Dental cavity liners for Class I and Class II resin-based composite restorations

BACKGROUND

Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure. This is an update of the Cochrane Review first published in 2016.

OBJECTIVES

The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 12 November 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 10) in the Cochrane Library (searched 12 November 2018), MEDLINE Ovid (1946 to 12 November 2018), Embase Ovid (1980 to 12 November 2018) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 12 November 2018). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs.

DATA COLLECTION AND ANALYSIS

We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification.

MAIN RESULTS

Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at 1 year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at 2 years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies.

AUTHORS' CONCLUSIONS

There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Dental cavity liners for Class I and Class II resin-based composite restorations

BACKGROUND

Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure.

OBJECTIVES

The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 May 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 4) in the Cochrane Library (searched 25 May 2016), MEDLINE Ovid (1946 to 25 May 2016), Embase Ovid (1980 to 25 May 2016) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 25 May 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs.

DATA COLLECTION AND ANALYSIS

We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification.

MAIN RESULTS

Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at one year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at two years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies.

AUTHORS' CONCLUSIONS

There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Survival of Adhesive Restorations for Primary Molars: A Systematic Review and Metaanalysis of Clinical Trials

PURPOSE

The purpose of this study was to assess the scientific evidence regarding the survival and clinical performance of adhesive materials for primary molars, comparing composite resin (CR), conventional glass ionomer cement (GIC), resin-modified glass ionomer (RMGIC), silver-reinforced glass ionomer cement, and compomer.

METHODS

Six databases were searched without restrictions regarding language or year of publication. Meta-analysis was conducted; risk ratios (RRs) and 95 percent confidence intervals (95% CI) were calculated.

RESULTS

Eleven clinical trials were included. Two studies found that the median survival time (MST) of SRGIC was less than that of GIC and RMGIC (P<0.005), and two studies found that the GIC had a lower MST than both RMGIC and compomer (P<0.05). Meta-analysis for CR, compomer, and RMGIC was conducted. These materials did not differ significantly regarding the number of restorations that survived over 24 months: CR versus RMGIC (RR equals 1.12, 95% CI equals 0.96 to 1.31); CR versus compomer (RR equals 1.04; 95% CI equals 0.96 to 1.13); and compomer versus RMGIC (RR equals 1.03; 95% CI equals 0.84 to 1.27).

CONCLUSIONS

Silver-reinforced glass ionomer cement has the worst survival rate among ionomers, and adhesive materials with a resin component have similar survival rates.

Comparative evaluation of microleakage of a carbomer/fluoroapatite-enhanced glass-ionomer cement on primary teeth restorations

AIM

Carbomer cement represents a novel glass-ionomer which gradually mineralises into fluoroapatite. Purpose of this study was to evaluate microleakage around restorations in deciduous teeth made with composite resin, conventional glass-ionomer cement, resin-modified glass-ionomer cement and carbomer/fluoroapatite-enhanced glass-ionomer cement.

MATERIALS AND METHODS

A group of 40 primary upper canines, primary upper and lower molars was divided into 4 groups (n=10). Class I cavities were prepared by diamond cylindrical bur at high speed and were restored with a composite resin (Group 1), with a glass- ionomer cement (Group 2), with a resin-modified glass-ionomer cement (Group 3) and with a carbomer/fluoroapatite-enhanced glass- ionomer cement (Group 4). Hard tissue's bonding involved, in the case of composite resin a total etch bonding procedure, and in glass ionomers the use of their respective primers. Restorations were finished and polished. A 24-hour water storage was followed by thermocycling (1500 cycles, 5°C - 36°C - 55°C - 36°C with a dwell time of 15 seconds) and dye penetration test with immersion in 5% methylene blue for 24 hours. In order to assess the degree of microleakage longitudinal cuts were produced by means of a microtome at 0.5 mm and at 1 mm from the restoration margin, and photographs were taken with a stereomicroscope at 100X. Microleakage was classified according to the number of surfaces and the depth at which dye penetration was observed. Data were analysed with ANOVA and post-hoc analysis was performed with Bonferonni test (p<0.05).

RESULTS

Statistical analysis exhibited no significant statistical difference between Group 2 and Group 3 (p>0.05). Statistical difference was exhibited between Group 3 and Group 4 (p<0.01), with Group 4 exhibiting lower microleakage values. Group 1 exhibited the lowest mean microleakage values and statistical difference in comparison with all groups (p<0.001). Group 4 exhibited the lowest microleakage values among the cements.

CONCLUSION

Superior marginal integrity is achieved in restored primary teeth when composite resin is used. If the clinical case suggests the use of a glass-ionomer cement, carbomer/fluoroapatite-enhanced glass-ionomer cement is prefered in terms of microleakage.

An In-VitroEvaluation of Microleakage at the Cervical Margin Between two Different Class II Restorative Techniques Using Dye Penetration Method

OBJECTIVE

To evaluate the coronal microleakage of packable composite using conventional incremental and posterior bulk fill flowable composite using Smart Dentine Replacement Single Step technique in the cervical margins of class II cavities in dentine using the dye penetration method.

STUDY DESIGN

In-vitroInterventional study.

PLACE AND DURATION OF STUDY

Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences (DIKIOHS), Karachi, from November 2012 to April 2013.

METHODOLOGY

One hundred and twenty extracted teeth (molars and premolars) were collected and randomly divided into two experimental groups (n=60 each) and were stored in normal saline until used. Fractured samples were excluded. Standardized class II proximal box only cavities were prepared and restored with conventional methacrylate based composite using incremental technique (Group A, n=40) and low stress methacrylate resin based composite SDR using single step technique (Group B, n=40). Samples were sectioned horizontally below the cervical margins and specimen disks were prepared. The specimens were thermocycled and sealed with acid resistant varnish leaving a 1-mm interface around cervical margin and immersed in 2% methylene blue buffered solution for 24 hours. Leakage was scored 0 - 4 and measured in mm. It washed and sectioned to evaluate under stereomicroscope.

RESULTS

Mean penetration was 2.4280 ±0.79 mm for Group Aand 1.015 ±0.45 mm for Group B (p < 0.001). Maximum dye penetration score for group Awas 4 and group B was 3.

CONCLUSION

SDR technique in combination with total etch technique at the cervical margin of class II restorations improved the marginal seal, when were placed in dentine and thermocycled.

Evaluation of Microtensile Bond Strength and Microleakage of a Self-adhering Flowable Composite

PURPOSE

To evaluate the microtensile bond strength (μTBS) and marginal sealing ability of a self-adhering flowable composite between dentin and composite interfaces, as well as the microleakage of Class V restorations.

MATERIALS AND METHODS

The occlusal thirds of 40 third molars were removed and randomly divided into 4 groups according to the applied adhesive: Adper Easy One (AEO, 3M ESPE), Clearfil SE Bond (CSEB, Kuraray), Prime & Bond NT (PBNT, Dentsply) and a self-adhering flowable composite (Dyad Flow, DF, Kerr). Filtek Flowable (3M ESPE) resin composite crowns were then built up in the first three groups; in group DF, composite crowns were built up without the application of an adhesive. Thirty stick-shaped microspecimens were prepared per group, 10 of which were used for morphological observation of bonded interfaces by scanning electron microscopy (SEM) after decalcification. The remaining microspecimens underwent microtensile bond strength testing and the failure mode was analyzed. Microleakage evaluation was performed on 10 premolars per group in which standardized box-shaped Class V cavities were prepared. After 500 thermocycles, the premolars were immersed in 1% methylene blue for 24 h, and three slices from each tooth were observed under a stereomicroscope and scored. Statistical analysis was performed using one-way ANOVA, Student-Newman-Keuls and chi-square tests.

RESULTS

The PBNT group presented the highest μTBS values, followed by the CSEB and AEO groups, which did not differ significantly from each other. The DF group showed the lowest μTBS values. No significant differences in microleakage were observed among these four groups.

CONCLUSION

Although individual usage of the self-adhering flowable composite showed the lowest bond strength, the same marginal sealing ability was observed as that of combining self-etching and etch-and-rinse adhesives with flowable composite.

British Society of Prosthodontics Debate on the Implications of the Minamata Convention on Mercury to Dental Amalgam--Should our Patients be Worried?

In 2013, the Minamata Convention on Mercury called for a global phase-down of amalgam use, with a view to reduce environmental mercury pollution. This will significantly impact UK dentistry, given the still extensive use of amalgam in U.K. general dental practice. However, until now there has been little national discussion or debate. In Spring 2015, The British Society of Prosthodontics dedicated a significant part of its Annual Conference to debating the implications of this issue. Clinical case examples were discussed with audience interaction and voting facilitated using innovative Audience Response System Technology. A remarkable range of concerns and opinions were given. The debate elicited specific concerns amongst clinicians regarding the suitability of mercury-free alternatives to amalgam; particularly where cavities are large and extend beneath the gingival anatomy. There are also anecdotal reports of Dental Foundation (DF) dentists not being adequately taught the use of dental amalgam in undergraduate dental schools. CPD/CLINICAL RELEVANCE: Many clinicians, especially those treating patients for whom moisture control is challenging, feel that amalgam should remain available for clinicians to choose in certain clinical circumstances for the restoration of posterior teeth, even in the event of a complete phase-down.

Ten-year Clinical Performance of Posterior Resin Composite Restorations

PURPOSE

To investigate the clinical behavior of two different resin-based restorative systems in Class II cavities in a controlled prospective split-mouth study over 10 years.

MATERIALS AND METHODS

Thirty patients received 68 resin composite restorations (Solobond M + Grandio: n = 36; Syntac + Tetric Ceram: n = 32) by one dentist in a private practice. 35% of cavities revealed no enamel at the bottom of the proximal box, 48% of cavities provided < 0.5 mm of remaining proximal enamel. Restorations were examined according to modified USPHS criteria at baseline, after 6 months, and 1, 2, 4, 6, 8, and 10 years.

RESULTS

Twenty-nine out of 30 patients attended the 10-year recall. The overall success rate of all restorations was 96.9%. One Grandio restoration suffered marginal fracture with exposed dentin and one Tetric Ceram restoration failed due to cusp fracture. After 10 years, Grandio showed higher surface roughness (p = 0.03) and less color match (p = 0.024; Mann-Whitney U-test). Molar restorations performed worse than premolar fillings regarding marginal integrity (4 and 10 years), filling integrity (4, 8, and 10 years), and tooth integrity (4, 8, and 10 years). The main reasons for degradation of resin composites were chipping and cracks in molar restorations after 8 years. Beyond the 4-year recall, marginal staining increased (43% bravo for stained margins at four years, 52% at 8 years, and 71% at 10 years). Tooth integrity deteriorated significantly due to more enamel cracks and chipping over time (9% at baseline and 89% after 10 years (p<0.05).

CONCLUSIONS

Direct resin composite restorations performed satisfactorily over 10 years of clinical service.

Dental Materials: What Goes Where? Class V Restorations

A large number of Class V restorations are placed per annum to restore cervical lesions. This paper evaluates the pathogenesis of these lesions, with particular reference to the role of occlusal factors, and reviews the literature in order to provide advice on the material(s) which are most likely to produce optimal longevity of a Class V restoration. CPD/CLINICAL RELEVANCE: Resin-modified glass ionomer materials appear to provide optimal survival for a Class V restoration, but a (flowable) comDosite miaht Droduce a better aesthetic result.

Fatigue resistance and crack propensity of novel "super-closed" sandwich composite resin restorations in large MOD defects

OBJECTIVES

To assess the influence of conventional glass ionomer cement (GIC) vs resin-modified GIC (RMGIC) as a base material for novel, super-closed sandwich restorations (SCSR) and its effect on shrinkage-induced crack propensity and in vitro accelerated fatigue resistance.

METHODS

A standardized MOD slottype tooth preparation was applied to 30 extracted maxillary molars (5 mm depth/5 mm buccolingual width). A modified sandwich restoration was used, in which the enamel/dentin bonding agent was applied first (Optibond FL, Kerr), followed by a Ketac Molar (3M ESPE)(group KM, n = 15) or Fuji II LC (GC) (group FJ, n = 15) base, leaving 2 mm for composite resin material (Miris 2, Coltène-Whaledent). Shrinkageinduced enamel cracks were tracked with photography and transillumination. Samples were loaded until fracture or to a maximum of 185,000 cycles under isometric chewing (5 H z), starting with a load of 200 N (5,000 X), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,000 X each. Groups were compared using the life table survival analysis (α = .008, Bonferroni method).

RESULTS

Group FJ showed the highest survival rate (40% intact specimens) but did not differ from group KM (20%) or traditional direct restorations (13%, previous data). SCSR generated less shrinkage-induced cracks. Most failures were re-restorable (above the cementoenamel junction [CEJ]).

CONCLUSIONS

Inclusion of GIC/RMGIC bases under large direct SCSRs does not affect their fatigue strength but tends to decrease the shrinkage-induced crack propensity.

CLINICAL SIGNIFICANCE

The use of GIC/ RMGIC bases and the SCSR is an easy way to minimize polymerization shrinkage stress in large MOD defects without weakening the restoration.

Technique Tips--The Cost of One Post-Operative Sensitivity following Placement of a Posterior Composite Restoration

Use a low shrinkage stress composite but, if not, use incremental placement and a layer of flowable at the gingival box; Ensure good bonding to dentine and enamel and avoid (over) etching the dentine; Ensure good adaptation at the gingival floor of a Class II box; Make sure that the restoration has received sufficient light; Provide good isolation; Use reliable and tested materials throughout.

Correlation Between Students' Dental Admission Test Scores and Performance on a Dental School's Competency Exam

The aim of this study was to investigate whether there was a statistically significant positive correlation between dental students' Dental Admission Test (DAT) scores, particularly on the Perceptual Ability Test (PAT), and their performance on a dental school's competency exam. Scores from the written and clinical competency exam administered in the fall quarter of the fourth year of the curriculum at Midwestern University College of Dental Medicine-Arizona were compared to DAT scores of all 216 members of the graduating classes of 2012 and 2013. It was hypothesized that students who performed highly on one or more sections of the DAT would perform highly on the competency exam. Backward stepwise regression analyses were used to analyze the data. The results showed that the PAT scores were most strongly correlated with the competency exam scores and were a positive predictor for all three clinical sections of the exam (operative dentistry, periodontics, and endodontics). Positive predictors for the written portion of the exam were total DAT score for patient assessment and treatment planning and the DAT reading comprehension score for prosthodontics; there were no predictors for periodontics. The total variance explained by the results ranged from 4% to 15%. While statistically significant relationships were found between the students' PAT scores and clinical performance, DAT scores explained relatively little variance in the competency exam scores. According to these findings, neither the PAT nor any of the DAT components contributed to predicting these students' clinical performance.

Are All Dentiform Teeth with Simulated Caries the Same? A Six-Year Retrospective Study in Preclinical Operative Dentistry

Dentiform teeth with simulated caries (DTSC), frequently used in preclinical courses, should show no variability in the amount of simulated caries from tooth to tooth. However, the level of caries variability among DTSC is currently unknown. The aim of this study was to assess the variation in simulated caries levels in one group of DTSC and determine whether variation among DTSC impacted the preclinical performance of dental students. In the study, 80 commercially available mandibular first molar DTSC with simulated mesio-occluso-distal caries were sectioned in coronal (n=40) and sagittal (n=40) planes where the caries depth/width was greatest. Section images were analyzed for variation in levels of simulated caries using image-processing software. Three years of practical performance data using DTSC were compared with three years of practical performance data using dentiform teeth without simulated caries, for a total of six years (students' performance on two exams, Practical 1 and Practical 2). The results showed that 70% of the coronally sectioned teeth had manufacturing defects that resulted in caries overextension at the dentino-enamel junctions (DEJs). Overextensions were found at the DEJ in 41.3% of the sagittally sectioned teeth. There was a statistically significant decrease in Practical 1 performance of the students who used DTSC as compared with students who used teeth without simulated caries (p=0.0001); there was no statistically significant difference on Practical 2 performance. Of the DTSC evaluated in this study, 56.6% contained manufacturing defects, and more than 80% were found to have excessive caries variation. Prediction of which DTSC will have caries overextension is not possible. Students preparing DTSC that contain caries overextension are therefore at increased risk of receiving undeserved negative summative assessment on practical examinations.

Agreement Among Dental Students, Peer Assessors, and Tutor in Assessing Students' Competence in Preclinical Skills

The aim of this study was to determine the level of agreement regarding assessments of competence among dental students, their student peers, and their clinical skills tutors in a preclinical skills program. In 2012-13 at the University of Edinburgh, second-year dental students learned to perform the following seven cavity preparations/restorations on primary and permanent Frasaco teeth: single-surface adhesive occlusal cavity; single-surface adhesive interproximal cavity; single-surface adhesive labial cavity; multi-surface adhesive cavity; multi-surface amalgam cavity; pre-formed metal crown preparation; and composite resin buildup of a fractured maxillary central incisor tooth. Each student, a randomly allocated student peer, and the clinical skills tutor used standardized descriptors to assign a competency grade to all the students' preparations/restorations. The grades were analyzed by chi-square analysis. Data were available for all 59 second-year students in the program. The results showed that both the students and their peers overestimated the students' competence compared to the tutor at the following levels: single-surface adhesive occlusal cavity (χ(2)=10.63, p=0.005); single-surface adhesive interproximal cavity (χ(2)=11.40, p=0.003); single-surface labial cavity (χ(2)=23.70, p=0.001); multi-surface adhesive cavity (χ(2)=12.56, p=0.002); multi-surface amalgam cavity (χ(2)=38.85, p=0.001); pre-formed metal crown preparation (χ(2)=40.41, p=0.001); and composite resin buildup (χ(2)=57.31, p=0.001). As expected, the lowest levels of agreement occurred on the most complicated procedures. These findings support the need for additional ways to help students better self-assess their work.

Marginal Quality of Class II Composite Restorations Placed in Bulk Compared to an Incremental Technique: Evaluation with SEM and Stereomicroscope

PURPOSE

To evaluate the marginal quality of composite resin restorations placed in extracted molars either in bulk (4 mm) or three increments.

MATERIALS AND METHODS

Sixteen extracted mandibular molars were selected and two two-surface cavities were prepared in each tooth (proximal depth 4 mm, occlusal width 5 mm). On one side of the tooth, Tetric EvoCeram Bulk Fill (Ivoclar Vivadent) was applied in a single increment; on the other side, Tetric EvoCeram (Ivoclar Vivadent) was applied in three increments: a horizontal gingival, an oblique buccal, and an oblique lingual increment. Each layer was light cured for 10 s with a Bluephase G2 curing light (1200 mW/cm2). Two adhesive systems were employed according to the instructions for use: the single-component etch-and-rinse system ExciTE F (Ivoclar Vivadent) and the self-etching two-component system AdheSE (Ivoclar Vivadent). The adhesive was light cured for 10 s with a Bluephase G2 curing light (1200 mW/cm2). Eight fillings were placed for each test group and all restoration margins were confined to the enamel. After 10,000 cycles of thermocycling (5°C/55°C), the quality of the proximal margins was semiquantitatively directly evaluated with a stereomicroscope at low magnification and a dental explorer using the SQUACE (semi-quantitative evaluation of restorations) method. In addition, replicas were made for SEM analysis, which was carried out four weeks later at high magnification (200X) by measuring the percentage of regular proximal margins in relation to the entire margin.

RESULTS

After thermocycling, statistically significantly higher percentages of regular margins were detected for those fillings placed with the etch-and-rinse system ExciTE F than for those placed with the self-etching system AdheSE - irrespective of the evaluation method (Mann-Whitney non-parametric test, p < 0.05). There was no statistically significant difference between the resin restorations placed in bulk and those placed in three increments (Mann-Whitney, p > 0.05). The semi-quantitative evaluation by means of a light microscope yielded statistically significantly higher values for regular margin than did the SEM evaluation for all 4 test groups (p < 0.05). Pearson's correlation coefficient for both evaluation groups was 0.87 (p < 0.0001).

CONCLUSIONS

The marginal quality of medium-sized Class II restorations of composite resins placed in one increment was similar to that of restorations placed in several increments. The semiquantitative evaluation of the marginal quality with an explorer at low magnification is an effective and rapid method to predict the clinical performance of direct restorations.

In vivo Evaluation of Proximal Resin Composite Restorations performed using Three Different Matrix Systems

OBJECTIVE

The aim of this in vivo study was to radiographically evaluate the proximal contour of composite resin restorations performed using different matrix systems.

MATERIALS AND METHODS

Patients with premolars needing class II type resin composite restorations involving the marginal ridge were selected. Thirty premolars were selected and randomly divided into three groups (n = 10 each) to receive restorations using different matrix systems: group 1: metal matrix coupled to a carrier matrix and wood wedge (G1-MMW); group 2: sectioned and precontoured metal matrix and elastic wedge (G2-SME); and group 3: a polyester strip and reflective wedge (G3-PMR). After the restorative procedure, bitewing radiographs were performed and analyzed by three calibrated professionals. The quality of the proximal contact and marginal adaptation of the proximal surfaces was classified as either correct or incorrect (undercontour/overcontour).

RESULTS

The Pearson Chi-square statistical test (α = 5%) revealed a statistically difference between frequencies of correct and incorrect restorations (α(2) = 6.787, p < 0.05). The group G2 SME produced a higher frequency of correct proximal contours (90%), while G1-MMW and G3-PMR had a ratio of 40% correct and 60% incorrect contours respectively.

CONCLUSION

None of the matrix systems was able to prevent the formation of incorrect proximal contours; however, the sectioned and precontoured metal matrix/elastic wedge configuration provided better results as compared to the other groups.

Biomechanical Behavior of Extensively Restored Premolars: Cusp Deformation, Marginal Integrity, and Fracture Resistance

PURPOSE

To study the biomechanical behavior of extensively restored premolars by determining the effect of the composite type, presence of cusp weakening, and compressive loading on the cusp deformation (CD), marginal integrity (MI), and fracture resistance (FR) of directly restored premolars.

MATERIALS AND METHODS

Forty premolars received Class II mesio-occlusal-distal (MOD) cavities and were divided into 4 groups (n = 10) in accordance with the two study variables: composite type (conventional: Filtek Z250 XT [Z250], 3M ESPE; low shrinkage: Venus Diamond [VD], Heraeus-Kulzer) and the presence of cusp weakening (with/without). Cusp deformation upon restoration was assessed using strain gauges during the restorative procedure and thereafter when the restorations were subjected to an occlusal load of 100 N. The samples were subjected to thermal and mechanical cycling. Epoxy resin replicas of the proximal tooth/restoration interfaces were made to analyze the marginal integrity (MI) using scanning electron microscopy. To determine the fracture resistance (FR), the teeth were loaded at a crosshead speed of 0.5 mm/min until fracture.

RESULTS

The conventional composite Z250 had higher CD, lower MI, and lower FR than the low-shrinkage composite VD. Cusp weakening had no influence on CD, but MI and FR decreased.

CONCLUSION

The low-shrinkage composite VD performed better in restoring extensively destroyed premolars than did Z250.

Randomized 3-year clinical evaluation of Class I and II posterior resin restorations placed with a bulk-fill resin composite and a one-step self-etching adhesive

PURPOSE

To evaluate the 3-year clinical durability of the flowable bulk-fill resin composite SDR in Class I and Class II restorations.

MATERIALS AND METHODS

Thirty-eight pairs of Class I and 62 pairs of Class II restorations were placed in 44 male and 42 female patients (mean age 52.4 years). Each patient received at least two extended Class I or Class II restorations that were as similar as possible. In all cavities, a one-step self-etching adhesive (XenoV+) was applied. One of the cavities of each pair was randomly assigned to receive the flowable bulk-fill resin composite SDR in increments up to 4 mm as needed to fill the cavity 2 mm short of the occlusal cavosurface. The occlusal part was completed with an ormocer-based nanohybrid resin composite (Ceram X mono+). In the other cavity, only the resin composite CeramX mono+ was placed in 2 mm increments. The restorations were evaluated using slightly modified USPHS criteria at baseline and then annually for 3 years. Caries risk and bruxing habits of the participants were estimated.

RESULTS

No post-operative sensitivity was reported. At the 3-year follow-up, 196 restorations - 74 Class I and 122 Class II - were evaluated. Seven restorations failed (3.6%), 4 SDR-CeramX mono+ and 3 CeramX mono+ only restorations, all of which were Class II. The main reason for failure was tooth fracture, followed by resin composite fracture. The annual failure rate (AFR) for all restorations (Class I and II) was 1.2% for the bulkfilled restorations and 1.0% for the resin composite-only restorations (p > 0.05). For the Class II restorations, the AFR was 2.2% and 1.6%, respectively.

CONCLUSION

The 4-mm bulk-fill technique showed good clinical effectiveness during the 3-year follow-up.

Is apical periodontitis in root filled teeth associated with the type of restoration?

OBJECTIVE

To study the association between type of restoration and apical periodontitis (AP) in root filled teeth.

MATERIALS AND METHODS

The present study used data from surveys conducted in 1983, 1993 and 2003. In 1983, 130 randomly selected subjects aged 3-80 years in the city of Jönköping, Sweden, were invited for a clinical and radiological examination. The study was repeated in 1993 and 2003. New participants were, thus, recruited with the same sampling criteria and sample size in the same geographical area in 1993 and 2003, respectively. In the present study, only dentate individuals aged 20-70 years with ≥1 root filled tooth were included, yielding a sample of 788 subjects with 2634 root filled teeth. Apical periodontitis on the tooth level was the dependent variable. Periapical status was assessed according to Periapical Index (PAI). Independent variables were root filling quality, recurrent caries, type of restoration, number of teeth with apical periodontitis, age and gender. Root fillings appearing homogenous and ending within 2 mm from radiographic apex were regarded as adequate, otherwise inadequate. All radiographs were re-studied by one observer regarding periapical status and root filling quality. Risk was analyzed by means of a GEE model.

RESULTS

Type of restoration, root filling quality, number of teeth with apical periodontitis within the individual and age were found to be predictors of AP in root filled teeth. Presence of recurrent caries and gender were not found to be associated with AP.

CONCLUSIONS

According to the present study, root filling quality and type of restoration may be predictive of AP in root filled teeth.

Curriculum time compared to clinical procedures in amalgam and composite posterior restorations in U.S. dental schools: a preliminary study

Dental clinicians have an expanding range of biomaterial choices for restoring tooth structure. Scientific developments in cariology, advances in dental biomaterials, and patients' esthetic concerns have led to a reduction in amalgam restorations and an increase in composite restorations. The aim of this study was to compare teaching time with students' clinical procedures in amalgam and composite posterior restorations in dental schools across the United States. Academic deans in 60 schools were invited to complete a survey that asked for the amount of instructional time for amalgam and composite posterior restorations and the number of clinical restorations performed by their Classes of 2009, 2010, and 2011. Of these 60, 12 returned surveys with complete data, for a 20% response rate. Responses from these schools showed little change in lecture and preclinical laboratory instruction from 2009 to 2011. There was a slight increase in two-surface restorations for both amalgam and composites; however, the total number of reported composite and amalgam restorations remained the same. Of 204,864 restorations reported, 53% were composite, and 47% were amalgam. There were twice as many multisurface large or complex amalgam restorations as composites. One-surface composite restorations exceeded amalgams. Among the participating schools, there was little to no change between curriculum time and clinical procedures. Findings from this preliminary study reflect a modest increase in two-surface resin-based restorations placed by dental students from 2009 to 2011 and little change in curricular time devoted to teaching amalgam restorations. The total number of posterior composite restorations placed by students in these schools was slightly higher than amalgams.

A study of primary teeth restored by intracoronal restorations in children participating in an undergraduate teaching programme at Cork University Dental School and Hospital, Ireland

AIM

To study the outcomes for restored primary molar teeth; to examine outcomes in relation to tooth type involved, intracoronal restoration complexity and to the material used.

DESIGN

Retrospective study of primary molar teeth restored by intracoronal restorations. A series of restored primary molar teeth for children aged 6-12 years was studied. The principal outcome measure was failure of initial restoration (re-restoration or extraction). Three hundred patient records were studied to include three equal groups of primary molar teeth restored with amalgam, composite or glass ionomer, respectively. Restorative materials, the restoration type, simple (single surface) or complex (multi-surface) restoration, and tooth notation were recorded. Subsequent interventions were examined. Data were coded and entered into a Microsoft Excel database and analysis undertaken using SPSS v.18. Statistical differences were tested using the Chi square test of statistical significance.

RESULTS

Of the 300 teeth studied, 61 restoration failures were recorded with 11 of those extracted. No significant differences were found between outcomes for upper first, upper second, lower first or lower second primary molars. Outcomes for simple primary teeth restored by intracoronal restorations were significantly better than those for complex intracoronal restorations (P = 0.042). Teeth originally restored with amalgam accounted for 19.7% of the 61 failures, composite for 29.5%, while teeth restored with glass ionomer represented 50.8% of all restoration failures. The differences were significant (P = 0.012).

CONCLUSIONS

The majority (79.7%) of the 300 restored primary teeth studied were successful, and 3.7% teeth were extracted. Restorations involving more than one surface had almost twice the failure rate of single surface restorations. The difference was significant. Significant differences in failure rates for the three dental materials studied were recorded. Amalgam had the lowest failure rate while the failure rate with glass ionomer was the highest.

The Use of Resin-based Composite in Children: An Update

Resin-based composites are an integral component of contemporary pediatric restorative dentistry. They can be utilized effectively for preventive resin restorations, moderate Class II restorations, Class III restorations, Class IV restorations, Class V restorations, and strip crowns. Tooth isolation to prevent contamination is a critical factor, and high-risk children may not be ideal candidates for resin-based composite restorations. Important factors to consider during composite placement are isolation, polymerization shrinkage, and extent of restoration. When utilized correctly, resin-based composites can provide excellent restorations in the primary and permanent dentition. The purpose of this paper was to update previous publications that addressed the use of resin-based composites in children with accepted recommendations through a Pediatric Restorative Dentistry Consensus Conference.

The use of amalgam in pediatric dentistry: new insights and reappraising the tradition

The debate on amalgam led to its being phased out in some countries. Results of clinical trials report failure rates of amalgams ranging from 12 percent to over 70 percent. Treatment of caries should meet the needs of each particular patient, based on his/her caries risk. In general, for small occlusal lesions, a conservative preventive resin restoration would be more appropriate than the classic Class I amalgam preparation. For proximal lesions, amalgam would be indicated for two-surface Class II preparations that do not extend beyond the line angles of primary teeth. This recommendation might not be appropriate for high-risk patients or restoring primary first molars in children four years old and younger where stainless steel crowns have demonstrated better longevity. Currently, amalgam demonstrates the best clinical success for Class II restorations that extend beyond the proximal line angles of permanent molars. The need to reduce the use of amalgam as a mercury-containing material is inevitable when aiming to reduce environmental contamination. It is important always to praise prevention and constantly search for biologically safe materials regarding health, clinical work, and environment. The purpose of this report was to summarize several factors that affect the effectiveness, advantages, and disadvantages of using dental amalgam in primary teeth.

A randomized 10-year prospective follow-up of Class II nanohybrid and conventional hybrid resin composite restorations

PURPOSE

To evaluate the 10-year durability of a nanohybrid resin composite in Class II restorations in a randomized controlled intraindividual comparison with its conventional hybrid resin composite predecessor.

MATERIALS AND METHODS

Each of 52 participants received at least two Class II restorations that were as similar as possible. The cavities were chosen at random to be restored with a nanohybrid resin composite (Excite/Tetric EvoCeram (TEC); n=61) and a conventional hybrid (Excite/Tetric Ceram (TC); n=61). The restorations were evaluated with slightly modified USPHS criteria at baseline and then annually for 10 years. The overall performance of the experimental restorations was tested after intra-individual comparison and their ranking was tested using Friedman's two-way ANOVA. The level of significance was set at 5%.

RESULTS

Four patient drop-outs with 8 restorations (4TEC, 4TC) were registered during the follow-up. A prediction of the caries risk showed that 16 of the evaluated 52 patients were considered as high risk patients. In total, 22 restorations, 11 TEC (3 premolars, 8 molars) and 11 TC (3 premolars, 8 molars) restorations failed during the 10 years. The main reason for failure was secondary caries (50%). 63% of the recurrent caries lesions were found in high caries risk participants. The overall success rate at 10 years was 80.7%, with an annual failure rate of 1.9%. No statistically significant difference was found in the overall survival rate between the two investigated resin composites.

CONCLUSION

The nanohybrid and the conventional hybrid resin composite showed good clinical effectiveness in extensive Class II restorations during the 10-year study.

Electrical Pulp Testing: Sources of Error

INTRODUCTION

Accurate identification and assessment of an inflamed or necrotic tooth is essentialfor endodontic treatment. The purpose of this research was to investigate possible sources of error associated with the use of the electric pulp tester (EPT).

METHODS

Forty-six intact teeth (23 tooth pairs) in 22 patients were evaluated in vivo. For the tooth pairs, one tooth had to have been previously endodontically treated and restored with a class II amalgam restoration. The restoration was required to have proximal contact with a class II amalgam of another vital posterior tooth. EPT was performed on pulpless and vital teeth for experimental groups (enamel, restoration, contacting, or isolated).

RESULTS

The highest rate of false positive responses (82%) was found in the pulpless restored contacting group, suggesting that EPT impulses are able to travel through proximal metallic contacts and stimulate teeth distant from the EPT probe. All vital tooth groups had a high rate of positive responses with no significant diferences.

CONCLUSIONS

If a tested tooth contains an interproximal restoration contacting adjacent restorations or the gingival, the teeth must be isolated (rubber dam) and the EPT probe should be placed in a region suspected to have uninterrupted tubule paths to the pulp.

In Situ Response of Nanostructured Hybrid Fluoridated Restorative Composites on Enamel Demineralization, Surface Roughness and Ion Release

Recurrent caries at the tooth-restoration margins is the main reason for composite failure. Fluoride-releasing nanohybrid composite resin may reduce the recurrent caries rates. A fluoride-releasing resin (FCR) and non-fluoride-releasing resin (CR) were tested using an in situ model. Demineralization (ΔS), ion release and surface roughness of composite specimens were determined. The F concentration in the group FCR was higher than the CR group. ΔS (Mean ± SD) was 2579 ± 1582 and 1705 ± 1292, respectively, for FCR and CR. Surfaces roughness was altered by biofilm accumulation. The hybrid fluorated restorative composites containing nanoparticles have a slight anticaries action without alteration of surface smoothness of the material.

Cuspal flexure, depth-of-cure, and bond integrity of bulk-fill composites

PURPOSE

Evaluate cuspal flexure caused by polymerization shrinkage stress, bond integrity, and depth-of-cure of bulk-fill composites.

METHODS

Twenty-eight extracted permanent molars were mounted in stainless steel rings. Slot-shaped Class II mesio-occlusal-distal preparations (four mm deep) were restored with Filtek Supreme Ultra (control; two two-mm increments) and bulk-fill composites (Tetric EvoCeram, Venus, Filtek Bulk Fill). The teeth were digitized using a 3D scanner before and after restoration. Before- and after-restoration scans were aligned, and cuspal flexure was calculated. Bond integrity along occlusal interfaces was assessed by dye penetration and measured after overnight immersion in basic fuchsin dye and cross-sectioning. Depth-of-cure was determined on the cross-sections using Vickers hardness. Statistical analysis was performed with one-way analysis of variance.

RESULTS

All composites caused inward cuspal flexure (10.4 to 13.6 μm). No statistical difference in flexure was found among the composites (P=.07). No significant difference in microhardness at any restoration depths was found for any composite (.35<P<.99). Dye penetration showed comparable bonding along occlusal interfaces for the tested composites.

CONCLUSIONS

Bulk-fill composites cured all the way through four-mm restoration depths. Cuspal flexure, caused by polymerization shrinkage, and bond integrity were not different between teeth restored with the bulk-fill and conventional incrementally placed restorative composites.

The minimally invasive management of early occlusal caries: a practical guide

Pits and fissures on the occlusal surfaces of posterior teeth are sites affected commonly by demineralisation caused by the caries process. Clinicians face daily challenges in detecting these lesions, accurately diagnosing their activity and choosing from a range of management options. Traditionally, the detection of an active (or potentially active) occlusal lesion invariably resulted in the preparation of a standardised occlusal cavity, often extending beyond the confines of diseased tissue, followed by the insertion of a direct restorative material, most commonly dental amalgam. The overwhelming weight of contemporary evidence now favours minimally invasive (MI) operative management when required (usually after non-operative prevention has failed), and a wide range of equipment, materials and operative techniques is available to help operators to preserve the maximum amount of healthy/repairable tooth tissue and to allow restoration with more biologically respectful, tooth-preserving materials. This paper aims to provide clinicians with practical guidance in the prevention, early detection, predictable diagnosis and minimally invasive management of early occlusal carious lesions.

Composite inlays: a systematic review

The purpose of this study is to review the available literature related to composite inlays. Electronic databases published up to November 2013 were searched. Studies that evaluate composite resin inlays for the restoration of posterior teeth were selected. The studies should compare composite inlays against gold inlays, ceramic inlays and direct composite fillings regarding longevity, aesthetic quality and postoperative sensitivity or comparing the clinical effectiveness of them on premolars versus molars or on 1-2 surface preparations versus multi-surface preparations. Despite the heterogeneity of the available clinical trials composite inlays seem to be an effective method for the restoration of posterior teeth.

Quality assurance study of caries risk assessment performance by clinical faculty members in a school of dentistry

The goal of this quality assurance study was to explore the decision making of clinical faculty members at the University of California, San Francisco School of Dentistry predoctoral dental clinic in terms of caries risk level assignment using the caries risk assessment (CRA) as part of the Caries Management by Risk Assessment (CAMBRA) concept. This research was done in part to determine if additional training and calibration were needed for these faculty members. The study tested the reliability and reproducibility of the caries risk levels assigned by different clinical teachers who completed CRA forms for simulated patients. In the first step, five clinical teachers assigned caries risk levels for thirteen simulated patients. Six months later, the same five plus an additional nine faculty members assigned caries risk levels to the same thirteen simulated and nine additional cases. While the intra-examiner reliability with weighted kappa strength of agreement was very high, the inter-examiner agreements with a gold standard were on average only moderate. In total, 20 percent of the presented high caries risk cases were underestimated at caries levels too low, even when obvious caries disease indicators were present. This study suggests that more consistent training and calibration of clinical faculty members as well as students are needed.

Finite element analysis of different restorative materials in primary teeth restorations

AIM

The purpose of this finite element analysis (FEA) study is to evaluate and compare the stress distributions at the primary molars and restorative materials according to the material used.

MATERIALS AND METHODS

A total of 12 3D models of Class II cavities in primary molars plus one control model were analysed. Study design: Three-dimensional FEA was used to compare stress distribution on enamel, dentin and restoration surfaces of cavities.

STATISTICS

Stresses occurring under occlusal forces were compared with the von Mises criterion.

RESULTS

The highest von Mises stress values at the enamel and restoration of restored tooth 84 were computed. On the basis of these results, all materials were ranked on enamel stress as: flowable composite resin (FCR)> compomer > resin modified glass ionomer cement (RMGIC) > giomer composite resin (GCR) > hybrid composite resin (HCR) > amalgam. Moreover, ranking of materials on restoration stress was FCR < compomer < RMGIC < GCR < amalgam < HCR.

CONCLUSION

A restorative material with appropriate elasticity module, able to balance stress concentrations, should be used to increase the survival rate of both the hard tissue of the tooth and the restoration material.

A three-year prospective randomized study of silorane- and methacrylate-based composite restorative systems in class II restorations

PURPOSE

To evaluate and compare the 3-year clinical performance of a silorane-based composite with that of a methacrylate-based composite in Class II restorations.

MATERIALS AND METHODS

Seventy-eight patients, each with two class II restorations under occlusion, were enrolled in this study. One hundred fifty-six restorations were placed, 50% for each material: a silorane-based composite, Filtek P90/ P90 System Adhesive and a methacrylate-based resin composite, Quixfil/ Prime &Bond NT. A single operator placed all restorations according to the manufacturers' instructions. Immediately after placement, the restorations were finished/polished. Clinical evaluation was performed at baseline and at yearly intervals after placement by two other independent examiners using slightly modified USPHS criteria. The changes in the USPHS parameters during the three-year period were analyzed with the Friedman test. The baseline scores were compared with those at the recall visits using the Wilcoxon signed rank test. The level of significance was set at p < 0.05.

RESULTS

All restorations were evaluated at 3 years. Post-operative sensitivity was observed in 6 patients (2 Filtek P90, 4 Quixfil) between 1 and 3 weeks. Seven failed restorations (4.5%) were observed during the follow up: 4 in the Filtek P90 (5.1%) and 3 in the Quixfil group (3.8%). This resulted in non-significantly different annual failure rates of 1.7% and 1.2%, respectively. Fracture of restoration was the main reason for failure.

CONCLUSION

After 3 years, no significant difference was seen in overall clinical effectiveness between the silorane- based and methacrylate-based composite restorative systems.

Differences between reported and actual restored caries lesion depths: results from The Dental PBRN

OBJECTIVE

The objectives of this research were to: (1) quantify the discordance between the caries lesion depth at which dentists restored initial lesions during a clinical study ("actual depth") and the lesion depth that they reported during a hypothetical clinical scenario ("reported depth"); (2) test the hypothesis that certain practitioner, practice, patient, and caries lesion characteristics are significantly associated with this discordance.

METHODS

Practitioner-investigators who perform restorative dentistry in their practices completed an enrollment questionnaire and participated in 2 consecutive studies on caries diagnosis and treatment. The first study was a survey asking about caries treatment. The second study collected data on restorations placed in routine clinical practice due to caries in patients over 19 years of age on occlusal surfaces only or proximal surfaces only. We report results on 2,691 restorations placed by 205 dentists in 1,930 patients with complete data.

RESULTS

Discordance between actual depth and reported depth occurred in only about 2% of the restorations done due to proximal caries, but about 49% of the restorations done due to occlusal caries. Practice type, restorative material used and the diagnostic methods used were significantly associated with discordance.

CONCLUSION

Dentists frequently restored occlusal caries at a shallower depth as compared to their reported depth, but the discordance was very small for proximal lesions. Discordance for occlusal caries was more common when radiographs were not taken or if a resin restoration was placed.

Using dental students' preclinical performance as an indicator of clinical success

The purpose of this study was to evaluate part of one dental school's predoctoral curriculum by investigating correlations between students' final grades in two preclinical courses and their performance in the related clinical courses. The sample consisted of 301 students at Tufts University School of Dental Medicine who graduated in 2010 and 2011. All final grades used as data were obtained from the Registrar's Office and evaluated anonymously. The average preclinical final grades differed significantly for students in the 2010 (M=84.92, SD=3.35) and 2011 (M=79.67, SD=4.67) classes, as did their average clinical final grades (2010: M=88.38, SD=2.13; 2011: M=87.45, SD=2.06). The data for each class were therefore examined separately. Results showed that the correlation between students' preclinical grades and clinical grades in operative dentistry and fixed prosthodontics was statistically significant (2010: r(2)=0.144, p<0.001; 2011: r(2)=0.261, p<0.001). This finding suggests there may be a positive relationship between preclinical and clinical performance of these students; however, the discrete factors contributing to that relationship were not investigated in this study and require further research.

Three-year prospective clinical performance of a one-step self-etch adhesive and a nanofiller hybrid resin composite in Class V lesions

PURPOSE

This 3-year prospective clinical study evaluated the clinical performance of a one-step self-etching adhesive (Futurabond NR) in combination with a nanohybrid composite (Grandio) for the treatment of different Class V cavities.

METHODS

122 restorations were placed in 42 patients (mean age of 54 +/- 13.2 years) evaluated according to modified Ryge-criteria at baseline, 6 months, 1, 2 and 3 years. The lesions comprised 91 Class V non-caries cervical lesions (NCCL) and 31 Class V cavities due to caries or restoration replacement. While carious lesions as well as restoration replacement required preparation of dentin, it was not roughened in case of NCCL. Macro-mechanical retention with undercuts was not used. The statistical analysis was carried out based on Bonferroni adjusted McNemar test (global alpha = 0.05) including the criteria marginal adaptation, color match, surface texture, anatomical form, retention and clinical acceptance and pain. The occurrence of secondary caries, preoperative and postoperative sensitivity was also examined.

RESULTS

After 3 years of clinical service the restorations showed a significant deterioration of all studied parameters. After 3 years, 65% of the restorations were rated as excellent or acceptable in terms of clinical acceptance, 9% appeared tolerable and 26% were rated as not acceptable which mainly resulted from restoration losses. Within the observed timeframe the retention rate decreased to 75%, which means that 30 out of the 122 restorations were partially or completely lost. There was a difference in the 3-year retention rate of NCCL (71%) and the caries/restoration replacement group (87%) but it was not statistically significant.

Clinical and radiographic outcomes of partial caries removal restorations performed in primary teeth

PURPOSE

To analyze the outcomes of partial caries removal (PCR) restorations in primary teeth.

METHODS

The sample of this retrospective study comprised primary teeth that had been treated with PCR by undergraduate students and were selected from the dental records of patients who were receiving treatment at the School of Dentistry, Federal University of Rio Grande do Sul - Brazil (UFRGS), from 2007 to 2012. Records containing clinical and/or radiographic follow-up data of restorations with PCR in primary teeth were included in the analysis. Factors potentially associated with treatment failure were investigated, such as the number of surfaces restored, type of capping material and restorative material used, the presence of visible plaque, and the gingival bleeding index.

RESULTS

The sample comprised 254 teeth in 118 subjects; the follow-up period ranged from 1 to 50 months. The overall success rate for PCR was 80.3% (204/254). A significant association was found between high final visible plaque index and PCR failure (P = 0.002).

Influence of MDPB-containing primer on Streptococcus mutans biofilm formation in simulated Class I restorations

PURPOSE

To evaluate the activity of a methacryloyloxydodecylpyridinium bromide (MDPB)-containing self-etching primer (Clearfil Protect Bond) against Streptococcus mutans and its ability to reduce biofilm formation on standardized experimental Class I restorations in vitro.

MATERIALS AND METHODS

Forty experimental Class I round restorations were prepared on enamel-dentin slabs using different adhesive strategies: group 1 = MDPB-containing adhesive system (Clearfil Protect Bond); group 2 = MDPB-free self-etching adhesive system (Clearfil SE Bond); group 3: MDPB-containing self-etching primer in combination with a fluoride-free bonding agent; group 4: MDPB-free self-etching primer in combination with a fluoride-containing bonding agent; group 5: a three-step etch-and-rinse adhesive system (Adper Scotchbond Multi Purpose). A Streptococcus mutans biofilm was grown for 48 h on the restoration surfaces and subsequently evaluated using scanning electron microscopy on three different areas: enamel, composite, and interface surfaces. Statistical analysis was performed by multiple ANOVA after data transformation.

RESULTS

Specimens in groups 2, 4 and 5 showed greater biofilm formation than those in groups 1 and 3 (p < 0.001) on all investigated substrates (enamel, composite, and interface areas).

CONCLUSIONS

Specimens prepared with an MDPB-containing primer exhibited significant decreases in biofilm formation on Class I restorations in vitro. Further in vitro and in vivo studies are required to clarify the role of quaternary ammonium compounds in reducing bacterial biofilm formation on restoration surfaces.

Standard and limit values of mandibular condylar and incisal movement capacity

A clinical functional status was obtained and an instrumental analysis of functional movement patterns of the mandible using the ultrasonic Jaw Motion Analyzer (JMA, Zebris; Isny, Germany) was performed on 259 subjects (100 male, 159 female) who were part of an associated project of the representative population-based Study of Health in Pomerania (SHIP 0). Standardized bilateral "arbitrary" skin points based on anatomical skin references were assumed as posterior reference points in the joint area. The recorded movement patterns were evaluated for condylar movement capacity right and left upon mouth opening (COR and COL, in mm), the incisal right-lateral and left-lateral excursion capacity (IR and IL, in mm), the incisal opening capacity (IO, in mm), and the maximum opening angle (OA, in degrees). For the determination of the standard and limit, the following means were determined with standard deviations and 5th and 95th percentiles: COR 14.52 +/- 4.188 (7.70, 21.40); (33.40; 56.10); OA 32.16 +/- 5.954 (21.40; 41.80). The values for men vs women for IR and for OW and in the age group below 40 years vs 40 years and above for IR were statistically significantly different. Interestingly, the interval between the 5th and 95th percentile in the group with a Helkimo clinical dysfunction index of 1 and approximately the same mean value was significantly greater than in the group with Helkimo 0. Based on this standard and limit values or ranges, individually measured values of functional mandibular movement can be compared and differentiated with respect to hypomobility/limitation (< 5th percentile) or hypermobility (> 95th percentile). This serves to indicate the therapeutic direction for functional treatment to improve the jaw's movement capacity in terms of biomechanical optimization. Objective kinematic measurements can be used for additional documentation of the treatment progress during the treatment course.