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

Multidisciplinary Approach to Fused Maxillary central Incisors: a Case Report

Introduction: The fusion of permanent teeth is a development anomaly of dental hard tissue. It may require a hard multidisciplinary approach with orthodontics, endodontics, surgery and prosthetics to solve aesthetic and functional problems. Case presentation: A 20-year-old Caucasian man presented to our Department to solve a dental anomaly of his upper central incisors. An oral investigation revealed the fusion of his maxillary central incisors and dyschromia of right central incisor. Vitality pulp tests were negative for lateral upper incisors and left central incisor. Radiographic examinations showed a fused tooth with two separate pulp chambers, two distinct roots and two separate root canals. There were also periapical lesions of central incisors and right lateral incisor, so he underwent endodontic treatment. Six months later, OPT examination revealed persistence of the periapical radiolucency, so endodontic surgery was performed, which included exeresis of the lesion, an apicoectomy and retrograde obturation with a reinforced zinc oxide-eugenol cement (SuperEBA) Complete healing of the lesion was obtained six months postoperatively. Fused teeth crowns were separated and orthodontic appliances were put in place. When correct teeth position was achieved (after nine months), the anterior teeth were prosthetically rehabilitated. Conclusion: Many treatment options have been proposed in the literature to solve cases of dental fusion. The best treatment plan depends on the nature of the anomaly, its location, the morphology of the pulp chamber and root canal system, the subgingival extent of the separation line, and the patient compliance. Following an analysis of radiographical and clinical data, it was possible to solve our patient’s dental anomaly with a multidisciplinary approach

Influence of laser-lok surface on immediate functional loading of implants in single-tooth replacement: a 2-year prospective clinical study.

he purpose of this study was to evaluate the influence of a Laser-Lok microtexturing surface on clinical attachment level and crestal bone remodeling around immediately functionally loaded implants in single-tooth replacement. Seventy-seven patients were included in a prospective, randomized study and divided into two groups. Group 1 (control) consisted of non-Laser-Lok type implants (n = 39), while in group 2 (test), Laser-Lok type implants were used (n = 39). Crestal bone loss (CBL) and clinical parameters including clinical attachment level (CAL), Plaque Index (PI), and bleeding on probing were recorded at baseline examinations and at 6, 12, and 24 months after loading with the final restoration. One implant was lost in the control group and one in the test group, giving a total survival rate of 96.1% after 2 years. PI and BOP outcomes were similar for both implant types without statistical differences. A mean CAL loss of 1.10 ± 0.51 mm was observed during the first 2 years in group 1, while the mean CAL loss observed in group 2 was 0.56 ± 0.33 mm. Radiographically, group 1 implants showed a mean crestal bone loss of 1.07 ± 0.30 mm compared with 0.49 ± 0.34 mm for group 2. The type of implant did not influence the survival rate, whereas Laser-Lok implants resulted in greater CAL and in shallower radiographic peri-implant CBL than non-Laser-Lok implants

Effect of layered double hydroxide intercalated with fluoride ions on the physical, biological and release properties of a dental composite resin

OBJECTIVES: The aim of this work was the preparation of a new fluoride-releasing dental material characterized by a release of fluoride relatively constant over time without any initial toxic burst effect. This type of delivery is obtained by a matrix controlled elution and elicits the beneficial effect of a low amount of fluoride on human dental pulp stem cells (hDPSCs) towards mature phenotype. METHODS: The modified hydrotalcite intercalated with fluoride ions (LDH-F), used as filler, was prepared via ion exchange procedure and characterized by X-ray diffraction and FT-IR spectroscopy. The LDH-F inorganic particles (0.7, 5, 10, 20wt.%) were mixed with a photo-activated Bis-GMA/TEGDMA (45/55wt/wt) matrix and novel visible-light cured composites were prepared. The dynamic thermo-mechanical properties were determined by dynamic mechanical analyzer. The release of fluoride ions in physiological solution was determined using a ionometer. Total DNA content was measured by a PicoGreen dsDNA quantification kit to assess the proliferation rate of hDPSCs. Alkaline phosphatase activity (ALP) was measured in presence of fluoride resins. RESULTS: Incorporation of even small mass fractions (e.g. 0.7 and 5wt.%) of the fluoride LDH in Bis-GMA/TEGDMA dental resin significantly improved the mechanical properties of the pristine resin, in particular at 37°C. The observed reinforcement increases on increasing the filler concentration. The release of fluoride ions resulted very slow, lasting months. ALP activity gradually increased for 28 days in hDPSCs cell grown, demonstrating that low concentrations of fluoride contributed to the cell differentiation. CONCLUSIONS: The prepared composites containing different amount of hydrotalcite filler showed improved mechanical properties, slow fluoride release and promoted hDPSCs cell proliferation and cell differentiation

Advanced leading edge thermal-structure concept. Direct bond reusable surface insulation to a composite structure

An advanced leading-edge concept was analyzed using the space shuttle leading edge system as a reference model. The comparison indicates that a direct-bond system utilizing a high temperature (2700 F) fibrous refractory composite insulation tile bonded to a high temperature (PI/graphite) composite structure can result in a weight savings of up to 800 lb. The concern that tile damage or loss during ascent would result in adverse entry aerodynamics if a leading edge tile system were used is addressed. It was found from experiment that missing tiles (as many as 22) on the leading edge would not significantly affect the basic force-and-moment aerodynamic coefficients. Additionally, this concept affords a degree of redundancy to a thermal protection system in that the base structure (being a composite material) ablates and neither melts nor burns through when subjected to entry heating in the event tiles are actually lost or damaged during ascent

Incappucciamento indiretto con Mineral trioxide aggregate (Mta) : caso clinico e follow-up

Aim: In this clinical case an indirect pulp capping was performed, using MTA, at 36 cariously damaged. Methodology: A 7 years old girl, affected by DEA presented a decayed 36 whose radicular formation was still incomplete. After cleaning the carious cavity, MTA was placed as intermediate medication and a temporary filling material was used over MTA. The clinical procedure can be considered safe and simple. Results and conclusions: Because of some problems of hers, this young girl returned after 6 months. The formation of hard tissue was observed and the rx control resulted in a clear evidence of root formation. We performed the final restoration of 36, using composite materials. At 6-months and at 7-years follow-up there aren't clinical and radiographic signs of pulpar and radicular pathology. In conclusion, MTA seemed to be a material that can be used for the preservation of the pulp tissue vitality. Furthermore it prevented any leakage of the surface below it, even in cases where a lost integrity of the temporary filling material took place

The Platform Switching Approach to Optimize Split Crest Technique

The split crest technique is a reliable procedure used simultaneously in the implant positioning. In the literature some authors describe a secondary bone resorption as postoperative complication. The authors show how platform switching can be able to avoid secondary resorption as complication of split crest technique

Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology