Maurizio Bossù

Calcium silicate and calcium hydroxide materials for pulp capping: Biointeractivity, porosity, solubility and bioactivity of current formulations

Aim The chemical-physical properties of novel and long-standing calcium silicate cements versus conventional pulp capping calcium hydroxide biomaterials were compared. Methods Calcium hydroxide–based (Calxyl, Dycal, Life, Lime-Lite) and calcium silicate–based (ProRoot MTA, MTA Angelus, MTA Plus, Biodentine, Tech Biosealer capping, TheraCal) biomaterials were examined. Calcium and hydroxyl ion release, water sorption, interconnected open pores, apparent porosity, solubility and apatite-forming ability in simulated body fluid were evaluated. Results All calcium silicate materials released more calcium. Tech Biosealer capping, MTA Plus gel and Biodentine showed the highest values of calcium release, while Lime-Lite the lowest. All the materials showed alkalizing activity except for Life and Lime-Lite. Calcium silicate materials showed high porosity values: Tech Biosealer capping, MTA Plus gel and MTA Angelus showed the highest values of porosity, water sorption and solubility, while TheraCal the lowest. The solubility of water-containing materials was higher and correlated with the liquid-to-powder ratio. Calcium phosphate (CaP) deposits were noted on materials surfaces after short aging times. Scant deposits were detected on Lime-Lite. A CaP coating composed of spherulites was detected on all calcium silicate materials and Dycal after 28 days. The thickness, continuity and Ca/P ratio differed markedly among the materials. MTA Plus showed the thickest coating, ProRoot MTA showed large spherulitic deposits, while TheraCal presented very small dense spherulites. Conclusions calcium silicate-based cements are biointeractive (ion-releasing) bioactive (apatite-forming) functional biomaterials. The high rate of calcium release and the fast formation of apatite may well explain the role of calcium silicate biomaterials as scaffold to induce new dentin bridge formation and clinical healing.

Condylar Position Indicator and T-Scan system II in clinical evaluation of temporomandibular intracapsular disease

INTRODUCTION The pathogenesis of temporomandibular joint intracapsular disease (TMJI) is multifactorial and its diagnosis is not easy. In this work authors show two types of clinical analysis: the Condylar Position Indicator (CPI) and T-Scan 2 system. MATERIAL AND METHODS Twenty patients (mean age of 24.5 years) with TMJI problem and 10 healthy matched subjects (mean age: 25.4 years) were selected. Analysis of TMJI was performed on each patient by means of Condylar Position Indicator (CPI) and T-Scan System II tests. RESULTS Eight patients presented vertical symmetrical condylar distraction greater than healthy subjects (P-value<0.001). T-Scan showed a difference of Percentage of Force (POF) not greater than 5%. Seven patients showed sagittal shift greater than healthy subject (P-value<0.001). T-Scan records showed a difference of POF greater than 5%. Five non-healthy subjects presented sagittal, vertical, transverse shift greater than healthy subjects (P-value<0.001). T-Scan records show a difference of POF greater than 5%. CONCLUSION In this work authors present a new method of analysis. CPI indicates discrepancy of the condyle position in CO from CR and T-Scan allows the operator to study all teeth contacts and occlusal forces taking place during dynamic jaw movement.

Wear and metallographic analysis of WaveOne and reciproc NiTi instruments before and after three uses in root canals

Reciprocating instruments made from M-wire alloy have been proposed to reduce the risk of fracture. No information is available on the surface alteration after single and multiple uses in root canals. Two reciprocating NiTi instruments were used on extracted teeth up to three times. ESEM/EDS analysis was conducted to determine defects, alterations, and wear features of the apical third of instruments and metallographic analysis was performed on the cross-section of new and used instruments to compare alloy properties. Topography of apical portion was evaluated by AFM before and after uses. Extracted single-rooted teeth were divided into two groups and instrumented according to the manufacturers recommendations with: (A) WaveOne Primary and (B) Reciproc R25. Each group was divided into three subgroups according to the number of canals instrumented: 1, 2, and 3, respectively. Chi square test was performed to verify homogeneity of defects distribution and GLM to evaluate the differences of RMS at baseline and after use for both groups (α level 0.05). No instrument fractured and no spiral distortions were observed under optical microscope even when the number of uses increased. Not significant differences were found for WaveOne and Reciproc. Blades presented a wrapped portion in WaveOne group and a more symmetrical feature in Reciproc group. Metallographic analysis revealed in both groups the presence of twinned martensitic grains with isolated flat austenitic areas. Both instruments demonstrated limited alteration, such as tip deformation and wear. This study confirmed the safe clinical use of both instruments for shaping multi-rooted teeth.

Use of calcium-containing endodontic sealers as apical barrier in fluid-contaminated wide-open apices.

Purpose The sealing of wide-open apex roots is still a challenge and requires the use of apical barrier techniques. The aim was to evaluate ex vivo the sealing and the apical morphology of 3 commercial calcium oxide (CaO)-containing sealers - namely, 2 zinc oxide-based (CRCS and Sealapex) and a calcium silicate MTA-based (TechBiosealer Endo) - placed in wet root canals with artificial wide-open apices. Methods Thirty human single-rooted teeth were shaped with Protaper and an artificial open apex (diameter size 110) was created. Each root was inserted in a custom-designed support containing simulated body fluid (Hanks balanced salt solution, HBSS) at the bottom simulating the presence of periapical fluid in the canal. Each sealer (TechBiosealer Endo, CRCS, Sealapex) was compacted to the apical 5 mm and the filled roots stored in HBSS at 37°C. The sealing was evaluated as micro-infiltrated fluid since 24 hours up to 6 months using a high-precision digital fluid flow meter. The sealers were also studied for setting time in HBSS, calcium releasing (statistical analysis by 2-way ANOVA followed by Student-Newman-Keuls test, P<0.05) and surface morpho-chemistry by environmental scanning electron microscope with energy dispersive X-ray (ESEM-EDX) and optical microscopy (OM) analysis. Results All sealers showed a stable seal. TechBiosealer Endo maintained a better seal than the other materials (P<0.05) and ESEM-EDX and OM analyses showed the presence of apatite deposits. Conclusions The clinical use of hydraulic hydrophilic MTA-based sealers can be recommended to stop/reduce the fluid flow rate through the apex. The artificial apical barrier in wet wide apices is a suitable technique able to seal wet root canals.

Antimicrobial activity of graphene nanoplatelets against Streptococcus mutans

In recent years, several studies have demonstrated the strong cytotoxicity toward bacteria of graphene-based materials, suggesting their use as antimicrobial agents. The objective of this study was to evaluate the antibacterial activity against Streptococcus mutans, the principal microbiological agent in the etiology of dental caries, of two types of graphene nanoplatelets (GNPs), characterized by different thickness and lateral dimensions of the flakes. The antimicrobial properties of GNPs were valued on some plaque and saliva samples extracted from children with dental caries. Our results show that the killing effect of GNPs on S. mutans cells is both lateral size and thickness dependent. In fact, lower thickness and smaller size GNPs exhibit stronger antibacterial activity than larger and thicker ones. Scanning electron microscopy analysis revealed that GNPs interact strongly with cells. This study suggests that GNPs may be highly effective against S. mutans and therefore caries.

Use of Lozenges Containing Lactobacillus brevis CD2 in Recurrent Aphthous Stomatitis: A Double-Blind Placebo-Controlled Trial

Recurrent aphthous stomatitis is a common disorder of the oral cavity, affecting mainly young people. It is characterized by small ulcers which can be very painful and generally heal spontaneously within 7–14 days. There is currently no therapy that can provide rapid healing. This study evaluated the efficacy and rapidity of response of a lozenge containing Lactobacillus brevis CD2. 30 patients were randomized to take 4 lozenges a day of active product or placebo for 7 days. Signs and symptoms as well as laboratory parameters in the saliva were assessed at the start of the study and after 7 days of treatment. The study demonstrated the efficacy and the rapidity of response of the Lactobacillus brevis CD2 lozenges in resolving the clinical signs and symptoms of aphthous stomatitis, with a significantly rapid improvement of pain. This is the first study confirming the efficacy of a probiotic product in this pathology.

Altered transcription of inflammation-related genes in dental pulp of coeliac children

BACKGROUND Coeliac disease is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten, and possible relationships between coeliac disease and dental pathogenic conditions during childhood have been poorly investigated. AIM The dental pulp plays a pivotal role in the immune defence against possible entry of pathogens from teeth, and the aim of this work was to investigate quantitative transcription levels of selected genes (IL-9, IL-11, IL-15, IL-18, IL-21, IL-27, MICA, IFN-γ) coding for pro-inflammatory immune innate activities in the pulp of primary teeth from healthy children and children with coeliac disease. DESIGN The pulp from primary teeth of 10 healthy children and 10 children with coeliac disease was used to extract RNA and prepare cDNA for quantitative PCR transcription analysis employing commercial nucleotide probes for selected genes. RESULTS In children with coeliac disease, the genes coding for pro-inflammatory cytokines IFN-γ, IL-11, IL-18, and IL-21 were significantly overexpressed, suggesting the possible importance of these cytokines in the relationships between coeliac disease and dental disorders. CONCLUSION For the first time, we reported in dental pulp of children possible relationships between coeliac disease and modulation in transcription of cytokine-dependent inflammatory activities.

Osteogenesis imperfecta and rapid maxillary expansion: Report of 3 patients

INTRODUCTION The aim of this study was to analyze the effects of orthopedic therapy with rapid maxillary expansion (RME) in growing patients affected by osteogenesis imperfecta and treated with bisphosphonates. METHODS Three boys with osteogenesis imperfecta (mean age, 10.6 years) were treated with RME. They all had treatment with quarterly intravenous infusions of bisphosphonates. They were in either the early or the late mixed dentition and had indications for RME. The expansion screw was activated twice daily until correction of the transverse relationships was achieved. The retention period with the expander in place was 6 months. In 2 Class III patients, RME was associated with the use of a facemask. In all patients, occlusal radiographs were taken at the end of active RME therapy to assess the opening of the midpalatal suture and 1 year after the end of active expansion therapy to evaluate the reossification and reorganization of the midpalatal suture. RESULTS In all patients, the opening of the midpalatal suture and the healing with reorganization of the midpalatal suture were documented with the occlusal radiographs. No complications were found after a 1-year follow-up. CONCLUSIONS In growing patients affected by osteogenesis imperfecta and treated with bisphosphonates, it is possible to perform RME with a standard protocol with no complications after a 1-year follow-up.

Today Prospects for Tissue Engineering Therapeutic Approach in Dentistry

In dental practice there is an increasing need for predictable therapeutic protocols able to regenerate tissues that, due to inflammatory or traumatic events, may suffer from loss of their function. One of the topics arising major interest in the research applied to regenerative medicine is represented by tissue engineering and, in particular, by stem cells. The study of stem cells in dentistry over the years has shown an exponential increase in literature. Adult mesenchymal stem cells have recently been isolated and characterized from tooth-related tissues and they might represent, in the near future, a new gold standard in the regeneration of all oral tissues. The aim of our review is to provide an overview on the topic reporting the current knowledge for each class of dental stem cells and to identify their potential clinical applications as therapeutic tool in various branches of dentistry.

Evaluation of the orthodontic treatment need in a paediatric sample from Southern Italy and its importance among paediatricians for improving oral health in pediatric dentistry

Background Data from epidemiological studies investigating the prevalence and severity of malocclusions in children are of great relevance to public health programs aimed at orthodontic prevention. Previous epidemiological studies focused mainly on the adolescence age group and reported a prevalence of malocclusion with a high variability, going from 32% to 93%. Aim of our study was to assess the need for orthodontic treatment in a paediatric sample from Southern Italy in order to improve awareness among paediatricians about oral health preventive strategies in pediatric dentistry. Material and Methods The study used the IOTN-DHC index to evaluate the need for orthodontic treatment for several malocclusions (overjet, reverse overjet, overbite, openbite, crossbite) in a sample of 579 children in the 2-9 years age range. Results The most frequently altered occlusal parameter was the overbite (prevalence: 24.5%), while the occlusal anomaly that most frequently presented a need for orthodontic treatment was the crossbite (8.8%). The overall prevalence of need for orthodontic treatment was of 19.3%, while 49% of the sample showed one or more altered occlusal parameters. No statistically significant difference was found between males and females. Conclusions Results from this study support the idea that the establishment of a malocclusion is a gradual process starting at an early age. Effective orthodontic prevention programs should therefore include preschool children being aware paediatricians of the importance of early first dental visit. Key words:Orthodontic treatment, malocclusion, oral health, pediatric dentistry.