Peri-Implant And Periapical Oral Bone Defects: Clinical Strategies To Achieve Alveolar Bone Stability And Experimental Bone Regeneration Procedures

Peri implant and periapical bone defects are widespread in the world population. Considering the high number of implant placement and root canal treatment performed every year, resolution of these bone defects will be of predominant interest in the next future. The present project has several aims: The first part of the project aimed to investigate how and what factors affect peri implant bone remodeling process. Microchemical analysis of the peri implant bone interface of retrieved human dental implants was performed. In addition, prospective clinical studies were conducted to evaluate the factors mostly related to peri implant bone loss. The second part of the project aimed to evaluate chemical physical and micromorphological properties of hydraulic calcium silicates based materials (CaSi), which gained a particular attention in the endodontic field. Use of these materials claimed to resolve several complex endodontic complications, however few information is present in literature. These materials were compared with some “gold standard” bioinert materials. Given the attractive biointeractive properties of CaSi based materials, the last part of the study will focus on the design and characterization of new mineral based scaffolds, aimed to be applied in future bone regeneration procedures. Scaffolds, composed of a polymeric matrix were doped with CaSi and calcium phosphates, in order to increase the materials biointeractive properties. A complete characterization of their chemical-physical-mechanical-thermal properties was performed, as well as the evaluation of apatite forming ability (bioactivity) and biocompatibility of these mineral based scaffolds. The combination of Human Periapical-cysts Mesenchymal Stem Cells (hPC-MSC) as a potential strategy to achieve periapical bone regeneration was evaluated. Finally, the angiogenesis potential of these scaffolds was investigated through the growth and proliferation of porcine vascular wall mesenchymal stem cells (pvw-MSC) was performed

Properties of a novel polydimethylsiloxane endodontic sealer

Abstract Aim: The study aims to assess sealing ability of a novel polydimethylsiloxane-based sealer in simulated wet root canals with wide apex, ion release (calcium and pH) and examine samples using ESEM. Materials and methods: GuttaFlow bioseal, GuttaFlow2, and RoekoSeal Automix (Coltène/Whaledent Inc.) were tested.Roots were prepared to obtain an apical diameter #40 using nickel-titanium rotary files (HyFlex CM, Coltène/Whaledent Inc.), each root was filled with single cone technique and immediately inserted into a simulated socket (filled with 0.02. mL of simulated body fluid) to reproduce the clinical conditions of a wet apical environment. Sealing ability was evaluated as fluid filtration rate at 1, 14, 28 days, and 10 months.After 28 days in simulated body fluid, apices were examined using an Environmental Scanning Electron Microscope (ESEM).Alkalinizing activity and calcium release was evaluated after 3. h and 1, 7, 14, and 28 days.Data were analysed using Kolmogorov-Smirnov test (p <. 0.05). Results: Fluid filtration analysis showed no significant difference within materials. Significant difference was observed between 10 months observation and other time frames (p <. 0.05) of the same group.GuttaFlow bioseal showed a significantly higher alkalinising activity (p <. 0.05). Calcium release ability showed no significant difference through time, however significant differences were observed among materials (p <. 0.05).Observation using ESEM at 28 days after root obturation showed the presence of the materials sealing the wide apical foramen. Conclusions: All materials showed satisfying sealing ability. However due to low calcium release, their use is not suggested when apical barrier formation and periapical bone regeneration are needed. © 2017 Società Italiana di Endodonzi

Chemical-Physical Properties and Bioactivity of New Premixed Calcium Silicate-Bioceramic Root Canal Sealers

The aim of the study was to analyze the chemical-physical properties and bioactivity (apatite-forming ability) of three recently introduced premixed bioceramic root canal sealers containing varied amounts of different calcium silicates (CaSi): a dicalcium and tricalcium silicate (1-10% and 20-30%)-containing sealer with zirconium dioxide and tricalcium aluminate (CERASEAL); a tricalcium silicate (5-15%)-containing sealer with zirconium dioxide, dimethyl sulfoxide and lithium carbonate (AH PLUS BIOCERAMIC) and a dicalcium and tricalcium silicate (10% and 25%)-containing sealer with calcium aluminate, tricalcium aluminate and tantalite (NEOSEALER FLO). An epoxy resin-based sealer (AH PLUS) was used as control. The initial and final setting times, radiopacity, flowability, film thickness, open pore volume, water absorption, solubility, calcium release and alkalizing activity were tested. The nucleation of calcium phosphates and/or apatite after 28 days aging in Hanks balanced salt solution (HBSS) was evaluated by ESEM-EDX, vibrational IR and micro-Raman spectroscopy. The analyses showed for NeoSealer Flo and AH Plus the longest final setting times (1344 +/- 60 and 1300 +/- 60 min, respectively), while shorter times for AH Plus Bioceramic and Ceraseal (660 +/- 60 and 720 +/- 60 min, respectively). Radiopacity, flowability and film thickness complied with ISO 6876/12 for all tested materials. A significantly higher open pore volume was observed for NeoSealer Flo, AH Plus Bioceramic and Ceraseal when compared to AH Plus (p &lt; 0.05), significantly higher values were observed for NeoSealer Flo and AH Plus Bioceramic (p &lt; 0.05). Ceraseal and AH Plus revealed the lowest solubility. All CaSi-containing sealers released calcium and alkalized the soaking water. After 28 days immersion in HBSS, ESEM-EDX analyses revealed the formation of a mineral layer that covered the surface of all bioceramic sealers, with a lower detection of radiopacifiers (Zirconium for Ceraseal and AH Plus Bioceramic, Tantalum for NeoSealer Flo) and an increase in calcium, phosphorous and carbon. The calcium phosphate (CaP) layer was more evident on NeoSealer Flo and AH Plus Bioceramic. IR and micro-Raman revealed the formation of calcium carbonate on the surface of all set materials. A thin layer of a CaP phase was detected only on AH Plus Bioceramic and NeoSealer Flo. Ceraseal did not show CaP deposit despite its highest calcium release among all the tested CaSi-containing sealers. In conclusion, CaSi-containing sealers met the required chemical and physical standards and released biologically relevant ions. Slight/limited apatite nucleation was observed in relation to the high carbonation processes

Green Hydrogels Composed of Sodium Mannuronate/Guluronate, Gelatin and Biointeractive Calcium Silicates/Dicalcium Phosphate Dihydrate Designed for Oral Bone Defects Regeneration

Innovative green, eco-friendly, and biologically derived hydrogels for non-load bearing bone sites were conceived and produced. Natural polysaccharides (copolymers of sodium D-mannuronate and L-guluronate) with natural polypeptides (gelatin) and bioactive mineral fillers (calcium silicates CaSi and dicalcium phosphate dihydrate DCPD) were used to obtain eco-sustainable biomaterials for oral bone defects. Three PP-x:y formulations were prepared (PP-16:16, PP-33:22, and PP-31:31), where PP represents the polysaccharide/polypeptide matrix and x and y represent the weight % of CaSi and DCPD, respectively. Hydrogels were tested for their chemical-physical properties (calcium release and alkalizing activity in deionized water, porosity, solubility, water sorption, radiopacity), surface microchemistry and micromorphology, apatite nucleation in HBSS by ESEM-EDX, FT-Raman, and micro-Raman spectroscopies. The expression of vascular (CD31) and osteogenic (alkaline phosphatase ALP and osteocalcin OCN) markers by mesenchymal stem cells (MSCs) derived from human vascular walls, cultured in direct contact with hydrogels or with 10% of extracts was analysed. All mineral-filled hydrogels, in particular PP-31:31 and PP-33:22, released Calcium ions and alkalized the soaking water for three days. Calcium ion leakage was high at all the endpoints (3 h–28 d), while pH values were high at 3 h–3 d and then significantly decreased after seven days (p &lt; 0.05). Porosity, solubility, and water sorption were higher for PP-31:31 (p &lt; 0.05). The ESEM of fresh samples showed a compact structure with a few pores containing small mineral granules agglomerated in some areas (size 5–20 microns). PP-CTRL degraded after 1–2 weeks in HBSS. EDX spectroscopy revealed constitutional compounds and elements of the hydrogel (C, O, N, and S) and of the mineral powders (Ca, Si and P). After 28 days in HBSS, the mineral-filled hydrogels revealed a more porous structure, partially covered with a thicker mineral layer on PP-31:31. EDX analyses of the mineral coating showed Ca and P, and Raman revealed the presence of B-type carbonated apatite and calcite. MSCs cultured in contact with mineral-filled hydrogels revealed the expression of genes related to vascular (CD31) and osteogenic (mainly OCN) differentiation. Lower gene expression was found when cells were cultured with extracts added to the culture medium. The incorporation of biointeractive mineral powders in a green bio-derived algae-based matrix allowed to produce bioactive porous hydrogels able to release biologically relevant ions and create a suitable micro-environment for stem cells, resulting in interesting materials for bone regeneration and healing in oral bone defects

3D Finite Element Analysis of Rotary Instruments in Root Canal Dentine with Different Elastic Moduli

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidit

Chemical-Physical Properties and Bioactivity of New Premixed Calcium Silicate-Bioceramic Root Canal Sealers

The aim of the study was to analyze the chemical&ndash;physical properties and bioactivity (apatite-forming ability) of three recently introduced premixed bioceramic root canal sealers containing varied amounts of different calcium silicates (CaSi): a dicalcium and tricalcium silicate (1&ndash;10% and 20&ndash;30%)-containing sealer with zirconium dioxide and tricalcium aluminate (CERASEAL); a tricalcium silicate (5&ndash;15%)-containing sealer with zirconium dioxide, dimethyl sulfoxide and lithium carbonate (AH PLUS BIOCERAMIC) and a dicalcium and tricalcium silicate (10% and 25%)-containing sealer with calcium aluminate, tricalcium aluminate and tantalite (NEOSEALER FLO). An epoxy resin-based sealer (AH PLUS) was used as control. The initial and final setting times, radiopacity, flowability, film thickness, open pore volume, water absorption, solubility, calcium release and alkalizing activity were tested. The nucleation of calcium phosphates and/or apatite after 28 days aging in Hanks balanced salt solution (HBSS) was evaluated by ESEM-EDX, vibrational IR and micro-Raman spectroscopy. The analyses showed for NeoSealer Flo and AH Plus the longest final setting times (1344 &plusmn; 60 and 1300 &plusmn; 60 min, respectively), while shorter times for AH Plus Bioceramic and Ceraseal (660 &plusmn; 60 and 720 &plusmn; 60 min, respectively). Radiopacity, flowability and film thickness complied with ISO 6876/12 for all tested materials. A significantly higher open pore volume was observed for NeoSealer Flo, AH Plus Bioceramic and Ceraseal when compared to AH Plus (p &lt; 0.05), significantly higher values were observed for NeoSealer Flo and AH Plus Bioceramic (p &lt; 0.05). Ceraseal and AH Plus revealed the lowest solubility. All CaSi-containing sealers released calcium and alkalized the soaking water. After 28 days immersion in HBSS, ESEM-EDX analyses revealed the formation of a mineral layer that covered the surface of all bioceramic sealers, with a lower detection of radiopacifiers (Zirconium for Ceraseal and AH Plus Bioceramic, Tantalum for NeoSealer Flo) and an increase in calcium, phosphorous and carbon. The calcium phosphate (CaP) layer was more evident on NeoSealer Flo and AH Plus Bioceramic. IR and micro-Raman revealed the formation of calcium carbonate on the surface of all set materials. A thin layer of a CaP phase was detected only on AH Plus Bioceramic and NeoSealer Flo. Ceraseal did not show CaP deposit despite its highest calcium release among all the tested CaSi-containing sealers. In conclusion, CaSi-containing sealers met the required chemical and physical standards and released biologically relevant ions. Slight/limited apatite nucleation was observed in relation to the high carbonation processes

Tissue-Level Laser-Lok Implants Placed with a Flapless Technique: A 4-Year Clinical Study

Background: The present study aims to analyze the use of Laser-Lok microtextured neck implants placed with a transmucosal surgical approach. The marginal bone level (MBL) and periodontal parameters were evaluated in a cohort prospective 4-year clinical study. Methods: A total of 41 implants were placed in 36 healthy consecutive patients (16 males, 20 females, mean age 60 ± 9 years). Tapered tissue level implants, characterized by a 2.0 mm laser-microtextured neck, were used with a flapless approach. Customized abutments and provisional resin crowns were positioned. Definitive metal-ceramic crowns were cemented approximately 4 months after insertion. Periapical radiographs were taken after 1, 3, 6, 12, 36 and 48 months from implant placement to evaluate MBL. Gingival thickness (thin/thick), plaque score (PS) and bleeding on probing (BoP) were evaluated. Results: After 48 months, all implants were safe from complications. No complications, peri-implantitis, early implant failures or mucositis occurred. The survival rate was 100%. Mean MBL during the follow-up was -0.15 ± 0.18 at T1, -0.29 ± 0.29 at T3, -0.45 ± 0.37 at T6, -0.53 ± 0.45 at T12, -1.06 ± 1.13 at T 36 and -1.10 ± 0.89 at T 48. Implants placed 2-3 months after tooth extraction revealed lower MBL variation when compared to those placed immediately (in fresh extraction sockets) or in completely healed ridges (delayed group). Narrower diameter implants (3.8 mm) showed significantly higher MBL variation when compared to 4.6 diameter implants. Multilevel analysis at T48 revealed that among all the evaluated variables, implant diameter was the factor mostly associated with MBL modifications (p = 0.027). Conclusion: This 4-year clinical study supports the use of Laser-Lok implants placed at tissue level with a flapless approach. A limited bone loss during the 48-month follow-up was observed. Periodontal parameters were stable with no sign of inflammation or soft tissue alteration. The use of Laser-Lok implants with transmucosal surgery represents a suitable technique with a minimally invasive approach

Āsana for Neck, Shoulders, and Wrists to Prevent Musculoskeletal Disorders among Dental Professionals: In-Office Yóga Protocol

: Extensive literature reports an increase in physical disorders (pain, pathologies, dysfunctions) and mental malaise/uneasiness (stress, burnout) affecting dental professionals in relation to fast and pressing rhythms of work, long working hours, increasingly demanding patients, ever-evolving technologies, etc. This project has been conceived to bring the science of yoga around the world to dental professionals as a preventive (occupational) medicine and to provide knowledge and means for self-care. Yoga is a concentrative self-discipline of the mind, senses, and physical body, that requires regular daily exercise (or meditation), attention, intention, and disciplined action. M&amp;M: The study aimed to design a Yoga protocol specifically devised for dental professionals (dentists, dental hygienists, and dental assistants) including positions (āsana) to be practiced/used in the dental office. The protocol is targeted for the upper body, namely neck, upper back, chest, shoulder girdle, and wrists, being areas greatly affected by work-related musculoskeletal disorders. This paper represents a yoga-based guideline for the self-cure of musculoskeletal disorders among dental professionals. Results: The protocol includes both sitting (Upavistha position) and standing (Utthana or Sama position) āsana, with twisting (Parivrtta), side bending (Parsva), flexion and forward bending (Pashima), and extension and arching (Purva) āsana to mobilize and decompress, and to provide nourishment and oxygen to the musculo-articular system. The paper delivers different concepts and theories developed and deepened by the authors and introduces and spreads yoga as a medical science among dental professionals for the prevention and treatment of work-related musculoskeletal disorders. We articulate notions ranging from stretching out using the vinyāsa method (breath-driven movement) and inward-focused attention to contemplative/concentrative science, interoceptive attention, self-awareness, the mind-body connection, and receptive attitude. The theory of "muscles are bone ties" is coined and delivered with regard to tensegrity musculoskeletal fascial structures connecting, pulling together, and nearing the bone segments where they are anchored. The paper describes over 60 āsana envisaged to be performed on dental stools or using the walls of a dental office or a dental unit chair. A detailed guideline on the work-related disorders that can find relief with the protocol is provided, including the description of breath control for the practice of āsana in vinyāsa. The foundations of the technique reside in the IyengarYoga method and ParināmaYoga method. Conclusions: This paper represents a guideline for self-cure in the prevention or treatment of musculoskeletal disorders affecting dental professionals. Yoga is a powerful concentrative self-discipline able to provide physical and mental well-being, representing great help and support in daily life and business for dental professionals. Yógāsana restores retracted and stiff muscles, giving relief to the strained and tired limbs of dental professionals. Yoga is not intended for flexible or physically performing persons but for people who decide to take care of themselves. The practice of specific āsana represents a powerful tool for the prevention or treatment of MSDs related to poor posture, forward head, chronic neck tension (and related headache), depressed chest, compressive disorders on wrists and shoulders as carpal tunnel, impingement syndromes, outlet syndrome, subacromial pain syndrome and spinal disc pathologies. Yoga, as an integrative science in medicine and public health, represents a powerful tool for the prevention and treatment of occupational musculoskeletal disorders and an extraordinary path for the self-care of dental professionals, sitting job workers, and healthcare providers suffering from occupational biomechanical stresses and awkward postures

Rehabilitation of anterior upper incisor area with combined therapy Maryland Bridge and Prama Implant: two case reports three

Background: New implant system with an innovative trasmucosal surface profile morphology (BOPT) have been recently developed. The transmucosal neck surface is characterized by a controlled passivation treatment and a conical morphology to allow a biological corrected prosthetic form of ceramic crown. Aim/Hypothesis: The aim of this clinical cases study was to evaluate the marginal crestal bone loss (MBL) and gingival/periodontal status of transmucosal implant placed in anterior upper area. Material and methods: Three healthy subjects with acute active periapical lesion of seriously compromised upper incisor requiring tooth extraction were consecutively included in the study. After tooth extraction, all patients were rehabilitated with the positioning of a Maryland bridge to preserve the aesthetic line. Approximately 3 months later a transmucosal zirconium blasted acidetched titanium (ZirTi) implant (PRAMA, Sweden & Martina, ITALY) was positioned with flapless technique. All implants had insertion torque of 50\u201365 N/cm. Each implant was finally loaded after 3 months with a provisional resin crown and a di-silicate ceramic crown as definitive restoration. Clinical and radiographic follow-up (mucosal profile, periodontal indices and MBL) was performed 1, 2, 3 months after implant placement and 3 and 6 months after loading. Results: No gingivitis and other complications were observed. No marginal bone loss was observed around the implants before and after loading. Adequate and corrected aesthetic crown profile was obtained with a reduced compression of mucosal marginal tissues. Conclusions and clinical implications: The combined prosthetic and surgery technique and the use of ZirTi implant system with BOPT profile showed valid aesthetic and biological profile and allow the placement of the ceramic crown with a corrected emergency profile that may prevent MBL

BIOACTIVITY (APATITE FORMING ABILITY) OF COMMERCIAL AND EXPERIMENTAL POLYSILOXANE-GUTTAPERCHA ENDODONTIC SEALERS. CALCIUM RELEASING, ALKALINIZING ACTIVITY, ESEM-EDX MORPHOLOGICAL ANALYSIS

INTRODUCTION There is a growing interest in sealers with bioactive (apatite forming) and biointeractive (release of biologically relevant ions) properties, especially when dealing with wide apices of immature and retreated teeth, root internal resorptions, blood contamination and refractory periapical lesions with large bone defects. OBJECTIVES The aim of this study was to assess the chemical properties (alkalinizing activity, calcium release) and the bioac- tivity (apatite forming ability) of experimental Polysiloxane-guttapercha Calcium Silicate-containing cements in simulated wet root canals. The ability to nucleate calcium phosphate on their surface upon immersion in a simulated body fluid (SBF) has been evaluated using Environmental Scanning Electronic Microscopy (ESEM) and Energy-dispersive X-ray analy- sis (EDX). MATERIALS AND METHODS A polysiloxane-guttapercha based sealer (GuttaFlow 2, Coltène/Whaledent Inc.) was mixed with three different calcium silicates materials, namely Calcium Silicates and Di Calcium Phosphate (CaSi/DCPD), Calcium Silicates (CaSi) and Hydroxyapatite (CaSi/HA) and Bioroot RCS (Septodont, Saint-Maur-de-Fosses, France). 4 experimental formulations were obtained: GuttaFlow 2 + 20% CaSi/DC GuttaFlow 2 + 20% CaSi/HAGuttaFlow 2 + 20% BioRoot RCS GuttaFlow 2 + 30% BioRoot RCS Materials were compacted into polyvinylchloride molds (8 mm diameter, 1.6 mm height; n=8 per group), imme- diately immersed in 10 mL of deionized water (pH 7.18) into polypropylene sealed containers and stored at 37°C. The soaking water was replaced at each endpoint (3 h and 1,3,7,14,28 days) and analyzed for pH and calcium content. Analyses were carried out under magnetic stirring at room temperature (24°C) by using a multiparameter laboratory meter (inoLab 750, WTW, Weilheim, Germany) connected to a selective electrode (Sen Tix Sur; WTW) for pH measurements or a calcium probe (Calcium ion electrode, Eutech Instruments Pte Ldt, Singapore. ESEM (Zeiss EVO 50; Carl Zeiss, Oberkochen, Germany) connected to a secondary electron detector for energy dispersive X-ray analysis (EDX; Oxford INCA 350 EDS, Abingdon, UK) was used to investigate apatite forming abil- ity on samples immediately immersed in Hank Balanced Saline Solution (HBSS), after 3 and 28 days. RESULTS All the materials demonstrated the ability to alkalinize the pH from 3 hours to 24 hours. These values were con- stant until 28 days. Calcium release demonstrated a progressive increase from 3 hours to 28 days. After 28 days immersion in HBSS, a layer of CaP was detected on all the experimental samples. DISCUSSION Conventional Guttaflow 2 does not release calcium ions, nor proved to alkalinize the local environment. Sealers with bioactive (apatite forming) and biointeractive properties may represent a new frontier for endodontic ther- apy. Release of biologically relevant ions (i.e Ca++ and OH-) may be useful for mineralizing cells activation and proving a slight antibacterial activity. Moreover, an alkaline environment favours apatite precipitation. All these conditions may allow a faster healing of the periapical bone. CONCLUSION Nano spherulites particles were detected in all formulations. Their composition was mainly calcium-phosphate and apatite. EDX confirmed the presence of calcium and phosphate