Current Strategies to Control Recurrent and Residual Caries with Resin Composite Restorations: Operator- and Material-Related Factors.

This review addresses the rationale of recurrent and/or residual caries associated with resin composite restorations alongside current strategies and evidence-based recommendations to arrest residual caries and restrain recurrent caries. The PubMed and MEDLINE databases were searched for composite-associated recurrent/residual caries focusing on predisposing factors related to materials and operator's skills; patient-related factors were out of scope. Recurrent caries and fractures are the main reasons for the failure of resin composites.

Verification of lateral flow antigen tests for SARS-CoV-2 by qPCR directly from the test device.

Objective: Fast and reliable detection of infection is a key to control the SARS-CoV-2 pandemic. Lateral flow antigen tests (LFATs) are inexpensive, easy to use, but have to be verified, as they are rather unspecific and can produce both, false positive and false negative results. Our objective was to combine the speed of LFAT for SARS-CoV-2 with the reliability of qPCR tests.

Direct and indirect eluates from bulk fill resin-based-composites.

Objectives: To compare elutable substances directly released from bulk-fill (BF) resin-based composites (RBCs) with indirect elution from teeth restored with a BF composite. In addition to (co)monomers, the analytical focus was on other potentially toxic ingredients or impurities. Furthermore, the barrier function of the residual dentin/adhesive layer was studied.

Special Teaching Formats during the COVID-19 Pandemic-A Survey with Implications for a Crisis-Proof Education.

Modern teaching formats have not been considered necessary during the COVID-19 pandemic with uncertain acceptance by students. The study's aim was to describe and evaluate all measures undertaken for theoretical and practical knowledge/skill transfer, which included objective structured practical examinations (OSPEs) covering a communication skills training. The students' performance in the OSPE as well as the theoretical knowledge level were assessed, of which the latter was compared with previous terms.

SARS-CoV-2 and regular patient treatment - from the use of rapid antigen testing up to treatment specific precaution measures.

Introduction: The COVID-19 pandemic poses a continued challenge for all parties involved especially for the dentist as routine operation must be resumed. Rapid Antigen Tests (RATs) are actually recommended to identify and minimize infectious risks. However, there is still no guideline on the implementation of RATs in a dental or medical setting.

Direct and indirect monomer elution from an RBC product family.

Objective: To develop a model for quantitative comparison of elutable substances by direct elution from resin-bonded composite (RBC) test specimens versus indirect elutability of substances from RBC-restored teeth. Furthermore, it was to be investigated whether the different composites of the Tetric® RBC product family release different types and amounts of substances.

Methods: Four different composite materials from the Tetric® product family were studied.

Bone augmentation by replica-based bone formation.

Objective: The sources of iliac crest bone grafts are limited. Alternatives are evaluated due to the progress in biomaterial sciences. Synthetical hydroxyapatite (HA), ß-tricalcium phosphate (ß-TCP) or biphasic compounds, or even a mélange of HA and ß-TCP will replace bovine ceramics.

An alternate methodology for studying diffusion and elution kinetics of dimethacrylate monomers through dentinal tubules.

Objective: Ethoxylated bisphenol A dimethacrylate (bisEMA) is a base monomer in several dental resin composites. It was the main aim of the present study to determine if bisEMA can reach the dental pulp by generally passive diffusion through the coronal dentinal tubules stimulated via eluent liquids surrounding the root structures only.

Methods: In 20 human third molar teeth, standard Class-I occlusal cavities were prepared and provided either with an adhesive system alone or additionally with a composite restoration, according to the instructions of the manufacturer.

Effectiveness of dentifrices with new formulations for the treatment of dentin hypersensitivity - A meta-analysis.

Purpose: This meta-analysis was conducted to evaluate if strontium-acetate- and arginine-containing dentifrices can significantly reduce dentin hypersensitivity (DH).

Methods: A systematic literature search was performed. The investigation period was from 2006 to 2015 with the search term "dentin hypersensitivity".

[Primary cancellous bone formation around micro-chambered beads].

Objectives: The question has been raised whether benign bone defects in patients can be treated with bone forming osteoconductive ceramics achieving primarily a cancellous bone scaffold, which is under load from the beginning.

Material And Methods: Ten reconstructions were performed in 9patients (6women and 3male), with a mean age of 49 (25-65)years, suffering a high variety of epi- and metaphyseal defects, four tibial fractures, two calcaneal fractures, one pathological phalangeal fracture, one chondroma of the distal femur and two open-wedge osteotomies were filled with micro-chambered ceramic beads of 4 and 6mm in diameter. The mean follow up was 22 (7- 8)months.

ε-Caprolactone in micro-chambered ceramic beads--a new carrier for gentamicin.

Purpose: The purpose of this preliminary and descriptive study was to evaluate a biodegradable drug delivery system in combination with an innovative ceramic implant.

Methods: The delivery of gentamicin of standardized samples was measured in the laboratory using ultra-high-performance liquid chromatography. Biocompatibility and biodegradation of the materials was investigated in an animal experiment in sheep up to 14 months.

The prevalence of tooth hypersensitivity following periodontal therapy with special reference to root scaling. A systematic review of the literature.

Purpose: To provide a current status of the art, answering the question whether a certain procedure of periodontal treatment is more reliable than another and where innovative developments could improve on the incidence of hypersensitivity by a systematic literature review.

Methods: Pubmed, Embase and Cochrane library were considered for the study. 2,656 articles of the PubMed search were found, from the beginning of 1945 until April 2011.

Swiss contributions to war surgery during the Great War.

Background: The role of neutral Switzerland during World War I is somewhat mysterious and its diplomatic history has never been fully disclosed. One of the activities might have determined its role: based on its relationship to the International Committee of the Red Cross, wounded multinational prisoners-of-war were interned in Swiss hospitals and Swiss physicians worked in a medical capacity in military hospitals on both sides of the front.

Questions/purposes: The main question is whether the activities of the Swiss authorities reflected a charitable diplomatic role while retaining the country's traditional neutral stance.

The bone-to-cement interface improvement by Ca-phosphate ceramics.

Background: Polymethylmethacrylate used in surgery is one of the first biomaterials. Conventional histology dissolves the resin; one of the reasons that only few complete histology is published. OBJECTIVES AND PURPOSE: The question is, whether a complete histology changes the understanding, influences the application and opens approaches for improvements.

Bulk-fill resin-based composites: an in vitro assessment of their mechanical performance.

The study aimed to assess the mechanical performance of seven bulk-fill RBCs (Venus Bulk Fill, Heraeus Kulzer; SureFil SDR flow, Dentsply Caulk; x-tra base and x-tra fil, VOCO; Filtek Bulk Fill, 3M ESPE; SonicFill, Kerr; Tetric EvoCeram Bulk Fill, Ivoclar Vivadent) by determining their flexural strength (σ), reliability (Weibull parameter, m), flexural modulus (Eflexural), indentation modulus (YHU), Vickers hardness (HV), and creep (Cr). The significant highest flexural strengths were measured for SonicFill, x-tra base, and x-tra fil, while x-tra base, SureFil SDR flow, and Venus Bulk Fill showed the best reliability. The differences among the materials became more evident in terms of Eflexural and YHU, with x-tra fil achieving the highest values, while Filtek Bulk Fill and Venus Bulk Fill achieved the lowest.

Osseointegration of hydroxyapatite and remodeling-resorption of tricalciumphosphate ceramics.

Background: Cancellous bone defects surrounded by still intact bone structures never heal. Ceramics offer a solution providing osteoconductive scaffolds.

Purpose: The purpose of the study is to evaluate whether structured β-TCP and HA implants can reconstruct cancellous bone defects, which role micro- and macro-porosity, stiffness and surface area play; finally the indication for both materials based on its resorbability.

Primary cancellous bone formation with BMP and micro-chambered beads: experimental study on sheep.

Problem: The physiological reconstruction of cancellous bone defects in surgery of the locomotor system is an unsatisfactorily solved problem.

Aims: The aims of this study are to examine whether micro-chambered ß-tricalcium-phosphate (ß-TCP) beads provide a certain capillary force suctioning in blood and bone marrow thus forming a stable "negative"-replica of the bone marrow spaces. If so, a new approach for osteoconduction would yield primarily a scaffold of lamellar cancellous bone under load without a long-lasting remodeling process.

Correlation of the degree of conversion with the amount of elutable substances in nano-hybrid dental composites.

Objectives: This study's purpose was to measure and compare the degree of conversion (DC) and the amount of elutable substances from modern resin-based composites (RBCs) as function of polymerization time. One nano-hybrid RBC based on tricyclodecane-(TCD)-urethane (Venus(®) Diamond) and two conventionally formulated RBCs (TetricEvo Ceram(®), Filtek™ Supreme XTE) were considered.

Method: DC (n=5) was investigated in real time for 5min by Fourier transform infrared spectroscopy (ATR-FTIR) in a filling depth of 2mm at varied irradiation times (5, 10, 20, 40s).

Resin-based composite light-cured properties assessed by laboratory standards and simulated clinical conditions.

SUMMARY The following parameters were varied: 1) irradiation technique: top and bottom polymerization according to the ISO standard, and polymerization from only the top, simulating clinical situations; 2) polymerization time: 5, 10, 20, and 40 seconds; 3) storage conditions: 24 hours in distilled water, thermocycling followed by storage for four weeks in artificial saliva or alcohol. Flexural strength (FS), flexural modulus (Eflexural), indentation modulus (E), Vickers hardness (HV), and degree of conversion (DC) were measured. The laboratory results were similar to those measured by mimicking clinical conditions only at high polymerization times and mild storage conditions (20 seconds and 40 seconds and storage for 24 hours in water, and 40 seconds with aging and storing in saliva).

Value and limits of μ-CT for nondemineralized bone tissue processing.

An experimental approach was performed on 20 giant rabbits to establish the possibilities and limitations of μ-CT for routine processing of nondemineralized bone tissue. Hydroxyapatite (HA) or β-tricalciumphosphate (β-TCP) bead implants or a melange of both, microchambered and solid, were implanted into a standardized and precise defect in the patellar groove. The bone-healing phase was chosen for the histology considering 1 or 2 days, and 2, 3, and 6 weeks.

How bone forms in large cancellous defects: critical analysis based on experimental work and literature.

The behaviour of physiological biomaterials, β-tricalciumphosphate and hydroxyapatite, is analysed based on current literature and our own experimental work. The properties of graft substitutes based on ceramic materials are clearly defined according to their scientific efficiency. The strength of the materials and their biodegradability are still not fully evaluated.

High-density polyethylene facial implants show surface oxidation in SEM and EDX examination: a pilot study.

Previous histopathological studies on explanted Medpor high-density polyethylene (HDPE) facial implants indicated signs of material destruction and claimed to observe phagocytized HDPE particles within the tissue samples beside the usual type IV reaction with severe fibrosis. We examined new and explanted Medpor material with scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The implant surface of three patient-derived specimens showed significantly higher oxygenation in EDX analysis and morphological changes in SEM compared to the new unused material directly after opening of the package and after 1 year of exposure to air.

Safety and efficiency of novel sonic scaler tips in vitro.

Background: The aim of the study was to evaluate a novel sonic scaler tip for subgingival root surface instrumentation combining high efficiency in calculus removal with minimized risk of root damage through subgingival debridement.

Methods: A metal sonic scaler tip with a paddle-like working end covered with spheroid convexities of 0.8 mm diameter and 0.

Assessment of root curvature and distance using computed tomography.

The safety and efficacy of subgingival root surface instrumentation may be enhanced by optimized adaptation between instrument and treated surface. Thus, detailed knowledge of root geometry may allow advances in instrument design. The aim of this study was therefore to measure root radii of various tooth types as well as distances between tooth roots using computed tomography.