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Class II Composite Restorations

METHODS: 100 matched pairs of restorations were originally entered into the trial. Each pair consisted of a direct composite inlay and a conventional composite restoration made from the same material. At 5 years it was possible to recall 65 pairs, of which 54 were complete. Clinical assessments were made using USPHS criteria (indirect measurements of occlusal wear were made using Ivoclar standard dies) and annual bite wing radiographs.

RESULTS: There was a trend to more failure of inlays than conventional composites (17.4 c.f. 7.5%) but this was not significant. The clinical performance of both types of restoration was similar and compared favourably with the results of studies of other materials. Secondary decay was diagnosed in only one restoration. Between 3 and 5 years there was some deterioration in cavo-marginal discoloration, marginal adaptation (occlusally) and surface roughness (occlusally). There was no apparent deterioration in colour match, proximal contact, shim stock contacts and Gingival Index. Wear rates of both types of restoration showed no significant difference and were essentially linear with a mean of 33-34 microm per year.

CONCLUSION: Both inlays and conventional composite restorations complied with ADA specification minimum requirements for posterior composite restorations. In this study the direct inlay technique gave no clinical advantage over conventional, incremental placement.

Compend Contin Educ Dent 1999 Dec;20(12):1138-44, 1146, 1148

Resin composites in the post-amalgam age.

Lutz F, Krejci I 

Department of Preventive Dentistry, Periodontology and Cariology School of Dentistry, University of Zurich, Switzerland.

Resin-based composites are now being used as either amalgam substitutes or amalgam alternatives for the direct placement of box-shaped, stress-bearing restorations in posterior teeth. The expected longevity of these restorations is 8 years. With amalgam substitutes, preservation of enamel and dentin and restoration of tooth form and function must be warranted for the full length of the envisaged service life. In addition, with amalgam alternatives, the restoration must be, and must remain, imperceptible at a normal talking distance. The limiting factor with amalgam substitutes is the elevated risk of secondary caries, which is a result of the marginal openings that are unavoidably associated with the nature of the operative technique. Restorations in permanent teeth using amalgam substitutes most likely fail in some critical aspect of the Swiss Dental Society quality guidelines. With amalgam alternatives, the high cost and the demanding operative technique remain the main criticisms. However, amalgam alternatives, if they are placed using a sophisticated operative technique resulting in perfectly adapted restorations, meet the high expectations outlined in the Swiss Dental Society quality guidelines and fit the clinical concept of the post-amalgam age.

J Esthet Dent 1999;11(5):234-49 

Packable composites: overview and technical considerations. 

Leinfelder KF, Bayne SC, Swift EJ Jr 

Department of Operative Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, USA.

OBJECTIVE: New composites, called packable or condensable composites, are being promoted as amalgam alternatives. The purposes of this review article are to identify these products, define new terminology associated with them, summarize the advertised properties for the materials, discuss the ideal properties for packable composites, review the properties of the major products, and critically evaluate the proposed handling procedures for these materials.

REVIEW: The term packable is preferable to condensable for describing this new class of materials. All materials should be considered amalgam alternatives, not amalgam substitutes. The compositions and physical properties reported by manufacturers reveal that none of the materials represents a remarkable improvement over the properties of more traditional universal composites. The designs of Solitaire (Heraeus Kulzer), ALERT (Jeneric-Pentron), and SureFil (Dentsply/Caulk) are discussed in detail. The distinguishing characteristics of all packable compositions are less stickiness or stiffer viscosity than conventional composites, which allow them to be placed in a manner that somewhat resembles amalgam placement.

CONCLUSION: Packable composites may allow more convenient placement in posterior sites and may offer some technique advantages over conventional composites. However, there is no evidence that their clinical properties are consistently better than those of conventional universal composites.

CLINICAL SIGNIFICANCE: Packable composites may be selected as alternatives to amalgam or conventional universal composites, but they are not equal to or better than dental amalgam in all respects. Also, in most cases, mechanical properties of packable composites are not substantially better than those of most conventional universal composites.

J Esthet Dent 1999;11(3):135-42 

Seventeen-year clinical study of ultraviolet-cured posterior composite Class I and II restorations. 

Wilder AD Jr, May KN Jr, Bayne SC, Taylor DF, Leinfelder KF 

Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, USA.

OBJECTIVES: To compare the clinical performance of four commercial ultraviolet light-cured composite materials, and to evaluate curing-system effects on long-term wear resistance of Class I and II restorations. MATERIALS AND

METHODS: Approximately 32 samples of each of four different ultraviolet light-cured composites (n = 130) were inserted into conventional Class I and II cavity preparations by two clinicians. Cavosurface margins of the preparations were not beveled. Enamel walls of the preparation were etched, and the respective bonding agent was applied. Each restoration was evaluated by two clinicians at 5, 10, and 17 years. Direct evaluations were performed using modified United States Public Health Service (USPHS) criteria. Indirect evaluations were performed using the Leinfelder cast evaluation method.

RESULTS: After 17 years, 65% of the restorations were recalled and pooled direct evaluations were conducted for color matching (94% alfa), marginal discoloration (100% alfa), marginal integrity (100% alfa), secondary caries (92% alfa), surface texture (72% alfa), and anatomic form (22% alfa). Mean occlusal wear from indirect evaluations at 5, 10, and 17 years was 197 +/- 85 microns, 235 +/- 72 microns, and 264 +/- 80 microns, respectively. For direct and indirect evaluations there were significant differences (p < or = .05) between the baseline and 5-year recall evaluations.

CLINICAL SIGNIFICANCE: This study demonstrated that the mean pooled occlusal wear of four ultraviolet light-cured posterior composites at 17 years was 264 microns (approximately 0.25 mm), and that most wear (75%) occurred in the first 5 years. Of all recalled restorations, 76% were judged clinically acceptable at 17 years, and 22% of those exhibited no clinically detectable wear.

Clin Oral Investig 1999 Dec;3(4):208-15 Related Articles, 

Internal adaptation and overhang formation of direct Class II resin composite restorations. 

Frankenberger R, Kramer N, Pelka M, Petschelt A 

University of Erlangen-Nuremberg, Policlinic for Operative Dentistry and Periodontology, Germany. frankbg@dent.uni-erlangen.de

The aim of the present in vitro study was to evaluate different restorative concepts for posterior resin composite fillings in terms of internal adaptation and overhang formation. Eighty standard occluso-distal cavities with and without a 1.5-mm bevel were restored in a phantom head using Syntac Classic and Tetric Ceram with and without Tetric Flow as thin lining or Solid Bond and Solitaire with and without FlowLine. The restorations were finished intraorally and afterwards subjected to thermal loading (1150 x +5 degrees C/+55 degrees C) for 24 h. The proximal margins of the original specimens were analyzed for overhangs under a stereo light microscope (100-fold magnification) before and after intraoral control with loupes, including additional polish. Afterwards the teeth were cut longitudinally, replicated, and their internal integrity analyzed under a SEM (200-fold magnification). The combination of flowable and viscous composites resulted in enhanced internal adaptation for both adhesive systems. However, Syntac Classic exhibited superior adaptation characteristics compared with Solid Bond. In terms of overhang formation, the use of flowable materials always led to higher percentages of marginal overhangs in beveled cavities. Higher viscous materials alone resulted in higher percentages of underfilled margins of beveled than box-shaped cavities. It was clear that the use of magnifying glasses during finishing was beneficial for reducing marginal overhangs up to 40%.

J Prosthet Dent 1999 Oct;82(4):391-7 Related Articles, 

Two-year clinical evaluation of direct and indirect composite restorations in posterior teeth. 

Scheibenbogen-Fuchsbrunner A, Manhart J, Kremers L, Kunzelmann KH, Hickel R 

School of Dentistry, Ludwig-Maximilians-University, Munich, Germany.

STATEMENT OF PROBLEM: Few long-term clinical studies have reported data of modern posterior composites as direct and indirect restorations. PURPOSE: This prospective, long-term clinical trial (1) evaluated direct and indirect composite restorations for clinical acceptability as posterior restoratives in single or multisurface carious teeth and (2) provided a survey on the 2-year results.

MATERIAL AND METHODS: Nine dental students placed 88 composite restorations (Tetric, blend-a-lux, Pertac-Hybrid Unifil), 43 direct composite restorations and 45 indirect inlays, under the supervision of an experienced dentist. The first clinical evaluation was performed 11 to 13 months after placement by 2 other experienced dentists, using modified USPHS criteria. A second follow-up of 60 restorations took place within 20 to 26 months after placement.

RESULTS: A total of 93% of indirect and 90% of direct composite restorations were assessed to be clinically excellent or acceptable. Two restorations (1 indirect composite inlay and 1 margin of a direct composite restoration) failed during the second year because of fracture. Indirect inlays demonstrated a significantly better "anatomic form of the surface" than direct composite restorations. Premolars revealed a significantly better margin integrity and postoperative symptoms than molars.

CONCLUSION: : Posterior composite restorations provided a satisfactory clinical performance over a 2-year period when placed by relatively inexperienced but supervised students.

J Prosthet Dent 1999 Aug;82(2):167-71 Related Articles, 

Fracture resistance of teeth restored with onlays of three contemporary tooth-colored resin-bonded restorative materials. 

Brunton PA, Cattell P, Trevor Burke FJ, Wilson NH 

Turner Dental School, The University of Manchester, Manchester, England. paul.brunton@man.ac.uk

STATEMENT OF PROBLEM: There are uncertainties regarding the use of large indirect composites and ceramics in the restoration of posterior teeth. PURPOSE: This study investigated the fracture resistance of teeth restored with restorations of 3 contemporary resin-bonded tooth-colored materials placed in a standardized onlay preparation.

MATERIAL AND METHODS: A random sample of preparations for tooth-colored onlays was obtained from a full service dental laboratory. A preparation was then duplicated in 30 natural teeth by copy milling. An additional 10 teeth were not prepared, and acted as a control. Ten onlays of each of the 3 materials (Belle Glass, SR Isosit, and Empress) were produced and resin bonded into place according to the manufacturers' instructions. The restorations were compressively loaded to fracture and the mode of failure recorded.

RESULTS: The fracture resistances obtained for the teeth restored with the composite material (mean 1.56 kN; SD 0.54) were greater than those obtained for the teeth restored with the ceramic material (mean 0.99 kN; SD 0.49) and the fiber-reinforced composite material (mean 0.99 kN; SD 0.56).

CONCLUSION: : Teeth restored with composite onlay restorations demonstrated a higher fracture resistance than equivalent sized onlay restorations produced from fiber-reinforced composite or a ceramic material. Failure under compressive loading may be found to be less catastrophic when a fiber-reinforced composite rather than a composite or ceramic material is used.

Community Dent Oral Epidemiol 1999 Apr;27(2):137-43 


Cost-effectiveness of composite resins and amalgam in the replacement of amalgam Class II restorations. 

Tobi H, Kreulen CM, Vondeling H, van Amerongen WE 

Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam, The Netherlands. h.tobi@acta.nl

OBJECTIVES: The replacement of an old amalgam Class II restoration is a common treatment and will remain so for decades. In addition to effectiveness, possible adverse health effects and esthetics, the costs of the treatment options will play a role in the choice of material. The aim of this study was to yield information on the relative cost-effectiveness of the use of composite resins and amalgam for the rerestoration of amalgam Class II restorations.

METHODS: As part of a larger randomized clinical trial, treatment effectiveness and treatment costs were estimated in 73 composite and amalgam Class II posterior re-restorations. The main treatment outcome was longevity. Secondary outcomes included need of repair and quality of the margin while in situ. Costs were analyzed from the perspective of dentistry, assuming a treatment strategy aimed at offering 'value for money'. From this perspective, differential costs were based on personnel costs as approximated by treatment time.

RESULTS: Replacing an amalgam Class II restoration with amalgam is associated with lower costs than replacing with a composite resin. A sensitivity analysis, considering type of composite, increasing proficiency with the material, and time needed for future removal of material, demonstrated that these differences are fairly robust. The materials performed equally well for the first 5 years after placement with respect to longevity. Differences in secondary outcomes were minor and not all in favor of the same material.

CONCLUSION: It is tentatively concluded that amalgams are more cost-effective than composites for replacing existing Class II amalgam restorations.

J Dent Res 1999 Feb;78(2):706-12 

Ceramic whisker reinforcement of dental resin composites. 

Xu HH, Martin TA, Antonucci JM, Eichmiller FC 

Paffenbarger Research Center, American Dental Association Health Foundation, Gaithersburg, Maryland 20899, USA.

Resin composites currently available are not suitable for use as large stress-bearing posterior restorations involving cusps due to their tendencies toward excessive fracture and wear. The glass fillers in composites provide only limited reinforcement because of the brittleness and low strength of glass. The aim of the present study was to reinforce dental resins with ceramic single-crystalline whiskers of elongated shapes that possess extremely high strength. A novel method was developed that consisted of fusing silicate glass particles onto the surfaces of individual whiskers for a two-fold benefit: (1) to facilitate silanization regardless of whisker composition; and (2) to enhance whisker retention in the matrix by providing rougher whisker surfaces. Silicon nitride whiskers, with an average diameter of 0.4 microm and length of 5 microm, were coated by the fusion of silica particles 0.04 microm in size to the whisker surface at temperatures ranging from 650 degrees C to 1000 degrees C. The coated whiskers were silanized and manually blended with resins by spatulation. Flexural, fracture toughness, and indentation tests were carried out for evaluation of the properties of the whisker-reinforced composites in comparison with conventional composites. A two-fold increase in strength and toughness was achieved in the whisker-reinforced composite, together with a substantially enhanced resistance to contact damage and microcracking. The highest flexural strength (195+/-8 MPa) and fracture toughness (2.1+/-0.3 MPa x m(1/2)) occurred in a composite reinforced with a whisker-silica mixture at whisker:silica mass ratio of 2:1 fused at 800 degrees C. To conclude, the strength, toughness, and contact damage resistance of dental resin composites can be substantially improved by reinforcement with fillers of ceramic whiskers fused with silica glass particles.

van, et al.-1999-Longevity of extensive class II open-sandwich restorations with a resin-modified glass-ionomer cement.-J Dent Res-78-1319-25-

Several new techniques have been introduced for use in the esthetic restoration of posterior cavities to substitute for the presumed toxicity of amalgam. Composite-laminated glass-ionomer cement restorations, the sandwich technique, have been recommended for caries-risk patients. Clinical evaluation of the use of conventional glass-ionomer cements in the open-sandwich restoration has shown a high failure rate. The aim of this study was to evaluate the durability and cariostatic effect of a modified open-sandwich restoration utilizing a resin-modified glass-ionomer cement (RMGIC) in large cavities. The materials consisted of 274 mostly extensive Class II Vitremer/Z100 restorations performed by four dentists in 168 adults. Six experimental groups were investigated. In four groups a thick and in two groups a thin layer of cement was placed. Cavity conditioning before application of the RMGIC self-etching primer was done in 3 groups with polyacrylic acid and in one group with maleic acid; in two groups, only water rinsing was performed. The restorations were evaluated at baseline and after 6, 12, 24, and 36 months according to modified USPHS criteria (van Dijken, 1986). After 3 years, 239 restorations were evaluated. Twelve (5%) were estimated as non-acceptable. Two were replaced, and seven were repaired with resin composite. Tooth fractures were observed in 2.5%. Slight erosion of the RMGIC part was seen in 4%, and in one case operative treatment was indicated. Post-operative sensitivity was reported for 9 teeth. Forty-three percent of the patients were considered as caries-risk patients. Only one restoration showed secondary caries. The three-year results indicated that the modified open-sandwich restoration is an appropriate alternative to amalgam including extensive restorations.,

Burke, et al.-1999-Restoration longevity and analysis of reasons for the placement and replacement of restorations provided by vocational dental practitioners and their trainers in the United Kingdom.-Quintessence Int-30-234-42-

OBJECTIVE: This study examined the reasons given by vocational dental practitioners and their trainers for placement and replacement of restorations.

METHOD AND MATERIALS: Each participant was asked to record the reason for placement or replacement of restorations. The age and class of the restoration being replaced were also recorded, as was the material being used and the material being replaced (if known).

RESULTS: Details of the reason for placement or replacement was received on 9,031 restorations. Of the restorations placed, 53.9% were amalgam, 29.8% were resin composite, and 16.3% were glass-ionomer cement. The reasons for placement or replacement of the restorations were principally primary caries (41.3%), secondary caries (21.9%), tooth fracture (6.4%), marginal fracture or degradation (6.1%), and noncarious defects (5.8%). Of the amalgam restorations, most were placed to restore Class II and Class I preparations (65.8% and 29.9%, respectively). Of the composite restorations, most were placed in Class III and Class V cavities (35.5% and 26.3%, respectively). Glass-ionomer cement was used predominantly to restore Class V cavities (63.5%).

CONCLUSION: : Secondary caries was the most prevalent reason for replacement of restorations, regardless of material. Statistical analysis indicated that amalgam provided significantly greater longevity than composite or glass-ionomer materials.,

Hilton-1999-Cavity preparation factors and microleakage of Class II composite restorations filled at intraoral temperatures. [In Process Citation]-Am J Dent-12-123-130-

PURPOSE: To determine if alteration of any of the following factors could reduce microleakage following placement of Class II resin-based composites (RBC) at intraoral temperature: cavity preparation (vertical wall bevels), finishing technique (delayed vs. immediate), or postoperative re-bonding (marginal sealing). An additional purpose was to determine if a decalcification/clearing protocol was a valid technique for assessing three-dimensional microleakage.

MATERIALS AND METHODS: Twenty recently extracted human molars had standardized Class II slot cavities prepared on the mesial and distal surfaces with the gingival floor located on dentin. The teeth were imbedded in a stone template, warmed to 37 degrees C and restored immediately upon removal from the oven with visible light-cured (VLC) adhesive (All-Bond 2) and three horizontal increments of VLC RBC (Bisfil P) using a metal matrix. Teeth were placed into one of four groups: (1) Control; (2) The preparation was modified to include 0.5-1.0 mm enamel bevels on the vertical walls (facial and lingual); (3) Finishing of the RBC was delayed 24 hours; (4) Following immediate finishing, all margins of the RBC restorations were sealed by dentin bonding agent application. Teeth were stored at 37 degrees C for 2 weeks, thermocycled 1000x at 5/55 degrees C, stained with silver nitrate, underwent a decalcification and clearing protocol, and evaluated for three-dimensional dye penetration.

RESULTS: Axial-occlusal enamel margins exhibited minimal leakage and no differences among the groups. Vertical walls without bevels exhibited pronounced microleakage. Beveled vertical proximal walls exhibited significantly less facial and lingual wall microleakage compared to all other groups, and less gingival marginal leakage compared to the control group.,

Opdam, et al.-1998-Necessity of bevels for box only Class II composite restorations.-J Prosthet Dent-80-274-9-

STATEMENT OF PROBLEM: The tooth preparation of a bevel is recommended to improve marginal quality of a composite restoration. However, in small Class II restorations, it is unclear if a bevel also contributed to a better marginal fit.

PURPOSE: This study investigated the influence of tooth preparation design on microleakage of minimal posterior Class II composite restorations.

MATERIAL AND METHODS: Box-shaped Class II tooth preparations for posterior composite restorations in maxillary premolars were restored with a total etch technique. The tooth preparations were beveled or non-beveled and the box prepared at a right angle cervically or additionally excavated. The facial and lingual box margins were also either beveled or unbeveled. The teeth were thermocycled and immersed in a dye solution. After sectioning specimens, dye penetration at the facial and palatal margins was recorded.

RESULTS: A bevel-reduced microleakage both at the cervical and ascending walls. Enamel cracks were observed along certain unbeveled margins as recorded in this study. The additional excavation did not contribute to reduction of microleakage.

CONCLUSION: Tooth preparation of a bevel is recommended for an optimal marginal seal in small box-type Class II composite restorations.,

Christensen-1998-Amalgam vs. composite resin: 1998.-J Am Dent Assoc-129-1757-9-

Class II resin restorations have been evolving in American dentistry for 30 years, but the concept has had significant difficulty being accepted because of stigma attached to early generations of composites. Currently available composite resins for posterior tooth restorations have physical characteristics justifying their use. Techniques for Class II resin placement have improved significantly, and mastery of them is within the ability of both dentists and dental students. Although composite resin materials and techniques present clinical challenges, so do amalgam materials and techniques. It is time to accept Class II resin restorations, improve dentist and student education about their use, increase acceptance by third-party organizations and various approving groups, and bring this concept into the mainstream of U.S. dentistry.,

Leinfelder and Prasad-1998-A new condensable composite for the restoration of posterior teeth.-Dent Today-17-112-6-

Undoubtedly the greatest resistance of clinicians to use composite resins in posterior teeth relates to technique sensitivity, time consumption, and complexity. Placing conventional posterior composite resins does not take into account that composites differ considerably from amalgam. This is particularly true with respect to its physical characteristics, especially insertion and packing properties. The development of a posterior composite resin that can be placed by an amalgam carrier and subsequently packed or condensed as an amalgam, should assist clinicians greatly in their ability to successfully restore class II cavity preparations. Acknowledgment is expressed to Bruce Small, DMD, for the clinical dentistry and slides.,

The efficiency of using prefabricated ceramic inlays to prevent microleakage has been discussed in different investigations. The purpose of this study was to evaluate the marginal microleakage of a new glass ceramic inlay system in combination with two different composite luting materials and one polyacid-modified composite, respectively. Standardized class II cavities (n = 60) were filled with (1) Empress inlays fixed with a highly viscous luting composite as a control group, and with glass ceramic inlays (Cerana) in combination with (2) a highly viscous luting composite, (3) a low-viscous luting composite and (4) a polyacid-modified composite, respectively. After thermocycling the marginal quality was analysed with scanning electron microscopy, and the dye penetration along the cavity walls was measured. The use of the Cerana inlays with a polyacid-modified composite resin did not reveal a good marginal adaptation. However, the combination of the Cerana and the Empress inlays with the highly viscous composite exhibited a comparable marginal fit. Within the limitations of an in vitro study it is concluded that the combination of the new glass ceramic inlays with a polyacid-modified composite cannot be recommended for clinical use.,

When patients exhibit Class II defects requiring restoration, the treatment modality and respective preparation requirements may present challenges to the clinician. Aesthetics, chairside time, and expense become factors for the consideration of both dentist and patient. However, a new sonically driven system for the preparation and restoration of proximal defects was recently introduced (SONICSYS, Ivoclar Vivadent, Amherst, NY). This system, composed of diamond-coated tips and prefabricated ceramic inserts, promises to enable clinicians to efficiently, confidently, and expertly prepare and restore Class II defects in a timely, consistent, and cost-efficient manner. This article describes the components of the system and demonstrates its utilization in a case report.,

This study evaluated the force necessary to cause failure at the marginal ridge of teeth prepared with conventional class II cavity design and teeth prepared with proximal box-only or vertical slot preparation. The teeth were restored with Herculite XR or Tetric Ceram. Mean failure loads were not found to be statistically significant between conventional class II preparations and proximal box-only preparations. The teeth restored with Tetric Ceram were significantly more resistant to the vertical load than teeth restored with Herculite.,

In this study, we recorded the type of restoration and the materials used in 24,429 restorations in permanent teeth by 243 Norwegian clinicians in general practice. Demographic information included patient's gender and age, and clinician's gender, years since graduation, and practice setting (private or salaried). The overall recorded use of restorative materials in permanent teeth shows that 32% are amalgams, just over 40% composites, and about 25% glass ionomer type materials. Three percent are "other" materials. A marked shift away from amalgam restorations is noted both in the clinician's estimated use during the last 2 decades and by comparing the present use of materials with that in failed restorations. Tooth-colored materials are more commonly used in adolescents, especially glass ionomer materials, and in female patients. In patients &lt; or = 18 years, amalgam is used in 25% of all restorations. The use of amalgam is similar in private practice and in public health service practice, but private practitioners use more composites and salaried dentists more glass ionomers. The clinician's gender does not have any effect on the selection of restorative materials. The change from amalgam to tooth-colored material is particularly noticeable for Class I and Class V restorations. Amalgam is the predominant material in 2- and 3-surface Class II restorations.,

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).,

In a two-month in vitro experiment we examined the marginal adaptation of ten dental materials. Fifty Class II restorations were prepared extending to the cemento-enamel junction. The cavities of the composite restorations were bevelled at the vestibulo-occlusal and -approximal enamel margins, on the other side enamel and gingival margins were prepared conventionally. The specimens were thermocycled and examined with SEM. The microleakage was measured at the vestibulo-occlusal and -approximal tooth-filling junction, where adhesive technique was used, and at the gingival, oroocclusal and -approximal margins, which were not bevelled before. The obviously most important

CONCLUSION: of the study is, that in the case of deep Class II cavities the amalgam has a better adaptation at the gingival margin than the examined composite resins.,

The purpose of this in vitro study was (1) to investigate the composite-to-enamel bond strength and (2) to analyze the marginal adaptation of resin composite restorations in class 2 cavities using three self-etching priming agents in comparison to conventional phosphoric acid etching and bonding application. In the first part of the study 24 extracted bovine incisors were embedded in acrylic resin and ground flat with 800-grit paper. The following three self-etching priming agents/composite resins were applied to the enamel surfaces of six teeth each: Clearfil Liner Bond 2/Clearfil AP-X (Group I), Etch & Prime 3.0/Degufill mineral (Group II), Resulcin AquaPrime + MonoBond/Ecusit (Group III). In Group IV Ecusit-Mono/Ecusit was used after enamel etching with phosphoric acid (37%). Shear bond strength values measured on a T22 K testing machine at a crosshead speed of 1 mm/min were: 24.2 +/- 3.0 MPa (Group I), 21.9 +/- 1.4 MPa (II), 34.0 +/- 3.6 MPa (III), and 26.3 +/- 1.8 MPa (IV). ANOVA revealed significant (P &lt; 0.05) differences in shear bond strength between groups, except comparison of Group I and II, and Group I and IV. In the second part of the study 24 standardized class 2 cavity preparations with the approximal box extending 1 mm above the CEJ were prepared in extracted human molars. Enamel margins were beveled and the teeth were divided into four groups of six teeth each. Cavities were restored using the self-etching priming agents Clearfil Liner Bond 2 (Group I), Etch & Prime 3.0 (Group II), and Resulcin AquaPrime + MonoBond (Group III). In Group IV composite resin restorations were placed after 37% phosphoric acid etching and bonding application (Ecusit-Mono). Quantitative SEM analysis of the marginal adaptation of the restorations after thermocycling (5-55 degrees C, 2500 cycles) and mechanical loading (100 N, 500,000 cycles) revealed excellent, gap-free margins in 91.2% (Group I), 93.0% (Group II), 92.0% (Group III), and 92.5% (Group IV) of the restorations' approximal area. There were no statistically significant differences between the four groups (P &lt; 0.05). In

CONCLUSION: , results of the present in vitro study indicate that use of self-etching primers may be an alternative to conventional phosphoric acid pre-treatment in composite-to-enamel bonding restorative techniques.,

OBJECTIVES: From a continuing investigation of the clinical performance of three different types of composite resin, the findings of the clinical evaluation at 8 years are presented.

METHODS: One operator placed 330 restorations in Class I and Class II preparations in the posterior teeth of 72 patients. Every patient received at least one restoration of each type of material: a microfilled composite, a small particle hybrid, a relatively coarse particle hybrid, and an amalgam control. Restorations were evaluated using clinical criteria.

RESULTS: Forty six patients attended the 8-year recall. Twenty-five of the 213 restorations (13.7% of the composites and 5.8% of the amalgams) originally placed in these 46 patients had previously failed or been lost from the study or were assessed as requiring replacement at the 8-year recall. Bulk fracture and secondary caries at the margin were the most common forms of failure in the composite restorations. Other failures or losses were associated with a non-margin defect in the composite, caries not associated with the restoration, pulpal considerations, extraction for orthodontics and reasons unknown. One-hundred and ninety-three restorations (including five that required replacement) were available for clinical evaluation at 8 years and these included 17 Class II restorations. Significantly fewer restorations placed with the coarse particle hybrid exhibited evidence of marginal deterioration.

CONCLUSION: : At 8 years, composite restorations in posterior teeth had failed at a rate two to three times that of amalgam restorations. The most common types of failure were bulk fracture and secondary caries at the margin.,

- The purpose of this investigation was to study the clinical performance of a new system with a proposed expanding liner for composite restorations introduced in the late 1980s. The present study reports on baseline data and the result after 3 years. One hundred and four class-II cavities in 95 patients were alternatively restored by Superlux Molar and the reference material P-50 APC by 12 general practitioners in 3 public dental health clinics. After 3 years 82 restorations (79%) were available for examination. The restorations were evaluated on the basis of USPHS criteria after 1 week and again after 3 years. Stone casts were used to quantitatively categorize wear in accordance with the Leinfelder method. Color slides and bitewings were taken to supplement the clinical evaluation of color match and marginal adaptation, respectively, and secondary caries. The failure rate (USPHS rating, Charlie) was four restorations of Superlux Molar and seven of P-50 APC. The average wear after 3 years of Superlux Molar was 131 microm and of P-50 APC, 128 microm. There were no statistically significant differences between the two materials with regard to, for example, handling characteristics, anatomic form, color match, marginal discoloration, or failures. A significantly higher wear rate was found after 3 years in patients with a high level of salivary lactobacilli (&gt; 10(5) colony-forming units (CFU)/mL at base line) compared with those with lower levels. This suggests that an acidic environment might enhance the wear rate.,

OBJECTIVES: The purpose of this study was to determine the longevity and quality of Class I and Class II resin composite (Herculite XR) restorations placed in private practice.

METHODS: One thousand two hundred and nine Class I and Class II composite restorations with margins in enamel were evaluated clinically after periods of between 12 months and 4.5 years in clinical service by two calibrated examiners using a modified version of established criteria.

RESULTS: Of the restorations investigated 94.8% were rated as 'good' (Alpha 79.3%) or 'clinically acceptable' (Bravo 15.5%). Significantly more restorations in premolar teeth were rated as Alpha (82%) than in permanent molar teeth (77%). The survival rate after 4 years was around 87%. The 50% survival-time, calculated by extrapolation according to Weibull, was approximately 9 years.

CONCLUSION: It is concluded that the composite investigated is an appropriate material for the restoration of Class I and Class II lesions with margins located in enamel in premolar and permanent molar teeth.

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