Amalgam phase down: baseline data preceding implementation in Nigeria

Immediate and delayed micro shear bond strength evaluation of two glass ionomer cements to composite resin by using different bonding techniques-an in vitro study

OBJECTIVE

Evaluating immediate and delayed micro shear bond strength (µSBS) between composite resin and glass ionomer cements using different adhesive systems and mechanical surface treatment.

MATERIALS AND METHODS

A total of 240 specimens of glass ionomer restorative materials were divided into two groups: Resin Modified Glass Ionomer Cement (RMGIC) namely Riva Light Cure and Conventional Glass Ionomer Cement (CGIC) namely Riva Self Cure. These were subdivided into immediate (24 h) and delayed (3 months) storage and further divided into smooth, medium, and rough surface treatment with either total etch (TE) or self-etch (SE) adhesive strategies. Composite resin was applied and µSBS of the sample was determined and failure modes were examined.

RESULTS

Immediate µSBS of RMGIC was superior than CGIC and TE was better than SE. Within RMGIC, smooth surface has significantly higher bond strength than medium and rough stone surface treatment. Delayed µSBS of RMGIC was superior than CGIC. Within RMGIC specimens, TE and smooth and medium grit had significantly better bond strength than SE and rough grit. Within CGIC, statistically higher bond strength values were found with medium grit compared to smooth while no difference was found between TE and SE.

CONCLUSION

Bonding composite resin to smooth RMGIC using TE yielded higher bond strength values than CGIC regardless of the time. Bonding composite resin immediately to CGIC is best done using a TE technique. However, delayed bonding to CGIC requires roughening of the CGIC surface prior to placement of the composite resin to obtain improved bonding.

Community social responsibility of continued and appropriate use of silver amalgam as dental restorative material in southern India: A cross-sectional study

Background

For more than 150 years, dental amalgam (DA) has been popular as a dental restorative material. Many organizations oppose its use due to perceived toxicity and environmental concerns. Hence, this study aimed to explore the continued use of DA from a South Indian dental practitioners' perspective.

Methods

This cross-sectional study was conducted among fifty-two private and public dental practitioners of Udupi district in Southern India. A self‑administered questionnaire was distributed, that involved assessment of their preferences, continuation of use and concerns of using DA as a restorative material. The percentage contribution of each variable was calculated. Preferences for continuation of use of silver amalgam based upon the age, experience and mercury toxicity as a risk factor were analyzed using Students-t test and Fisher's Exact Test test.

Results

Most dentists were satisfied (87%) with the results of the DA, found minimal failures (96%) and found DA more economical (89%). More than half (54%) of the participants reported that they would not continue the use of DA owing to mercury toxicity and environmental concerns. Dentists with higher age and longer clinical experience preferred continuation of DA.

Conclusions

Despite satisfaction with DA for its minimal failure, longevity and affordability, the authors found that most practitioners did not prefer its continued usage. This highlights their concerns over mercury toxicity and soft tissue lesions and accentuates their community social responsibility. There is also an urgent need to educate dentists on mercury hygiene, mercury waste management and disposal.

Epidemiology of pediatric schistosomiasis in hard-to-reach areas and populations: A scoping review protocol

Background: Schistosomiasis is a neglected tropical disease (NTD) that affects millions of people. Children are the most vulnerable group to developing overt disease. An estimated 779 million people are at risk of schistosomiasis and 50 million preschool-age children (PSAC) need treatment. PSAC are not currently targeted by national chemotherapy campaigns due to a lack of suitable pediatric formulations of praziquantel. The Pediatric Praziquantel Consortium has developed an orally dispersible praziquantel formulation (arpraziquantel) and is facilitating its adoption for schistosomiasis control by endemic countries through the ADOPT program - an implementation research program that paves the way for the large-scale delivery of the child-friendly formulation to treat schistosomiasis in preschool-aged children in endemic countries. A key challenge for comprehensive NTD control including schistosomiasis is reaching all at-risk populations, including those hard to reach. Main access barriers include geographic, social and economic conditions. Objective : This scoping literature review aims to document the epidemiology of schistosomiasis in children under 6 years of age living in hard-to-reach areas and populations. Methods : This review will adopt the five-stage scoping review process of identifying the research question, identifying relevant studies, study selection, charting data and collating, summarizing and reporting results. Electronic databases including Medline, Web of Science, Embase (Ovid), LILACS and African Journals OnLine (AJOL) will be searched for relevant articles. Two independent reviewers will screen identified articles using a two-stage approach of reviewing the title/abstract and then the full text of provisionally retained articles. Relevant literatures will be downloaded into EndNote X9 to maintain and manage citation and facilitate the overall review process. A meta-analysis will be conducted if indicated. Relevance : The results will provide insights into the burden of schistosomiasis among marginalized PSAC, aiming to produce evidence on the need for inclusion of this population when designing the expansion of preventive chemotherapy programs.

Preparation of Silica Aerogel/Resin Composites and Their Application in Dental Restorative Materials

As the most advanced aerogel material, silica aerogel has had transformative industrial impacts. However, the use of silica aerogel is currently limited to the field of thermal insulation materials, so it is urgent to expand its application into other fields. In this work, silica aerogel/resin composites were successfully prepared by combining silica aerogel with a resin matrix for dental restoration. The applications of this material in the field of dental restoration, as well as its performance, are discussed in depth. It was demonstrated that, when the ratio of the resin matrix Bis-GMA to TEGDMA was 1:1, and the content of silica aerogel with 50 μm particle size was 12.5%, the composite achieved excellent mechanical properties. The flexural strength of the silica aerogel/resin composite reached 62.9546 MPa, which was more than five times that of the pure resin. Due to the presence of the silica aerogel, the composite also demonstrated outstanding antibacterial capabilities, meeting the demand for antimicrobial properties in dental materials. This work successfully investigated the prospect of using commercially available silica aerogels in dental restorative materials; we provide an easy method for using silica aerogels as dental restorative materials, as well as a reference for their application in the field of biomedical materials.

Evaluation of Shear Bond Strength between Resin Composites and Conventional Glass Ionomer Cement in Class II Restorative Technique-An In Vitro Study

The success of dental restorations depends mainly on the ability to bond to other filling materials and tooth substances, in order to resist the multitude of forces acting on the bond within the oral cavity. Although the shortcomings of composite resins have been significantly reduced over the past three decades, microleakage due to shrinkage under masticatory loads is unavoidable. In order to overcome such problems, two materials laminated with matched properties can be used to achieve optimum results. The sandwich technique is an approach in which dentine is replaced by glass ionomer cement (GIC), and enamel is replaced by composite resin. In the past, numerous materials have been proposed with adequate properties to be used in this manner, but the results are conflicting in terms of bonding to the various forms of GIC, and the appearance of microcracks or gap formation during functional loading. This study aimed to evaluate the shear bond strength (SBS) and mode of failure between the following core materials: composite resins (CR) (Methacrylate Z350™, Ceram X™, and Spectrum™) with a base material of glass ionomer cement (GIC, Ketac Molar™). Eight samples were made with the help of polytetrafluoroethylene sheets (TEFLON, Wilmington, DE, USA). Each sheet consisted of holes which were 4 mm in diameter and 2 mm in thickness. The combination of materials was sandwiched. The samples were stored in distilled water and then placed in an incubator for 24 h in order to ensure complete polymerization. The samples were thermocycled for 500 cycles between 5–55 °C/ 30 s. Following thermocycling, SBS testing was performed using a universal testing machine. Additionally, scanning electron microscopy (SEM) was performed on representative samples for the bond failure analysis between GIC and the composite resins. The Ceram-X™ nanocomposite showed significantly higher bond strength than Methacrylate Z350™ or Spectrum™ (p = 0.002). The Methacrylate Z350™ and the Spectrum™ composite specimens demonstrated a similar SBS (p = 0.281). The SBS of the Ceram X™ to GIC was the highest compared to Methacrylate Z350™ and Spectrum™. Therefore Ceram X™ may produce a better bond with GIC, and may protect teeth against recurrent caries and failure of the restoration. Methacrylate Z350™ is comparable to Spectrum™ CR and can be used as an alternative. A combination of adhesive and mixed failure was observed in Methacrylate Z350™ CR and GIC, while adhesive failure was predominantly found in both Ceram X™ and Spectrum™ with GIC restorations.

Mercury hygiene and biomedical waste management practices among dental health-care personnel in public hospitals in Lagos State, Nigeria

BACKGROUND

Indiscriminate disposal of hospital wastes including mercury/amalgam wastes pose a serious threat to life and environment. There is a growing concern about biomedical waste (BMW) management among health care workers, however there are limited reports on BMW management by dental personnel in developing countries.

OBJECTIVES

This study investigated the level of knowledge of BMW, observance of proper mercury hygiene and BMW management practice among public dental personnel in Lagos State, Nigeria.

METHODS

A cross-sectional study regarding BMW management across public hospitals in Lagos State, Nigeria was conducted following institutional ethics committee approval. A self-administered questionnaire was utilized to obtain data from different facilities selected by purposive and simple random sampling techniques as applicable. The questionnaires were distributed among 437 respondents by convenience sampling. The resulting data were statistically tested using Chi-square and G-test with p-value < 0.05 indicating significant level.

RESULTS

Amongst 437 respondents, majority were females (62.5%) and the highest proportion fell within the age range of 25-34 years (44.4%). Only 17.2% of the respondents had good knowledge of BMW management/legislation and 4.1% had good BMW practice. Less than half (49.4%) of respondents disposed mercury-contaminated materials inside the trash and majority (92.2%) did not observe proper mercury hygiene. Significantly better mercury hygiene practices were observed in secondary facilities (p=0.040).

CONCLUSION

A minor proportion of public dental personnel had good knowledge and practice of proper mercury hygiene and BMW management. This shows there is an urgent need for training of health personnel on proper BMW handling and disposal in developing countries like Nigeria.

Dental Care for Asylum-Seekers in Germany: A Retrospective Hospital-Based Study

Background: The growing immigration to Germany led to more patients whose medical needs are divergent from those of the domestic population. In the field of dental health care there is a debate about how well the German health system is able to meet the resulting challenges. Data on asylum-seekers' dental health is scarce. This work is intended to reduce this data gap. Methods: We conducted this retrospective observational study in Halle (Saale), Germany. We included all persons who were registered with the social welfare office (SWO) in 2015 and received dental treatments. From the medical records, we derived information such as complaints, diagnoses, and treatments. Results: Out of 4107 asylum-seekers, the SWO received a bill for 568 people. On average, there were 1.44 treatment cases (95%-CI: 1.34-1.55) and 2.53 contacts with the dentist per patient (95%-CI: 2.33-2.74). Among those, the majority went to the dentist because of localized (43.2%, 95%-CI: 38.7-47.7) and non-localized pain (32.0%, 95%-CI: 27.8-36.2). The most widespread diagnosis was caries (n = 469, 98.7%, 95%-CI: 97.7-99.7). Conclusion: The utilization of dental care is lower among asylum-seekers than among regularly insured patients. We assume that the low prevalence rates in our data indicate existing access barriers to the German health care system.