Acquired oral syphilis: A multicenter study of 339 patients from South America

OBJECTIVE

To report the clinicopathologic features of acquired oral syphilis cases in South American countries.

MATERIALS AND METHODS

Clinical data were retrospectively collected from the records of 18 oral diagnostic services in Argentina, Brazil, Chile, Colombia, Venezuela, Uruguay, and Peru. Serologies of nontreponemal and treponemal tests were used for diagnosis.

RESULTS

The series comprised 339 cases of acquired oral syphilis. Secondary syphilis ranked as the most common stage (86.7%). Lesions were more frequent among males (58.0%) and young adults with a mean age of 33.3 years. Individuals aged 20-29 years were most affected (35.3%). The most commonly involved sites were the tongue (31.6%), lip/labial commissure (25.1%), and hard/soft palate (20.4%). Clinically, acquired oral syphilis usually presented as mucous patches (28.4%), papules (25.7%), and ulcers (18.1%). Skin manifestations occurred in 67.7% of individuals, while lymphadenopathy and fever were observed in 61.3% and 11.6% of all subjects, respectively. Most patients were treated with the benzathine penicillin G antibiotic.

CONCLUSION

This report validates the spread of acquired oral syphilis infection among young adults in South America. Our directives include accessible diagnostic tools for proper disease screening, surveillance, and counselling of affected individuals, especially in low- and middle-income countries.

In Vivo Evaluation of Permeable and Impermeable Membranes for Guided Bone Regeneration

Background: The degree of biodegradation and the inflammatory response of membranes employed for guided bone regeneration directly impact the outcome of this technique. This study aimed to evaluate four different experimental versions of Poly (L-lactate-co-Trimethylene Carbonate) (PTMC) + Poly (L-lactate-co-glycolate) (PLGA) membranes, implanted in mouse subcutaneous tissue, compared to a commercially available membrane and a Sham group. Methods: Sixty Balb-C mice were randomly divided into six experimental groups and subdivided into 1, 3, 6 and 12 weeks (n = 5 groups/period). The membranes (1 cm²) were implanted in the subcutaneous back tissue of the animals. The samples were obtained for descriptive and semiquantitative histological evaluation (ISO 10993-6). Results: G1 and G4 allowed tissue adhesion and the permeation of inflammatory cells over time and showed greater phagocytic activity and permeability. G2 and G3 detached from the tissue in one and three weeks; however, in the more extended periods, they presented a rectilinear and homogeneous aspect and were not absorbed. G2 had a major inflammatory reaction. G5 was almost completely absorbed after 12 weeks. Conclusions: The membranes are considered biocompatible. G5 showed a higher degree of biosorption, followed by G1 and G4. G2 and G3 are considered non-absorbable in the studied periods.

In Vivo Comparative Evaluation of Biocompatibility and Biodegradation of Bovine and Porcine Collagen Membranes

Mechanical barriers prevent the invasion of the surrounding soft tissues within the bone defects. This concept is known as Guided Bone Regeneration (GBR). The knowledge about the local tissue reaction and the time of degradation of absorbable membranes favors the correct clinical indication. This study aimed to evaluate the biocompatibility and biodegradation of a bovine collagen membrane (Lyostypt^®, São Gonçalo, Brazil) and compare it to a porcine collagen membrane (Bio-Gide^®) implanted in the subcutaneous tissue of mice, following ISO 10993-6:2016. Thirty Balb-C mice were randomly divided into three experimental groups, LT (Lyostypt^®), BG (Bio-Gide^®), and Sham (without implantation), and subdivided according to the experimental periods (7, 21, and 63 days). The BG was considered non-irritant at seven days and slight and moderate irritant at 21 and 63 days, respectively. The LT presented a small irritant reaction at seven days, a mild reaction after 21, and a reduction in the inflammatory response at 63 days. The biodegradation of the LT occurred more rapidly compared to the BG after 63 days. This study concluded that both membranes were considered biocompatible since their tissue reactions were compatible with the physiological inflammatory process; however, the Bio-Gide^® was less degraded during the experimental periods, favoring the guided bone regeneration process.

Nanostructured Carbonated Hydroxyapatite Associated to rhBMP-2 Improves Bone Repair in Rat Calvaria

Many biomaterials are used for Bone Morphogenetic Proteins (BMPs) delivery in bone tissue engineering. The BMP carrier system's primary function is to hold these growth factors at the wound's site for a prolonged time and provide initial support for cells to attach and elaborate the extracellular matrix for bone regeneration. This study aimed to evaluate the nanostructured carbonated hydroxyapatite microspheres (nCHA) as an rhBMP-2 carrier on rats calvaria. A total of fifteen male Wistar rats were randomly divided into three groups (n = 5): clot (control group), rhBMP-2 associated with collagen membrane (COL/rhBMP-2) or associated with the microspheres (nCHA/rhBMP-2). After 45 days, the calvaria defect samples were evaluated through histological, histomorphometric, and SR-µCT analyses to investigate new-formed bone and connective tissue volume densities. The descriptive histological analysis showed that nCHA/rhBMP-2 improved bone formation compared to other groups. These results were confirmed by histomorphometric and SR-µCT analysis that showed substantially defect area filling with a higher percentage of newly formed (36.24 ± 6.68) bone than those with the COL/rhBMP-2 (0.42 ± 0.40) and Clot (3.84 ± 4.57) (p < 0.05). The results showed that nCHA is an effective carrier for rhBMP-2 encouraging bone healing and an efficient alternative to collagen membrane for rhBMP-2 delivery.

Microspheres of alginate encapsulated minocycline-loaded nanocrystalline carbonated hydroxyapatite: therapeutic potential and effects on bone regeneration

Background and objective: Tetracycline and its derivatives, combined with calcium phosphates, have been proposed as a delivery system to control inflammatory processes and chronic infections. The objective of this study was to evaluate the microspheres of alginate encapsulated minocycline-loaded nanocrystalline carbonated hydroxyapatite (CHAMINO) as a biomimetic device to carry out target-controlled drug delivery for alveolar bone repair.

Methods: CHAMINO microspheres were implanted in a rat central incisor socket after 7 and 42 days. New bone was formed in both groups between 7 and 42 days of implantation. However, the bone growth was significantly higher for the CHAMINO microspheres.

Results: The minocycline (MINO) loading capacity of the nanocrystaline carbonated hydroxyapatite (CHA) nanoparticles was 25.1±2.2 µg MINO/mg CHA for adsorption over 24 hrs. The alginate microspheres containing minocycline-loaded CHA were biologically active and inhibited the Enterococcus faecalis culture growth for up to seven days of the MINO release. An osteoblastic cell viability assay based on the resazurin reduction was conducted after the cells were exposed to the CHAMINO powder and CHAMINO microspheres. Thus, it was found that the alginate extracts encapsulated the minocycline-loaded CHA microspheres and did not affect the osteoblastic cell viability, while the minocycline-doped CHA powder reduced the cell viability by 90%.

Conclusion: This study concluded that the alginate microspheres encapsulating the minocycline-loaded nanocrystalline carbonated hydroxyapatite exhibited combined antibacterial activity against Enterococcus faecalis with cytocompatibility and osteoconduction properties. The significant improvement in the new bone formation after 42 days of implantation suggests that the CHAMINO microsphere has potential in clinical applications of bone regeneration.

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite

Objective

This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials.

Methods

Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance.

Results

The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups.

Conclusion

The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria

The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing β-tricalcium phosphate (ZnHA/βZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

Objective

The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA).

Material and Methods

The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance.

Results

The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42^nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7^th day.

Conclusion

CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption.

Early osseointegration driven by the surface chemistry and wettability of dental implants

Objective

The objective of this study was to investigate the impact of two different commercially available dental implants on osseointegration.

The surfaces were

sandblasting and acid etching (Group 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (Group 2).

Material and Methods

X-ray photoelectron spectroscopy (XPS) was employed for surface chemistry analysis. Surface morphology and topography was investigated by scanning electron microscopy (SEM) and confocal microscopy (CM), respectively. Contact angle analysis (CAA) was employed for wetting evaluation. Bone-implant-contact (BIC) and bone area fraction occupied (BAFO) analysis were performed on thin sections (30 μm) 14 and 28 days after the installation of 10 implants from each group (n=20) in rabbits’ tibias. Statistical analysis was performed by ANOVA at the 95% level of significance considering implantation time and implant surface as independent variables.

Results

Group 2 showed 3-fold less carbon on the surface and a markedly enhanced hydrophilicity compared to Group 1 but a similar surface roughness (p>0.05). BIC and BAFO levels in Group 2 at 14 days were similar to those in Group 1 at 28 days. After 28 days of installation, BIC and BAFO measurements of Group 2 were approximately 1.5-fold greater than in Group 1 (p<0.05).

Conclusion

The surface chemistry and wettability implants of Group 2 accelerate osseointegration and increase the area of the bone-to-implant interface when compared to those of Group 1.

Maxillary ameloblastic fibroma: a case report

Ameloblastic fibroma is a relatively rare benign odontogenic tumor in which both the epithelial and ectomesenchymal components are neoplastic. An 8-year-old Caucasian boy was referred to the dentist for evaluation of failed eruption of the maxillary left first molar. The panoramic radiograph showed a well-circumscribed unilocular radiolucency involving an unerupted maxillary left first permanent molar. The lesion was enucleated and the material was sent for histopathologic examination. Microscopically, it was composed by cords and islands of odontogenic epithelium in a myxoid cell-rich stroma that closely resemble the dental papilla with histopathological diagnosis of ameloblastic fibroma. After 24 months of follow-up no recurrence was observed and the maxillary left first molar erupted spontaneously through the buccal mucosa and was aligned with a fixed orthodontic appliance. This case emphasized the importance of careful differential diagnosis of intraosseous oral lesions and reported a rarity of the lesion and its atypical location.