Università degli studi di Modena e Reggio Emilia

Dental implants are one of the most frequently used treatment options for tooth replacement, and titanium is the metal of choice due to its demonstrated superiority in resisting corrosion, lack of allergic reactions and mechanical strength. Surface roughness of titanium implants favors the osseointegration process; nevertheless, its topography may provide a suitable substrate for bacterial biofilm deposition, causing peri-implantitis and leading to implant failure. Subgingival prophylaxis treatments with cleansing powders aimed to remove the bacterial accumulation are under investigation. Two different air-polishing powders-glycine and tagatose-were assayed for their cleaning and antimicrobial potential against a Pseudomonas biofilm and for their effects on human dental pulp stem cells (hDPSCs), seeded on sandblasted titanium disks. Immunofluorescence analyses were carried out to evaluate cell adhesion, proliferation, stemness and osteogenic differentiation. The results demonstrate that both the powders have a great in vitro cleaning potential in the early period and do not show any negative effects during hDPSCs osteogenic differentiation process, suggesting their suitability for enhancing the biocompatibility of titanium implants. Our data suggest that the evaluated cleansing systems reduce microbial contamination and allow us to propose tagatose as an adequate alternative to the gold standard glycine for the air-polishing prophylaxis treatment.

In clinical daily practice, there are situations in which implant sites have vertical and/or horizontal bone defects and often we must improve their morphology and dimensions before fixture insertion. It is crucial to carefully evaluate the surgical site as regards the characteristics of both hard and soft tissues. The orthodontic extrusion technique can be used for nonsurgical augmentation of the implant site as an alternative to traditional regenerative/reparative surgical therapies. The orthodontic extrusion is based on a biological mechanism that uses the portion of periodontal ligament, still present on the root before the tooth extraction, for the increase of hard and soft tissues. In the literature, there is no evidence of common guidelines for this technique but only tips based on personal experience and/or previous studies. The aim of this study was to investigate and to validate the reliability of a new orthodontic extrusion technique (MF Extrusion Technique, by Dr. Mauro Fadda) by means of a retrospective consecutive case-series study. After we have done a review of the literature, we evaluated the X-rays of twelve consecutively treated patients before the orthodontic extrusion (T0) and after the stabilization period (T1), in order to quantify, by two different measurements, area and linear, the bone gain obtained by the application of the new technique. All the patients examined showed a significant increase in bone areas with an average value of 31.575 mm2. The linear bone gain had an average value of 4.63 mm. Data collected were statistically analysed by the Wilcoxon signed-rank test. The results obtained both from area and linear measurements at T0 and at T1 times showed that there was a statistically significant bone gain with p<0.01.

Dental implants are crucial therapeutic devices for successful substitution of missing teeth. Failure cases are mainly pathogen-associated events, allowing clinical progression toward peri-mucositis or peri-implantitis. The aim of this study was to compare the performance of two mechanical decontamination systems, Nickel-Titanium brush (Brush) and Air-Polishing system with 40 μm bicarbonate powder (BIC-40), by means of a novel bioluminescence-based model that measures microbial load in real time. Briefly, 30 disks were contaminated using the bioluminescent Pseudomonas aeruginosa strain (BLI-P. aeruginosa), treated with Brush (30 s rounds, for 90 s) or BIC-40 (30 s, at 5 mm distance) procedure, and then assessed for microbial load, particularly, biofilm removal and re-growth. Our results showed that Brush and BIC-40 treatment reduced microbial load of about 1 and more than 3 logs, respectively. Furthermore, microbial re-growth onto Brush-treated disks rapidly occurred, while BIC-40-treated disks were slowly recolonized, reaching levels of microbial load consistently below those observed with the controls. In conclusion, we provide evidence on the good performance of BIC-40 as titanium device-decontamination system, the clinical implication for such findings will be discussed.

Peri-implantitis-an infection caused by bacterial deposition of biofilm-is a common complication in dentistry which may lead to implant loss. Several decontamination procedures have been investigated to identify the optimal approach being capable to remove the bacterial biofilm without modifying the implant surface properties. Our study evaluated whether two different systems-Ni-Ti Brushes (Brush) and Air-Polishing with 40 µm bicarbonate powder (Bic40)-might alter the physical/chemical features of two different titanium surfaces-machined (MCH) and Ca++ nanostructured (NCA)-and whether these decontamination systems may affect the biological properties of human STRO-1+/c-Kit+ dental pulp stem cells (hDPSCs) as well as the bacterial ability to produce biofilm. Cell morphology, proliferation and stemness markers were analysed in hDPSCs grown on both surfaces, before and after the decontamination treatments. Our findings highlighted that Bic40 treatment either maintained the surface characteristics of both implants and allowed hDPSCs to proliferate and preserve their stemness properties. Moreover, Bic40 treatment proved effective in removing bacterial biofilm from both titanium surfaces and consistently limited the biofilm re-growth. In conclusion, our data suggest that Bic40 treatment may operatively clean smooth and rough surfaces without altering their properties and, consequently, offer favourable conditions for reparative cells to hold their biological properties.

Mesenchymal stromal cells (MSCs) can be easily isolated form craniofacial bones during routine dentistry procedures. Due to their embryological origin from neural crest, they represent a suitable cell population to study cell-biomaterial interaction in the craniofacial field, including osteoinductive/osteointegrative processes. The biological and immunomodulatory properties of MSCs may be influenced by chemistry and topography of implant surfaces. We investigated if and how three different titanium surfaces, machined (MCH), sandblasted with resorbable blasting medium (RBM), and Ca++-nanostructured (NCA), may affect biological activity, osseointegration, and immunomodulatory properties of craniofacial MSCs. Cell proliferation, morphology, osteogenic markers, and FasL were evaluated on MSCs isolated from the mandibular bone after seeding on these three different surfaces. No statistically significant differences in cell proliferation were observed whereas different morphologies and growth patterns were detected for each type of surface. No difference in the expression of osteogenic markers was revealed. Interestingly, FasL expression, involved in the immunomodulatory activity of stem cells, was influenced by surface properties. Particularly, immunofluorescence analysis indicated that FasL expression increased on MCH surface compared to the others confirming the suggested role of FasL in promoting osteogenic differentiation. Titanium surface treatments and topography might reflect different biological behaviours of craniofacial MSCs and influence their osseointegration/immunomodulation properties.

The roughness of the implant surface and its chemistery and toporaphy were demonstrated to impact cells biological properties. A moderate roughness seems to allow better and faster adhesion and proliferation and to accelerate the biological processes. The different physical and chemical procedures used to obtain a certain microtopography modify the surface chemical composition and, in consequence of it, can affect the biological cell behavior. The ideal surface shuold be obtained through processes that do not modify the chemical composition maintaining a right roughness and microtopography. The aim of this investigation was to study the morphology, proliferation and pattern of distribution of human Dental Pulp Stem Cells (hDPSCs) after 5 days of growth on a laser micro-grooved implant surface (Laser-Lock, Bio Horizons IPH, Inc. Birmingham, AL 35244, USA) characterized by a micro geometric design obtained by computer-aided laser ablation without any chemical treatment. Data from SEM surface observation and XPS chemical analysis have highlighted the absence of contaminating chemical elements. The results from cell cultures indicated that the hDPSCs maintained a good morphology and well proliferated following the microgrooves direction.

Implants with rough surfaces are today widely used. It has been speculated that rough surfaces (Ra [ 0.2 lm) provide a better ‘‘substrate’’ for retention and accumulation of plaque in terms of area, thickness and colony- forming unit that can eventually lead to peri mucositis and/or peri-implantitis. The aim of this investigation was to evaluate in vivo the plaque accumulation after 48 h on three implant surfaces with different treatments. For this investigation, we used 21 sterilized titanium disks, with a diameter of 8mm and a thickness of 3 mm, provided by the manufacturer: 7 with machined surface, as smooth control, 7 with HA grit sand- blasted RBM surface and 7 with Ca?? incorporated in tita- nium Xpeed surface. One disk for each surface treatment was characterized at time 0 by SEM and AFM to study, respec- tively, the surface morphology and roughness. The other 18 disks were mounted randomly on three upper acrylic bites in a buccal lateral position, worn for 48 h by three volunteer stu- dents for plaque accumulation. After 48 h each disk was removed and analyzed qualitatively and quantitatively by an independent operator, not involved into the study, in order to avoid bias. Data collected were statistically analyzed by one- way ANOVA. The qualitative analysis showed no differences in terms of total plaque accumulation between the surfaces. Data from quantitative analysis using Anova Test showed no significance between all groups. In this in vivo investigation all the surfaces studied promoted plaque formation. The degree of surface roughness seems not to be a critical factor for plaque accumulation.

The aim of this study was to investigate, using three-dimensional nite element analysis [3D-FEA], the stress and/or strain distribution of ve di erent resin composites used in combination with carbon bre posts. FEA models of ve di erent light-cured composites were employed. The stress distribution of composite in combination with carbon bre post was analysed under two di erent loading conditions: (i) polymerization shrinkage and (ii) load of 150 N with a 35° tilt to the long axis of the tooth. The Material Fatigue Rate [MFR%] of composite materials, dentin and bre post was calculated. The highest stress values were recorded for Heliomolar and Clear l-Photo P. The lowest stresses and MFR% values were attained when using Diamond Crown. High MFR% value [>45%] for carbon posts were found in all the tested cases under load. Composite materials with a Young’s modulus similar to that of dentin should be selected for the restoration of endodontically-treated teeth when using carbon bre posts. The peak of the polymerization stress of the composite core is localized at the ferrule level. This might induce an open margin with higher risk of coronal leakage.

BACKGROUND: Recently, rotating brushes with titanium bristles have been introduced for the debridement of implant surfaces when peri implant problems occur. This study inves- tigated the effects induced by titanium brushes on different implant surfaces previously contaminated in vivo METHODS: n°9 disks, going sterilized directly from manu- facturer, (Megagen Implant Co, Ltd, Korea) (n=3 with HA grit sandblasted RBM surface; n=3 with a Ca2+ incorporated in titanium XPEED surface and n=3 with machined surface) Ø 8mm x 3mm were used for this investigation. N°1 disk for each surface treatment (tot. n°3 disks) were characterized at time 0 by SEM to study the surface morphology and by AFM to study the surface roughness. The other six disks were mounted on an acrylic bite embedded in a buccal lateral posi- tion (three for each side) worn for 48 hours by a student from Dental School, for biofilm accumulation. After 48 hours each disk was removed and randomly assigned to the control group (to study only plaque accumulation) and to the test group (toinvestigate the effects of the cleaning procedure using tita- nium brushes). All disks were treated by the same operator. The Nickel-Titanium brushes (I.C.T. De Ore, Verona, Italy) were used (one for each disk treated) mounted on a handpiece at 500 rpm speed and 100 N torque for 60 sec time with a calibrated pressure of 25 gr and a continue irrigation of NaCl 0.9%. All disks were then analyzed by SEM at 40x, 500x and 2000x, also in backscattering, and by AFM for the Ra (medium value of roughness) and Rp-v (max peak-max depth value) measurement. All Ni-Ti brushes used were analyzed by SEM and compared to a no used one. RESULTS: The MACHINED surface, after instrumentation, appeared well cleansed. However, the SEM images, revealed considerable surface alterations following treatment. The roughness values increased. The RBM surface showed a mini- mum percentage of residual material and after cleaning had some morphological changes. The typical RBM sandblasted structure appear flattened. The roughness values confirm this change by the reduction in value of R p-v. The cleaning effi- cacy of the brush on the XPEED surface was excellent but the surface morphology changed. The SEM images showed the presence of grooves and flattening caused by the use of brush that have eliminated most of the irregularities and of the peaks, confirmed by the roughness values measured. The EDX spectroscopy provided the evidence that part of the Ca ++ ions coating remains on the surface even after treatment. The statistical analysis shows that the Ra difference was statis- tically significant. (p<0.5) The brush used for Xpeed surface is the only one, among those used, that appeared more com- promised after its use. The bristles are very twisted. CONCLUSIONS: In conclusion we can say that the trial of toothbrushes NiTi has shown a good efficacy of cleansing on rough and smooth surfaces. The efficiency of the treatment was, however, accompanied by a visible change in the surface characteristics. While the machined surface at the end of treat- ment showed an increase of roughness values, the rough sur- faces undergo a flattening process with consequent decrease of the roughness measurements. Further studies will be needed to verify if and how these morphological changes will affect biological processes of healing.

BACKGROUND: To evaluate by means of scanning electron microscopy the effectiveness of different irrigation systems in the removal of calcium hydroxide from round and oval canals. METHODS: 76 extracted single-rooted teeth were selected. Criteria for tooth selection included one single root canal; no visible root caries, fractures, or cracks; and a completely formed apex under light microscope examination (10x). Radiographs in bucco-lingual and mesio-distal direction were taken to cal- culate the ratio between canal diameters measured in the two projections. If ratio was less than or equal to 2.5, the canal was considered round, otherwise was considered oval. According to ratio and root length teeth were divided into 8 groups, with 2 control samples. After access cavity preparation, working length was determined 1 mm short of the length where the file extruded the apical foramen. To simulate clinical conditions the apex was sealed with glue. Glide path and canal instrumentation were performed with Path File size 13, 16, 19 and ProTaper Universal rotary system in a crown-down sequence to size 40 at the WL. A size 25 lentulo spiral was used to fill teeth with calci- um hydroxide. Radiographs were taken to confirm the complete filling of the canals. Samples were kept in an incubator at 37° C for a week. Canals were cleaned with Irrisafe, Endovac, Xp Endo Finisher and conventional endodontic needle irrigation. Teeth were split along their long axis in a bucco-lingual direc- tion into 2 halves. For scanning electron microscopic analysis, tooth halves were fixed on aluminum stubs, gold sputter coated and observed with a scanning electron microscope. Apical, middle, and coronal thirds were established by dividing the roots according to their length. The center of each third was examined at 500x magnification. Images were taken using backscattered mode and analyzed with a digital processing software (ImageJ v. 1.49, National Institutes of Health, NIH, USA) for a quantitative analysis. The efficacy of the irriga- tion system was evaluated calculating the amount of calcium hydroxide left inside the canal, expressed as percentage of the total area of the image. To compare the 8 groups, the results were statistically analyzed using the analysis of variance test (ANOVA) with Bonferroni test or T-test (P<0.05). RESULTS: No statistically significant differences were observed among different thirds for each group. Comparing canal shape for each instrument, significant differences were found only for Endovac, where coronal and middle thirds of oval canals were cleaner than round ones. Analyzing the whole canal, significant difference can be found between irrigation systems and conventional irrigation in the oval ones. In round canals Irrisafe and Xp Endo Finisher are more effective compared to conventional irrigation, but only Irrisafe is more effective compared to Endovac. No statistical- ly significant differences can be observed between Endovac and conventional irrigation. CONCLUSIONS: None of the investigated techniques removed the calcium hydroxide completely. However, the results demonstrate greater removal of calcium hydroxide if the irrigant solutions are activated, compared with conven- tional endodontic irrigation. Therefore, it is recommended to activate the irrigant solutions to enhance chemical debride- ment of the root canal system.

BACKGROUND: Malignant epithelioid hemangioendothelioma, or high-risk epithelioid hemangioendothelioma, is a low- to intermediate-grade vascular malignancy originally described by Weiss and Enzinger in 1982 as a vascular neo- plasm of endothelial origin. Epithelioid hemangioendothelio- mas have been reported in numerous locations, particularly the lungs, liver, soft tissues, viscera, skin, and bone. The World Health Organisation describes MEH as an intermedi- ate malignant neoplasm. MEHs are extremely rare in the oral cavity. Only eleven cases referred to MEH of the maxillary or mandibular gingiva. CASE REPORT: A 33-year-old male was referred to our Oral and Maxillofacial Service in 2009 for the evaluation of a forma- tion on the alveolar mucosa. A panoramic radiograph review showed a radiolucency between lateral incisor and second pre- molar roots. CT scans showed diffuse cortical bone loss. No signs of radiographic root resorption were detected. The patient denied any history of pain or swelling. A tissue punch biopsy was performed by removing two punches of tissue. A microscopic evaluation revealed fragments composed of a proliferation of spindled, ovoid, and epithelioid cells arranged in nests, cords, and short strands. The neoplastic cells were large and polygonal with an abundant and granular cytoplasm, nuclear pleomorphism, and nuclear hyperchromatism. The lesion exhibited small vascular channels with a moderate cel- lular inflammatory infiltrate, composed mainly of lympho- cytes, plasma cells, and eosinophils surrounding the vessels. Focal mitotic activity was identified, and the Ki-67 percentage score was 20%. After immunohistochemistry a diagnosis of MEH was made. No signs of metastasis were detected (cN0) by an investigation of the patient’s neck nodes, computed tomography, and ultrasonography. Anterior mandibular bone excision, including eight teeth and all related soft tissues, was performed under general anesthesia. A histologic examination of the lesion confirmed the diagnosis of MEH. The limits of resection were investigated to ensure clean and safe excision margins. No neck dissection was performed at this time. The patient was followed up at 15 days, 1 month, 3 months, 6 months, and then every 6 months for 4 years with a clinical investigation of soft tissues, clinical and ultrasonographic evaluations of lymph nodes, and radiographic assessment of bone healing. The entire follow-up period was 46 months. DISCUSSION: No consistent clinical or histologic criteria for predicting the biologic behavior of MEHs have been identified. A higher mortality rate is observed when epithelioid hemangioendotheliomas occur in bone, liver, or the lungs; therefore, the importance of immunohistochemical analyses to establish a definitive diagnosis should be emphasised. In this context, the majority of intraoral epithelioid hemangioendothelioma lesions were immunoreactive for CD34, CD31, fac- tor VIII-Rag, and vimentin, which characterise the epithelioid endothelial origin of this entity. It was not possible to identify common risk factors for MEH. The literature review indicated a mean age at diagnosis for MEH of 17±13.01 years, suggesting a predisposition to dis- ease in young people. Systemic metastases have been described in the literature at a rate of 21%, and a mortality rate of 17% has been described for cutaneous MEH, in accordance with the histological aspects of the malignancy. In gingival MEH no metastases has been described in literature before our report. Due to the potential malignancy of epithelioid hemangioen- dotheliomas, wide local excision is the treatment of choice for oral cavity cases according to the literature. The mean recurrence time was 21.33±23.44 months. Given the possibility of recurrence and metastasis several years after clean and safe excision, clinicians should apply at least 5 years of follow-up.

BACKGROUND: There is an ongoing debate in the literature whether patients with oral lichen planus (OLP) carry an increased risk of developing a squamous cell carcinomas. Nevertheless, there is a tendency to accept that there is. The annual malignant transformation rate amounting less than 0.5%. This chronic disorder mainly affects middle-aged people. The etiopathogenesis is still poorly understood. There is no effective treatment and there are no preventive measures either. An important obstacle in the discussion on the possible potentially malignant character of oral lichen planus is caused by the lack of clear clinical and histopathologic diag- nostic criteria of oral lichen planus, resulting in a poor clin- icopathologic correlation in the diagnosis. One of the major problems of interpretation of malignant potential studies of OLP is the inexistence of strict diagnostic criteria to differentiate lichenoid processes. Some studies have included cases of OLP with OLL and vice versa. The differentiation between OLP and OLL has become important, since the latter might have a greater malignant potential. For this reason, it is important to establish precise clinical and histopathological criteria of differentiation of the lesions. CASE REPORT: 1st) A 73 years old woman with a 12 months histological diagnosis of oral lichen planus localized on tongue dorsum, previously biopsied and studied in a differ- ent structure, came to our attention to investigate an ulcerative lesion on tongue midline. No smoking habit, alcohol abuse, anemia or previous malignancies diagnosis were referred; topical corticosteroid therapy was referred. An incisional biopsy was performed showing lichenoid lesion, atypia and high grade of dysplasia at histological examination. Subsequently, lesion was radically removed with wide excision margins. Microscopic examination returned diagnosis of mild differentiated squamous cell carcinoma arose on lichenoid lesion. Resection margins were clean without perineural or vascular invasion. After 18 months follow-up, symptoms of dull pain and burn sensation were referred. Tongue dorsum was macroscopically altered, with an ulcer-like lesion surrounded by edematous mucosa. Consequently, an incisional biopsy was performed showing the presence of a low differentiated squamous cell carcinoma. Lesion was radically excised, margins were widened and examined with frozen sections. Patient underwent to bilateral SND (level I-III) and RTP. Histological examination returns a diagnosis of recurrent pT1 pN1 micro-invasive squamous cell carcinoma. Microscopic signs of lichenoid lesion were still evident. 2nd) A 74 years old woman, with a 20 months history of