White cell and platelet content affects the release of bioactive factors in different blood-derived scaffolds.

Platelet-derived factors are biomaterials that might accelerate healing process in oral, maxillofacial, and several other applications. Release of specific factors by platelet concentrates is critical to achieving a successful outcome. Here, we have shown that platelet-rich fibrin (PRF) clots were beneficial sources of leukocytes, which may directly affect the release of chemokines and growth factors. When compared with the standard leukocyte-PRF (L-PRF), the experimental low-force modified procedure [defined as advanced-PRF (A-PRF)] entrapped the same content of viable leukocytes, released a similar amount of inflammatory cytokines, but secreted 3-, 1.6-, 3-, and 1.2-fold higher levels of Eotaxin, CCL5, platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF), respectively. A leukocyte-free scaffold, such as plasma rich in growth factors (PRGF), released only platelet-specific factors and, in particular, the F3 fraction, the richest in growth factors, secreted higher amount of CCL5 and PDGF compared to F1 and F2 fractions. In conclusion, different procedures and leukocyte content affect cytokine, chemokines, and growth factor release from platelet derivatives, which may be helpful in different clinical settings.

Parental knowledge, attitude and practice regarding paediatric dental trauma. A systematic review.

AIM: Dental trauma is one of the major oral health problems faced during the developmental ages. Most of the traumatic events occur at home; therefore, parents are frequently required to provide appropriate first aid measures. This systematic review aimed to synthesize the available evidence parents have regarding the topic of dental trauma, with a focus on their level of knowledge, attitude, and practice. METHODS: The systematic review was performed according to PRISMA guidelines. The research question was structured using the PICO framework (PROSPERO ID: CRD42023397318). CONCLUSION: Parents' knowledge about dental trauma management is quite limited, and this has a negative impact on the long-term prognosis of traumatised teeth. It is crucial to increase parents' knowledge and awareness about the importance of dental traumas in paediatric age.

Effect of autoclaving on the surfaces of TiN -coated and conventional nickel-titanium rotary instruments.

AIM: To evaluate the effects of repeated autoclave sterilization cycles on surface topography of conventional nickel-titanium ( NiTi ) and titanium nitride ( TiN )-coated rotary instruments. METHODOLOGY: A total of 60 NiTi rotary instruments, 30 ProTaper (Dentsply Maillefer) and 30 TiN -coated AlphaKite (Komet/Gebr. Brasseler), were analysed. Instruments were evaluated in the as-received condition and after 1, 5 and 10 sterilization cycles. After sterilization, the samples were observed using scanning electron microscope (SEM), and surface chemical analysis was performed on each instrument with energy dispersive X-ray spectroscopy (EDS). Moreover, the samples were analysed by atomic force microscopy (AFM), and roughness average (Ra) and the root mean square value (RMS) of the scanned surface profiles were recorded. Data were analysed by means of anova followed by Tukey's test. RESULT: Scanning electron microscope observations revealed the presence of pitting and deep milling marks in all instruments. EDS analysis confirmed that both types of instruments were composed mainly of nickel and titanium, whilst AlphaKite had additional nitride. After multiple autoclave sterilization cycles, SEM examinations revealed an increase in surface alterations, and EDS values indicated changes in chemical surface composition in all instruments. Ra and RMS values of ProTaper significantly increased after 5 (P = 0.006) and 10 cycles (P = 0.002) with respect to the as-received instruments, whilst AlphaKite showed significant differences compared with the controls after 10 cycles (P = 0.03). CONCLUSIONS: Multiple autoclave sterilization cycles modified the surface topography and chemical composition of conventional and TiN -coated NiTi rotary instruments.

Use of piezosurgery device in management of oral surgery complications: clincal case and clinical experience report.

The root displacement into the maxillary sinus could be a complication of oral surgery in the upper jaw. In these cases, the root removal is needed in order to avoid the occurrence of sinus pathologies. Piezosurgery techniques could assure a safer management of such complications, because of the clear surgical visibility and the selective ability of cut. The aim of this article is to present a case of oral surgery complication (root displacement in the right maxillary sinus), in which piezosurgery technique helped for a correct and safe clinical management, allowing to reduce the soft tissue damage.

In vitro comparative study on the mechanical behavior of Zirconia and Polyetheretherketone in applied dental sciences.

OBJECTIVE: Recently, Zirconia and polyaryletherketone (PEEK) have attracted increasing interest as reliable and safe materials in dental applications, mainly because of their good biomechanical characteristics. The aim of this study was to investigate the response to different loads by prosthetic frameworks for supported fixed partial dentures (FPDs), thus simulating osseointegrated implants. MATERIALS AND METHODS: The specimens were divided into two groups (n= 5 each). Group A: FDPs in zirconia-ceramic; Group B: FDPs in PEEK-composite. These 2 groups were subjected to vertical loads so to evaluate structural deformation; then, they have been analyzed by scanning electron microscopy (SEM) at different magnifications. RESULTS: In tested samples, different types of mechanical failures have been observed. In Zirconia-specimens, chipping is the main failure noticed in this study, mostly in distal margins of the structure. Also, peek-specimens show failure and fracture. CONCLUSIONS: Zirconia and PEEK could be considered both good materials, but several investigations are needed to use these materials as an alternative to metals for fixed partial dentures.

The treatment of the large periradicular endodontic injury.

AIM: Periradicular lesions of endodontic origin are characterized by polymicrobial infections, part of which appear to play a crucial role in the facultative anaerobic bacterical species. In literature there is a strong disagreement about the choice of treatment in large periradicular lesions of endodontic origin: some authors propose the orthograde root canal therapy, others surgical therapy with apicectomia, retrograde filling of the cavity and review instrument. The purpose of this study was to demonstrate the effectiveness of orthograde endodontic treatment in case of periapical lesions of endodontic origin of dimensions larger than 20 mm. METHODS: It was evaluated a sample of 60 cases, ages between 18 and 70 years, 32 men and 28 women. The cases have been treated by orthograde endodontic. Were included mono and pluriradicular teeth with periapical lesion of endodontic origin primary or secondary at endodontic incongruous treatment, with dimensions larger than 20 mm. The sample was divided into Group A: 19 cases in which was possible to complete the root canal therapy in the same event; Group B: 41 cases in which there was drainage. Dressing was applied with pure calcium hydroxide, which was renewed every 10 days for a maximum of 30, was eventually completed the endodontic therapy. RESULTS: Group A: 13 out of 19 cases showed healing at 5 years. Of the remaining 6, there were three failures, a crown-root fracture, missed two follow-up. At 10 years of the 13 successes, 2 cases showed relapse. Group B: 41 cases, later reduced to 30 we had 19 successes in 5 years. Of the remaining 11: 3 crown-root fractures, 2 missed the follow-up, 6 failures. At 10 years of the 19 successes, two were lost because of fracture, one for a relapse. Discussion. The results show the importance of drainage, which can affect the apical seal and therefore the success of endodontic therapy, but allows decompression of the periradicular lesion and symptoms regression. The use of calcium hydroxide in the intermediary dressings allows the neutralization of acidic compounds, alkaline phosphatase activation creating a significant development of the antibacterial action. Proper instrumentation and cleansing of root canals allows the reduction of over one thousand times the bacterial load. The coronal seal has, through the adhesive techniques of restorative materials, a crucial role in closing the doors of entry the bacterial contamination of treated root canals. CONCLUSION: The endodontic therapy by orthograde is considered primary therapeutic choice in case of large endodontic lesions, given the success at rate both 5 (Group A 68,41%, Group B 63,33%) and 10 years (Group A 57.88%, Group B 53.32%).

Extraction of mandibular third molars: proposal of a new scale of difficulty.

We evaluated the accuracy of a new scale of surgical difficulty for the extraction of impacted mandibular third molars, which includes consideration of previously underestimated variables. Two hundred patients with impacted third molars were enrolled, and a preoperative clinical and radiographic assessment of difficulty was made by an oral surgeon using the new index. Five oral surgeons with similar degrees of experience then evaluated the surgical difficulty during operation. The kappa test and weighted kappa were used to evaluate the level of agreement between the preoperative and postoperative evaluations. This was 0.73, which indicated a substantial concordance between the preoperative and postoperative assessments of difficulty indicated by the new scale. The linear weight of kappa was 0.8 and the quadratic weight 0.87. We recommend this new scale of surgical difficulty for the extraction of impacted third molars for use in clinical practice.

Long-Term Fluoride Release from Dental Resins Affects STRO-1+ Cell Behavior.

Fluoride-releasing restorative dental materials can be beneficial to remineralize dentin and help prevent secondary caries. However, the effects of fluoride release from dental materials on the activity of dental pulp stem cells are not known. Here we investigate whether different fluoride release kinetics from dental resins supplemented with modified hydrotalcite (RK-F10) or fluoride-glass filler (RK-FG10) could influence the behavior of a human dental pulp stem cell subpopulation (STRO-1(+) cells) known for its ability to differentiate toward an odontoblast-like phenotype. The 2 resins, characterized by similar physicochemical properties and fluoride content, exhibited different long-term fluoride release kinetics. Our data demonstrate that long-term exposure of STRO-1(+) cells to a continuous release of a low amount of fluoride by RK-F10 increases their migratory response to transforming growth factor ß1 (TGF-ß1) and stromal cell-derived factor 1 (SDF-1), both important promoters of pulp stem cell recruitment. Moreover, the expression patterns of dentin sialoprotein (dspp), dentin matrix protein 1 (dmp1), osteocalcin (ocn), and matrix extracellular phosphoglycoprotein (mepe) indicate a complete odontoblast-like cell differentiation only when STRO-1(+) cells were cultured on RK-F10. On the contrary, RK-FG10, characterized by an initial fluoride release burst and reduced lifetime of the delivery, did not elicit any significant effect on both STRO-1(+) cell migration and differentiation. Taken together, our results highlight the importance of taking into account fluoride release kinetics in addition to fluoride concentration when designing new fluoride-restorative materials.

Evaluation of leakage of bacteria and endotoxins in teeth treated endodontically by two different techniques.

Root canal recontamination occurs after contact between oral-bacterial flora and the coronal extremity of the root canal. The aim of this study was to evaluate the time required for endotoxins and bacteria to penetrate through root-canal obturations performed with vertical and lateral gutta-percha condensation techniques. Specimens prepared by the two alternative methods were exposed to contaminated saliva, and leakage into the root was evaluated over time. None of the obturated roots was infiltrated by endotoxins after 31 days. On the contrary, between day 13 and day 37 bacteria had infiltrated all specimens.

Inhibition by glass-ionomer cements of protein synthesis by human gingival fibroblasts in continuous culture.

The effects of several glass-ionomer cements (Baseline and Chem Fil of De Trey; Ketac Fil and Ketac Bond of ESPE; Vitrebond and Vitremer of 3 M) on the protein synthesis of cultured gingival fibroblasts were studied. The presence of cements in the culture medium inhibited protein synthesis, although the relative effectiveness varied significantly. The cements tested have been ranked in three groups, group A (Chem Fil and Ketac Fil), group B (Ketac Bond and Baseline) and group C (Vitrebond and Vitremer), showing 50, 75 and 100% reduction in protein synthesis, respectively. Incubation of cells with medium previously conditioned by Baseline and Ketac Fil caused only transient inhibition of protein synthesis followed by almost complete recovery. This recovery was not observed when the medium was conditioned with Vitrebond. A characterization of the factors determining the inhibitory effect of one cement in each group was attempted. The cements, irrespective of the type, produced small but reproducible decreases in the pH of the medium but released fluoride ions to a different extent. Both changes in the pH of the medium and in the fluoride concentration inhibited protein synthesis by cultured gingival fibroblasts. The different action of cements can be explained, at least in part, by a differing release of fluoride ions.

[Hyperthrophic-hyperplastic gingival diseases. Etiopathogenic, clinical assessment and diagnostic guide]. / Le gengivopatie ipertrofico-iperplastiche. Inquadramento etiopatogenetico, clinico ed indirizzi diagnostici.

The clinical and histological aspects of hypertrophic and hyperplastic gum diseases were examined in order to clarify the aetiopathogenesis of such conditions and facilitate their diagnosis. The latter is far from simple, given the variety of pathological pictures expressing a large number of conditions that present macroscopic similarities despite their different aetiopathogenesis.

[Vertical and lateral canal obturation technics: an SEM study]. / Tecniche di otturazione canalare: verticale e laterale al S.E.M.

After a critical review of the literature on root canal filling techniques, an SEM study of the differences between the vertical and lateral condensation techniques is described.

[Desquamative gingivitis: etiopathogenetic and clinical assessment]. / La gengivite desquamativa: inquadramento etiopatogenetico e clinico.

The aetiopathogenetic, diagnostic, clinical and therapeutic aspects of a particular form of gingival condition given various names in the past but presently defined as "chronic desquamative gingivitis" have been examined. Desquamative gingivitis is an uncommon clinical condition whose aetiology remains uncertain. It has therefore not yet been definitely established wether it is a specific entity or whether, as is confirmed by much clinical evidence and laboratory data, it is merely an oral clinical sign of dermatological type pathologies (pemphigus vulgaris, benign mucosal pemphigoid, bullous pemphigoid, erosive lichen ruber planus, psoriasis).

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.