Physical and chemical mechanisms involved in adhesion of orthodontic bonding composites: in vitro evaluations.

BACKGROUND: Bond strength of orthodontic composite is strongly influenced by molecular and structural mechanisms. Aim of this in vitro study was to compare bond strength of light-cure orthodontic composites by measuring debonding forces and evaluating locations of bond failure. Investigations on chemical compositions clarified adhesive behaviors and abilities, exploring effects of ageing processes in this junction materials. METHODS: Twelve enamel discs, from human premolars, were randomly coupled to one orthodontic adhesive system (Transbond XT™ 3 M UNITEK, USA, Light-Cure Orthodontic Paste, LEONE, Italy and Bisco Ortho Bracket Paste LC, BISCO, Illinois) and underwent to Shear Bond Strength test. Metallic brackets were bonded to twenty-seven human premolar, with one of the adhesive systems, to quantify, at FE-SEM magnifications, after debonding, the residual material on enamel and bracket base surfaces. Raman Spectroscopy analysis was performed on eight discs of each composites to investigate on chemical compositions, before and after accelerated aging procedures in human saliva and sugary drink. RESULTS: Orthodontic adhesive systems showed similar strength of adhesion to enamel. The breakage of adhesive-adherent bond occurs in TXT at enamel-adhesive interface while in Bisco and Leone at adhesive-bracket interface. Accelerated in vitro aging demonstrated good physical-chemical stability for all composites, Bisco only, was weakly contaminated with respect to the other materials. CONCLUSION: A similar, clinically adequate and acceptable bond strength to enamel for debonding maneuvers was recorded in all orthodontic adhesive systems under examination. No significant chemical alterations are recorded, even in highly critical situations, not altering the initial mechanical properties of materials.

Antibacterial activity of first and latest generation bioceramic sealers on the elimination of enterococcus faecalis: An in vitro study.

The main concern of endodontics are bacteria: the microorganisms and the toxins they release determine tissue destruction and inflammatory changes that trigger the pulpal and periapical pathology. Enterococcus faecalis is a particularly hostile bacterium; it is strongly associated with refractory periapical pathology. In this study 3 materials were tested: Aureoseal (OGNA, Italy) (Aur) (first generation bioceramic sealer); Endo Seuqence BC sealer (Brasseler USA, Savannah, GA, USA) (EsBC) (latest generation bioceramic sealer); Endoidrox (OGNA, Italy) (Endx) (calcium hydroxide material). The antimicrobial activity of these materials against Enterococcus faecalis was evaluated using agar diffusion test (ADT). The results confirm the antibacterial activity of bioceramic sealers, which however do not show significant differences in the obtained values; it can therefore be concluded that there has been no increase in the antibacterial efficacy of the latest generation bioceramic sealers compared to those of the first generation.

Aesthetic correction of double tooth: simplified technique.

The aim of this study is to report aesthetic conservative treatment of double tooth anomaly. Case report: A 7.5-year-old patient presents an anomaly of the maxillary right upper central incisor with a bifid crown and an increased mesio-distal width and a central incisal notch, probably amenable to a gemination. Single tooth anesthesia and conservative enameloplasty procedure was performed, with universal adhesive and a single shade universal composite restorative material. Adhesive aesthetic restorations allow to resolve dental anomalies quickly, cheaply and asily for pediatric dentistry.

Epidemiological study on radiographic dental health in Albania.

The aim of this epidemiological study is to assess the dental health status of the Albanian population and the most frequently performed dental treatments, also highlighting the differences between sex, geographic area and educational level. The study was performed by analyzing digital orthopanoramic radiographs of 739 Albanian patients, male and female, divided into 5 age groups. In addition, the patients were divided according to regions of origin in North, Centre and South and classified according to the level of education. The parameters examined are as follows: Missed Teeth (MT), Filled teeth (FT), Endodontically treated teeth (TT), Prosthetic restorations (PR). There are no statistically significant results regarding the distribution by area. Subjects with at least one missing tooth (MT) decreases with increasing education level. The percentage of individuals with Missed Teeth in the population increases with increasing age groups. Educational background affects health. This study highlights the need to introduce a national oral health system in Albania that would extend interventions to a wider segment of the population.

Effect of pressure and light curing of composite micro hardness.

The aim of this study is to evaluate the micro hardness Vickers of a composite micro hybrid polymerized under constant pressure. Twelve experimental samples were made equally divided into two groups: an experimental group and a control. Enamel plus HRi (Micerium) microbiotic composite resin, UD3 colour, was inserted into a syringe heater (ENA HEAT Composite Heating Conditioner) so that the material could be brought to a temperature of 39°C. A defined amount of composite resin is taken from the syringe with a Heidemann spatula and placed between two slides, previously cleaned with 90 ° alcohol. The samples are then inserted one at a time into a special device for constant pressure application. Vickers hardness measurements were made on the top of surfaces. The mean value of the samples belonging to the experimental group is 56.81 ± 0.71. The mean value of the control samples is 52.02 ± 2. The results obtained allow us to state that applying a constant pressure during the cementation phase of indirect adhesive restorations allows to obtain better mechanical characteristics of the composite used as a cementing agent.

Dentinal substrate variability and bonding effectiveness: SEM investigation.

Though the literature reports a well-documented scientific evidence of the performance of modern adhesive systems on normal dentin, few researches are available on the interaction between adhesives and compromised dentin. In this study, the authors analyzed the microscopic structural aspects of the adhesive interface on two common altered dentin substrates: dentin contaminated by metallic oxides and caries affected dentin. Thirty teeth were selected and divided in three groups of ten teeth according to the different dentin substrate they had: (A) normal dentin, (B) caries-affected dentin and (C) dentin contaminated by metallic oxides. The experimental cavity preparation was realised exposing in each sample, portion of pathologic dentin and portion of sound dentin as control. Each cavity was restored with micro-hybrid composite, with total etching and a two-step adhesive system. Each sample was sectioned in two halves analysed with two SEM micro-morphological methods: direct observation and decalcification. SEM investigations were able to show the difference in thickness and morphology of the adhesive interface with the two different dentin variables. Caries affected dentin determined the formation of less distinctive resin tags with few micro-tags. Discoloured dentin showed a poor infiltration with few resin tags probably due to alterations in the tubular structures. The micro-morphological variability of dentin substrate influences the clinical efficacy of bonding restorations determining significant differences in the qualitative and quantitative aspects of resin tags.

The effectiveness of endodontic sealers and endodontic medicaments on the elimination of enterococcus faecalis: an in vitro study.

The aim of this study was to investigate the efficacy of endodontic sealers and endodontic medicaments: Aureoseal (OGNA), MTA (DENTSPLY), calcium hydroxide (CH) (Endoidrox OGNA) and iodoformic paste (OGNA) against Enterococcus faecalis. Thirty-six Biomeraux plates (18 MH and 18 DCO) were inoculated with the experimental suspensions. The E. faecalis broth culture suspensions were prepared and adjusted to no. 0.5-0.7 McFarland standard. In each agar plate, three cavities were created, each measuring 4mm in depth and 7mm in diameter, and then completely filled with the product to be tested. To investigate the root canal sealers' antimicrobial activity, the agar diffusion method is used. The diameters of the zones of microbial inhibition were measured in millimeters around the plate. The results showed that the antimicrobial activity of Aureoseal was superior to those of MTA, iodoformic paste and calcium hydroxide for the microorganisms tested. The study confirmed the resistance of Enterococcus faecalis to endodontic sealers. Aureoseal and Calcium hydroxide showed the best results in inhibition test suggesting to employ them in clinical cases.

Clinical fitting of a cast metal post and core obtained by means of an intraoral optical scanning (IOS) and digital workflow.

Customization of post-and-cores using computer-aided-design and computer-aided-manufacturing (CAD-CAM) requires the scanning of a pattern and the subsequent digital design. This case report describes the production of a CAD-CAM customized post-and-core designed from an intraoral scan and milled from a metal block. The use of an intraoral scanner (IOS) for post-endodontic rehabilitation could lead to a faster and more efficient CAD-CAM customized post-and-core realization. The use of a high resistance material such as metal is paramount in cases with high loss of coronal structure. The patient has been treated with bisphosphonate (BP) for years. The risk of osteonecrosis of the jaw after extraction was high.

Comparative analysis of cleaning ability of two rotary instrument systems: Mtwo and ProTaper® universal. An in vitro scanning electron microscopic study.

This study is to compare the cleaning effectiveness of two Ni-Ti files systems. Thirty single-rooted human teeth were selected and two NiTi rotary systems were used. Group A: canal shaping with ProTaper® Universal (Dentsply Tulsa Dental Specialties, Tulsa, OK) (PTU); Group B: (n=15) canal shaping with Mtwo Ni-Ti instruments (Sweden and Martina, Padova, Italy) and apical finishing with Mtwo Apical Ni-Ti instruments (Sweden and Martina, Padova, Italy). The amount of debris and smear layer were quantified on a basis of a numerical evaluation scale. The data established for scoring the debris and the smear layer was recorded separately and statistically analysed using the Kruskal-Wallis test. No significant differences were found for debris. Mtwo instruments resulted in significantly less smear layer (P less than 0.05) compared with ProTaper® Universal. Under the conditions of this study, Mtwo resulted in significantly less smear layer compared with canal preparation with ProTaper® Universal.

An overview on periodontal changes and dental movements.

Only in recent times has been enhanced the importance of gingival crevicular fluid in periodontal health and in particular in maintaining the integrity of periodontium during application of orthodontic forces. The aim of this short review is to evaluate the importance of substances as valid biomarkers of periodontal health during orthodontic movements. A search on PubMed and Cochrane database was performed considering the literature from 2003 to 2014, using the following key words: gingival crevicular fluid, biomarkers of periodontal tissue, orthodontic movements. After abstracts screening, the full-texts of selected papers were analyzed and the papers found from the reference lists were also considered. The search focused on clinical applications documented in studies in the English language: levels of evidence included in the literature analysis were I, II and III. Literature analysis showed 28 papers that fulfilled the inclusion criteria. The conclusion is that GCF is a powerful vehicle for clinical diagnostics, since it contains different biochemical and cellular arrays in relation to different clinical situations indicative of the state of periodontal health during orthodontic treatment.

Chlorhexidine gel used as antiseptic in periodontal pockets.

The aim of this study was to evaluate the adjunctive benefit offers by the administration of a chlorhexidine based local drug deliver (Chlo-SITE) into periodontal socket after a full mouth disinfection session. The study design was a randomized, crossover, clinical trial conducted on 60 non-smokers subjects with chronic periodontitis. Each volunteer was subjected to a one-stage full mouth disinfection session and, immediately after that, test product (Chlo-SITE) was inserted in 1 pocket in 2 quadrant. The 1° and 4° quadrant were used for the study with the application of antiseptic (Test); the 2° and 3° as a control. Periodontal probe (PD), bleeding on probing (BOP) and plaque index (PI) was collected at baseline (T0), after 7 days (T1), after 4 weeks (T2). The results of this study suggest that the application of xanthan-based chlorhexidine gel (Xan-CHX) offers a great benefit in improving of the indices in chronic periodontitis.

Periodontal disease in subjects suffering from coronary heart disease.

The aim of present study is to evaluate the greater risk of periodontal disease in subjects affected by cardiovascular disease. The statistical study includes 200 patients equally divided into a test and a control group. The test group is made up of hospitalized patients from the cardiology division of the S. Salvatore hospital of L'Aquila and the second made up of subjects that frequented a dental clinic. All patients were subject to anamnesis and clinical evaluation for periodontal disease. The index used for this clinical examination were CPTIN index (Community Periodontal Index for Treatment Needs), pocket depth index (PPD), probing bleeding index (PBI), and plaque index (Silness, Loe). All data were collected and a comparative analysis was done of the results obtained from the two groups. Analysing the data concerning the average of lost and present teeth in the oral cavity and the damage of periodontal attachment we notice that cardiopathic subjects had a loss of periodontal attachment 2 times greater than in the control group and major condition of edentulism. A frequency test called the "chi-square test" showed that cardiopathic patients had a greater frequency of periodontal disease. The development of periodontal disease in subject suffering from coronary heart disease is faster and more aggressive than in healthy subjects. Therefore, the prevention of periodontal disease is simple and effective way to reduce the risk of cardiovascular disease.

Periodontitis and cerebrovascular disease: a new novel in medicine.

The aim of this review is to determine if there is a relationship between periodontal disease and stroke. The included case-control and cohort studies mediate the incidence of stroke and periodontal disease by analyzing different parameters. A literature review was carried out in PubMed, Scopus and Embase databases using the key word "stroke" AND "periodontal disease". An amount of 932 articles came out from our research on these three databases. These articles were selected according to PRISMA criteria. The following inclusion criteria were established: studies conducted in humans, articles published in English and published in the last ten years. Exclusion criteria were: experimental studies on animals, articles published more than 10 years ago, non-English language articles, articles of non-indexed journals, and articles not directly related to the association between stroke and periodontitis. These criteria reduced the number of articles from 932 to 399. At the end, articles that appeared to be repeated in different databases have been eliminated: 254 articles remained. All these articles titles were reviewed by the authors, who decided whether or not to include them in the review. We selected an amount of 43 articles. These studies were reviewed by reading the titles and abstracts, and by finally selecting the ones with the same topic of this review. When titles or abstracts were not clear, the complete article was read. At the end 7 articles were selected. In addition, 2 systematic reviews and 1 article, cited in the discussion, and regarding the protocol used in patients suffering from cardiovascular diseases and periodontitis, were selected. The quality of these articles was evaluated through the JADAD system. In conclusion, patients with stroke have a higher prevalence of periodontitis.

Comparison of coronal leakage of different root canal filling techniques: an ex vivo study.

The aim of this study was to compare the quality of the coronal seal, using an in vitro bacterial invasion test, of three different root canal filling systems. Twenty-seven freshly extracted mandibular premolars were selected and divided into three experimental groups (G1, G2 and G3 n=7) and two control groups (Ct+ and Ct- n=3). All teeth in the experimental groups were prepared using NiTi Mtwo rotating instruments and then the endodontic treatments were completed using the three-tested warm guttapercha root filling techniques: Microseal (G1), Thermafil (G2) and System B (G3). All root filling techniques were performed using the same endodontic sealer (Pulp Canal Sealer). Three teeth were instrumented and not filled, serving as positive controls (Ct+) and the last three teeth, with intact crowns and no endodontic treatment, served as negative controls (Ct-). All samples were mounted in a two-chamber apparatus and exposed to Enterococcus faecalis performing a bacterial infiltration test. All samples were observed for a maximum period of 60 days checking for turbidity of the BHI broth on a daily basis recording when contamination occurred. A quantitative evaluation of the bacterial CFU/ml was performed using the URO-QUICK™ system. On day 32 an overall value was recorded of contamination of 42.85% for group G1, 71.42% for G2 and 42.85% for G3; after 60 days, the final contamination result was 85.71% for group G1, and 100% for both G2 and G3 groups. Considering the number of contaminated samples at the end of the observation period, the three techniques showed no statistically significant differences. The study highlighted the bacterial permeability of gutta-percha/seal barrier, underlining the importance of an effective coronal restoration to ensure a durable seal after root canal treatment.

Dental Stem Cells: Current research and future applications.

The literature on "dental stem cells" from 2002 to 2009 is composed of 936 works, mainly basic research articles, 159 reviews, 1 clinical study and only 6 case reports concerning endodontics and periodontology. After the year 2009 (1) the interest on this research topic has increased leading to 5177 new articles, including 757 reviews on different stem cell types, biomaterials and the possibility of "banking". The 46 clinical trials published in the last 9 years are clinical applications in periodontics and endodontics. However, still no definitive clinical guidelines are available (2,3). Regenerative therapy in endodontics, through the use of dental stem cells, is still an open question (4). The idea of healing the pulp instead of treating it by means of a conventional endodontic therapy is fascinating, but the current experimental protocol is limited to immature permanent teeth with pulp necrosis, which are a minority of endodontic treatments. Since 2005, with the first stem cell bank (Hiroshima University "Three Brackets") (5), attention has also been paid to the creation of private or university centres where it is possible to preserve autologous dental stem cells. In particular, due to the ease and natural availability, the interest is directed to SHED, Stem cells from Human Exfoliated Deciduous teeth (6). SHED are easy to collect, have excellent differentiation potential and, most importantly, are more cost-effective if compared with umbilical cord cells (5). For these reasons in 2008 the Norwegian Institute of Public Health and the University of Bergen started to collect and store the exfoliated teeth of 100,000 children. To date there are several collection centres in the northern emisphere: USA (Bioeden, Stem Save, Store a Tooth), Europe (Bergen, Future Health), India (Stemade biotech), Japan (Teeth Bank, Advanced Center of Tissue Engineering, Hiroshima University and Nogoya University), Taipai (Taipai Medical University), and recently China (National Dental Stem Cells Bank) (7). Dental stem cells are readily and easily available and are a promising resource not just in dentistry but for regenerative medicine in general (8). This is confirmed by the literature, since 25% of papers on stem cells involve the study and dissemination of research on dental tissues-derived stem cells. Currently there are only a few registered clinical trials for stem cell applications in dentistry and the results are still unavailable. To date, there are no dental treatments involving harvested stem cells but this is definitely an emerging science that might lead to important outcomes in the future.

Indirect adhesive rehabilitation by cementation under pressure of a case of Dentinogenesis Imperfecta type II: follow-up after 13 years.

AIM: Dentinogenesis imperfecta (DI) is an autosomal dominant genetic disease that affects both deciduous and permanent teeth, with an incidence of 1 out of 6,000 to 1 out of 8,000. Teeth affected with DI type II present bulbous crowns, short and constricted roots, marked cervical constriction, translucent enamel and amber dentin. Also, they present a partial or total obliteration of pulp space, due to continuous dentin production. SEM analysis has shown an undulated dentin-enamel junction (DEJ) with irregularities and locally wide spaces between the two structures instead of a strict junction and a regular linear surface. Treatment options for patients affected by DI-II are intended to protect and restore function and aesthetics of both posterior and anterior teeth. In literature are presented many different therapies, but mainly centered on cemented prosthetic restorations instead of adhesive restorative procedures. We present in this paper a DI-II case successfully treated in 2005 with extensive adhesive rehabilitation. CONCLUSION: The 13 years follow-up proves the reliability of adhesion to dentine and enamel for indirect adhesive restorations even on this kind of anomalous substrates.

External Cervical Resorption: a case report.

AIM: External cervical resorption is a form of root resorption which begins in the cervical region of the tooth and spreads out in the thickness of the dentin in an irregular way; clinically, it may be not visible and, as it is generally asymptomatic before involvement of the pulp, it is often an occasional finding in radiographic examination. Several factors are related to its aetiology. This paper reports a case of external cervical resorption in a mandibular right first molar of a 17-year-old patient; the tooth was extracted and histological analysis was performed. MATERIALS AND METHODS: Radiographic examination showed a progressive external cervical resorption of the lower right first molar; extension of the lesion and pulp involvement indicated tooth extraction; the sample underwent histological analysis. RESULTS: The histological study confirmed the presence of vascular connective tissue in the resorptive lacunae, invading the dentin from the external surface of the root, and perforations from the defect into the pulp; it was also noticed the presence of bone-like tissue.

Composition and microstructure of MTA and Aureoseal Plus: XRF, EDS, XRD and FESEM evaluation.

AIM: The aim of this study was to determine the chemical composition and the phases' microstructure of Aureoseal Plus (OGNA, Italy) and ProRoot MTA (Dentsply Tulsa Dental, USA) and to compare their characteristics. MATERIALS AND METHODS: Study Design: Comparing Aureoseal Plus and ProRoot MTA microstructure by means of several analyses type. The chemical analysis of the two cements was assessed following the UNI EN ISO 196-2 norm. X-Ray fluorescence (XRF) was used to determine the element composition. The crystalline structure was analysed quantitatively using x-ray diffraction (XRD). Powders morphology was evaluated using a scanning electron microscope (SEM) with backscattering detectors, and a field emission scanning electron microscope (FESEM). Elemental analysis was performed by energy dispersive x-ray analysis (EDS). RESULTS: The semi-quantitative XRF analysis showed the presence of heavy metal oxides in both cements. The XRD spectra of the two cements reported the presence of dicalcium silicate, tricalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, bismuth oxide and gypsum. SEM analysis showed that ProRoot MTA powder is less coarse and more homogeneous than Aureoseal. Both powders are formed by particles of different shapes: round, prismatic and oblong. The EDS analysis showed that some ProRoot MTA particles, differently from Aureoseal, contain Ca, Si, Al and Fe. Oblong particles in ProRoot and Aureoseal are rich of bismuth. CONCLUSIONS: The strong interest in developing new Portland cement-based endodontic sealers will create materials with increased handling characteristics and physicochemical properties. A thorough investigation on two cement powders was carried out by using XRF, XRD, SEM and EDS analysis. To date there was a lack of studies on Aureoseal Plus. This cement is similar in composition to ProRoot MTA. Despite that it has distinctive elements that could improve its characteristics, resulting in a good alternative to MTA.

Recurrent aphthous stomatitis (RAS): guideline for differential diagnosis and management.

AIM: Recurrent aphthous stomatitis (RAS) is a painful and common ulcerative form that can pose a diagnostic challenge. In fact, similar oral ulcers can appear secondary to a variety of well-defined pathological conditions. Thus, the purpose of this work was to update the current knowledge about RAS METHODS: A narrative review is presented aiming to clarify the extensive differential diagnosis of RAS and its management. CONCLUSION: As a first aid in relieving the pain, topical applications of corticosteroids, antibiotics, and analgesics are highly recommended, while systemic therapy of RAS should be used in the case of multiple painful ulcerations compromising the quality of life of the patient. Also, natural anti-inflammatory substances from medicinal herbs, in the form of essential oils and extracts are promising agents in the management of RAS.

State-of-the-art on MIH. Part. 1 Definition and aepidemiology.

Molar incisor hypomineralization (MIH) is one of the most pressing issues in paediatric dentistry. It is a qualitative enamel defect of systemic origin that affects at least one first permanent molar and can also be associated with permanent incisors. However, the same defects have also been observed on primary molars and other permanent teeth. Hypomineralised enamel has less distinct prisms edges and crystals and the interprismatic space is more marked. Children with MIH undergo dental treatment nearly 10 times more than unaffected children. Preventive treatment following the diagnosis of MIH should take into account patient's age and collaboration, patient's caries risk, type and extension of demarcated lesions and hypersensitivity. Risk assessment and early diagnosis are key factors to an effective and conservative treatment.