Selection defines design

The era of "extension for prevention" used restorative materials and cavity preparation designs in an attempt to arrest the caries process. In the new era of "prevention to eliminate extension," many of the old limitations are no longer applicable because of advances in research and technology. The advances in restorative materials and adhesive technology require the use of an adhesive design concept when considering restorative material selection, preparation designs, and adhesive protocol and placement procedures and techniques. This adhesive design concept has been instrumental in the paradigm shift from the principles of extension for prevention to an ultraconservative principle of prevention to eliminate extension. From the early onset of the disease to initial placement of the restoration, this modern philosophy has three clinical objectives: prevention, preservation, and conservation. The clinician should strive to preserve the maximum integrity of the natural dentition by preventing the placement of the initial restoration, preserving and conserving tooth structure during the preparation of restoration, and conserving the tooth and restoration by increasing the longevity of the restoration between replacements. This article describes an incremental layering technique that uses a conservative restorative adhesive design concept (adhesive preparation design and protocol) for preparing, restoring, and finishing a Class IV restoration, and it demonstrates how the selection of a small-particle hybrid composite influences the preparation design.     

A nonmechanical etiology: The adhesive design concept.

Advances in restorative material formulations and adhesive technology have expanded and created new treatment possibilities for dental practitioners. Due to this evolution, composite resins are being used with increasing frequency in posterior restorations. In order to successfully place these restorations, the clinician must understand the rationale for restorative material selection, preparation design, adhesive protocol, and composite resin placement. This article illustrates these considerations for placing a Class I posterior composite restoration.     

Microleakage of high-strength glass ionomer: resin composite restorations in minimally invasive treatment

Atraumatic Restorative Treatment (ART) has been investigated as an alternative caries treatment. The technique involves removal of loose tooth structure with a spoon excavator, followed by placement of an adhesive restorative material, often a high-strength glass ionomer. This study compares the microleakage of a high-strength glass ionomer/resin composite and two occlusal resin composite restoration techniques.     

Restorations of eroded areas

Class V erosion lesions must be restored to reinstate esthetic appearance, overcome sensitivity, or prevent further loss of tooth structure. Restoration has been a problem, but, with the advent of adhesive techniques, it is far less traumatic. The most widely advocated method currently uses composite resin as the primary restorative material with dentin bonding agents. Type III glass ionomer lining cements are also suggested to provide bonding to the dentin. This paper details the requirements for clinical success in the restoration of the Class V erosion lesion using Type II restorative esthetic glass ionomer cements as the primary restorative material with the possible addition of composite resin as a final veneer only if circumstances warrant it.     

Treatment of localized anterior tooth wear with a glass-fiber-reinforced composite resin: a clinical report

Developments in adhesive dentistry have provided the dental profession with new restorative materials and technology to restore esthetics and function to the worn anterior dentition. This clinical report describes treatment of localized anterior tooth wear with fiber-reinforced composite resin restorations as an alternative treatment method.     

Reasons for restorative therapy and the longevity of restorations in adults

The aim of this study was to obtain information on the restorative dental care of adults in Finland. A random sample of private dentists was drawn from the register, and in spring 2000 they were sent a questionnaire requesting them to record information for each restoration placed during one ordinary working day. A total of 800 dentists were contacted and 548 responded. The dentists reported placement of 3,455 restorations. Of these, 5% were Class I, 36% were Class II, 13% were Class III, 9% were Class IV, 21% were Class V, and 16% were extensive restorations including 4 or more surfaces. Overall, composite resin was the most common restorative material, and it was used in 79% of the restorations, whereas amalgam was used in 5%, compomers in 4%, and glass ionomers (either conventional or resin‐modified) in 7% of cases. In 5% of the cases, the tooth was restored with indirect restorative methods, using either gold or ceramic materials. Of the treatments, 65% were replacements of previous restorations. Secondary caries was the most common reason for replacement (36%, 52%, and 41% for composite, glass ionomer, and amalgam, respectively). Other common reasons were fractures of the tooth or restoration (23%, 11%, and 22% for composite, glass ionomer, and amalgam, respectively) and lost composite restorations (16%). The median age of failed restorations was 15 years for amalgam, 6 years for composite, and 7 years for conventional glass ionomer. Although the longevity of tooth coloured restorations was shorter than that of amalgam, comparisons with our previous studies indicate improved survival periods for tooth coloured materials.     

Composite restorations: influence of flowable and self-curing resin composite linings on microleakage in vitro

This in vitro study evaluated the microleakage at enamel (occlusal) and dentin (gingival) margins of MOD resin composite restorations made with different incremental insertion techniques. MOD cavities were prepared on 60 extracted human molars with the proximal margins placed 1 mm below the cemento-enamel junction. All teeth were acid-etched and treated with One-Step adhesive, then restored with a hybrid resin composite (Renew) with and without a flowable composite (AEliteflo) or a self-curing composite (Bisfil 2B) as the first increment in the proximal boxes. The time of placement of the second increment in relation to curing of the first increment was also varied. After polishing, the teeth were soaked in 0.5% basic fuchsin for 24 hours, sectioned and evaluated for dye penetration. None of the restorative techniques prevented microleakage at the enamel and dentin margins. However, microleakage at dentin margins were significantly reduced by the use of a flowable composite as the first increment in the proximal boxes. Time of placement in relation to curing had no influence on microleakage. Microleakage was lower at enamel margins than at dentin margins; however, besides microleakage at the enamel-restoration interface, 37 of the 60 restored teeth (62%) displayed at least one white line in enamel adjacent to the composite restoration.     

Controlling contacts and contours using preformed ceramic inserts

Current adhesive techniques and materials that seal both enamel and dentin have revolutionized modern restorative dentistry. Unfortunately, the durability problems associated with direct polymeric materials of the past have not been adequately solved. Nevertheless, when cost and esthetics form part of the treatment decision process, patients presenting with Class 2 defects are most often provided with a direct restorative option. Direct composite resin restorations are fraught with problems largely related to the mechanical stresses that accompany polymerization shrinkage. A partial solution is to incorporate prefabricated ceramic inserts into the substance of the composite resin, thereby decreasing the volume of directly cured restorative material and effectively reducing the magnitude of the polymerization stresses. SONICSYS approx is a unique addition to the restorative continuum that takes the insert strategy one step further by using specifically shaped sonically driven diamond-coated preparation tips to adjust the cavity form to fit presized ceramic proximal inlays. The SONICSYS approx system represents a technique intermediate between a direct resin composite and a laboratory fabricated inlay. This article describes the background of this development, and the components and application of the system. In addition, within the presentation of a case study, operative innovations are introduced that improve interfacial integrity and allow for the conveyance of predictable contacts and proper physiological contour.     

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复合树脂充填材料用于牙体修复已超过半个世纪的时间,随着科技的进步,粘接系统和复合树脂材料已达到既牢固又美观的临床使用要求,成为牙体直接修复中的首选技术。复合树脂直接粘接修复技术的适应证包括修复各种原因造成的前牙牙体缺损及色泽、形态的异常等,修复的最终目的是恢复患牙的形态和美观。对于牙釉质的粘接需使用磷酸酸蚀粘接系统,对于牙本质的粘接则使用全酸蚀或自酸蚀牙本质粘接系统,修复材料则应选择复合树脂材料。修复中可根据患者的要求及患牙的条件选择单色、双色和多色树脂修复技术,以满足不同的美学修复目标。唇舌侧贯通的牙体组织缺损,应在舌侧充填具有遮色效果的树脂以减小口腔暗背景对修复体色泽的影响。唇面缺损的修复应体现牙体组织的细节和个性化解剖特征。对于外伤冠折牙齿的美学修复,可以用粘接系统将断离牙冠与剩余牙体组织对位粘接,必要时还可以用纤维桩增强固位。复合树脂直接粘接修复技术有保守、隐形、快捷等优势,但不适用于牙体组织缺损过大、色泽等严重异常的患牙。     

Critical appraisal. Class II composite resin restorations with gingival margins in dentin

The rising demand for esthetic restorations has considerably increased the number of direct composite restorations being placed in private practices. While composite resin is often selected primarily for its esthetic qualities, another significant advantage of direct composite restorations is the ability to perform conservative cavity preparations. The traditional configuration used for amalgam restorations is no longer mandatory; thus, more sound tooth structure can be preserved.
The technique of composite placement is complex when compared to amalgam placement. The use of adhesive systems prior to placement of composite restorations requires not only excellent isolation to avoid contamination, but also precise manipulation of the adhesive system. While stable bonds to enamel are routinely obtained, the heterogeneous composition and intricate morphology of dentin makes this substrate more challenging to restore. In addition, the cavity configuration (C-factor) and inherent polymerization shrinkage of composite resin play an important role in the durability of the composite–dentin interface. Class II preparations often have gingival margins in root surfaces because of the location of the caries lesion. Clinicians are then faced with a preparation that is challenging to isolate, has a relatively high C-factor, and relies on optimal bonding to dentin to secure long-lasting marginal integrity. Various restorative techniques, such as incremental placement or the use of an intermediate layer (flowable composite or resin-modified glass ionomer cements—open sandwich technique), have been some of the methods proposed to increase the longevity of composite restorations, especially those with margins in dentin. This review evaluates some of the published research on Class II composite resin restorations with margins in the dentin/cementum.     

Reasons for restorative therapy and the longevity of restorations in adults

The aim of this study was to obtain information on the restorative dental care of adults in Finland. A random sample of private dentists was drawn from the register, and in spring 2000 they were sent a questionnaire requesting them to record information for each restoration placed during one ordinary working day. A total of 800 dentists were contacted and 548 responded. The dentists reported placement of 3,455 restorations. Of these, 5% were Class I, 36% were Class II, 13% were Class III, 9% were Class IV, 21% were Class V, and 16% were extensive restorations including 4 or more surfaces. Overall, composite resin was the most common restorative material, and it was used in 79% of the restorations, whereas amalgam was used in 50%, compomers in 4%, and glass ionomers (either conventional or resin-modified) in 7% of cases. In 5%, of the cases, the tooth was restored with indirect restorative methods, using either gold or ceramic materials. Of the treatments, 65% were replacements of previous restorations. Secondary caries was the most common reason for replacement (36%, 52%, and 41% for composite, glass ionomer, and amalgam, respectively). Other common reasons were fractures of the tooth or restoration (23%, 11%, and 22% for composite, glass ionomer, and amalgam, respectively) and lost composite restorations (16%). The median age of failed restorations was 15 years for amalgam, 6 years for composite, and 7 years for conventional glass ionomer. Although the longevity of tooth coloured restorations was shorter than that of amalgam, comparisons with our previous studies indicate improved survival periods for tooth coloured materials.     

Rehabilitation of an extracted anterior tooth space using fiber‐reinforced composite and the natural tooth

Abstract – Conservative solutions for the restoration of a single edentulous space in the anterior maxilla present an esthetic challenge to the clinician. A 45‐year‐old male patient whose right upper central tooth was planned to be extracted was referred to our clinic for a conservative, rapid, and economic treatment. After radiographic and clinical examinations, it was decided that the tooth which was to be extracted should be used for the restoration of its own extracted area. The extracted tooth was splinted to adjacent teeth with the aid of the grooves and fiber‐reinforced composite (everStick^®, StickTech Ltd., Turku, Finland). Following an early and unexpected failure of the restoration, the fiber layer was thickened twice with a flowable composite resin (Stick Flow, Stick Tech Ltd.) which fit better to the grooves. The restoration satisfied the patient with a good mechanical behavior, esthetics, and long‐term durability after 12 months while. Restoring the missing tooth area with the patient’s own tooth is advantageous when combined with modern adhesive techniques. The clinician must pay attention to the mechanical adaptation of the restoration and the technique sensitivity of the applied adhesive system.     

A modified technique on the reattachment of permanent tooth fragments following dental trauma. Case report

Fractured anterior teeth can be restored by adhesive bonding of the fractured fragment to the remaining tooth structure. One of the major challenges for the practitioner treating traumatized anterior teeth with immediate fragment reattachment is disguising the fracture line, through the correct use of masking and restorative resins to make the restorations imperceptible to the eye as well as improve the retention of the restoration. This paper discusses a modified technique for reattaching a permanent tooth fragment following dental trauma. The initial procedure involved simple reattachment using light cured composite resin between the fragment and the remnant part of the tooth, without additional preparation. The surplus resin was spread across it in an attempt to optimize marginal seal and improve the aesthetics of the restoration. Finally, after taking into account the occlusion, the lingual surfaces of the teeth were veneered with microfilled composite to improve the retention of the reattached fragments.     

Fracture strength of Class I versus Class II restored premolars tested at the marginal ridge. 2. Cavosurface bonding and cavosurface plus internal enamel bonding

The purpose of this study was to test the difference between the strength of the marginal ridge of extracted teeth with a Class I composite resin restoration and the strength of the marginal ridge of teeth with a Class II amalgam restoration with retention grooves. A statistically significant difference in fracture strengths was found among groups. No statistically significant difference was found among restored preparations, beveling technique, and restorative material. Statistically significant differences in fracture strength were found between the whole tooth group and treatment groups; between the whole tooth group and Class II amalgam restoration group; and between the unrestored tooth preparation group and all other tooth groups.     

Er,Cr:YSGG激光制洞对光固化复合树脂边缘微渗漏的影响

目的:比较在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制备与传统牙钻制备离体牙牙颈部洞对光固化复合树脂边缘微渗漏的影响。方法:将20个因正畸拔除的新鲜完整无龋损、无隐裂、无充填物的前磨牙随机分为两组(n=10),分别使用牙钻和Er,Cr:YSGG激光制备牙颈部洞。窝洞制备后均匀涂覆FL-BOND,用TPH复合树脂进行分层充填,打磨、抛光,37℃生理盐水中存放7 d后,进行500次温度循环实验(5±2)℃—(55±2)℃。将上述所有样本置0.5%碱性品红液中室温浸泡24 h后,沿牙体长轴通过修复体正中纵行剖开,采用染料渗入法和扫描电镜方法观察充填体微渗漏情况,运用SPSS 11.0软件包进行统计学处理。结果:牙钻制备组与激光组相比,无论牙合壁还是龈壁的染料渗入评分和边缘微缝隙宽度均无显著性差异(P>0.05)。结论:在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制洞不能显著减少光固化复合树脂边缘微渗漏的发生。     

Achieving form and function for Class II restorations using aesthetic resin stratification.

It can be challenging to reproduce the appropriate three-dimensional contours when the proximal walls of posterior teeth have been lost. This presentation will demonstrate the fundamentals required to achieve predictable success when placing direct posterior composites in these Class II sites. The keys to successful placement of resin materials (eg, adhesive technique, integration of form and function, color match) are covered herein. When placing a direct resin restoration, clinicians must have a sound understanding of tooth morphology, combined with the proper techniques, outlined in the clinical case, in order to obtain an acceptable aesthetic restoration.     

The effect of flowable resin composite on microleakage in class V cavities

This in vitro study investigated the microleakage of flowable resin composite as a restorative material and as a liner (either light cured separately or co-cured with hybrid resin composite) in Class V cavities. A light-cured hybrid resin composite was used as a control. Twenty extracted human premolars were prepared with standardized Class V cavity outlines on the buccal and lingual surfaces. The occlusal margin of the cavities was on enamel and the gingival margin was on dentin. One bottle adhesive system (Single Bond) was used after etching enamel and dentin with 34.5% phosphoric acid for 15 seconds. The cavities were randomly divided into four groups of 10 each and restored according to the manufacturers' instructions: Group I-Hybrid resin composite (Z100); Group II-Flowable resin composite (Filtek Flow); Group III-Flowable resin composite (Filtek Flow)+Hybrid resin composite (Z100); light cured separately; Group IV-Flowable resin composite (Filtek Flow)+Hybrid resin composite (Z100); co-cured. The samples were thermocycled 200 times with a 30-second dwell time. They were then immersed in a 0.5% basic fuchsin solution for 24 hours, sectioned and analyzed by stereomicroscopy. The degree of dye penetration was recorded and analyzed with the Kruskal-Wallis and Mann-Whitney U tests. The results of this study indicate that there was no leakage at the occlusal margin for either restoration. Statistically significant differences were found among the groups at the gingival margin. No statistically significant difference was observed between the occlusal and gingival margins except in Group IV. The combination of flowable resin composite and hybrid composite light cured separately yielded the best result in this study. The most leakage was observed when this combination was co-cured. The resistance to microleakage of flowable resin composite as a restorative material is similar to that of hybrid resin composite.     

Class IV preparations for fractured anterior teeth restored with composite resin restorations

Pediatric dentists play a major role in treating most of the anterior teeth fractures due to the fact that most patients who suffer such traumatic injuries are between the ages of seven and fourteen. Several techniques has been developed to restore the fractured incisors to the original shape and color, these include full-coverage of the traumatized tooth, or restoring the incisors with a resin. The purpose of this study is to find the ideal combination of tooth preparation and restorative material, namely, to determine if stair step chamfer preparations provide more retention in class IV restorations than the plain chamfer preparation technique when restored with a combination of a hybrid composite resin and a microfilled composite resin. This was done by comparing the shear strength values between the buccal stair-step chamfer preparation, and a modification on it (buccal and lingual stair-step chamfer preparation) and the plain chamfer preparation techniques in class IV restorations on anterior incisors using different composite resin materials. The Instron machine was used to test shear strength. One hundred and two bovine incisor teeth were freshly harvested from the slaughterhouse. The teeth were prepared and restored according to the following six groups; Plain Chamfer preparation with Tetric Ceram Composite, Plain Chamfer preparation with Renamel Composite, buccal stair-step chamfer preparation with Tetric Ceram composite, buccal stair-step chamfer preparation with Renamel composite, Buccal and lingual stair-step preparation with Tetric Ceram Composite, Buccal and lingual stair-step chamfer preparation with renamel composite. All samples were fractured using the Instron testing machine then the surface area were measured using Image-J software. Shear strength for every sample was calculated using the load numeric result from the Instron machine and the measured surface area. The Two-Factorial (AB) Analysis of Variance For Independent Samples showed that the buccal stair-step chamfer preparation showed significantly higher shear strength and fracture resistance than plain chamfer or the buccal and lingual stair-step chamfer preparation. The combination of Renamel Hybrid and Renamel Microfill composite materials showed better results than the Tetric Ceram composite when used with all three preparation techniques, but did not show a statistical significance. It was concluded that buccal stair-step preparation technique provided the ideal preparation technique with bonded composite resins in fractured anterior teeth. Only 7% of the entire sample size had an adhesion failure versus 93% that had cohesion failure. There was no significant difference in shear strength, between the restorative materials used, in conjunction with all the preparation techniques.     

Marginal adaptation of Class V restorations using different restorative techniques

This in vitro study compares the marginal adaptation of Class V restorations with margins located half in enamel and half in dentine, which were placed using different restorative techniques. Five operative procedures were evaluated both in saucer-shaped erosion lesions and in box-shaped cavities with bevels in enamel. The five procedures included a composite inlay technique using both the chemically and the light curing versions of a resin based composite cement, a bulk placement technique using a chemically curing composite resin, an incremental technique and an incremental technique combined with a built-up base, using a light curing composite resin. A combination of Gluma/Clearfil served as the dentinal adhesive. The micromorphology of the tooth/restoration interface was analysed before and after thermal cycling; the marginal seal was analysed after thermal cycling only. In the conventional cavities, the restorations showed less leakage, and micromorphologically a better, but statistically insignificant superior marginal adaptation. The inlay technique rendered the best marginal quality in both enamel and dentine before and after thermal cycling. Due to the unique curing characteristics of the chemically cured composite resin and cement resulting in a significantly reduced rigid contraction, the inlays cemented with the chemically curing cement and the restorations placed with the chemically curing composite resin were superior to their light cured counterparts. The built-up base yielding a reduction of the composite mass did not enhance marginal adaptation because of the partial replacement of the strong adhesion to dentine mediated by the Gluma/Clearfil combination by the weaker bond promoted by the etched glass ionomer cement.     

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复合树脂粘接修复技术近年来发展迅速,许多传统观念发生了彻底改变。本文讨论了后牙复合树脂粘接修复中的几个临床关键问题,回顾了近年来相关研究的最新进展,从而为临床医生提供参考。