Implant surfaces exposed to the oral cavity and treated with toothpaste containing oxygen releasing compound : a morphological controlled clinical trial

Aim of the present in vivo study is to assess if a toothpaste containing an oxygen releasing compound (AX) is able to reduce the biofilm formation on implants with rough surface compared to a control toothpaste, without affecting the microstructure of the tested surface. Methods: In this double blind, cross-over, controlled clinical trial, a total of fourteen healthy volunteers were recruited. For each subject, two mandibular splints (test and control) were created with one implant fixed on the right lingual side of the mandibular arch. The splint was continuously worn for 5 days and the daily hygiene was performed wearing the splint and using the test (AX) or control toothpaste. Implants were analyzed at scanning-electron-microscopy and at laser profilometer for the assessment of biofilm adhesion (% of areas free from biofilm-FA) and surface changes (morphology and roughness). Results: FA resulted significantly higher in test than in control implants. No differences were found between groups in term of biofilm organization, surface microstructure and roughness. Discussion: Daily use of toothpaste containing AX seems to reduce the amount of biofilm adherent to the rough implant surface without corrosion or degradation of the titanium surface

Histomorphometrical evaluation of the effects of Aminogam® gel in oral healing process of post-surgical soft tissue

Wound healing is a dynamic process that involves a complex interaction of inflammatory cells, cytokines and mediators of extracellular matrix [1]. One of the processes that occur during tissue regeneration is angiogenesis and it is considered to have a pivotal role in wound repair. Previous studies have shown that a topical application of proteins and sodium hyaluronate to wounds can expedite the repair of damaged tissue [2]. The aim of this preliminary study is to evaluate the efficacy of Aminogam\uae gel (A\uae) (ErreKappa Euroterapici SpA, Milano), a topical medication which contains 4 amino acids (glycine, leucine, proline, lysine) and sodium hyaluronate, used to improve and accelerate gingival flap healing following molar extraction by analyzing collagen fibers amount, orientation and microvascular distribution (MVD). Ten patients (mean age 49ys) were included in the study. Two teeth (38 and 48) were extracted at an interval of 30 days. The \u201ctest\u201d site (AM) was treated with A\uae while the \u201ccontrol\u201d site (no AM) was not. Dental extraction was performed and the flaps were sutured with a consequent excess of tissue for histological processing (T0). A\uae had been applied only at the AM site for 10 days post-extraction. At suture removal, a gingivoplasty was performed and the exceeding tissue was histologically analysed (T1). Paraffin blocks were cut and slides were stained with haematoxylin-eosin and Sirius Red. No signs of inflammatory infiltrate or necrosis were observed. Sirius Red staining highlighted a lower degree of organized collagen fibers at T1 vs T0. At T0 the fibers were organized in closely packed and well-oriented bundles. At T1-no AM fibers were thin and formed a disorganized grid. At T1-AM fibers appeared thicker and the tissue appeared more mature compared to T1-no AM. Immunohistochemistry against CD31 was performed to mark endothelial cells and to calculate MVD by stereological method [3]. MVD resulted highest at T1-AM. The T1 data normalized on T0 presented a statistically significant difference (p=0.012) between AM and no AM group. In conclusion, A\uae gel seems to increase new blood vessels formation and to promote collagen deposition and organization. References [1] Gurtner et al. Nature. 2008;453(7193):314-21. [2] Zhu et al. BMC Oral Health. 2015;15:60. [3] Canullo et al. J Clin Periodontol. 2016;38:86-94

Histo-Pathological Assessment of Zinc Oxide Eugenol Canal Sealer on Periodontal Tissues: Three Case Reports

Purpose: Sealers used in endodontic dental treatment may leak into the periradicular tissues, increasing the risk of retained particles in oral mucosa, tissue irritation or discoloration, delayed healing or interfering on the erupting permanent teeth. Three clinical cases of primary teeth pulpectomy using Zinc Oxide Eugenol (ZOE) paste were observed, showing retained particles of filling cement in the oral mucosa during permanent dentition eruption. The aim of the study was to histologically analyze the possible causes of discoloration and to assess the effects of the sealer on cells by evaluating ultrastructure. Materials and Methods: Three healthy children undergoing orthodontic therapy were enrolled in this study for the presence of gingival pigmentation. For all patients a biopsy of the discolored area was performed and histologically analyzed. Furthermore, sealer was added to the culture of SAOS-2 to evaluate cytotoxicity effects by Alamar blue tests and ultrastructure evaluation using Transmission Electrons Microscope (TEM). Results: Black extracellular granules were appreciable in all Hematoxylin Eosin-stained sections. Deposition of pigment was observed particularly in the blood vessel walls, in connective tissue and in intercellular ground substance. In cell culture, sealers reduced viability about 43% after 24h, 17% after 48h and 12% after 72h compared with untreated cells. Furthermore, sealer affected morphology creating vacuoles inside the cytoplasmic area. Conclusions: Sealer resulted to be mild toxic for the cells. Retention granules of bismuth in the oral mucosa after root canal treatment of deciduous teeth and subsequent mucosal discoloration analyzed in this study should alert pediatric dentists to use the filling materials very carefully and to check the radicular and filling paste resorption in order to prevent the prolonged retention of the overfilled material