Acute toxicity during external-beam radiotherapy for localized prostate cancer: comparison of different techniques

PURPOSE

The chronic and acute toxicities associated with conventional radiotherapy of localized prostate cancer are well documented. However, the degree and incidence of toxicities with conformal techniques are not known. Studying side effects associated with modern radiotherapeutic techniques is more important now since there has been a general trend to use computerized tomography-based techniques in recent years; beam's eye view-based conformal techniques are also becoming more commonplace. It is possible that the local disease control can be improved with the delivery of higher doses than currently used. Conformation of the treatment volume to the target volume may facilitate such dose-escalation. However, prior to such dose-escalation, it is important to know the toxicities associated with such techniques with conventional doses.

METHODS AND MATERIALS

We have compared week-by-week acute toxicities associated with conventional (Group A, 16 patients), computerized tomography-based, manual (Group B, 57 patients) and beam's eye view-based (Group C, 43 patients) techniques during 7 weeks of radiotherapy. Group B and C patients were treated contemporaneously (1988-1990).

RESULTS

Acute side effects gradually increased from week 1 through weeks 4-5 and generally declined or plateaued after that. The incidence of acute toxicities was significantly less with the beam's eye view/based technique than with the other two methods. For instance, the percentages of Grade 2 acute genitourinary toxicities for Groups A, B, and C were as follows: Week 1-0, 0, 0; Week 2-6, 0, 0; Week 3-6, 9, 2; Week 4-12, 14, 9; Week 5-35, 14, 9; Week 6-31, 16, 7; Week 7-33, 8, 8, respectively. The p values associated with differences in acute genitourinary toxicities for Weeks 1-7 using chi-square test were 0.072, 0.627, 0.389, 0.538, 0.123, 0.06, and 0.012; the p values for acute gastrointestinal toxicities were 0.512, 0.09, 0.031, 0.031, 0.003, < 0.0001, and 0.004, respectively. Pairwise comparison (Wilcoxon rank-sum test) showed statistically significant lower acute toxicity in Group C than Group B (e.g., p values, Weeks 1-7 for gastrointestinal toxicity: 0.633, 0.056, 0.010, 0.014, < 0.0001, < 0.0001, and < 0.0001, respectively) in the latter part of the treatment course. No correlation was found between the extent of toxicity and the patient age or the overall treatment time. Also, no correlation was found between the degree of toxicity and the radiation dose and fraction size, within the narrow ranges used (65-70 Gy and 180-200 cGy, respectively). A trend suggesting increased severity of toxicity with increase in the volume of treatment was seen.

CONCLUSION

The findings in this retrospective study need to be confirmed by other prospective studies.

Relationship between number of proximal contacts and survival of root canal treated teeth

AIM

The present study tested the hypothesis that having two proximal contacts (PCs) at access is associated with improved survival of root canal treated (RCT) teeth, controlling for important presenting conditions, endodontic variables and restorative factors.

METHODOLOGY

A treatment database at the University of Iowa College of Dentistry was used to identify permanent teeth undergoing obturation between 1 July 1985 and 31 December 1987. The list was restricted to teeth of patients with at least one dental visit in each two-year interval from 1985 to 1996, and a simple random sample of 280 patients (n = 400 teeth) was selected. Dental charts, radiographs, and computerized databases were examined to ascertain variables of interest and to verify study inclusion criteria. Kaplan-Meier survival estimates were generated for the 221 teeth satisfying study inclusion criteria. Multivariate Cox models were developed, with standard errors adjusted to account for clustering of teeth within patients.

RESULTS

The final Cox model showed that teeth with < or =1 PC at access were lost at a rate three times that of teeth with 2 PCs (hazard ratio = 3.1; 95% confidence interval = 1.9-5.1), controlling for tooth type, presence of radiographic caries at access, and presence of a crown before or after obturation.

CONCLUSIONS

Because RCT teeth with two PCs at access experienced substantially better survival than teeth with fewer than two PCs, the influence of PCs on prognosis should be recognized during treatment planning. Future research should employ prospective study designs, capture additional variables, and provide data to support endodontic treatment decisions.

Dietary patterns related to caries in a low-income adult population

The aim of this study was to examine the relationship between dietary patterns and caries experience in a representative group of low-income African-American adults. Participants were residents of Detroit, Michigan, with household incomes below 250% of the federally-established poverty level (n = 1,021). Dietary histories were obtained by trained interviewers in face-to-face interviews with the adult participants, using the Block 98.2 food frequency questionnaire. Caries was measured by the ICDAS criteria (International Caries Detection and Assessment System). There were 200 dietary records whose data were judged to be invalid; these participants were omitted from the dietary analyses to leave n = 821. Factor analysis identified patterns of liquid and solid food consumption, and the resulting factor scores were used as covariates in multivariable linear regression. Caries was extensive, with 82.3% of the 1,021 participants (n = 839) having at least one cavitated lesion. Nearly three quarters of the adult participants were overweight or obese. This population had severe caries, poor oral hygiene, and diets that are high in sugars and fats and low in fruits and vegetables. Apart from tap water, the most frequently consumed food item by adults of all ages was soft drinks; 19% of all energy from sugar came from soft drinks alone. In both the bivariate analyses and in the regression model, frequency of soft drink consumption and the presence of gingival plaque deposits were significantly associated with caries. Interventions to promote oral health are unlikely to be successful without improvements in the social and physical environment.

Longitudinal associations between children's dental caries and risk factors

Dental caries is a common disease in children of all ages. It is desirable to know whether children with primary, mixed, and permanent dentitions share risk factors for cavitated and non-cavitated caries.

OBJECTIVE

To assess the longitudinal associations between caries outcomes and modifiable risk factors.

METHODS

One hundred and fifty-six children in the Iowa Fluoride Study met inclusion criteria of three dental examinations and caries-related risk factor assessments preceding each examination. Surface-specific counts of new non-cavitated caries and cavitated caries at the primary (Exam 1: age 5), mixed (Exam 2: age 9) and permanent (Exam 3: age 13) dentition examinations were outcome variables. Explanatory variables were caries-related factors, including averaged beverage exposure frequencies, tooth brushing frequencies, and composite water fluoride levels collected from 3-5, 6-8, and 11-13 years, dentition category, socioeconomic status, and gender. Generalized linear mixed models (GLMMs) were used to explore the relationships between new non-cavitated or cavitated caries and caries-related variables.

RESULTS

Greater frequency of 100 percent juice exposure was significantly associated with fewer non-cavitated and cavitated caries surfaces. Greater tooth brushing frequency and high socioeconomic status (SES) were significantly associated with fewer new non-cavitated caries. Children had significantly more new cavitated caries surfaces at the mixed dentition examination than at the primary and permanent dentition examinations.

CONCLUSIONS

There were common caries-related factors for more new non-cavitated caries across the three exams, including less frequent 100 percent juice exposure, lower tooth brushing frequency and lower SES. Less frequent 100 percent juice exposures might be associated with higher exposures to several other cariogenic beverages.

Factors associated with dental caries experience in 1-year-old children

OBJECTIVES

Dental caries in early childhood is an important public health problem. Previous studies have examined risk factors, but they have focused on children during the later stages of the disease process. The purpose of this study was to assess the factors associated with caries in children aged 6 to 24 months as part of a cross-sectional analysis.

METHODS

Two hundred twelve mothers with children 6 to 24 months of age were recruited from Special Supplemental Nutrition Program for Women, Infants, and Children clinic sites in southeastern Iowa for participation in a longitudinal study of dental caries. Baseline assessments included detailed questions regarding the children's beverage consumption, oral hygiene, and family socioeconomic status. Dental caries examinations using the d(1)d(2-3)f criteria and semiquantitative assessments of salivary mutans streptococci (MS) levels of mother and child were also conducted. Counts of the number of teeth with visible plaque were recorded for maxillary and mandibular molars and incisors.

RESULTS

Of the 212 child/mother pairs, 187 children had teeth. Among these children, the mean age was 14 months, and 23 of the children exhibited either d(1), d(2-3), or filled lesions. Presence of caries was significantly associated with older age, presence of MS in children, family income <$25,000 per year, and proportion of teeth with visible plaque.

CONCLUSIONS

Results suggest that not only microbial measures, including MS and plaque levels, are closely associated with caries in very young children, but that other age-related factors may also be associated with caries. Continued study is necessary to more fully assess the risk factors for caries prevalence and incidence in preschool children.

Efficacy of Direct Restorative Materials in Proximal Box Elevation on the Margin Quality and Fracture Resistance of Molars Restored With CAD/CAM Onlays

PURPOSE

The purpose of this study was to investigate the effect of four direct restorative materials that can be used in the proximal box elevation (PBE) technique.

METHODS AND MATERIALS

Seventy-five molar teeth were randomly assigned to one of five groups (n=15): type II glass ionomer (GI), type II resin-modified glass ionomer (RMGI), resin-based composite (RBC), bulk-fill (BF) resin-based composite, and a control with no box elevation procedure. Specimens were prepared for a standard mesio-occlusal-distal, computer-aided design/computer-aided manufactured (CAD-CAM) resin, nanoceramic onlay with mesial cervical margins located 1 mm above the cementoenamel junction (CEJ) and distal cervical margins located 2 mm below the CEJ. PBE was used to elevate the distal margins to 1 mm above the CEJ in all groups except the control group. For the control group the onlay margin was placed directly on the prepared distal tooth structure without PBE. A Lava Ultimate CAD/CAM resin, nanoceramic onlay restorative was manufactured and bonded on all specimens with RelyX Ultimate adhesive resin cement. The quality of the tooth-PBE material and PBE material-onlay interface was evaluated with scanning electron microscopy using epoxy resin replicas before and after cyclic loading (100,000 cycles, 1.2 Hz at 65N and 37°C). In addition to margin quality, the fracture resistance of each group was measured using a universal testing machine. Fracture pattern was recorded by visual examination. The Levene test for homogeneity and the Welch analysis of variance were completed for fracture resistance and margin quality. A χ² test was completed for break mode.

RESULTS

For dentin margins, a statistically significant difference was detected between the RMGI and control groups at baseline (p=0.0442). All other groups-GI, RBC, and BF-showed no difference from the control at baseline (p>0.05). No statistical significance was observed among groups for post-cyclic fatigue (p=0.8735). For onlay margins, no statistical significance was observed among groups for pre-cyclic fatigue, post-cyclic fatigue, or change (p=0.9713, p=0.528, p=0.4385, respectively). No significant difference was observed for the fracture resistance among groups or for the type of break by material used (p=0.1593, p=0.77, respectively).

CONCLUSION

Within the parameters of this study, after mechanical fatigue, the materials used for PBE: RMGI, RBC, and BF, did not influence results in terms of margin quality and fracture resistance. Therefore, collective findings suggest that these materials might be suitable for PBE procedures. Nevertheless, clinical caution is recommended with any PBE procedure and further testing of GI materials is needed.

Dental caries clusters among adolescents

OBJECTIVES

There have been very few longitudinal studies of dental caries in adolescents, and little study of the caries risk factors in this age group. The purpose of this study was to describe different caries trajectories and associated risk factors among members of the Iowa Fluoride Study (IFS) cohort.

METHODS

The IFS recruited a birth cohort from 1992 to 1995, and has gathered dietary, fluoride and behavioural data at least twice yearly since recruitment. Examinations for dental caries were completed when participants were ages 5, 9, 13 and 17 years. For this study, only participants with decayed and filled surface (DFS) caries data at ages 9, 13 and 17 were included (N=396). The individual DFS counts at age 13 and the DFS increment from 13 to 17 were used to identify distinct caries trajectories using Ward's hierarchical clustering algorithm. A number of multinomial logistic regression models were developed to predict trajectory membership, using longitudinal dietary, fluoride and demographic/behavioural data from 9 to 17 years. Model selection was based on the akaike information criterion (AIC).

RESULTS

Several different trajectory schemes were considered, and a three-trajectory scheme-no DFS at age 17 (n=142), low DFS (n=145) and high DFS (n=109)-was chosen to balance sample sizes and interpretability. The model selection process resulted in use of an arithmetic average for dietary variables across the period from 9 to 17 years. The multinomial logistic regression model with the best fit included the variables maternal education level, 100% juice consumption, brushing frequency and sex. Other favoured models also included water and milk consumption and home water fluoride concentration. The high caries cluster was most consistently associated with lower maternal education level, lower 100% juice consumption, lower brushing frequency and being female.

CONCLUSIONS

The use of a clustering algorithm and use of Akaike's Information Criterion (AIC) to determine the best representation of the data were useful means in presenting longitudinal caries data. Findings suggest that high caries incidence in adolescence is associated with lower maternal educational level, less frequent tooth brushing, lower 100% juice consumption and being female.

Knowledge of Oral Cancer and Screening Practices of Primary Care Providers at Federally Qualified Health Centers

OBJECTIVES

Primary care providers (PCPs) who worked in Federally-Qualified Health Centers (FQHC) in Michigan were surveyed to assess their knowledge level and practices related to screening and preventing oral cancer.

METHODS

A questionnaire was developed with the assistance of dental and medical experts, and revised through focus groups. The questionnaire included one case scenario describing a suspicious oral lesion in a 55-year old female patient, followed by questions assessing PCPs' knowledge level, attitude, opinion, and screening practices for oral cancer. This mail survey was conducted in 2003.

RESULTS

Survey response rate was 56.4%. Over 70% of the respondents reported that they screen patients for oral cancer during a routine physical examination. Forty-four percent of PCPs had high knowledge level, based on the scenario questions. Those who had high knowledge level were more likely to be physicians, males, and more likely to perform screening for oral cancer than those with low knowledge level. There was no difference in age and race/ethnicity between high and low knowledge groups. Perceived barriers included (1) lack of education; (2) lack of specialists to refer patients; and (3) lack of reimbursement.

CONCLUSIONS

The majority of PCPs in this survey had positive attitudes about performing screening for oral cancer. To involve PCPs in screening for oral cancer, oral health programs should focus on providing up-to-date education, setting up a referral system, and providing proper reimbursement.

Mutans Streptococci and Dental Caries: A New Statistical Modeling Approach

Survival analyses have been used to overcome some of the limitations encountered with other statistical analyses. Although extended Cox hazard modeling with time-dependent variables has been utilized in several medical studies, it has never been utilized in assessing the complex relationship between mutans streptococci (MS) acquisition (time-dependent covariate) and time to having dental caries (outcome). This study involved secondary analyses of data from a prospective study conducted at the University of Alabama at Birmingham. Low socioeconomic status, African-American preschool children from Perry County, AL, USA (n = 95) had dental examinations at age 1 year and annually thereafter until age 6 years by three calibrated dentists. Salivary MS tests were done at ages 1, 1.5, 2, 2.5, 3, and 4 years. The patterns of and relationship between initial MS detection (time-dependent covariate) and dental caries experience occurrence were assessed, using extended Cox hazard modeling. The median time without MS acquisition (50% of the children not having positive MS test) was 2 years. Approximately 79% of the children had positive salivary MS tests by the age of 4 years. The median caries experience survival (50% of the children not having dental caries) was 4 years. During the follow-up period, 65 of the children (68.4%) had their initial primary caries experience. Results of the extended Cox hazard modeling showed a significant overall/global relationship between initial caries experience event at any given time during the follow-up period and having a positive salivary MS test at any time during the follow-up period (hazard ratio = 2.25, 95% CI 1.06-4.75). In conclusion, the extended Cox modeling was used for the first time and its results showed a significant global/overall relationship between MS acquisition and dental caries. Further research using causal mediation analysis with survival data is necessary, where the mediator "presence of MS" is treated as a time-dependent variable.

Timing of primary tooth emergence among U.S. racial and ethnic groups

OBJECTIVES

To compare timing of tooth emergence among groups of American Indian (AI), Black and White children in the United States at 12 months of age.

METHODS

Data were from two sources - a longitudinal study of a Northern Plains tribal community and a study with sites in Indiana, Iowa and North Carolina. For the Northern Plains study, all children (n = 223) were American Indian, while for the multisite study, children (n = 320) were from diverse racial groups. Analyses were limited to data from examinations conducted within 30 days of the child's first birthday.

RESULTS

AI children had significantly more teeth present (Mean: 7.8, Median: 8.0) than did Whites (4.4, 4.0, P < 0.001) or Blacks (4.5, 4.0, P < 0.001). No significant differences were detected between Black and White children (P = 0.58). There was no significant sex difference overall or within any of the racial groups.

CONCLUSIONS

Tooth emergence occurs at a younger age for AI children than it does for contemporary White or Black children in the United States.

Teeth with large amalgam restorations and crowns

BACKGROUND

The authors evaluated the factors associated with the receipt of subsequent treatment by teeth restored with a large amalgam restoration or a large amalgam restoration and crown restoration after 10 years.

METHODS

The authors used retrospective data from the University of Iowa College of Dentistry (Iowa City, Iowa) administrative database and patient records to evaluate patient and tooth factors for their association with the two primary outcomes: receipt of any subsequent treatment and receipt of catastrophic treatment (extraction, endodontic therapy).

RESULTS

The authors followed 518 teeth over a 10-year period (49 percent with large amalgam restorations and 51 percent with crowns). Sixty-four percent of the large amalgam restorations and 32 percent of the crowns received subsequent treatment during the 10 years. In addition to restoration type, the patient's sex, history of grinding teeth and having a broken tooth were related to the tooth's receiving subsequent treatment. Twenty-two percent of large amalgam restorations and 12 percent of crowns received catastrophic treatment with the odds of teeth with large amalgam restorations receiving a catastrophic treatment being 2.1 times the odds of teeth with crowns receiving catastrophic treatment.

CONCLUSIONS

Teeth with crowns were less likely to receive any treatment or catastrophic treatment over 10 years than were teeth with large amalgam restorations. Patient and tooth factors also were related to a tooth experiencing subsequent treatment.

CLINICAL IMPLICATIONS

Teeth with crowns received less subsequent treatment than teeth with large amalgam restorations. This could be related to both the difference in longevity between the two restorations, as well as how appropriately treatment was planned for each procedure. Cost differences between the two restorations need to be factored into the decision-making process.

Service-learning's impact on dental students' attitude towards community service

BACKGROUND

This study evaluated service-learning programme's impact on senior dental students' attitude towards community service at Virginia Commonwealth University (VCU) School of Dentistry. Experience gained through service-learning in dental school may positively impact dental students' attitude towards community service that will eventually lead into providing care to the underserved.

MATERIALS AND METHODS

Two surveys (pre- and post-test) were administered to 105 senior dental students. For the first survey (post-test), seventy-six students of 105 responded and reported their attitude towards community service immediately after the service-learning programme completion. Three weeks later, 56 students of the 76 responded to the second survey (retrospective pre-test) and reported their recalled attitude prior to the programme retrospectively.

RESULTS

A repeated-measure mixed-model analysis indicated that overall there was improvement between pre-test and post-test. Scales of connectedness, normative helping behaviour, benefits, career benefits and intention showed a significant pre-test and post-test difference. An association between attitude towards community service and student characteristics such as age, gender, ethnicity and volunteer activity was also examined. Only ethnicity showed an overall significant difference. White dental students appear to have a differing perception of the costs of community service.

CONCLUSIONS

The service-learning programme at VCU School of Dentistry has positively impacted senior dental students' attitude towards community service.

The associations between dietary intakes from 36 to 60 months of age and primary dentition non-cavitated caries and cavitated caries

OBJECTIVE

To examine risk factors for non-cavitated caries, as well as cavitated caries.

METHODS

Subjects were participants in the Iowa Fluoride Study cohort. Dietary data were collected at 36, 48, and 60 months old using 3-day dietary diaries, and a dental examination was conducted at about age 5. We compared the frequencies of dietary intakes of three groups: a) children having only d1 caries (n = 41); b) children having only cavitated (d2+f) caries (n = 46); and c) children having both d1 and d2+f caries (n = 49) with a forth group; d) those of caries-free children (n = 257).

RESULTS

Multinomial and binomial logistic regression was used, where the categorical outcome was based on the 4 caries groups, and the caries-free group was designated as the reference. In the final model, sevenvariables were associated with the caries outcome. Lower milk consumption frequency at meals and greater presweetened cereal consumption frequency at meals were significantly associated with a greater likelihood of being in the d1 group. Greater regular soda pop consumption frequency and greater added sugar consumption frequency at snacks were significantly associated with being in the cavitated caries (d2+f and/or d1 d2+f) groups. Lower socioeconomic status and less frequent toothbrushing increased the likelihood of being in the d1 group.

CONCLUSIONS

The results suggest that different food and beverage categories are associated with being in the d1 group compared with the cavitated caries groups. More frequent toothbrushing, greater milk consumption at meals, and avoiding presweetened cereal consumption at meals might reduce the risk of developing non-cavitated caries.

Decline in Dental Fluorosis Severity during Adolescence: A Cohort Study

Dental fluorosis occurs from overingestion of fluoride during tooth formation. However, there is little evidence in the literature on whether or how fluorosis prevalence and severity change over time after tooth eruption. Permanent dentition dental examinations were conducted at ages 9, 13, 17, and 23 as part of the Iowa Fluoride Study, which has followed a cohort from birth. Fluorosis was assessed using the Fluorosis Risk Index (FRI) and Russell's criteria for differential diagnosis. Measures of fluorosis severity at the person and tooth level were calculated: second highest FRI score at the person level (the maximum FRI score for each tooth was determined and the tooth with the second highest maximum FRI score was used) and highest FRI score at the tooth level. At both the person and tooth levels, a decline in mild to moderate fluorosis severity was observed across adolescence and young adulthood. Across each pair of adjacent examinations at the person level, for participants with a baseline second highest FRI of 0, most participants stayed at 0 (82% to 91%). Many participants with a baseline second highest FRI of 1 had a follow-up score of 0 (47% to 54%), while about a third had a follow-up score of 1 (34% to 38%), and a lower percentage had an increase to a score of 2 (9% to 15%). For participants with baseline second highest FRI score of 2, between 25% and 44% of participants had follow-up FRI scores each of 0, 1, and 2. Similar patterns were observed at the tooth level. These results were consistent with most of the existing, limited literature. Overall, fluorosis severity, which was initially mild to moderate, tended to decline during adolescence and young adulthood. Additional study of how this trend affects esthetic perceptions of fluorosis is warranted.

The Cost-Effectiveness of Large Amalgam and Crown Restorations Over a 10-Year Period

OBJECTIVE

To assist clinical decision making for an individual patient or on a community level, this study was done to determine the differences in costs and effectiveness of large amalgams and crowns over 5 and 10 years when catastrophic subsequent treatment (root canal therapy or extraction) was the outcome.

METHODS

Administrative data for patients seen at the University of Iowa, College of Dentistry for 1735 large amalgam and crown restorations in 1987 or 1988 were used. Annual costs and effectiveness values were calculated. Costs of initial treatment (large amalgam or crown), and future treatments were determined, averaged and discounted. The effectiveness measure was defined as the number of years a tooth remained in a state free of catastrophic subsequent treatment. Years free of catastrophic treatment were averaged, and discounted. The years free of catastrophic treatment accounted for individuals who dropped out or withdrew from the study.

RESULTS

Teeth with crowns had higher effectiveness values at a much higher cost than teeth restored with large amalgams. The cost of an addition year free of catastrophic treatment for crowns was 1088.41 dollars at 5 years and 500.10 dollars at 10 years. Teeth in women had more favorable cost-effectiveness ratios than those in men, and teeth in the maxillary arch had more favorable cost-effectiveness ratios than teeth in the mandibular arch.

CONCLUSIONS

Neither the large amalgam or crown restoration had both the lowest cost and the highest effectiveness. The higher incremental cost-effectiveness ratio for crowns should be considered when making treatment decisions between large amalgam and crown restorations.

Effect of polishing direction on the marginal adaptation of composite resin restorations

PROBLEM

Polishing composite resin restorations may lead to marginal defects and gap formation.

PURPOSE

To assess the effect of polishing direction on the marginal adaptation of composite resin restorations using two composite resins and two polishing systems.

MATERIALS AND METHODS

Forty extracted human molars were sectioned along their mesio-distal axis. Buccal and lingual enamel was flattened and a triangular preparation, 0.87-mm deep and 3-mm wide, representing two 60° bevels, was performed. Specimens were randomly assigned to eight groups (N = 20) and restored with two composite resins: a nanofilled (Filtek Supreme Ultra, 3M ESPE, St. Paul, MN, USA) or a microhybrid (Point 4, Kerr, Orange, CA, USA) and finished with two polishing techniques: polishing discs (Sof-Lex XT, 3M ESPE) or rubber polishers (HiLuster Plus, Kerr, Bioggio, Switzerland). On each specimen, both margins were polished with the same technique, one margin from composite resin to tooth and the other from tooth to composite resin. Replicas were made for field emission scanning electron microscope observation (200×) and quantitative margin analysis was performed based on four criteria. Data were analyzed with a paired-sample t-test, a two-sample t-test, and one-way analysis of variance or their nonparametric analog.

RESULTS

Significant differences were found in most groups between polishing directions with better marginal adaptation from composite resin to tooth than from tooth to composite resin. Differences between composite resins and polishing techniques seemed to be dependent on certain combinations of composite resin, polishing technique, and polishing direction.

CONCLUSION

Polishing from composite resin to tooth leads to better marginal adaptation than polishing from tooth to composite resin.

CLINICAL SIGNIFICANCE

The results obtained from this in vitro study suggest that polishing direction influences the marginal adaptation of composite resins and that polishing from composite resin to tooth structure should be clinically performed whenever possible on accessible margins to preserve marginal integrity and esthetics.

The Timing of Subsequent Treatment for Teeth Restored with Large Amalgams and Crowns: Factors Related to the Need for Subsequent Treatment

Crowns and large amalgams protect structurally compromised teeth to various degrees in different situations. The aim of this investigation was to evaluate the survival of teeth with these two types of restorations and the factors associated with better outcomes. Retrospective administrative and chart data were used. Survival was defined and modeled as: (1) receipt of no treatment and (2) receipt of no catastrophic treatment over five- and 10-year periods. Analyses included: Kaplan-Meier survival curves, Log-Rank tests, and Cox proportional hazards regression modeling. Crowns survived longer with no treatment and with no catastrophic treatment; however, mandibular large amalgams were least likely to have survived with no treatment, and maxillary large amalgams were least likely to have survived with no catastrophic treatment. Having no adjacent teeth also decreased survival. Crowns survived longer than large amalgams, but factors such as arch type and the presence of adjacent teeth contributed to the survival of large amalgams.

Retrospective analysis of factors associated with the success of stepwise excavation procedure in deep carious lesions

BACKGROUND

Recent scientific evidence regarding the stepwise excavation procedure (SWP) has not addressed the consideration of patient factors when selecting SWP as treatment for deep carious lesions (DCLs). This study assessed patient factors predicting a successful SWP defined as a tooth restored with SWP and did not result in root canal treatment or a dental extraction.

METHODS

SWPs completed in 626 patients without symptomatic irreversible pulpitis at the University of Iowa College of Dentistry from January 2004 through December 2012 were evaluated. Patient demographic and tooth-specific characteristics were assessed in their relationship with the main outcome.

RESULTS

SWPs had a 75% success rate when evaluated within 36 months of the initial treatment. Findings showed that patients who had successful SWP treatment of DCLs were somewhat younger than patients whose SWP treatment was not successful (mean age, 37.4 years and 40.5 years, respectively; odds ratio, 0.981; 95% confidence interval, 0.967 to 0.994; P = .0058). Patients who returned to their second appointment within 5 to 9 months were more likely to have a successful SWP treatment than those returning sooner than 5 months (odds ratio, 0.338; 95% confidence interval, 0.210 to 0.545; p < .0001).

CONCLUSION

Treatment of deep carious lesions with SWP is effective for pulp preservation and patient age may influence the outcome.

PRACTICAL IMPLICATIONS

Although a somewhat younger mean patient age was associated with successful treatment of DCLs, SWP can be successful regardless of patient age and clinicians should consider SWP in treating DCLs.

Survival analysis of caries incidence in African-American school-aged children

OBJECTIVES

To conduct an assessment of time-dependent covariates related to dental caries of the permanent dentition among a low socioeconomic status, understudied cohort of children, incorporating time-dependent covariates through the application of extended Cox proportional hazards modeling.

METHODS

This study modeled the time to first cavitated dental caries in permanent teeth among school-aged children and assessed factors associated with this event. A cohort of 98 low socioeconomic status African-American children with mean age of 5.85 years at baseline was recruited in Uniontown, Alabama and followed prospectively for 6 years. None of these children had dental caries on permanent teeth at baseline, and oral examinations were performed annually. Caries-free survival curves were generated to describe time to event (having first decayed, filled, or missing permanent surface). Bivariate and multivariable extended Cox hazards modeling was used to assess the relationships between time-dependent and time-independent covariates and time to event.

RESULTS

Twenty-eight children (28.6 percent) had their first permanent tooth caries event during the 6-year follow-up. Multivariable results showed that greater consumption of water was associated with lower dental caries hazard, while previous primary tooth caries experience was associated with greater dental caries hazard after adjustment for frequency of consumptions of milk, added-sugar beverages, and 100 percent juice.

CONCLUSIONS

There was a global/overall significant caries protective effect of water consumption during the school-age period of child development.

Prevalence of non-cavitated lesions and progression, regression, and no change from age 9 to 23 years

OBJECTIVES

Some non-cavitated caries lesions (D₁ ), the initial stage of caries, progress to cavitation. This article reports participant-level and surface-level D₁ prevalence and changes in status of D₁ lesions through different periods from age 9 to 23.

METHODS

The Iowa Fluoride Study (IFS) participants were followed longitudinally; all permanent tooth surfaces were examined clinically for caries at ages 9, 13, 17, and 23 using standardized criteria for sound (S), questionable (D₀ ), non-cavitated (D₁ ), cavitated (D₂₊ ), filled (F), or missing due to decay (M). D₁ lesions at the beginning of each interval were reassessed at each follow-up age to determine transitions (to the 5 categories or no transition).

RESULTS

The sample had relatively high socioeconomic status (SES), with about 52%-55% high SES, 32-35% middle SES, and 12-13% low SES. Person-level prevalences of D₁ lesions were 23%, 38%, 60%, and 45% at ages 9, 13, 17, and 23, respectively. Surface-level prevalences were less than 1% at ages 9 and 13, 3% at 17, and 2% at 23. Thirteen percent of D₁ s at age 9 progressed at 13, 18% progressed from 13 to 17, and 11% progressed from 17 to 23. The percentages regressing (to sound or D₀ ) were 72%, 54%, and 72%, respectively.

CONCLUSION

Non-cavitated lesions were more prevalent at age 17 than at ages 9, 13, and 23. The high rates of regression compared to progression or no change suggest that many non-cavitated lesions do not progress to cavitated lesions and could be reversed; therefore, surgical intervention should not be the treatment of choice for incipient lesions.

Masking and Penetration Ability of Various Sealants and ICON in Artificial Initial Caries Lesions In Vitro

PURPOSE

The purpose of the present in vitro study and survey was to compare the masking ability and the penetration capacity of three resin composite sealers as well as a resin infiltrant in shallow artificial caries lesions.

MATERIALS AND METHODS

Panels of artificial initial caries lesion with an average depth of 200 µm were created on buccal and lingual surfaces of 75 extracted human molars. Specimens were randomly assigned to 5 groups: ICON (DMG America), Biscover LV (Bisco), Optiguard (Kerr Hawe), Permaseal (Ultradent), and control (no treatment). Teeth were hemi-sectioned yielding two halves, each with a panel of artificial caries lesion. Lesions on one hemi-section were used to assess the esthetic improvement following caries lesion penetration with the 4 resins based on photographs evaluated using a 100-mm visual analogue scale (VAS) by 17 raters. Lesions on opposite hemi-sections were used to measure the resin penetration area percentage (PA%) and the resin penetration depth percentage (PD%) visualized using a confocal laser scanning microscope (CLSM, Leica).

RESULTS

ICON, Optiguard, and Permaseal yielded significantly greater average VAS scores compared to Biscover. The mean PA% and PD% were significantly higher for ICON, intermediate for Optibond and Permaseal, and significantly lower for Biscover. A moderately large positive correlation was noticed between the average VAS scores and the penetration measures.

CONCLUSION

All the resin sealers (Biscover, Optiguard, and Permaseal) penetrated the artificial initial caries lesions. However, ICON resulted in the deepest penetration and the largest penetration area percentages. The masking ability of Optiguard and Permaseal of the artificial caries lesions was similar to ICON.

Repair versus replacement of defective direct restorations: A cross-sectional study among US dentists

BACKGROUND

Repair increases the longevity of restorations and is well-accepted by patients. In this study, the authors assessed the acceptance of dental restoration repair by dentists and determined the main variables of repair versus replacement of defective restorations.

METHODS

A 15-item questionnaire was developed and distributed electronically to the American Dental Association Clinical Evaluators panel members (n = 785) during a 2-week period in 2019. Descriptive, bivariate, and multivariable analyses were conducted.

RESULTS

Of the 387 respondents, 83.7% stated that they repair defective restorations, and 16% stated that they always replace them. Reasons to forego a restoration repair among dentists who perform repairs included defect size and carious lesion extension (42%) and negative personal experience or lack of success (37.9%). However, the latter was considerably higher for dentists who do not perform repairs (60.7%). The most commonly cited patient-related reason and tooth condition to repair restorations were limited patient finances (67%) and noncarious marginal defects (86%), respectively. Neither sex nor age group was significantly associated with the practice of restoration repair (P = .925 and P = .369, respectively). However, sole proprietors were more likely to perform repairs than those in an employee, associate, or contractor practice setting (P = .008). The most significant reason to forego restoration was negative experience or lack of success (P = .002).

CONCLUSIONS

Restoration repair is considered a treatment option for managing defective restorations. Negative personal experience or lack of success and practice setting influenced the dentists' decision to repair or replace a defective restoration.

PRACTICAL IMPLICATIONS

Understanding dentists' clinical challenges and practice environment is necessary when advocating for this approach.