损中的效果。方法 :选择个体条件基本相同的楔形缺损患牙 ,以光固化复合树脂分别采用玻璃离子夹层和直接充填 2种方法修复 ,共 2 2 5例 6 6 3个牙。结果 :所有牙齿治疗后 8～ 2 4个月随访复查 ,两组有效率分别为 90 .4 %和 70 .6 % ,有显著性差异(P <0 .0 1)。结论 :用玻璃离子夹层技术修复楔形缺损比直接用光固化复合树脂修复疗效更理想。     

Nine-year evaluation of a polyacid-modified resin composite/resin composite open sandwich technique in Class II cavities

OBJECTIVES: The aim of this study was to evaluate in an intraindividual comparison the durability of a polyacid-modified resin composite/resin composite open sandwich restoration in a 9 years follow-up. A polyacid-modified resin composite (PMRC; compomer, Dyract) was placed as an intermediate layer and covered with resin composite (RC, Prisma TPH). A direct RC restoration was used as control. METHODS: Each of 57 patients, received at least one pair of Class II restorations, one open sandwich and one resin composite control. In total 75 pairs of Class II restorations, 68 premolars and 82 molars, all in occlusion, were placed by two dentists. Most of the cavities were surrounded by enamel. The restorations were evaluated at baseline, 6, 12, 24, 36 months and 9 years by slightly modified USPHS criteria. Survival of restorations grouped on the two different techniques was determined using Kaplan-Meier survival curves. RESULTS: After 9 years, 14 of 135 evaluated restorations were estimated as unacceptable, 6 in the sandwich group and 8 in the control group. Over all annual failure rate during the 9-year period was 1.1%. The survival rate was not significant different between the two techniques (p=0.604). Reasons of failure were: secondary caries (8), fracture of tooth (1), fracture of restoration (2), endodontic treatment (3). CONCLUSIONS: Both restorative techniques showed good durability during the 9-year period. No clinical advantage was observed for the sandwich technique.     

Clinical requirements for a successful 'sandwich'--dentine to glass ionomer cement to composite resin

The composite resins are now being used extensively in restorative dentistry although there are still some problems remaining. Long-term prevention of microleakage continues to be an area of controversy particularly in relation to the margins between dentine and composite resin. Chemical adhesion between glass ionomer cement and dentine is accepted as being a long-term union and it has recently been shown that a mechanical union is possible between composite resin and glass ionomer cement. This has led to the development of the so-called 'sandwich technique' where glass ionomer cement is used as a lining under composite resin restorations particularly where the cavo-surface margin is in dentine. This paper discusses the various levels of adhesion in the 'sandwich' and suggests the best methods of obtaining optimum results from the clinical application of the technique. Particular attention is drawn to the wide variation in the strength of the union depending on the materials used and the methods of handling.     

One-year clinical performance of a resin-modified glass ionomer and a resin composite restorative material in unprepared Class V restorations

This study evaluated the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over one year. Thirty-seven pairs of restorations of Fuji II LC and Z250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline and 6 and 12 months, using modified Ryge/USPHS criteria. No significant difference (p>0.05) was observed in performance of both materials, although retention of the Z250 restorations was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. Little difference in the restorations' appearance was observed.     

The marginal seal of Class II restorations: flowable composite resin compared to injectable glass ionomer

The objective of this study was to investigate the effect of a flowable composite resin (Tetric Flow) versus an injectable glass ionomer (Fuji II LC) on microleakage at the cavosurface margin of the proximal box of Class II restorations in permanent teeth in-vitro. Thirty caries and restoration-free human bicuspids were prepared with mesial and distal slot preparations and were filled either with a bonding agent (Optibond) plus a flowable composite resin (Tetric Flow), Group I; bonding agent (Optibond) plus a flowable glass ionomer (Fuji II LC), Group II; or a flowable glass ionomer (Fuji II LC) with no bonding agent, Group III. All specimens were then immersed in a 2% solution of basic fuschin dye for 24 hours to allow for dye penetration into possible existing gaps. These teeth were then carefully sectioned mesially/distally into two pieces using an Isomet saw. The teeth were then studied under a binocular microscope to measure depths of dye penetrations as an indication of marginal microleakage at the gingival cavosurface margin and scored as follows: 0 = no dye penetration, 1 = dye penetration into enamel only, 2 = dye penetration into enamel and dentin, 3 = dye penetration into the pulp. The specimens were also evaluated using a SEM. The results showed that there were statistically significant differences between Groups I (Tetric Flow) and (Fuji II LC plus bonding agent), II in favor of Group I; between Groups I and (Fuji II LC with no bonding agent), III in favor of Group I; as well as Groups II and III in favor of Group II (Fuji II LC plus bonding agent). Group I (bonding agent plus flowable composite resin) showed significantly less microleakage. Group II (bonding agent plus flowable glass ionomer) demonstrated a bond that existed between the bonding agent and the glass ionomer but microleakage within microgaps of the glass ionomer itself Group III (flowable glass ionomer plus no bonding agent) demonstrated significant microleakage between the glass ionomer and tooth structure, microgaps within the glass ionomer, and lack of retention of the restoration. It appears that the use of a flowable composite resin (Tetric Flow) plus a bonding agent (Optibond) in the proximal box of a Class II restoration in permanent teeth will significantly reduce the microleakage at the cavosurface margin when compared with an injectable glass ionomer (Fuji II LC) with or without a bonding agent (Optibond).     

Aesthetic properties of three Type II glass polyalkenoate (ionomer) cements

The aesthetic properties of three recently marketed Type II glass polyalkenoate (ionomer) cements were evaluated in a combined laboratory and clinical study. The materials investigated were Fuji Cap II, ChemFil II in capsules and Ketac-fil Aplicap. The aesthetic properties of a glass ionomer restoration were represented by iss translucency, the colour match with surrounding enamel and marginal adaptation. The translucency of all shades of the selected glass ionomer cements was measured under laboratory conditions and expressed as the optical density on transillumination. Colour match and marginal adaptation were evaluated in a clinical study. Twenty Class V restorations of each of the three products were placed. After finishing, the marginal adaptation was rated by two clinicians and colour slides of the restoration were made. Five clinicians assessed the colour match of the restorations from colour slides. ChemFil II and Ketac-fil Aplicap shades were considerably more translucent than the Fuji Cap II shades. The colour match of the ChemFil II restorations was significantly better than the Fuji Cap II and Ketac-fil Aplicap restorations. Marginal adaptation was judged excellent for all three products.     

Five-year study of Class II restorations in permanent teeth using amalgam, glass polyalkenoate (ionomer) cermet and resin-based composite materials

The aim of this study was to compare the clinical performance of an amalgam, a glass polyalkenoate (ionomer) cermet material and a resin-based composite material used in small Class II cavities in permanent teeth. All restorations were inserted under rubber dam. They were examined yearly for 3 years. One clinician continued the study up to 5 years. The clinical examination focused on two criteria: clinically acceptable and failure. In addition, impressions were taken of the prepared cavities immediately before restoration and at each clinical examination using an elastomeric material. The study comprised 274 Class II restorations (88 amalgams, 95 cermets and 91 resin composites) placed in 142 adolescent patients. One hundred and sixty-seven restorations were in molar and 107 in premolar teeth. Patient dropout after 5 years resulted in the loss of 161 restorations, evenly distributed for restorative material and type of tooth involved. Four amalgam restorations, 22 glass ionomer cermet and nine resin composite restorations failed. The glass ionomer cermet and amalgam restorations failed primarily due to bulk fractures, while the resin composite restorations failed due to secondary caries and bulk fractures.     

Microleakage of glass ionomer/composite resin restorations: A laboratory study. 1. The influence of glass ionomer cement

Acid-etching of enamel margins, often combined with bevelling and use of a low viscosity resin, has resulted in improved sealing of composite restorations. When enamel is absent and margins involve dentine or cementum, microleakage is more often observed. The use of glass ionomer cement, as both a restorative material and as a base combined with a veneer of composite resin, has been advocated as a means of minimizing microleakage where margins are placed in dentine or cementum. Four restorative techniques incorporating glass ionomer cement were used, in vitro, to restore cervical cavities. After thermal cycling, dye penetration was scored along occlusal and gingival margins. In all instances the gingival margin exhibited a less reliable seal than the occlusal margin. The sandwich restorations produced a superior seal at both occlusal and gingival margins when compared with glass ionomer restorative cement.     

Marginal adaptation to enamel of a polyacid-modified resin composite (compomer) and a resin-modified glass ionomer cement in vivo

Recently, new restoratives, such as resin-modified glass ionomer cements (RMGIC) and polyacid-modified resin composites (PMC) were introduced for class III and class V cavities. Both materials use simplified cavity conditioning methods. The well-established treatment of enamel with phosphoric acid has been replaced with treatment using weaker acids. The purpose of this study was to investigate in vivo the quality and durability of the marginal bond to enamel of these restorative system and compare it with a resin composite restorative. Seventeen patients received class III restorations of each of the three restoratives. At baseline and after 1 year replica impressions were made for investigation of the vestibular margins with the scanning electron microscope. Semi-quantitative analysis of the enamel-restorative interfaces was performed at ×200 and ×1000 magnifications. The three restorative systems showed good marginal adaptation and high percentages of the length of the margins investigated at baseline were gap-free (82% – 92%). The resin composite showed significantly better adaptation than the other materials. The marginal quality decreased significantly after 1 year for the resin composite and the polyacid-modified resin composite. The RMGIC showed improved sealing after 1 year in vivo, probably due to continuing water uptake. The percentages of gap-free margins of the total marginal length observed at 1 year were 73%, 90%, and 84%, respectively, for the PMC, the RMGIC and the resin composite. The difference between the PMC and the RMGIC was significant. In conclusion, a good marginal quality was seen for all three restorative systems in class III cavities after a period of 1 year. Received: 9 June 1997 / Accepted: 8 September 1997