Higher experience of caries and lower income trajectory influence the quality of restorations: A multilevel analysis in a birth cohort.

OBJECTIVES: This study aimed to evaluate the quality of posterior restorations (amalgam or composite) placed in adults from a birth cohort and its association with clinical and socioeconomic determinants experienced during their life course. METHODS: A representative sample (n=539) of all 5914 births occurring in Pelotas (Brazil) in 1982 was prospectively investigated. Quality of posterior restorations (satisfactory or unsatisfactory) was assessed at 31 yrs-old, using modified USPHS criteria. Trained and calibrated dentists performed clinical examination. Explanatory variables included demographic and socioeconomic, oral health and dental service utilization patterns during the life course. Tooth related variables (type of tooth, material, size of cavity) were also analyzed. Untreated caries and socioeconomic status were assessed by group-based trajectories analyses. Multilevel Regression models were used to determine factors associated with restoration outcomes. RESULTS: In total 2123 restorations (53% composite) were evaluated of which 107 (5%) were assessed as failed. The main reasons for failure were tooth/restoration fracture (50.5%) and secondary caries (30.7%). Failures in posterior restorations showed a significant association with socioeconomic aspects (lower tertile of income at age 30 - prevalence ratio (PR) 2.21 [95% CI 1.19-4.09]), clinical variables (trajectory of higher untreated caries - PR 2.11 [95% CI 1.23-3.61]) and also with tooth-related factors (Restorations involving three or more surfaces - PR 5.51 [95% CI 3.30-9.19]) after adjustment for each other. CONCLUSIONS: These findings suggest that, although tooth-related variables have an important role in restoration longevity, patient-related factors, such as socioeconomic variables and untreated caries are also associated with failure and should be taken into account when evaluating longevity of posterior restorations. CLINICAL SIGNIFICANCE: This was the first study assessing long-term trajectory of untreated caries, showing an association between higher experience of caries during the life-course and unsatisfactory restorations. The findings suggest that individual related factors should be considered when planning treatment and in future research evaluating the longevity of dental restorations.

An initial assessment of haptics in preclinical operative dentistry training.

AIM: The purpose of this study was to assess novice student perception of haptic-based manual dexterity training. The short-term impact of haptic training in the early phase of preclinical operative dentistry education was also investigated. METHODS: Dental students performed a class II amalgam and a class III resin tooth preparation in a typodont model at baseline. The experimental group performed exercises on the manual dexterity module of the IDEA™ software using a haptic device. The exercises required removing the maximum amount of three-dimensional geometric shapes within a predetermined width and depth. Tooth preparations were repeated 2 weeks later. A questionnaire survey was given to assess the subjective evaluation of the haptic simulation exercise. RESULTS: Tooth preparations were scored regarding external outline, internal form, and integrity of adjacent tooth. Improvement of overall tooth preparation scores post-haptic use was not statistically significant compared to controls (P > 0.05). However, students found the game-feature of the haptic device made the learning experience more fun and interesting. CONCLUSION: The haptic exercises with the manual dexterity module software were not superior in improving the dexterity of students for tooth cavity preparations in short-term. Benefits of ease of use and fun learning experience can be further investigated in future studies.

Dental students' self-assessment of operative preparations using CAD/CAM: a preliminary analysis.

The Commission on Dental Accreditation (CODA)'s accreditation standards for dental schools state that "graduates must demonstrate the ability to self-assess." Therefore, dental schools have developed preclinical and clinical self-assessment (SA) protocols aimed at fostering a reflective process. This study comparing students' visual SA with students' digital SA and with faculty assessment was designed to test the hypothesis that higher agreement would occur when utilizing a digital evaluation. Twenty-five first-year dental students at one dental school participated by preparing a mesial occlusal preparation on tooth #30 and performing both types of SAs. A faculty evaluation was then performed both visually and digitally using the same evaluation criteria. The Kappa statistic was used to measure agreement between evaluators. The results showed statistically significant moderate agreement between the faculty visual and faculty digital modes of evaluation for occlusal shape (K=0.507, p=0.002), proximal shape (K=0.564, p=0.001), orientation (K=0.425, p=0.001), and definition (K=0.480, p=0.001). There was slight to poor agreement between the student visual and faculty visual assessment, except for preparation orientation occlusal shape (K=0.164, p=0.022), proximal shape (K=-0.227, p=0.032), orientation (K=0.253, p=0.041), and definition (K=-0.027, p=0.824). This study showed that the students had challenges in self-assessing even when using CAD/CAM and the digital assessment did not improve the amount of student/faculty agreement.

Do socioeconomic determinants affect the quality of posterior dental restorations? A multilevel approach.

OBJECTIVES: This study aimed to evaluate posterior restorations placed in young adults, investigating the association between social determinants experienced during the life course and the quality of tooth fillings. METHODS: A representative sample (n=720) of all 5914 individuals who were born in Pelotas in 1982 was prospectively investigated, and posterior restorations were assessed at 24 years of age. Exploratory variables included demographic and socioeconomic, oral health and dental service payment mode during the life course. Tooth-related variables (type of tooth, material and size of cavity) were also analysed. RESULTS: Multilevel logistic regression models showed that individuals who were always poor from birth to age 23 [odds ratio (OR) 2.35 (1.38-4.00)] and whose mothers had less years of education at their birth (OR 2.60 (1.44-4.68)) were with unsatisfactory restorations in posterior teeth more often. In addition, caries presence at age 15 (high decayed, missing, filled teeth (DMFT) tertile) (OR 1.95 (1.25-3.03)) and cavities with four or more surfaces (OR 18.67 (9.25-37.68)) were associated with the outcome. CONCLUSIONS: These results show that socioeconomic characteristics of the individuals play an important role in restoration failures, reinforcing the need for preventive dental strategies and public policies to reduce inequalities as a major topic of oral health. In addition, the size of cavity appears as the most important determinant for restoration failure. CLINICAL SIGNIFICANCE: Individual socioeconomic characteristics were associated with failure in posterior restorations in detriment of other clinical variables such as restorative material and type of tooth.

Amalgam or composite resin? Factors influencing the choice of restorative material.

OBJECTIVES: This study aimed to investigate the patient and tooth factors associated with selection of restorative material in direct posterior restorations in young adults from a population-based birth cohort. METHODS: A representative sample (n=720) of all 5914 births occurring in Pelotas in 1982 were prospectively investigated, and posterior restorations were assessed in 2006, when the patients were 24 years old. Tooth-related variables (individual level) included restorative material (amalgam or composite), type of tooth, size of cavity, and estimated time in mouth. Data regarding demographic and socio-economic characteristics, oral health, and service utilization patterns during the life course were also assessed (contextual level). RESULTS: Logistic Regression Multilevel models showed that individuals who have accessed dental services by private insurance by age 15 [odds ratio (OR)=1.66 (0.93-2.95)] and who had a higher dental caries index at age 15 (high DMFT tertile) [OR 2.89 (1.59-5.27)] presented more amalgam restorations in the posterior teeth. From tooth-level variables, the frequency of amalgams decreases with increasing number of surfaces enrolled in the cavity preparation (p<0.001) and was almost 5 times greater in molars than in premolars. CONCLUSIONS: The present findings suggest that variables related to type of dental service, dental caries (higher DMFT index), and cavity characteristics (tooth type, size) determine the choice of dentists for restorative materials. Other individual characteristics such as demographic and socioeconomic status have not influenced this choice. CLINICAL SIGNIFICANCE: This is the first population-based study that assesses the determinant factors for the choice of dentists for composite or amalgam in posterior direct restorations, showing that, independently of socioeconomic and demographic characteristics, type of payment of dental services and clinical factors are associated with this choice.

Non-destructive assessment of cavity wall adaptation of class V composite restoration using swept-source optical coherence tomography.

The purpose of this study was to evaluate gap formations under class V restoration using swept-source optical coherence tomography (SS-OCT). Wedge-shaped cavities were prepared on the buccal surface of 40 extracted premolar teeth at 2 locations; 1) cemento-enamel junction (CEJ) with enamel and cementum margin and 2) root surfaces with cementum margin. The cavity was treated with Clearfil S(3) Bond, restored with Clearfil Majesty and polished with abrasive disks. The specimens were kept in water at 37°C for 24 hours and subjected to a thermocycling procedure. Gap formations at the tooth-restoration interface were measured with SS-OCT image and conventional dye leakage under a microscope. There was no effect of the locations of the cavity and the margins of the cavity on the gap formation. Therefore, a significant effect of the observational methods was observed. The gap formation was 0.89±0.48 mm with the SS-OCT, and the gap formation was 0.34±0.41 mm with the dye leakage. The observation with SS-OCT demonstrated a greater degree of gap formation than the observation with dye leakage.

Clinical assessment of postoperative sensitivity in posterior composite restorations.

This incidence of postoperative sensitivity was evaluated in resin-based posterior restorations. Two hundred and ninety-two direct restorations were evaluated in premolars and molars. A total of 143 Class I and 149 Class II restorations (MO/OD and MOD) were placed in patients ranging in age from 30 to 50 years. After the cavity preparations were completed, a rubber dam was placed, and the preparations were restored using a total-etch system (Prime & Bond NT) and a resin-based restorative material (TPH Spectrum). The patients were contacted after 24 hours and 7, 30 and 90 days postoperatively and questioned regarding the presence of sensitivity and the stimuli that triggered that sensitivity. The Chi-square and Fisher's Exact Test were used for statistical analysis. Evaluation at 24 hours after restorative treatment revealed statistically significant differences among the types of cavity preparations restored and the occurrence of postoperative sensitivity (p = 0.0003), with a higher frequency of sensitivity in Class II MOD restorations (26%), followed by Class II MO/DO (15%) and Class I restorations (5%). At 7, 30 and 90 days after restorative treatment, there was a decrease in the occurrence of sensitivity for all groups. The percentage of sensitivity among the groups was not significantly different. This study shows that the occurrence of sensitivity is correlated with the complexity of the restoration.

Teaching the placement of posterior resin-based composite restorations in U.S. dental schools.

BACKGROUND: In light of the increased use of and demand for posterior resin-based composite restorations in dental practice, the authors investigated U.S. dental schools' current teaching with regard to placement of posterior composite restorations. METHODS: In early 2005, the authors invited 52 schools to participate in an e-mailed survey. RESULTS: The authors received 47 completed responses, for a 90 percent response rate. Although all schools provided didactic and clinical teaching in the placement of occlusal resin-based composites in posterior teeth, the survey results showed variation in teaching the use of two- and three-surface occlusoproximal composites. CONCLUSIONS: The survey findings demonstrate a marked change in instruction in placement of posterior resin-based composite restorations in U.S. dental schools during the last five to 10 years. However, the authors found much variation in the nature and extent of the instruction and techniques taught. CLINICAL IMPLICATIONS: Dental schools need to ensure that their graduating students are well-prepared for independent clinical practice.

Assessment of the resistance to fracture of endodontically treated molars restored with amalgam.

STATEMENT OF PROBLEM: Controversy exists concerning the preferred type of final restoration of endodontically treated molars regarding their resistance to fracture under occlusal load. PURPOSE: The aim of this study was to assess the resistance to fracture of endodontically treated molars with various degrees of tooth structure loss restored with amalgam under simulated occlusal load. MATERIAL AND METHODS: . The study teeth consisted of 90 noncarious, nonrestored molars stored in physiological saline solution. The teeth were endodontically treated and randomly divided into 9 experimental groups of 10 specimens each with various degrees of tooth loss, ranging from a conservative endodontic access to removal of all cusps. All teeth were restored with a standardized technique to their original contour with amalgam. Each specimen was mounted onto a specialized jig for loading at the central fossa at a 30-degree angle to the long tooth axis. The resistance to fracture, under continuous compressive force at a cross-head speed of 2 mm/minute, was applied by a universal testing machine and was recorded. One-way analysis of variance with Scheffé contrast was used to statistically compare the differences between the groups at significance level P<.05. RESULTS: One-way analysis of variance showed that the group with a conservative endodontic access (1137.6 +/- 311.6 N) and the group with removal of all cusps (1261.4 +/- 195.1 N) presented a significantly higher resistance to fracture when compared with the other groups (P<.05). There was no significant difference in resistance to fracture under the simulated load between the other 7 groups, which ranged from 655.8 +/- 229.4 to 906.3 +/- 168.1 N (P>.05). CONCLUSION: Within the limitations of this study, the endodontically treated molars with a conservative endodontic access or after removal of all cusps that were restored to their original contour with amalgam presented the highest resistance to fracture under a simulated occlusal load.

Practical posterior composites. Efficient placement and predictable results.

Certainly, we could spend more time matching shades, applying characterizations, placing secondary anatomy, and even finishing. However, if posterior composite restorations are to be a viable alternative to amalgam in appropriate cases, we must accomplish efficient and predictable placement so that fees for the two types of restorations are somewhat in line. Contact must be solid, sensitivity must be kept to a minimum, and placement and finishing must be fairly simple and organized. If the problems with posterior composites aren't kept to a minimum, all of dentistry will suffer. Our contacts are excellent most of the time, but occasionally we need to redo a "light" one. Our best estimate is that about one in 100 fillings that had no preoperative symptoms needed some postoperative care after restoring. Usually these complaints are corrected by occlusal adjustment, and very rarely by replacing the restoration. We have not yet made a perfect restoration in our practice--we are still trying.

Assessment of manual restorative treatment (MRT) with amalgam in high-caries Filipino children: results after 2 years.

BACKGROUND: The atraumatic restorative treatment (ART), using only hand instruments and glass-ionomer cement as adhesive material is recommended for restorative dental treatment in disadvantaged communities lacking electricity and sophisticated dental equipment. Research is required on more durable restorative materials appropriate for populations with high-caries experience. OBJECTIVES: The aim of the study was to evaluate, under field conditions, the applicability and effectiveness of an encapsulated amalgam as restorative material in ART prepared cavities in permanent teeth of children with high-caries rates. As the definition of ART restricts the manual treatment to adhesive materials the approach used is called the manual restorative treatment (MRT). METHODS: Two dentists and two trained healthcare workers, using hand instruments and an encapsulated amalgam that was mixed with a manually driven triturator, placed a total of 934 restorations in the permanent dentition in 466 children. Due to irregular school attendance of Filipino children only 611 restorations could be evaluated by one independent dentist. The average age at reassessment of restorations was 27 +/- 4.5 months. RESULTS: 93.3% of the restorations were acceptable. The failure rate of occlusal surface restorations was 5.6% compared with 13.6% of buccal surface fillings. The survival rate of large occlusal restorations was 95.1% compared with 93.7% for small restorations. The survival of MRT restorations was not influenced by the experience and professional level of the operator. CONCLUSIONS: Amalgam is a suitable MRT material, especially for extensive occlusal lesions in high-caries populations. Studies of longer duration are needed to confirm this finding.

Quality assessment of marginal sealing using 7 dentin adhesive systems.

OBJECTIVE: The goal of this investigation was to assess in vitro the quality of marginal sealing of composite-dentin adhesive systems and human dentin. METHOD AND MATERIALS: Forty intact human premolars and third molars were extracted from subjects of both sexes and of different ages. After the enamel layer was removed, a Class V cavity was formed on the buccal surface, and a wedge cavity was formed on the lingual surface. These were restored with resin composite materials and their corresponding dentin adhesive systems. The quality of marginal sealing was evaluated by assessing the linear penetration of silver nitrate dye. RESULTS: The best marginal sealing between composite materials and the cavity walls, in both wedge erosions and Class V cavities, was provided by Scotchbond Multi-Purpose/Valux and Syntac/Helioprogres systems. Dye penetration was slightly greater with the XR-Bond/Herculite, Gluma/Pekafill, and Superlux Universal Bond 2/Superlux Solar systems. The greatest microleakage was observed in Tripton/Opalux and Denthesive/Charisma specimens. CONCLUSION: The use of an adhesive system and the corresponding resin composite does not eliminate microleakage completely when the cavity margins are in dentin.

Review of bonded amalgam restorations, and assessment in a general practice over five years.

This study reviewed the literature on bonded amalgam restorations and assessed the failure, marginal fracture and marginal staining behavior of 366 Permite C amalgam restorations lined with five dentin bonding resins (Scotchbond 2, Panavia Ex, Amalgambond, Amalgambond Plus, Geristore) and a polyamide cavity varnish (Barrier). The restorations were placed in the posterior permanent teeth of 190 adult patients and examined at intervals over periods of up to five years. There were five restoration failures (1.4%), usually from tooth fracture, involving Class II preparations in molar teeth. No instances of persistent pulpal sensitivity or recurrent caries were reported. The marginal deterioration of the restorations was assessed indirectly using photographs for comparison with two standard sets of enlarged color transparencies. Most of the marginal fracture and marginal staining scores were low, with little difference between the six lining materials at any period.

Amalgam marginal quality assessment: a comparison of seven methods.

Black's class I classic cavities were cut in 120 sound extracted human premolars and restored with one of two silver amalgams, six different base combinations, with or without cavity varnish and then aged for 3 months or 1 year. Thereafter, the restored teeth were subjected to a bacterial or acid broth in vitro carious challenge for 36 days. Resin cast impressions were made of the restoration margin of each specimen before and after the carious challenge giving a total of 240 replicas. The replicas were examined in a scanning electron microscope (SEM) and the margins subjected to seven marginal assessment procedures: (i) ranking using micrographs of the margin; (ii) percentage length of marginal discrepancy; (iii) Mjor assessment using six groups; (iv) number of margin segments showing a discrepancy; (v) greatest gap size; (vi) ranking based firstly on gap size and then number of margin segments showing a discrepancy; and (vii) ranking based firstly on gap size and then percentage length of marginal discrepancy. The data from procedures (i), (ii), (vi) and (vii) were examined using one-way ANOVA; a linear logistic statistical analysis examined data from procedures (iii)-(v). Statistical significance was chosen at P < 0.05. It was found that procedure (vii) was able to discriminate between variables to a greater degree than all other procedures. It is recommended that a ranking system based on greatest gap size and percentage length of marginal discrepancy be used to assess marginal quality of amalgam restorations.

Long-term survival and cost-effectiveness of five dental restorative materials used in various classes of cavity preparations.

This retrospective study examined the survival and cost-effectiveness of five different types of dental materials used to restore various classes of cavity preparations in permanent teeth. Information on the restorations was obtained from the casenote records of 100 long-term adult patients treated at various times by 20 dentists in three city practices. Patients attended for checkups and restorative treatments on a regular basis for around 25 years on average, ranging from 10 to 46 years. All of the restorative materials lasted well, despite the frequent patient checkups and changes of dentists. Cusp-covered amalgams were approximately 3.8 times more cost-effective than were either cast gold or ceramometal crowns, and resin composites were approximately 3.7 times more cost-effective than were cast gold inlays for restoring Class IV preparations. However, there were no significant differences found in the cost-effectiveness of using either resin composites or glass-ionomer cements to restore Class III preparations, or between using either of these two materials, or amalgams, to restore Class V preparations.

Assessment of marginal leakage of class II amalgam-sealant restorations.

This study addresses the question of whether conservative methods of restoration may be applied efficaciously in permanent posterior teeth with proximal lesions and intact occlusal sealants. It evaluates the effect of in vivo experimental conditions on micro-leakage, using primary molars in this study, for information applicable to permanent molars.