Endodontic complications after plastic restorations in general practice. Long-term clinical evaluation of fracture and pulp injury following glass-ionomer cement or composite resin applied as a base filling in teeth restored with amalgam. Pulpal inflammatory responses following non-carious class V restorations. Ten-year longitudinal clinical evaluation of a visible light cured posterior composite resin. Human pulpal response to direct pulp capping with an adhesive system. Resin-dentin interfaces of endodontically-treated restored teeth. Composite resin restoration and postoperative sensitivity: clinical follow-up in an undergraduate program. Effect of different adhesive protocols vs calcium hydroxide on primary tooth pulp with different remaining dentin thicknesses:24-month results The clinical performance of a posterior composite resin restorative material, Heliomolar R.O.: 3-year report. A clinical and histological evaluation of conservative pulpal therapy in human teeth. Carboxylesterase expression in human dental pulp cells: role in regulation of BisGMA-induced prostanoid production and cytotoxicity. Pulpal reaction to a dental adhesive in deep human cavities. A clinical study of the "open sandwich" technique in pediatric dental practice. A practice-based, randomized, controlled clinical trial of a new resin composite restorative: one-year results. Randomized clinical comparison of endodontically treated teeth restored with amalgam or with fiber posts and resin composite: five-year results. Immune function effects of dental amalgam in children: a randomized clinical trial. Two-body abrasion of commercial and experimental restorative and coating resins and an amalgam. Survival rates and reasons for failure of posterior composite restorations in multicentre clinical trial. Incomplete caries removal in deep lesions: a 10-year prospective study. Clinical performance of posterior composite resin restorations. Repair or replacement of restorations: do we accept built in obsolescence or do we improve the evidence? Four-year clinical evaluation of posterior resin-based composite restorations placed using the total-etch technique. Survival and reasons for failure of amalgam versus composite posterior restorations placed in a randomized clinical trial.
AIM To test the hypothesis that dentine and pulp protection by conditioning- and -sealing is no less effective than using a conventional calcium hydroxide lining . METHODOLOGY A cohort of healthy adults requiring a new or replacement restoration in a posterior tooth was recruited in six general practice s. All procedures received local Ethics Committee approval . Exclusion criteria included signs and symptoms of pulp necrosis or inflammation , and patients unable to commit to a long-term trial . Cavity preparations were r and omized to receive a calcium hydroxide lining or conditioning- and -sealing with a smear-removing bonding system . Choice of bulk restorative material ( composite resin or amalgam ) was at the discretion of the dentist . The key outcome measure was evidence of pulpal breakdown identified at unscheduled ( emergency ) or scheduled recall examinations . Postoperative sensitivity was recorded on 100 mm VAS at 24 h , 4 days and 7 days . Pulp status was assessed at 6 , 12 , 24 and 36 month recall , and at any emergency recall appointment . The relationship between pre-treatment and treatment variables and pulp breakdown was assessed by logistic regression ( P = 0.05 ) . RESULTS A total of 602 teeth were recruited , with comparable numbers of cavities lined ( 288 , 47.8 % ) or conditioned and sealed ( 314 , 52.2 % ) . The majority ( 492 , 81.7 % ) were replacement restorations , and amalgam was the most common bulk restorative material ( 377 , 62.6 % ) . A total of 390 ( 64.8 % ) restored teeth were review ed at 6 months , 307 ( 51 % ) at 12 months , 363 ( 60.3 % ) at 24 months , and 279 ( 46.3 % ) at 36 months post-restoration . Sixteen cases of pulp breakdown were identified within 36 months of restoration placement , 11 presenting as emergencies and five detected at routine recall examination . Logistic regression showed that preoperative pain , cavity treatment by lining or conditioning- and -sealing and the use of rubber dam isolation had no association with pulp breakdown . Pulp breakdown was associated with deep or pulpally exposed cavities ( P < 0.001 , odds ratio 7.8 ) and with composite rather than amalgam restorations ( P = 0.001 , odds ratio 2.13 ) . Re-coding to identify teeth with pulp exposures revealed that pulpal exposure was the key determinant of adverse pulp outcomes ( P < 0.0001 , odds ratio 28.4 ) and that composite resin restorations were again more likely to be associated with pulp breakdown than amalgam ( P = 0.017 , odds ratio 3.92 ) . CONCLUSIONS Considered within the context of routine primary dental care : Dentists can be confident that pulps will be equally well protected from post-restorative breakdown up to 36 months by calcium hydroxide lining and conditioning- and -sealing with adhesive resins .  Residual dentine thickness appears to be a key determinant of pulp responses after restorative dental treatment . In deep and pulpally exposed cavities in posterior teeth , composites were associated with more pulpal breakdown than amalgams The aim of this research was to analyse the long-term clinical behaviour of two dental material s applied as filling under  silver amalgam restorations  : glass-ionomer cement ( GIC ) and composite resin with adhesive system ( CR ) . In this study , 117 posterior teeth ( 29 premolars and 88 molars ) were selected with carious lesions which result ed in great loss of dentin and cusps with unsupported enamel . After caries removal , cavities were prepared and totally filled with GIC or with CR . In a following visit , new cavities were prepared , leaving the employed filling material as a base and support for the enamel , which were then restored with silver amalgam . Restorations were evaluated periodically after 6 months and up to 5 years . Both fracture and pulpal involvement rates were low . Although differences could be observed in the behaviour of the material s , statistical survival estimation showed that the performances of GIC and CR as filling material were similar . There was a significant association both between kind of tooth ( molar or premolar ) and long-term survival of the restorations ; and between degree of unsupported enamel and the same long-term survival . Our results confirmed that the technique in which GIC or CR are used as filling under  silver amalgam restorations is clinical ly acceptable The effects of inflammatory activity following surgical intervention can injure pulp tissues ; in severe cases it can lead to pulpal complications . With this article , the authors report on the effects of cavity preparation and restoration events and how they can interact together to reduce or increase the severity of pulpal inflammatory activity in 202 restored Class V cavities . Although some inflammatory activity was observed in the absence of bacteria , the severity of pulpal inflammatory activity was increased when cavity restorations became infected . Zinc oxide eugenol and resin-modified glass ionomer cement prevented bacterial microleakage in cavity restorations , with no severe inflammatory activity observed with these material s. Bacteria were observed in cavities restored with enamel bonding resin and adhesive bonded composites and were associated with severe grade s of inflammatory activity . The cavity remaining dentin thickness influenced the grade of inflammatory activity . In the absence of infection , the grade of inflammatory activity decreased after 20 weeks post-operatively . In the presence of infection , the grade of pulpal inflammation remained stable until a minimum of 30 weeks had elapsed Using modified USPHS criteria , we evaluated annually for ten years 91 cases restored with visible light cured posterior composite resin LFP ( Base resin : UDMA ; filler : micro crushed type , alumino-silicate , barium glass and silica , 85 wt% , 74 vol% ) . The 91 cases restored with LFP decreased to 68 in ten years . Of the 23 cases that were lost , one result ed from a pulpal reaction immediately following restoration , four were extracted owing to periodontal disease or extrusion of third molars , two became abutments owing to loss of an adjacent tooth , eight had recurrent caries , and eight were lost owing to caries on a surface having no relationship to the composite resin restoration . Because we observed comparatively little wear , good marginal adaptability , and no discoloration , we concluded that the ten-year clinical success of LFP was on the whole very good , and that this resin has adequate clinical merit as a restorative material for posterior teeth when restricted to restorations covering comparatively small areas PURPOSE To evaluate clinical ly and microscopically the human pulp response when directly capped with an adhesive system or calcium hydroxide over short ( 9 - 12 days ) and long ( 53 - 204 days ) experimental periods . MATERIAL S AND METHODS Fifty-one sound human premolars scheduled for orthodontic extraction , had their pulp horns gently exposed with a diamond point . Debris in the pulp wound was washed out with a sterile saline solution . The pulps were then capped with either an adhesive system ( Scotchbond Multi- Purpose Plus ) or calcium hydroxide . All teeth were subsequently restored with resin-based composite ( Z-100 ) according to the manufacturer 's instructions . After the experimental periods , the teeth were extracted and processed for light microscopic examination . RESULTS Short-term : the pulp tissue capped with SBMP-P exhibited dilated and congested blood vessels associated with a moderate inflammatory response and blanching of pulp cell nuclei . Long-term : no evidence of healing and bridge formation was observed . A persistent mild inflammatory pulp response was present . Micro-abscesses were detected in three cases associated with bacterial infiltration . Calcium hydroxide stimulated early pulp repair and dentin bridging which extended into the longest period PURPOSE To compare by confocal and scanning electron microscopy the post-resin-dentin interfaces of endodontically-treated teeth which had been restored with dentin-bonding systems and composite and needed to be extracted after 6 months to 6 years of clinical service . MATERIAL S AND METHODS Sixteen single rooted teeth showing proximal lesions penetrating the pulp chamber were included in the investigation and divided into two groups . Group 1 teeth were endodontically-treated , restored with carbon fiber posts and resin-based composite . Group 2 teeth were treated in the same way and covered with porcelain fused-to-metal crowns . RESULTS Two thirds of the observed interfaces showed resin penetration of the root dentin in the middle and coronal third of the post space preparation , while only one third of the interface showed resin infiltration in the apical third of the post space preparation . Debonding of the adhesive from the resin infiltrated dentin area and debonding of the composite cement from the adhesive were the most frequently observed failure modes and were observed in one third of the observed interfaces . There was no difference between the post-resin-dentin interfaces of teeth covered and teeth not covered with porcelain-fused to metal crowns . Teeth extracted after longer periods of clinical service showed more abundant areas of debonding of the adhesive from the resin-dentin interdiffusion zone . The presence of bacteria in resin infiltrated dentin tubules was observed in two specimens OBJECTIVES To analyze the relationship between the cavity depth and liners with postoperative sensitivity of  resin composite restorations .  METHODS A clinical follow-up was conducted on 319 resin composite restorations made in the final year of an undergraduate program over a 3-year period . Along with the analyses of cavity type , cavity depth , type of pulpal protection and the material s used , the postoperative sensitivity was also examined on each restoration . RESULTS Thirty-nine percent of the restorations had no protective layer ( Group 1 ) . As the depth of the prepared cavities increased , the restorations received one of the three pulpal protection methods ; a calcium hydroxide base ( Group 2 ) , glass ionomer cement ( Group 3 ) , or protection with a calcium hydroxide base in combination with glass ionomer cement ( Group 4 ) . The incidence of postoperative sensitivity showed no significant difference among Groups 1 , 2 and 3 , but was significantly lower in Group 1 than in Group 4 . The restorations made in shallow and medium depth cavities demonstrated significantly less-postoperative sensitivity than those made in deep cavities . The newer generation dentine-bonding agents showed a significantly lower incidence of postoperative sensitivity than the early generation group . CONCLUSIONS Postoperative sensitivity in resin  composite restorations was not related to the absence of protective layers but increased with the depth of cavities restored with the resin composite . The type of dentine-bonding agents could also be responsible for postoperative sensitivity The aim of this r and omized , controlled , single-blind and prospect i ve study was to evaluate the clinical and radiographic success rates of three different bonding protocol s vs calcium hydroxide liner for protection of the dentin – pulp complex of primary molars with different remaining dentin thicknesses . Two hundred forty primary molar teeth with moderate to deep occlusal caries were restored in 97 children who met inclusion criteria . After cavity preparation , the teeth were r and omly assigned into four groups ( n = 60/group ) with respect to the material used for protection of the dentin – pulp complex : ( 1 ) total-etching with 36 % phosphoric acid followed by an acetone-based adhesive ( Prime&Bond NT ) , ( 2 ) a self-etch adhesive system ( Xeno III ) , ( 3 ) an acetone-based adhesive ( Prime&Bond NT ) without prior acid conditioning , and ( 4 ) control : calcium hydroxide cement ( Dycal ) . Teeth in groups 1–3 were restored with a polyacid-modified resin-based composite ( Dyract AP ) and those in group 4 with amalgam . The remaining dentin thickness was calculated using image analysis software ( ImageJ ) . The teeth were evaluated clinical ly and radiographically for 24 months . The distribution of restored teeth with minimal remaining dentin thickness ( ≤0.5 mm ) was 3.3 , 8.3 , 8.3 , and 10 % for groups 1 , 2 , 3 , and 4 , respectively . Despite the absence of pulpal protection in groups 1–3 , none of those teeth exhibited any significant clinical or radiographic symptom during the study period . After 2 years , the clinical and radiographic success rate of restorative treatments was 100 % . Protection of the dentin – pulp complex with the tested bonding protocol s result ed in similar outcomes in mainly shallow and medium deep cavities as compared to calcium hydroxide amalgam in more deep cavities , when indirect pulp treatment was performed in class I compomer restorations A  posterior composite resin restorative material  was evaluated over a 3-year period by means of a controlled clinical trial . A total of 52 composite resin restorations and 52 amalgam alloy restorations were included in this trial , and were examined with regard to marginal integrity , surface texture , anatomical form and proximal contact with adjacent teeth . There were no significant differences in clinical performance between test and control material s , which both gave good service over the period of evaluation . Only five restorations ( one of amalgam and four of composite resin )  failed during the trial . Plastic replica dies were used to support the clinical examinations of the restorations , and such dies were found to be helpful Three intermediary base material s , a zinc oxide-eugenol ( Cavitec ) and two calcium hydroxide liners ( Life and Dycal ) , were selected at r and om for use as a base beneath  amalgam or composite restorations on humans following complete caries removal .  Life and Dycal , selected at r and om , were also used as direct and indirect pulp capping agents as clinical ly indicated . Clinical evaluations of signs and symptoms were made before treatment and at one-week , six-month , and one-year intervals following treatment . Histological evaluations were performed on three complete caries removal teeth and 18 direct pulp capping teeth six months following treatment . No significant differences in clinical symptomatology result ed between the material s in the complete caries removal group or the indirect and direct pulp capping groups Biocompatibility of  dentin bonding agents ( DBA ) and composite resin  may affect the treatment outcome ( e.g. , healthy pulp , pulpal inflammation , pulp necrosis )  after operative restoration .  Bisphenol-glycidyl methacrylate ( BisGMA ) is one of the major monomers present in DBA and resin . Prior studies focused on salivary esterase for metabolism and degradation of resin monomers clinical ly . This study found that human dental pulp cells expressed mainly carboxylesterase-2 ( CES2 ) and smaller amounts of CES1A1 and CES3 isoforms . Exposure to BisGMA stimulated CES isoforms expression of pulp cells , and this event was inhibited by catalase . Exogenous addition of porcine esterase prevented BisGMA- and DBA-induced cytotoxicity . Interestingly , inhibition of CES by bis(p-nitrophenyl ) phosphate ( BNPP ) and CES2 by loperamide enhanced the cytotoxicity of BisGMA and DBA . Addition of porcine esterase or N-acetyl-l-cysteine prevented BisGMA-induced prostagl and in E(2 ) ( PGE(2 ) ) and PGF(2α ) production . In contrast , addition of BNPP and loperamide , but not mevastatin , enhanced BisGMA-induced PGE(2 ) and PGF(2α ) production in dental pulp cells . These results suggest that BisGMA may induce the cytotoxicity and prostanoid production of pulp cells , leading to pulpal inflammation or necrosis via reactive oxygen species production . Expression of CES , especially CES2 , in dental pulp cells can be an adaptive response to protect dental pulp against BisGMA-induced cytotoxicity and prostanoid release . Resin monomers are the main toxic components in DBA , and the ester group is crucial for monomer toxicity In the last years several dental adhesives have been developed . They are supposed to chemically adhere to dentin and a liner to protect the pulp is not used . The aim of this study was to compare the short-term pulpal reaction , in an intra-toothpair study , between a dental adhesive , Scotchbond 2 , and a lining system , Tubulitec , in combination with P-50 in surface-sealed cavities . Deep buccal cavities in 16 human pairs of premolars , 32 teeth , were restored in vivo with a light cured composite resin , P-50 . To minimize bacterial contamination all cavities were treated with a cleanser , Tubulicid , and the cavities were surface-sealed with temporary cement , Coltosol . One tooth in each pair , the test , was treated with Scotchprep Dentin Primer and Scotchbond 2 Light Cure Dental Adhesive . In the other tooth in the pair , the control , Tubulitec Primer and Liner were used . The teeth were extracted after 6 - 14 days . The sections were evaluated for degree of inflammation and the presence of bacteria . Irrespective of treatment of dentin the majority of teeth , 23 , including one pulpal exposure , revealed no inflammation or a few inflammatory cells . In four test teeth , including one pulpal exposure , and two controls , growth of bacteria was found on the cavity walls and slight or moderate inflammation was seen in the corresponding pulps . In one test and two control teeth slight inflammation was seen but no bacteria could be detected . In the absence of bacteria Scotchbond 2 did not seem to irritate the pulp . ( ABSTRACT TRUNCATED AT 250 WORDS PURPOSE This study evaluated the clinical efficacy of the " open s and wich " restoration for pediatric dental practice . METHODS Three pediatric dentists used a st and ardized preparation and restorative technique to place the restorations . The prepared tooth was etched with a phosphoric acid semigel and rinsed . A resin modified glass ionomer ( Fuji II LCor Photac-Fil ) was placed short of the margins and then light cured . The resin modified glass ionomer was covered with an occlusal layer of a microhybrid flowable composite ( Aeliteflo or Flow-it ) . The same preparation for the experimental restorations was used for the control conventional amalgam ( Tytin ) restorations . The restorations were evaluated at 6-month intervals and ranked with a modified United States Public Heath Survey ( USPHS ) scale as follows : Alfa : No discernible marginal opening or stain ; Beta : Slight opening of margin discernible with dental explorer , but without stain ; Charlie : Open margin and stain ; Delta : Recurrent caries or restoration failure . Restoration failures were categorized according to etiology , pulpal necrosis , bruxism , marginal leakage , isthmus fracture , or adhesive failure . RESULTS All recalled experimental restorations , except 8 , were rated as either Alpha or Beta . Six failed due to isthmus fracture and 2 due to pulpal necrosis . Fifteen restorations had delaminating of the flowable composite from the resin modified glass ionomer . The use of the " open s and wich " technique compared favorably with a similar study using adhesive amalgam restorations . CONCLUSIONS The " open s and wich " technique can be successfully used in a pediatric dental practice This study evaluated the performance of a low-shrinking resin composite compared with an amalgam for restoration of Class I and II cavities of moderate size in posterior teeth in a general practice setting . Fifty-two pairs of test and control restorations were placed in 49 patients . Clinical evaluations and assessment s of replica models were carried out at baseline , six months and one year . Patients recorded their level of satisfaction with the restorations by means of  visual analog scales . Apart from one control restoration that failed due to a fractured cusp , all of the restorations review ed at six months and one year were intact with no unacceptable scores for any of the evaluation criteria . It was concluded that the resin composite evaluated , when used in conjunction with the recommended adhesive system , may be an appropriate alternative to amalgam in the restoration of posterior teeth over one year in clinical service Prospect i ve clinical studies comparing the results of different types of restorations of endodontically treated teeth are lacking . This study compared the clinical success rate of endodontically treated premolars restored with fiber posts and direct composite to the  restorations of premolars using amalgam . Premolars with Class II carious lesions were selected and r and omly assigned to one of two experimental groups : ( 1 ) restoration with amalgam or ( 2 ) restoration with fiber posts and composite .  One hundred and nine teeth were included in Group 1 and 110 in Group 2 . Patients were recalled after 1 , 3 and 5 years . No statistically significant difference was found between the proportion of failed teeth in the two experimental groups . Significant differences were observed between the proportion of root fractures ( p=0.029 ) and caries ( p=0.047 ) , with more root fractures and less caries observed in the teeth restored with amalgam at the five-year recall . Within the limits of this study , it can be concluded that restorations with fiber posts and composite were found to be more effective than amalgam in preventing root fractures but less effective in preventing secondary caries BACKGROUND Dental amalgam is a widely used restorative material containing 50 percent elemental mercury that emits mercury vapor . No r and omized clinical trials have determined whether there are adverse immunological effects associated with this low-level mercury exposure in children . The objective of this study was to evaluate a sub population of the participants in the New Engl and Children 's Amalgam Trial for in vitro manifestations of immunotoxic effects of dental amalgam . METHODS The authors conducted a r and omized clinical trial in which children requiring dental restorative treatment were r and omly assigned to receive either amalgam for posterior restorations or resin-based composite restorations . They assessed 66 children , aged 6 to 10 years , for total white blood cell counts , specific lymphocyte ( T-cell and B-cell ) counts and lymphocyte , neutrophil and monocyte responsiveness across a five-year period . Because of the small number of participants , the authors acknowledge that the study is exploratory in nature and has limited statistical power . RESULTS The mean number of tooth surfaces restored during the five-year period was 7.8 for the amalgam group and 10.1 for the composite group . In the amalgam group , there was a slight , but not statistically significant , decline in responsiveness of T cells and monocytes at five to seven days after treatment ; the authors consistently observed no differences at six , 12 or 60 months . CONCLUSIONS The findings of this study confirm that treatment of children with amalgam restorations  leads to increased , albeit low-level , exposure to mercury . In this exploratory analysis of immune function , amalgam exposure did not cause overt immune deficits , although small transient effects were observed five to seven days after restoration placement . CLINICAL IMPLICATION S These findings suggest that immunotoxic effects of amalgam restorations are minimal and transient in children and most likely do not need to be of concern to practitioners considering the use of this restorative dental material The rates of abrasion of six composite restorative resins , an unfilled resin , a dental amalgam , two experimental formulations of commercially available composites , and two coating material s  were determined with use of a two-body abrasion test . The  wear of composite restorative resins , coating material s , and a dental amalgam was evaluated by a two-body abrasion test . Commercial composite resins were ranked . The rate of abrasion of the dental amalgam was similar to that of the composites but less than that of a commercial unfilled resin . The coating material s were abraded more rapidly than the composites . An experimental composite resin containing quartz was abraded less rapidly than one containing lithium aluminum silicate and barium aluminum silicate . This study evaluates the wear of composite restorative resins by an abrasion test .  Composite restorative resins , an  unfilled resin  , and a dental amalgam  are ranked . Two experimental formulations , one the resin matrix of a composite material and the other the resin matrix and inorganic filler without a silane coupling agent , are compared for each of two commercial composite restorative material s. Finally , the abrasion resistance of two commercial coating ( glazing ) material s is evaluated n a multicentre clinical trial consisting of 12 centres , 232 amalgam and 932 composite Class I and Class II restorations were placed in 447 adult patients . At the 4-year review 76 per cent of patients with 71 per cent of the restorations were retrieved . In 8 centres after 4 years and 4 centres after 5 years a total of 12 amalgam  and 92 Occlusin restorations  had been replaced , having been considered to have failed . The reasons for failure were classified into three types : Type 1 , related to the restoration ( loss of material , recurrent caries and unacceptable marginal adaptation ) ; Type 2 , related to the restorative process ( pulpal involvement , primary caries , tooth fracture and unacceptable contact ) and Type 3 , caused by external factors . A greater proportion of the restorations of Occlusin were replaced than the restorations of amalgam . For the restorations of Occlusin the reasons for failure were : Type 1 , 59 per cent ; Type 2 , 32 per cent and Type 3 , 9 per cent . Loss of material and recurrent caries accounted for the failure of 35 and 13 restorations of Occlusin respectively . The main Type 2 reasons for failure of the restorations of Occlusin were pulpal involvement ( 16 restorations ) and primary caries ( 9 restorations ) . The overall 4-year survival of Occlusin restorations relative to Type 1 and to Type 1 + Type 2 reasons for failure was 96 per cent and 93 per cent respectively . The centre was found to have a significant influence on the survival rate in both analyses PURPOSE To follow-up teeth with deep caries lesions su bmi tted to incomplete caries removal over a 10-year period . METHODS 27 subjects ( 32 permanent posterior teeth ) with deep caries lesions composed the sample . In this single-arm long-term prospect i ve study , the inclusion criteria were risk of pulp exposure during caries excavation , positive response to the cold test , absence of spontaneous pain or sensitivity during percussion , and radiographic absence of a periapical lesion . Subjects were su bmi tted to the following procedures : complete caries removal from the surrounding cavity walls , incomplete caries removal from the pulpal wall , capping with a calcium hydroxide cement , and sealing with a modified zinc oxide-eugenol cement . After 6 - 7 months , the temporary sealing was removed for method ological purpose s ( no further excavation was performed ) , and teeth were capped with a calcium hydroxide cement and filled with resin composite .  Clinical and radiographic assessment s were conducted after 6 - 7 months , 1.5 , 3 , 5 and 10 years . Success was defined as clinical and radiographic signs and symptoms of pulp sensitivity while failure was defined as endodontic treatment need . RESULTS Over 10 years , one tooth was excluded from the sample ( pulp exposure during treatment ) , five were lost to recall , 10 had therapy failure ( five fractures and four necroses leading to endodontic treatment need , and one extraction ) and 16 had therapy success ( pulp sensitivity ) . Overall survival rates were 97 % , 90 % , 82 % and 63 % at 1.5- , 3- , 5- and 10-year follow-ups , respectively . Teeth with two or more restored surfaces failed significantly more than teeth with one restored surface ( P= 0.01 ) Two formulations of posterior composite resin ( P-30 and Bisfil-P ) were evaluated and compared to a high-copper , dispersed-phase amalgam ( Dispersalloy ) .  One hundred twenty-eight restorations were placed in 27 patients so that each patient received at least one of each material . After 3 years of clinical service , all three restorative material s produced clinical ly acceptable restorations , according to US Public Health Service and Leinfelder criteria . The amalgam restorations , however , underwent less wear ( 44 microns ) than did the posterior composite resin restorations ( 60 to 74 microns ) . Stratification of data by type of tooth , class of restoration , and size of restoration produced the same ranking of wear from lowest to highest : Dispersalloy , Bisfil-P , and P-30 . Resin restorations showed 45 % more wear in molars than in premolars , and more wear was associated with moderately sized restorations than with conservative restorations . The surface texture of restorations of composite resin with porous strontium glass filler was nearly as smooth as that of enamel and was significantly smoother than that of the restorations of composite resin with zinc glass filler or of unpolished amalgam Introduction Controversy surrounds decisions on whether to repair or replace defective dental restorations . The concept of built-in obsolescence , ie periodic replacement of dental restorations , is largely accepted as the modus oper and i if not the default mode in restorative care . In this article we examine the current best available evidence underpinning the effectiveness of replacement versus repair of direct amalgam and resin composite restorations .  Method This article builds on two recent Cochrane systematic review s which have reported on the evidence base supporting the effectiveness of replacement versus repair of amalgam and direct resin composites  and translates the results of their research conclusions into recommendations for the dental clinician . Results As no relevant r and omised controlled trials ( RCTs ) were identified in either of these systematic review s , the evidence regarding the effectiveness of repair versus replacement of amalgam and composite restorations  is weak and incomplete . The evidence as it currently st and s seems to favour repair over replacement , but this is insufficient to make firm recommendations . Conclusion In view of the absence of high level evidence there is a need for further well design ed RCTs . To add value to the evidence base these trials should be conducted in a general practice setting which will strengthen the generalisability and applicability of the research conclusions and enable dentists and patients to make informed decisions PURPOSE To report the 4-year clinical performance of  posterior resin-based composite restorations placed using the total-etch technique . MATERIAL S AND METHODS Over a period of 1 year , 726 restorations ( 248 molars , 478 premolars ; 260 Class I , 466 Class II ; 540 replacements , 186 primary decay ) were placed on conservative preparations , using the incremental placement technique in a clinical environment . Baseline data were collected , and the restorations were evaluated after 4 years . Z100 and Scotchbond Multi- Purpose ( SBMP ) ( 3 M Dental Products , St. Paul , Minnesota ) were used as the restorative system . The criteria evaluated were color match , marginal adaptation , anatomic form , cavosurface marginal discoloration , axial contour , interproximal contact , secondary caries , postoperative sensitivity , and tooth vitality . RESULTS At baseline , 24 % of the teeth restored presented postoperative sensitivity ; 86 % of the sensitive teeth were from the replacement group . At 4 years , all teeth were vital to cold test . Eighteen restorations ( 2.5 % ) presented clinical ly detectable marginal fracture . The shade was acceptable in all restorations . Cavosurface marginal discoloration was observed in 47 restorations ( 6.5 % bravo scores ) . Axial contour , interproximal contact , and marginal adaptation received 100 % alfa scores . No secondary caries was diagnosed in any of the teeth examined . None of the examined restorations required replacement . CLINICAL SIGNIFICANCE Under controlled clinical conditions , posterior resin-based composite restorations placed with the total-etch technique and restorative Z100/SBMP have the potential to present a high success rate at 4 years . None of the examined restorations required replacement , and there was no clinical ly detectable wear in any of the restorations . Simultaneous etching of enamel and dentin followed by the application of a resin adhesive can be considered an adequate modality of pulp protection in nonexposed tooth preparations BACKGROUND Failure of dental restorations is a major concern in dental practice . Replacement of failed restorations constitutes the majority of operative work . Clinicians should be aware of the longevity of , and likely reasons for the failure of , direct posterior restorations . In a long-term , r and omized clinical trial , the authors compared the longevity of  amalgam and composite .  SUBJECTS , METHODS AND MATERIAL S : The authors r and omly assigned one-half of the 472 subjects , whose age ranged from 8 through 12 years , to receive amalgam restorations in posterior teeth and the other one-half to receive resin-based composite restorations .  Study dentists saw subjects annually to conduct follow-up oral examinations and take bitewing radiographs . Restorations needing replacement were failures . The dentists recorded differential reasons for restoration failure . RESULTS Subjects received a total of 1,748 restorations at baseline , which the authors followed for up to seven years . Overall , 10.1 percent of the baseline restorations failed . The survival rate of the amalgam restorations was 94.4 percent ; that of composite restorations was 85.5 percent . Annual failure rates ranged from 0.16 to 2.83 percent for amalgam restorations and from 0.94 to 9.43 percent for composite restorations .  Secondary caries was the main reason for failure in both material s. Risk of secondary caries was 3.5 times greater in the composite group . CONCLUSION Amalgam restorations performed better than did composite restorations . The difference in performance was accentuated in large restorations and in those with more than three surfaces involved . CLINICAL IMPLICATION S Use of amalgam appears to be preferable to use of composites in multisurface restorations of large posterior teeth if longevity is the primary criterion in material selection
The included studies reported few , if any , endodontic complications .
Little or no differences emerged between teeth restored with  composite resins  and those restored with amalgam .
Composite resin is used extensively for restoration of teeth with vital pulps .
Although cell culture studies have disclosed harmful effects on pulpal cells , any untoward clinical effects , manifest as adverse pulpal responses , have yet to be determined .
This study comprises a systematic review , design ed to address the question of whether the risk of endodontic complications is greater with  composite resin restorations  than with  other restorative material s  , such as  amalgam .