Ten year survival of bridges placed in the General Dental Services in England And Wales

Comparing two intraoral porcelain repair systems for shear bond strength in repaired cohesive and adhesive fractures, for porcelain-fused-to-metal restorations: An in vitro study

Aim

The objective of research was to evaluate the shear bond strength of two commercially available intraoral porcelain repair systems, Clearfil repair system (Kuraray) and P and R repair system (Shofu) for repairing cohesive and adhesive fracture in metal-ceramic restorations.

Settings and Design

In vivo - comparative study.

Materials and Methods

Ninety samples of Nickel-Chromium metal discs were fabricated. Each disc was veneered with 2 mm thickness of ceramic material using custom made metal jig. Samples were divided into control (Group I n = 10) and two test groups (Group II n = 40 and Group III n = 40). Adhesive and cohesive fractures were created in test group samples, Group II (Ceramic substrate or cohesive defect) and Group III (metal substrate or adhesive defect). The samples of ceramic substrate (Group II) and metal substrate (Group III) were further subdivided into A and B containing 20 samples each according to the repair material used (A; Clearfil porcelain repair system and B; P and R porcelain repair system). All specimens were subjected to a standard shear load in the UTM until fracture occurred. Data were analyzed using one-way analysis of variance and post hoc Bonferroni test.

Statistical Analysis used

One-way analysis of variance (ANOVA) and post hoc Bonferroni test.

Results

Clearfil repair system showed significantly higher shear bond strength value (29.16 Mpa) as compared to P and R repair system (27.23 Mpa) for cohesive fractures. Whereas if compared for repairing adhesive fractures P and R repair system had significantly higher shear bond strength values (26.59 Mpa) than Clearfil repair system (25.74 Mpa).

Conclusions

From the present study, it was be concluded that for cohesive fracture Clearfil repair system is a better material and for adhesive fractures P and R repair material gives better results.

Ending the neglect of global oral health: time for radical action

Oral diseases are a major global public health problem affecting over 3·5 billion people. However, dentistry has so far been unable to tackle this problem. A fundamentally different approach is now needed. In this second of two papers in a Series on oral health, we present a critique of dentistry, highlighting its key limitations and the urgent need for system reform. In high-income countries, the current treatment-dominated, increasingly high-technology, interventionist, and specialised approach is not tackling the underlying causes of disease and is not addressing inequalities in oral health. In low-income and middle-income countries (LMICs), the limitations of so-called westernised dentistry are at their most acute; dentistry is often unavailable, unaffordable, and inappropriate for the majority of these populations, but particularly the rural poor. Rather than being isolated and separated from the mainstream health-care system, dentistry needs to be more integrated, in particular with primary care services. The global drive for universal health coverage provides an ideal opportunity for this integration. Dental care systems should focus more on promoting and maintaining oral health and achieving greater oral health equity. Sugar, alcohol, and tobacco consumption, and their underlying social and commercial determinants, are common risk factors shared with a range of other non-communicable diseases (NCDs). Coherent and comprehensive regulation and legislation are needed to tackle these shared risk factors. In this Series paper, we focus on the need to reduce sugar consumption and describe how this can be achieved through the adoption of a range of upstream policies designed to combat the corporate strategies used by the global sugar industry to promote sugar consumption and profits. At present, the sugar industry is influencing dental research, oral health policy, and professional organisations through its well developed corporate strategies. The development of clearer and more transparent conflict of interest policies and procedures to limit and clarify the influence of the sugar industry on research, policy, and practice is needed. Combating the commercial determinants of oral diseases and other NCDs should be a major policy priority.

Tooth loss after periodontal treatment-Mining an insurance database

OBJECTIVES

The aim of this study was to evaluate tooth loss after periodontal treatment.

METHODS

The data was collected from the digital database of a major German national health insurance company. Periodontal treatment was the intervention in the treatment group. Kaplan-Meier survival analyses on the patient level with the primary outcome extraction were carried out over four years. A control group without treatment was matched and analysed. Differences were tested with the Log-Rank-test. Extraction incidences were calculated over a matched observation period six years before and four years after treatment for both treatment and control group.

RESULTS

A total of 415,718 periodontal treatments could be traced. Focussing on the outcome "extraction", the cumulative four-year survival rate was 63.8% after periodontal treatment. The matched control group without periodontal treatment showed a survival rate of 72.5%. These differences were significant (p < 0.0001). The extraction incidence over time was higher in a four-year period after periodontal treatment compared to a six-year period before periodontal treatment.

CONCLUSIONS

The outcome of periodontal treatment was acceptable. In about two thirds of the patients, extractions could be completely avoided within a four year period after treatment.

CLINICAL SIGNIFICANCE STATEMENT

This study within the German national health insurance system shows that extractions were not observed after periodontal treatment in the majority of cases. Although periodontitis is a chronic disease, patients suffering from periodontitis have a considerable chance to prevent further tooth loss.

A practice based longevity study on single-unit crowns

OBJECTIVES

This retrospective longitudinal study aimed to assess the longevity of single unit crowns placed by several dentists and to investigate risk factors associated with crown failures.

METHODS

From patient files, longevity of 3404 full crown restorations placed in 1557 patients by 8 Dutch dentists between 1996 and 2011 were analyzed. Annual failure rates (AFRs) were calculated and variables associated with failure (success and survival of crowns) were assessed by multivariate Cox-regressions analysis with shared frailty for patients.

RESULTS

Most of crowns were PFM (63.8%) placed in molars (58.1%) and non endodontically treated teeth (65.4%). The observation time of restorations varied from 3 weeks to 11 years with a mean of 7 years, resulting in a mean AFR at 11 years of 2.1% and 0.7% for success and survival of crowns, respectively. Among dentists a relevant variation for type of interventions was observed with AFR varying between 1.2% and 3.5%. The most significant risk factor for failure of crowns was the presence of an endodontic treatment, resulting in Hazard ratios of 1.31 for success [95%CI 1.07-1.61] and 1.89 [95%CI 1.35-2.65] for survival of crowns. Tooth type, tooth position (jaw) and gender showed also a significant influence on success of crowns. For survival, increase in patients' age results in a higher risk for failure.

CONCLUSIONS

Overall, crowns placed by a selected group of dentist showed a good to acceptable success and survival rates, mainly dependent from the practice. The presence of an endodontically treated tooth was a significant risk factor leading to more failures.

Four-year outcomes of restored posterior tooth surfaces-a massive data analysis

OBJECTIVES

There is only sparse knowledge concerning the outcomes of treatments with posterior permanent restorations in general practice settings. This study aimed at evaluating outcomes based on a large dataset by using a novel approach on a tooth surface basis.

MATERIALS AND METHODS

The study based on routine data from a major German national health insurance company. Respective treatment fee codes allowed for tracking the clinical courses on a tooth surface level. The study intervention was defined as the placement of a restoration on an interproximal or occlusal posterior tooth surface regardless of its actual extension and material on which no information was available. All surfaces restored between January 1st, 2010 and December 31st, 2013 were included. Kaplan-Meier survival analyses were conducted to estimate four-year survival. The primary outcome was a restorative re-intervention on the same tooth surface. Separate analyses were performed for the secondary outcomes "crowning" and "extraction".

RESULTS

Over ten million interproximal surfaces and eight million occlusal surfaces in nine million posterior teeth had been restored. At 4 years, the cumulative survival rates concerning the primary outcome "re-intervention" for mesial surfaces (81.4%; CI 81.3-81.5%) and distal surfaces (81.2%; CI 81.1-81.2%) differed significantly from those for occlusal surfaces (77.0%; CI 76.9-77.0%). Restored surfaces in premolars showed significantly higher survival rates compared to molars. Four-year survival rates for the secondary outcome "crowning" were 91.9% (CI 91.8-91.9%) for mesial surfaces, 92.1% (CI 92.1-92.2%) for distal surfaces and 93.3% (CI 93.2-93.3%) for occlusal surfaces. The respective rates for the secondary outcome "extraction" were 94.5% (CI 94.5-94.5%) for mesial surfaces, 94.8% (CI 94.7-94.8%) for distal surfaces and 95.4% (CI 95.4-95.5%) for occlusal surfaces.

CONCLUSIONS

Re-interventions after restorative treatment play a significant role in general practice settings. Surface-related survival rates of restorations reveal a need for improvement.

CLINICAL RELEVANCE

This study allows the estimation of the probability of re-interventions after restoring posterior tooth surfaces. It is based on several million cases from general practises under the terms and conditions of a national health insurance system.

Re-interventions after restoring teeth-Mining an insurance database

OBJECTIVES

The aim of this study was to examine re-interventions after restorative treatment.

METHODS

The data was collected from the digital database of a major German national health insurance company. Only permanent teeth were observed. Placing a permanent restoration other than a crown regardless of involved surfaces and material was the study intervention. The data did not allow for a differentiation between fillings and inlays that were estimated only a very small portion of the restorations. Success was defined as not undergoing any restorative re-intervention with fillings or inlays on the same tooth (primary outcome) and assessed with Kaplan-Meier survival analyses over four years. An additional analysis was conducted rating "crowning" and "extraction" of respective teeth as target events. Differences were tested with the Log-Rank-test. A multivariate Cox regression analyses was carried out.

RESULTS

A total of 17,024,344 restorations placed in 4,825,408 anterior teeth and 9,973,177 posterior teeth could be traced. Focussing on the primary outcome re-intervention, the cumulative four-year success rate was 69.9% for one surface restorations, 74.8% for two surface restorations, 66.6% for three surface restorations and 61.0% for four surface and more extended restorations. These differences were significant (p<0.0001). Focussing on all three target events re-intervention, crowning and extraction, the cumulative four-year success rate was 66.1% for one surface restorations, 67.5% for two surface restorations, 63.0% for three surface restorations and 55.8% for four surface and more extended restorations. The number of restoration surfaces as well as the tooth position remained significant in the multivariate Cox regression.

CONCLUSIONS

The sustainability of restorative dental treatment under the terms and conditions of the German national health insurance system shows room for improvement. From a public health perspective, special focus should be laid on primary and secondary prevention to minimize the restorative treatment need.

CLINICAL SIGNIFICANCE STATEMENT

This study shows that re-interventions are observed regularly after restorative treatment. Therefore, preventive and restorative strategies should be revisited and optimised.

An in vitro evaluation of resonant frequency analysis to measure fixed bridge stability

Objectives/Aims:

To determine whether a clinically available resonance frequency analysis (RFA) device (Osstell Mentor), designed to assess implant integration, could identify a single uncemented retainer on fixed–fixed bridges, in vitro.

Materials and Methods:

All-metal fixed–fixed bridges were cemented to acrylic tooth analogue abutments with simulated periodontal ligaments. Dental stone bases provided 100 or 50% ‘bone support’ groups (n = 50 in each). Control groups had both retainers cemented, whereas the test groups had the ‘premolar’ uncemented, mimicking clinical failure. A RFA device was used to measure bridge stability, expressed as a modified Implant Stability Quotient (Bridge Stability Quotient—BSQ) from a Smartpeg temporarily affixed to the bridge via composite.

Results:

The BSQ recorded at the premolar site in both 100 and 50% support models demonstrated highly statistically significant differences (P <0.003) between the control and test groups. Sensitivity and specificity, area under the curve (receiver operating characteristic), analyses showed moderate test accuracy (0.735) for the 100% support group and good accuracy (0.96) for the 50% support group.

Conclusion:

The investigation suggests that RFA measurements were able to identify, reliably and non-destructively, in vitro, fixed–fixed bridges where the anterior retainer was uncemented. Further clinical research is required to determine whether this technique may allow early diagnosis of failing bridgework.

Time until first dental caries for young children first seen in Federally Qualified Health Centers: a retrospective cohort study

OBJECTIVES

The study assessed the time until first dental caries for young children seen at five Federally Qualified Health Centers (FQHC) in Iowa and the relationship with the frequency and gaps (in months) of dental episodes, the number of topical fluoride treatments, and the number of dentists caring for the subject.

METHODS

Forty children were randomly selected at each FQHC (n = 200). All children were continuously enrolled in the Medicaid program and had their first dental visit prior to age 6. Dental chart findings, claims data for the child and family, and birth certificate information were merged into one dataset. Dental visits were followed for a minimum of 36 months, including dental visits external to the FQHCs. Using time until first caries as the dependent variable, the data were subject to left, interval, and right censoring and were analyzed via Weibull regression.

RESULTS

Slightly more than half of the 200 children experienced caries. Regression analysis indicated that the hazard of first dental caries increased by approximately 2% with each additional month that transpired between preventive recall examinations. In addition, children with older siblings who had a dental visit at the same center during the previous year prior to the subject's first visit were more likely to have a longer time until first dental caries.

CONCLUSIONS

Timing of dental care episodes was associated with caries experience in young children from low income families. Dental professionals should focus on regularity of dental care to prevent or delay caries experience in young children.