Medication-related osteonecrosis in torus palatinus: Report of a case and literature review

BACKGROUND

Medication-related osteonecrosis of the jaw bones have been frequently reported. However, its occurrence in torus palatinus is very rare with only 10 cases published in the English-language literature.

CASE REPORT

We describe an additional case in a 79-year-old woman, who was referred for evaluation of a painful swelling with areas of suppuration on the hard palate.

CONCLUSION

Conservative treatment was performed and after spontaneous sequestrectomy, total healing was achieved.

Contribution of public oral pathology services to the diagnosis of oral and oropharyngeal cancer in Brazil

This study aimed to evaluate the contribution of oral and maxillofacial pathology laboratories (OMPLs) in Brazilian public universities to the diagnosis of lip, oral cavity, and oropharyngeal squamous cell carcinoma (SCC). A cross-sectional study was performed using biopsy records from a consortium of sixteen public OMPLs from all regions of Brazil (North, Northeast, Central-West, Southeast, and South). Clinical and demographic data of patients diagnosed with lip, oral cavity, and oropharyngeal SCC between 2010 and 2019 were collected from the patients' histopathological records. Of the 120,010 oral and maxillofacial biopsies (2010-2019), 6.9% (8,321 cases) were diagnosed as lip (0.8%, 951 cases), oral cavity (4.9%, 5,971 cases), and oropharyngeal (1.2%, 1,399 cases) SCCs. Most cases were from Brazil's Southeast (64.5%), where six of the OMPLs analyzed are located. The predominant profile of patients with lip and oral cavity SCC was Caucasian men, with a mean age over 60 years, low schooling level, and a previous history of heavy tobacco consumption. In the oropharyngeal group, the majority were non-Caucasian men, with a mean age under 60 years, had a low education level, and were former/current tobacco and alcohol users. According to data from the Brazilian National Cancer Institute, approximately 9.9% of the total lip, oral cavity, and oropharyngeal SCCs reported over the last decade in Brazil may have been diagnosed at the OMPLs included in the current study. Therefore, this data confirms the contribution of public OMPLs with respect to the important diagnostic support they provide to the oral healthcare services extended by the Brazilian Public Health System.

Oral squamous cell carcinoma cancer stem cells have different drug sensitive to pharmacological NFκB and histone deacetylation inhibition

Despite many progresses in the development of new systemic therapies for oral squamous cell carcinoma (OSCC), the five-year survival rate of OSCC is low. The traditional chemotherapies approach (cisplatin - CDDP) shows some limitations like drug toxicity, limited efficacy, and drug resistance. Promising studies suggested OSCC cancer stem cells (CSC) presented resistance to CDDP. We have previously studied many targets, and we extensively showed the efficacy of the NFκB signaling and the role of histones acetylation, on different malignant tumors, including adenoid cystic carcinoma and mucoepidermoid carcinoma, but until then the effects of the NFkB inhibitor and histone deacetylase (HDAC) inhibitor on the biology of OSCC were not evaluated. Here we assessed the pharmacological inhibitor of NFκB emetine and HDAC inhibitor SAHA on the behavior of CSC derived from OSCC. Our data suggested that CDDP administration resulted in reduced viability of bulk OSCC cells and increased CSC. A single and isolated shot of emetine and SAHA were able to disrupt CSC by inhibiting the NFκB pathway and increasing the histone acetylation levels, respectively. Further, the combined administration of emetine and SAHA presented the same CSC disruption as seen in emetine alone.

Oral follicular lymphoma: a clinicopathologic and molecular study

Follicular lymphoma is a hematolymphoid neoplasm that originates from germinal center B cells. It is made up of a combination of small cleaved centrocytes and a varying quantity of larger non-cleaved centroblasts to describe the clinical, microscopic, immunohistochemical, and molecular features of oral follicular lymphomas. Follicular lymphomas affecting the oral cavity were retrieved from pathology files. Immunohistochemistry was performed to confirm the diagnosis, and fluorescence in situ hybridization (FISH) was employed to detect rearrangements in BCL2, BCL6, and MYC genes. Clinical and follow-up data were obtained from the patient's medical and pathology files. Twenty cases were obtained. There was an equal sex distribution (10 males: 10 females) and a mean age of 60.9 years (range: 10-83 years-old). Lesions presented as asymptomatic swellings, usually in the palate (10 cases) and the buccal mucosa (7 cases). Five patients presented with concomitant nodal involvement. Microscopic evaluation depicted the follicular growth pattern with diffuse areas in six cases. Grades 1 and 2 follicular lymphomas represented 12 cases, while grade 3A neoplasms accounted for other 8 cases. Two cases showed rearrangements in MYC, BCL2, and BCL6 genes, while single BCL2 translocation was found in eight cases. Two cases had no translocation. Three patients deceased and the 2-year overall survival achieved 88%. Follicular lymphoma affecting the oral cavity is uncommon, usually affects the palate as a non-ulcerated swelling and the presence of a systemic disease most always be ruled out.

Clinicopathological Features of Metastasis to the Oral and Maxillofacial Region-Multicenter Study

BACKGROUND

This study aimed to investigate the clinicopathological features of metastases in the oral and maxillofacial regions.

METHODS

In this retrospective study, biopsy records were obtained from referral centers for oral and maxillofacial diagnosis in Brazil, Guatemala, Mexico, and South Africa.

RESULTS

A total of 120 cases were evaluated. Of these, 53.78% affected female patients, with a mean age of 57.64 years. Intraosseous lesions were more frequent, particularly in the posterior region of the mandible (49.58%). Clinically, most cases presented with symptomatic swelling, with an average evolution time of 25 months. The clinical diagnostic hypothesis in most instances was that of a malignant lesion. Breast cancer was the most common primary tumor location in females, while lung origin was most common in males. In most cases, the primary cancer was an adenocarcinoma (44.73%). The follow-up period was available for 29 cases, and out of these, 20 had died due to the disease.

CONCLUSION

Although this is a rare condition, clinicians should be aware that any oral lesions have the possibility of being metastatic, particularly in individuals with a previous history of cancer. The findings from this study could assist clinicians in prompt diagnosing these lesions and subsequent conducting oncologic assessments and treatment.

Human Papillomavirus-Associated Oral Epithelial Dysplasia: Report of 5 Illustrative Cases from Latin America

BACKGROUND

Human papillomavirus-associated oral epithelial dysplasia (HPV-OED) is a distinct oral epithelial disorder characterized by viral cytopathic changes caused by transcriptionally active high-risk HPV. The aim of the present study was to report 5 additional cases from Latin America.

METHODS

Clinical data from five patients with HPV-OED were obtained from the archives of three oral pathology services from Brazil and Chile. All cases were submitted to morphological, p16 expression and in situ hybridization (ISH) for HPV analyses.

RESULTS

Four patients were male and one patient was female, with a mean age of 55.4 years. Four patients were HIV seropositive and two were smokers. Three cases affected the buccal mucosa and commissure, one of which had an additional plaque in the soft palate, and one case each occurred on the floor of mouth and lower labial mucosa. Most cases presented as well-demarcated white plaques with a verrucous surface. One case presented multiple lesions ranging from normal to white-colored slightly elevated plaques with a cobblestone surface. Peripheral mucosal pigmentation was observed in two cases. All five cases presented with the characteristic microscopic features of HPV-OED, including severe dysplasia with numerous karyorrhectic and apoptotic cells, full-thickness "block positivity" for p16 and high Ki-67 index (> 90%) sharply demarcated from the adjacent non-dysplastic epithelium. Wide-spectrum DNA ISH-HPV was positive in 4 cases. All patients were treated with conservative surgical excision with no signs of recurrence after a mean of 39-month follow-up.

CONCLUSION

This represents the first series of HPV-OED from Latin America; most cases presented as well-demarcated papillary white plaques affecting the buccal mucosa and commissure of HIV-positive middle-aged men, two of them exhibiting peripheral pigmentation caused by reactive melanocytes. The typical microscopic findings of HPV-OED were observed in all cases, which also showed strong p16 positivity in a continuous band through the full thickness of the epithelium and high Ki67.

Sociodemographic and clinical characterization of cases of 1,103 non-syndromic and 66 syndromic odontogenic keratocyst: a Brazilian multicenter study

OBJECTIVES

This multicenter study aimed to evaluate cases of non-syndrome and syndromic odontogenic keratocyst, as well as cases of recurrence within these two groups.

METHODS

This descriptive, analytical, retrospective cross-sectional study evaluated the sex, age and presence of multiple lesions in 1,169 individuals seen at 10 Brazilian oral and maxillofacial pathology centers. Of these, 1,341 odontogenic keratocysts were analyzed regarding clinical diagnosis, size, site, imaging appearance, signs and symptoms, type of biopsy, treatment, and recurrence.

RESULTS

There was a similar distribution by sex. The median age of non-syndromic and syndromic patients was 32 and 17.5 years, respectively. The posterior mandible was the site most affected by small and large lesions in both groups and in recurrent cases. Unilocular lesions were more frequent, also in recurrent cases. Mainly small lesions showed this imaging appearance. Signs and symptoms were absent in most cases. Conservative treatment was the most frequent modality in all age groups, regardless of the patient's condition and recurrence. Recurrences were uncommon.

CONCLUSION

This study showed a higher frequency of non-syndromic keratocysts in the population. Clinicopathological features related to the involvement of multiple sites, age, and recurrence may differ between syndromic and non-syndromic cases. Furthermore, we found an association between lesion size and some clinical features and between the time interval to recurrence and the syndromic spectrum.

CLINICAL RELEVANCE

To contribute to a better understanding of the distribution and association between clinical, imaging, and sociodemographic characteristics in each spectrum of the lesion.

The altered metabolic pathways of diffuse large B-cell lymphoma not otherwise specified

Altered metabolic fingerprints of Diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS) may offer novel opportunities to identify new biomarkers and improve the understanding of its pathogenesis. This study aimed to investigate the modified metabolic pathways in extranodal, germinal center B-cell (GCB) and non-GCB DLBCL NOS from the head and neck. Formalin-fixed paraffin-embedded (FFPE) tissues from eleven DLBCL NOS classified according to Hans' algorithm using immunohistochemistry, and five normal lymphoid tissues (LT) were analyzed by high-performance liquid chromatography-mass spectrometry-based untargeted metabolomics. Partial Least Squares Discriminant Analysis showed that GCB and non-GCB DLBCL NOS have a distinct metabolomics profile, being the former more similar to normal lymphoid tissues. Metabolite pathway enrichment analysis indicated the following altered pathways: arachidonic acid, tyrosine, xenobiotics, vitamin E metabolism, and vitamin A. Our findings support that GCB and non-GCB DLBCL NOS has a distinct metabolomic profile, in which GCB possibly shares more metabolic similarities with LT than non-GCB DLBCL NOS.

A primary oral mucosal melanoma of the hard palate with no recurrence: Report of a 10 years follow-up

BACKGROUND

Primary oral mucosal melanoma (OMM) represents an extremely rare and aggressive tumor that arises from malignant transformation and clonal expansion of melanocytes in the oral cavity. The prognosis of patients affected by OMM is quite unfavorable, with survival rates lower than those described for patients with cutaneous melanoma.

CASE REPORT

Here, we report a case of OMM in a 59-year-old Caucasian woman, who was referred for evaluation of a large asymptomatic pigmented lesion on the left side of the hard palate under the removable total denture. Incisional biopsy was performed, and histopathological analysis revealed the proliferation of spindle-shaped and pigmented epithelioid cells, with cellular pleomorphism. These cells were positive for Melan A, S-100, HMB-45, SOX-10, and Ki-67 confirming the diagnosis of OMM. The patient underwent partial maxillectomy and adjuvant radiotherapy. After treatment, she was rehabilitated with a palatal obturator prosthesis and has been in follow-up for 10 years with no evidence of disease. Due to the rarity in the oral cavity and the nonspecific signs and symptoms, the diagnosis of OMM is difficult and often overlooked.

CONCLUSION

Therefore, multidisciplinary management from diagnosis, treatment, and rehabilitation is important to increase the expectation of cure.

Clinical diagnostic approach for oral lymphomas: a multi-institutional, observational study based on 107 cases

OBJECTIVE

To evaluate oral lymphomas' clinical manifestations and investigate whether clinical features are associated with lymphoma subtypes.

STUDY DESIGN

Oral lymphomas with at least 1 representative clinical image were evaluated. They were classified according to their microscopic grade (high vs low), predominant cell size (small vs medium/large), and cellular lineage (B cell vs T cell). Clinical images were described according to tumor location, number, swelling, ulcer, necrosis, telangiectasia, predominant color, and lobulation. Lymphomas affecting the palate were compared with salivary gland tumors (SGTs) affecting this location.

RESULTS

Data from 107 cases were included. High-grade subtypes (80.4%), with medium/large-sized cells (52.3%), and diagnosed as diffuse large B cell lymphomas (29%) predominated. High-grade lymphomas often presented as painful, ulcerative, and osteolytic diseases (P < .05). Tumors predominantly composed of medium/large-sized cells were associated with painful lesions, ulcerated, with necrosis and bone destruction (P < .05). When only palate tumors were considered, multiple and bilateral lesions, the presence of pain, ulceration, and necrosis were significantly more associated with a diagnosis of lymphoma than SGT (P < .001).

CONCLUSION

High-grade oral lymphomas are more associated with destructive presentation than low-grade subtypes, and bilateral lesions in the palate are more associated with a lymphoma diagnosis than SGT.

Oral and maxillofacial tuberculosis: A systematic review

OBJECTIVES

This study aimed to analyze the demographic, clinical, histopathological, diagnosis, treatment, and follow-up data on the occurrence of oral and maxillofacial tuberculosis (OMTB).

METHODS

Electronic searches without publication date restrictions were undertaken in four databases. Case reports and case series describing the occurrence of OMTB were included. Critical evaluation of studies was done using the Joanna Briggs Institute - University of Adelaide tool for case reports or case series.

RESULTS

A total of 217 studies were included in the qualitative synthesis, for a total of 301 cases of OMTB. Of these patients, 192 (63.7%) were male, with an average age of 39.6 ± 19.8 (15 months to 81 years). The tongue (n = 80/26.6%) represented the most common affected site, followed by the mandible (n = 43/14.3%). The clinical presentation consisted mainly of a painful ulcerated lesion (n = 156/56.5%). Histopathological analysis showed a granulomatous inflammation in most cases (n = 156/63.1%). The main diagnostic methods used were sputum test (n = 53/26.8%), culture (n = 49/24.7%) and purified protein derivative (PPD), or Mantoux test (n = 49/24.7%). Antituberculosis therapy was used in 244 cases (100.0%) and 5.2% of patients died.

CONCLUSIONS

This systematic review provided clinical, demographic data and information about diagnostic methods of OMTB lesions and served as an important guide to assist health professionals in the early diagnosis of these lesions.

Clinicians' perception of oral potentially malignant disorders: a pitfall for image annotation in supervised learning

OBJECTIVE

The present study aims to quantify clinicians' perceptions of oral potentially malignant disorders (OPMDs) when evaluating, classifying, and manually annotating clinical images, as well as to understand the source of inter-observer variability when assessing these lesions. The hypothesis was that different interpretations could affect the quality of the annotations used to train a Supervised Learning model.

STUDY DESIGN

Forty-six clinical images from 37 patients were reviewed, classified, and manually annotated at the pixel level by 3 labelers. We compared the inter-examiner assessment based on clinical criteria through the κ statistics (Fleiss's kappa). The segmentations were also compared using the mean pixel-wise intersection over union (IoU).

RESULTS

The inter-observer agreement for homogeneous/non-homogeneous criteria was substantial (κ = 63, 95% CI: 0.47-0.80). For the subclassification of non-homogeneous lesions, the inter-observer agreement was moderate (κ = 43, 95% CI: 0.34-0.53) (P < .001). The mean IoU of 0.53 (±0.22) was considered low.

CONCLUSION

The subjective clinical assessment (based on human visual observation, variable criteria that have suffered adjustments over the years, different educational backgrounds, and personal experience) may explain the source of inter-observer discordance for the classification and annotation of OPMD. Therefore, there is a strong probability of transferring the subjectivity of human analysis to artificial intelligence models. The use of large data sets and segmentation based on the union of all labelers' annotations holds the potential to overcome this limitation.

Cell block preparation as an adjunctive tool after fine-needle aspiration cytology for screening oral and maxillofacial diseases

OBJECTIVE

To describe the use of cell block (CB) preparation from fine-needle aspiration cytology for diagnosing oral and maxillofacial diseases.

STUDY DESIGN

We performed a retrospective analysis of 568 samples collected by our laboratory for CB preparation from fine-needle aspiration cytology of the oral and maxillofacial region between January 2001 and October 2021. We performed cytologic diagnoses and compared them with the available histopathologic diagnoses to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CB preparation for identifying malignant lesions.

RESULTS

The most frequent diagnosis was pleomorphic adenoma (n = 44, 7.7%), followed by metastatic squamous-cell carcinoma (n = 28, 4.9%) and odontogenic keratocyst (n = 26, 4.6%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CB preparation, which revealed detailed morphologic and architectural patterns, were 70.0%, 100.0%, 100.0%, 62.5%, and 80.0%, respectively.

CONCLUSIONS

Cell block preparation from fine-needle aspiration cytology of the oral and maxillofacial region may be a useful adjunctive diagnostic tool for diagnosing oral and maxillofacial diseases because it reveals morphologic and architectural patterns similar to those shown on histopathologic slides, leading to the better categorization of diseases.

The importance of early treatment of oral squamous cell carcinoma: Case report

BACKGROUND

Oral squamous cell carcinoma (OSCC) is frequently diagnosed at an advanced stage, with the five-year survival rate varying around 50%, however, ifs the sooner OSCC in early-stage is treated, the lower the chances of recurrence and death. In this study, we described an OSCC diagnosed early, highlighting how the early surgical excision prevents the morbidity.

CASE REPORT

A 74-year-old man presented a whitish and symptomatic plaque and a discreet ulcerated area on the right lateral border of the tongue. Due to close contact with the second inferior molar, a clinical diagnosis of a frictional keratosis was suspected, however as the lesion persisted after two weeks of follow-up, an incisional biopsy was performed and the microscopic features revealed an OSCC. Early surgical resection was performed, preventing the morbidity and improve benefits to patient.

CONCLUSION

OSCC can manifest of several clinical forms, including indolent appearances, which can delay the diagnosis, and consequently the prognosis. Further, it is important to recognize and not neglect any intraoral lesions, in order to avoid the far more invasive surgery that a more advance disease would imply.

Clinicopathological study and survival outcomes of sialoblastoma: A systematic review

Sialoblastoma is a rare malignant salivary gland tumor. The aim of this study was to review the available published data on sialoblastoma in a comprehensive analysis of its clinicopathologic characteristics, treatment, and outcomes. An unrestricted electronic search was performed in the following databases: MEDLINE/PubMed, EMBASE, Scopus, Web of science, and gray literature databases. Eligibility criteria included publications with sufficient clinical, imaging, and histopathological information to confirm the diagnosis of sialoblastoma. Data were evaluated descriptively and analytically. A total of 52 studies met the eligibility criteria. In total, 62 patients were evaluated. There was no gender predilection, with the parotid being the most affected primary site (n = 28; 45.2%). In the log-rank test, there was a significant increase in disease-associated survival in patients younger than 1 year of age (82.8% vs. 44.4%; p = 0.003), individuals with lesions in major salivary glands (79.4% vs. 38.5%; p = 0.005), patients without metastases (77.8% vs. 14.3%; p = 0.011), encapsulated lesions (85.7% vs. 0%; p < 0.0001), congenital lesions (83.3% vs. 25.0%; p < 0.0001), and lesions that do not show perineural invasion (89.5% vs. 40%; p = 0.035). Kaplan-Meier curves estimated overall survival and disease-free survival at 5 years of 95.5% and 68.1%, respectively. In the multivariate Cox regression model, only the presence of metastasis was identified as an independent prognostic factor (hazard ratio [HR] = 9.81; p = 0.010). Although sialoblastoma presents good prognosis, the tumor has a high recurrence rate.

Acinic cell carcinoma of the oral and maxillofacial region: an international multicenter study

The aim of this study was to describe the prevalence, clinicopathological, and prognostic features of acinic cell carcinoma (AciCC) of the oral and maxillofacial region. AciCC cases were retrospectively retrieved from 11 pathology centers of three different countries. Medical records were examined to extract demographic, clinical, pathologic, and follow-up information. A total of 75 cases were included. Females (65.33%) with a mean age of 45.51 years were mostly affected. The lesions usually presented as an asymptomatic (64.28%) nodule (95.66%) in the parotid gland (70.68%). The association of two histopathological patterns was the most common finding (48.93%) and the tumors presented mainly conventional histopathological grades (86.11%). Surgical treatment was performed in the majority of the cases (59.19%). Local recurrence was observed in 20% of the informed cases, regional metastasis in 30.43%, and distant metastasis in 12.50%. The statistical analysis showed that the cases with a solid histopathological pattern (p=0.01), high-grade transformation (p=0.008), recurrence (p=0.007), and regional metastasis (p=0.03) were associated with poor survival. In conclusion, high histopathological transformation, presence of nodal metastasis, and recurrence were prognostic factors for AciCC of the oral and maxillofacial region.

SYMPTOMATIC SUBGEMMAL NEUROGENOUS PLAQUE IN PATIENTS WITH COVID-19: IS THERE AN ASSOCIATION?

BACKGROUND

Subgemmal neurogenous plaques (SNP) are composed of neural structures found in the posterolateral portion of the tongue, rarely biopsied as most of them are asymptomatic or eventually only clinically managed. We aimed to investigate a case series of possible correlation of symptomatic subgemmal neurogenous plaque (SNP) with coronavirus disease 2019 (COVID-19).

METHODS

Eleven formalin-fixed paraffin-embedded cases from patients with previous confirmed COVID-19 (by RT-PCR) were retrieved from two pathology files. Histological sections were morphologically studied, and then submitted to immunohistochemical reactions against S-100 and neurofilament proteins, neuron-specific enolase, Glial fibrillary acidic protein (GFAP), synaptophysin, CD56, Ki67, cytokeratins (7, 8-18, 19, 20), nucleocapsid and spike proteins (SARS-CoV-1; and -2) and epithelial membrane antigen (EMA) antibodies. Clinical data were retrieved from the patients' medical files, including the symptoms and the complete history of the progression of the disease.

RESULTS

The patients who had COVID-19 included in this study experienced painful lesions in the tongue that corresponded to prominent or altered SNP. Microscopically, neural structures were positive for S-100, GFAP and neurofilament protein. And the cellular proliferative index (by Ki-67) was very low.

CONCLUSION

Thus, based on the current results, we hypothesize that symptomatic SNP may be a late manifestation of COVID-19 infection. This article is protected by copyright. All rights reserved.

Revisiting the evidence of photodynamic therapy for oral potentially malignant disorders and oral squamous cell carcinoma: an overview of systematic reviews

BACKGROUND

This study summarized the available evidence about the use of photodynamic therapy (PDT) for the management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC).

METHODS

An overview of systematic reviews was undertaken based on the 2020 PRISMA statement. Electronic searches were performed in five databases. Studies published up to November 2022 were included. Risk of bias was assessed with the AMSTAR 2 tool.

RESULTS

A total of 30 studies enrolling 9,245 individuals with OPMD (n=7,487) or OSCC (n=1,758) met the selection criteria. All studies examined the efficacy and/or safety of PDT. OPMD were investigated individually in 82.8% of the studies, the most common being oral lichen planus and actinic cheilitis. OSCC was addressed separately in 10.3% of the studies, while only 6.9% evaluated both OPMD and OSCC. Fourteen different types of photosensitizers were described. PDT was used according to the following setting parameters: 417-670 nm, 10-500 mW/cm², 1.5-200 J/cm², and 0.5-143 minutes. Regarding OPMD, leukoerythroplakia showed the best response rates, while oral lichen planus presented a partial or no response in nearly 75% of documented cases. A complete response was observed in 85.9% of OSCC cases, while 14.1% had no resolution.

CONCLUSION

Overall, the response to PDT depended on the type of OPMD/OSCC and the parameters used. Although PDT is an emerging candidate for the treatment of OPMD and OSCC, there is heterogeneity of the methodologies used and the clinical data obtained, particularly regarding the follow-up period.

Epithelial salivary gland tumors in pediatric patients: An international collaborative study

OBJECTIVE

Salivary gland tumors (SGT) are a diverse group of uncommon neoplasms that are rare in pediatric patients. This study aimed to characterize the clinicopathological profile of pediatric patients affected by SGT from a large case series derived from an international group of academic centers.

STUDY DESIGN

A retrospective analysis of pediatric patients with SGT (0-19 years old) diagnosed between 2000 and 2021 from Brazil, South Africa, and the United Kingdom was performed. SPSS Statistics for Windows was used for a quantitative analysis of the data, with a descriptive analysis of the clinicopathological characteristics and the association between clinical variables and diagnoses.

RESULTS

A total of 203 cases of epithelial SGT were included. Females were slightly more commonly (56.5%), with a mean age of 14.1 years. The palate was the most common site (43.5%), followed by the parotid gland (29%), lip (10%), and submandibular gland (7.5%). The predominant clinical presentation was a flesh-colored, smooth, and painless nodule. Pleomorphic adenoma (PA) was the most frequently diagnosed SGT (58.6%), followed by mucoepidermoid carcinoma (MEC) (26.6%). Surgery (90.8%) was the favored treatment option.

CONCLUSIONS

Benign SGT in pediatric patients are more commonly benign than malignant tumors. Clinicians should keep PA and MEC in mind when assessing nodular lesions of possible salivary gland origin in pediatric patients.

Impact of photobiomodulation in a patient-derived xenograft model of oral squamous cell carcinoma

BACKGROUND

Photobiomodulation therapy (PBMT) is an effective method for the prevention of oral mucositis. However, the effects of PBMT on oral squamous cell carcinoma (OSCC) have not yet been fully elucidated. This study aimed to evaluate the impact of PBMT in an OSCC-patient-derived xenograft (OSCC-PDX) model.

METHODS

BALB/c nude mice with OSCC-PDX models were divided into Control, without PBMT (n = 8); Immediate irradiation, PBMT since one week after tumor implantation (n = 6); and Late irradiation, PBMT after tumors reached 200 mm³ (n = 6). OSCC-PDX were daily irradiated (660 nm; 100 mW; 6 J/cm² ; 0,2 J/point) for 12 weeks. The tumors were collected and submitted to volumetric, histological, immunohistochemistry, and cell cycle analysis.

RESULTS

No significant differences in the volumetric measurements (p = 0.89) and in the histopathological grade (p > 0.05) were detected between the groups. The immunohistochemical analysis of Ki-67 (p = 0.9661); H3K9ac (p = 0.3794); and BMI1 (p = 0.5182), and the evaluation of the cell cycle phases (p > 0.05) by flow cytometry also did not demonstrate significant differences between the irradiated and non-irradiated groups.

CONCLUSION

In this study, PBMT did not impact the behavior of OSCC-PDX models. This is an important preclinical outcome regarding safety concerns of the use of PBMT in cancer patients.

Lymphomas Affecting the Sublingual Glands: A Clinicopathological Study

BACKGROUND

Lymphomas affecting the sublingual glands are extremely rare and very few case reports are currently available. Therefore, the aim of the current study is to describe the clinicopathological features of a series of lymphomas involving the sublingual glands.

METHODS

Cases diagnosed in four pathology services were assessed and the formalin-fixed paraffin-embedded tissue blocks were retrieved for diagnosis confirmation. Clinical data were obtained from patients' medical files.

RESULTS

We obtained seven cases of lymphomas in the sublingual glands, representing two follicular lymphomas, two diffuse large B cell lymphomas not otherwise specified (DLBCL NOS), two extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphomas) and one mantle cell lymphoma (MCL). In all cases the tumor cells infiltrated the glandular parenchyma, although in two of them the neoplastic cells were located more superficially and permeated the glandular acini and ducts. Clinically, the tumors presented as asymptomatic nodules and two patients (affected by DLBCL NOS and MCL) died, while the other five patients remained alive at last follow-up.

CONCLUSION

Lymphomas affecting the sublingual glands are usually of the mature B cell lineage, often represent low-grade subtypes and may clinically resemble other more common lesions in the floor of the mouth like salivary gland tumors.

Synchronous jawbone diseases: a multicenter retrospective study

The aim of this study is to report an original case series of synchronous jawbone diseases. Data of patients seen over 13 years were extracted from the files of three Oral Radiology and Pathology diagnostic centers in Brazil. The clinical, radiographic, and laboratory characteristics were tabulated and analyzed by the authors; the patients were described according to lesion type. Seventy-two synchronous jawbone diseases were included in this study. Florid osseous dysplasia, Gorlin-Goltz syndrome, and cherubism were the most frequent disorders reported in this case series. In addition, the posterior mandible area was the main site of manifestation. Florid osseous dysplasia and Gorlin-Goltz syndrome represented two-thirds of our samples. With the utilization of adequate demographic, clinical, and radiologic information, it is possible to diagnose most of the synchronous lesions of jawbones. Sometimes, however, we need complementary exams, such as histopathologic and biochemical analysis or dosing of calcium, phosphorus, and alkaline phosphatase.

Active search screening for oral potentially malignant disorders and oral cancer in the city of Piracicaba

Oral cancer is a public health problem worldwide with approximately 300,000 new cases diagnosed every year and more than 170,000 deaths annually. Squamous cell carcinoma (SCC) accounts for approximately 90% of all oral malignancies and it is frequently preceded by lesions known as oral potentially malignant disorders (OPMDs). Screening programs for early detection of oral lesions have been conducted. Therefore, the objective of this research was to carry out an active search in a screening program in the city of Piracicaba, Brazil. High-risk patients were identified at the city's health center through their medical records and referred for dental consultation. Other patients who opportunistically sought dental care were also seen and if they did not present risk factors for SCC, they were considered low-risk. A total of 756 patients were examined, and 445 met the criteria for the high-risk group and 311 for the low-risk group. It was possible to diagnose 27 OPMDs and six SCCs - 21 OPMDs and six SCCs occurred in high-risk patients and six OPMDs in low-risk patients. A chi-square test was applied and a statistically significant value (p = 0.006) was obtained for the detection of OPMD and SCC in patients of the high-risk group. Screening of high-risk patients through active search proved to be an effective program for diagnosing OPMD and SCC. Therefore, we encourage its implementation on a large scale to reduce the current scenario of this disease.

Repurposing NFκB and HDAC inhibitors to individually target cancer stem cells and non-cancer stem cells from mucoepidermoid carcinomas

Drug resistance remains a major obstacle in the treatment of mucoepidermoid carcinomas (MEC) leading to tumor recurrence, disease progression, and metastasis. Emerging evidence suggests that drug resistance is mediated by the presence of a highly adaptative subpopulation of cancer cells known as cancer stem cells (CSC). We have previously reported that solid tumors use NFkB signaling as a chemotherapy-resistant mechanism. We have also shown that interfering with the epigenome of solid tumors is an effective strategy to control the population of CSC. Here, we sought to investigate the effects of the NFkB inhibitor emetine and the HDAC inhibitor SAHA on the biology of MEC CSC and assessed whether this combination therapy would favor the standard of care therapy comprised of the administration of Cisplatin (CDDP). Our findings suggested that the administration of low concentrations of emetine and SAHA is more effective in disrupting CSC in MEC, while the administration of emetine in combination with CDDP constitutes an effective therapy to target non-CSC MEC tumor cells.

A meta-analysis reveals the protein profile associated with malignant transformation of oral leukoplakia

The search for biomarkers associated with oral leukoplakia malignant transformation is critical for early diagnosis and improved prognosis of oral cancer patients. This systematic review and meta-analysis aimed to assess protein-based markers potentially associated with malignant transformation of oral leukoplakia. Five database and the grey literature were searched. In total, 142 studies were included for qualitative synthesis, where 173 proteins were investigated due to their potential role in malignant progression from oral leukoplakia (OL) to oral squamous cell carcinoma (OSCC). The abundance of these proteins was analyzed in fixed tissues and/or biofluid samples, mainly by immunohistochemistry and ELISA, and 12 were shared by both samples. Enrichment analysis revealed that the differential abundant proteins are mostly involved with regulation of cell death, regulation of cell proliferation, and regulation of apoptotic process. Also, these proteins are mainly expressed in the extracellular region (55.5%), cell surface (24.8%), and vesicles (49.1%). The meta-analysis revealed that the proteins related to tumor progression, PD-L1, Mdm2, and Mucin-4 were significantly associated with greater abundance in OSCC patients, with an Odds Ratio (OR) of 0.12 (95% CI: 0.04-0.40), 0.44 (95% CI: 0.24-0.81), and 0.18 (95% CI: 0.04-0.86), respectively, with a moderate certainty of evidence. The results indicate a set of proteins that have been investigated across OSCC initiation and progression, and whose transcriptional expression is associated with clinical characteristics relevant to the prognosis and aggressiveness. Further verification and validation of this biomarkers set are strongly recommended for future clinical application.

Effect of bleaching gels with different thickeners under normal and hyposalivation conditions: in situ study

BACKGROUND

Bleaching gel thickeners induce important changes in tooth enamel and these changes are reversed by saliva.

OBJECTIVE

This in situ study aimed to evaluate the effect of bleaching gels with different thickeners on tooth enamel under normal and hyposalivation conditions.

METHODOLOGY

Of 28 participants, 14 had normal salivary flow and 14 had low salivary flow. For each salivary flow, four types of treatment were performed with different thickeners: no bleaching (negative control), bleaching with a commercial 10% carbamide peroxide (CP) gel with carbopol (positive control) and bleaching with experimental 10% CP gels with natrosol and aristoflex. Participants used a palatal appliance containing bovine enamel/dentin specimens for 15 days. From day 2 to day 15, specimens were bleached extraorally. The bleaching gel was applied according to the groups for four hours. When the bleaching gel was removed, the palatal appliance was inserted again in the participants' mouth until the next day for another bleaching application. This procedure was repeated for 14 days and on day 15, surface microhardness (SMH), color (ΔE*ab and ΔE00), surface roughness (Ra), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometry (EDS) analyses were performed and data were subjected to statistical analysis.

RESULTS

Neither salivary flow nor thickeners influenced ΔE*ab and ΔE00 results. Carbopol had the lowest SMH, the highest Ra, and the lowest Ca% among all groups. For normal flow, natrosol and aristoflex had higher SMH. For low flow, aristoflex had higher SMH and natrosol and aristoflex had lower Ra. Aristoflex had higher Ca% and Ca/P and differed from carbopol for normal flow.

CONCLUSION

For normal flow, 10% CP gels with natrosol and aristoflex caused fewer surface changes, and for low flow, only the 10% CP gel with aristoflex.

Tongue hamartomas in pediatric patients: an international case series and literature review

This study reports 9 additional tongue hamartomas in children paired with a literature review. A retrospective analysis was performed from 3 Oral Pathology laboratories. Additionally, a literature review was conducted through 5 electronic databases and gray literature. A total of 9 cases were identified in the retrospective analysis. Females outnumbered males with a ratio of 1.25:1. The age of presentation ranged from 2 weeks to 7 years. The posterior dorsum tongue was the most affected subsite (n = 4). One case was seen in a patient with oro-facial-digital syndrome, 2 cases in patients with cleft palates, and one case with an encephalocele. The most common predominant component was salivary gland tissue (n = 4). A literature search included 79 pediatric patients presenting with 95 tongue hamartomas. A slight female (n = 47) predilection was observed, with ages varying from 15 hours to 19 years. The posterior tongue dorsum (n = 31) was the most affected site. Seven cases were seen in association with syndromes. The most common predominant component was smooth muscle (n = 35). Although hamartomas are rare in the oral cavity, they should be considered in the differential diagnosis of masses involving the posterior tongue dorsum in children.

To extract or not extract teeth prior to head and neck radiotherapy? A systematic review and meta-analysis

PURPOSE

Teeth with poor prognosis are generally recommended to be extracted prior to head and neck radiotherapy (RT) to reduce the risk of developing osteoradionecrosis (ORN), although controversies have been reported. The present systematic review aimed to determine whether tooth extraction prior to head and neck RT may be associated with a reduced risk of developing ORN compared to dental extraction during or after RT.

METHODS

The review protocol was registered in PROSPERO (CRD42021241631). The review was reported according to the PRISMA checklist and involved a comprehensive search of PubMed, Scopus, Embase, Cochrane Library, LILACS, and Web of Science, in addition to the gray literature. The selection of studies was performed in two phases by two reviewers independently. The risk of bias of individual studies was analyzed using the Joanna Briggs Institute checklist for cross-sectional studies, and the certainty of evidence was assessed using the GRADE tool.

RESULTS

Twenty-eight observational studies were included in the qualitative synthesis, which showed substantial heterogeneity regarding the association between the timing of tooth extraction and ORN development. Twenty-seven of 28 studies were pooled in a meta-analysis that demonstrated a significant association between an increased risk of ORN and post-RT tooth extraction (odds ratio: 1.98; 95% CI: 1.17-3.35; p = 0.01).

CONCLUSION

It was confirmed with moderate certainty that dental extractions should be performed prior to the start of head and neck RT to reduce the risk of ORN.

Brazilian organic propolis for prevention and treatment of radiation-related oral acute toxicities in head and neck cancer patients: A double-blind randomized clinical trial

Background: Oral mucositis (OM) is one of the most important acute toxicities from radiotherapy (RT) in head and neck cancer patients and can impair oncologic treatment. Dysphagia, dysgeusia, pain, and oral candidiasis are other common toxicities. Brazilian Organic Propolis (BOP) is a recently described propolis variant and BOP types 4 and 6 have shown important antioxidant, anti-inflammatory, and antifungal properties.

Purpose: To investigate the use of BOP as a preventive and/or complementary therapeutic option for radiotherapy-induced oral mucositis, dysphagia, dysgeusia, pain, and oral candidiasis. Additionally, proinflammatory cytokines were assessed to investigate their anti-inflammatory role.

Methods: Sixty patients were included in this randomized, double-blind, controlled clinical trial. Patients were randomized to receive either aqueous suspension of a BOP or placebo throughout RT. Also, all patients underwent low-level laser therapy as routine oral care. OM, dysphagia, and dysgeusia were assessed weekly according to WHO and NCI scales. Pain-related to OM was assessed according to a Visual Analog Scale and the presence or absence of oral candidiasis was checked by intraoral examination. Protein levels of TNF-α and IL-1β from oral mucosa were assessed by ELISA.

Results: Patients in the propolis group had a lower mean score of OM, dysphagia, dysgeusia, and most patients reported moderate pain. Fewer patients developed oral candidiasis in the propolis group, and the number of episodes was lower among patients that used BOP (p &lt; 0.05). In addition, the BOP group presented significantly lower levels of IL-1β since the beginning of treatment when compared with placebo patients (p &lt; 0.05) and a lower level of TNF-α at the end of treatment (p &lt; 0.001).

Conclusion: Topic use of BOP reduced TNF-α and IL-1β levels, oral candidiasis episodes, and seems to be a useful complementary option for the prevention and treatment of the main acute oral toxicities of RT.

Clinical Trial Registration:http://www.ensaiosclinicos.gov.br/rg/RBR-9f8c78/, identifier RBR-9f8c78

Sézary syndrome: Report of a rare case with perioral manifestation and review of the literature

This report aimed to describe a rare case of Sézary syndrome (SS) diagnosed in an Oral Medicine service. A 54-year-old female presented a generalized pruritus and erythema of the skin of 2 years in duration, which had been treated with antihistamines, corticosteroids, and hydrating creams, without resolution. Extra-oral examination showed a painful lymphadenopathy on the right supraclavicular region. Ultrasound-guided fine-needle aspirationbiopsy did not detect any abnormalities. The patient's skin was remarkably dry and thickened, with erythroderma, fissures, and ulcerations. The perioral region exhibited extreme peeling and angular cheilitis. Immunophenotyping of peripheral blood revealed proliferation of undifferentiated T-cells and a massive proportion of TCD4+ cells relative to TCD8+ cells. PET/CT examination demonstrated multiple lymphadenopathies, and bone marrow biopsy was negative for neoplastic cell infiltration. A diagnosis of SS was established, and the patient is currently being treated with UVB phototherapy, methotrexate, doxepin, and folic acid, with mostly complete regression of signs and symptoms.

Molecular profile of head and neck rhabdomyosarcomas: A systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to identify the molecular alterations of head and neck rhabdomyosarcomas (HNRMS) and their prognostic values.

STUDY DESIGN

An electronic search was performed using PubMed, Embase, Scopus, and Web of Science with a designed search strategy. Inclusion criteria comprised cases of primary HNRMS with an established histopathological diagnosis and molecular analysis. Forty-nine studies were included and were appraised for methodological quality using the Joanna Briggs Institute Critical Appraisal tools. Five studies were selected for meta-analysis.

RESULTS

HNRMS predominantly affects pediatric patients (44.4%), and the parameningeal region (57.7%) is the most common location. The alveolar variant (43.2%) predominates over the embryonal and spindle cell/sclerosing types, followed by the epithelioid and pleomorphic variants. PAX-FOXO1 fusion was observed in 103 cases of alveolar RMS (79.8%). MYOD1 mutation was found in 39 cases of sclerosing/spindle cell RMS (53.4%). FUS/EWSR1-TFCP2 gene fusions were identified in 21 cases of RMS with epithelioid and spindle cell morphologies (95.5%). The 5-year overall survival rate of patients was 61.3%, and MYOD1 mutation correlated with significantly higher mortality.

CONCLUSION

The genotypic profile of histologic variants of HNRMS is widely variable, and MYOD1 mutation could be a potential prognostic factor, but more studies are required to establish this.

Over 300 Radiation Caries Papers: Reflections From the Rearview Mirror

Radiation caries (RC) is an aggressive oral toxicity in head and neck cancer survivors, which develops 6 to 12 months after head and neck radiotherapy. It initially affects the tooth cervical/incisal surfaces, and if not promptly diagnosed/managed, progresses to dental crown amputation and risk of osteoradionecrosis. It results from a multidimensional cluster of treatment-induced oral symptoms, including hyposalivation, dietary changes, and oral hygiene impairment. Although recognized as a frequent complication of radiotherapy and extensively assessed by a myriad of retrospective, in vitro, and in situ studies, RC patients are still orphans of clinically validated methods for risk prediction, prevention, and treatment of early lesions. This review provides a historical overview of science-based concepts regarding RC pathogenesis and treatment, emphasizing the growing demand for interventional clinical studies (randomized trials).

Diagnostic accuracy of a telediagnosis service of oral mucosal diseases: A multicentric survey

OBJECTIVE

The aim of this multicentric study was to assess the diagnostic accuracy of a telediagnosis service for oral mucosal disorders.

STUDY DESIGN

This study included 100 patients seen at the oral medicine outpatient clinic of 3 Brazilian Dental Schools (University of Campinas, Federal University of Pernambuco, and Federal University of Santa Catrina) from March 2019 to October 2019. In addition to the face-to-face assistance provided by graduate students and the final diagnosis validated by the professors of these institutions, a remote evaluation was requested for these patients through the EstomatoNet/TelessaúdeRS platform.

RESULTS

The sensitivity and specificity of telediagnosis were compared with those of the face-to-face approach and found to be 100% and 97.4%, respectively. The concordance between the examiners was 95%, and case management was relatively simple in approximately 60% of cases.

CONCLUSIONS

Based on the results, telediagnosis for oral diseases can be considered a reliable method, representing a promising alternative for the clinical support of health professionals, particularly in remote locations.

State-of-the-science concepts of HPV-related oropharyngeal squamous cell carcinoma: a comprehensive review

High-risk (HR) human papillomavirus (HPV) infection is recognized as a primary etiologic factor of anogenital cancers and more recently of a subgroup of oropharyngeal squamous cell carcinomas (OPSCC). The incidence of HPV-related OPSCC has increased dramatically in several developed countries in the past 3 decades and is currently the most common cancer caused by HR-HPV in the United States and Germany, surpassing cervical cancer. Consequently, the patient's demographic and clinicopathologic profile has shifted to nonsmoking and nondrinking younger men with higher schooling level and with a history of multiple oral sex partners. Patients with HPV-related OPSCC often show better treatment outcomes and higher survival rates than their HPV-unrelated counterparts, which has led to a change in tumor staging for HPV-related cases. HPV vaccination is emerging as an effective primary prevention strategy, and systematic screening of HPV DNA in blood and salivary oral rinse samples of HR patients is being examined to determine if it may provide a surveillance method and support early diagnosis of HPV-related OPSCC. In this context, a narrative review was conducted to provide an overview of the state-of-the-art of HPV-related OPSCC, including epidemiology, risk factors, clinicopathologic and molecular features, screening, prevention, management, and prognosis.

Adenocarcinoma not otherwise specified (NOS) arising in the sublingual gland: Rare case report and follow-up

BACKGROUND

Adenocarcinoma not otherwise specified (AdCaNOS) is a rare malignant salivary gland tumor that occurs with higher frequency in the parotid gland of male patients. In this study, we described a second case of AdCaNOS arising in the sublingual gland, in a female patient with 39 years of age, highlighting the clinical, radiographic, microscopic, treatment features and follow-up.

CASE REPORT

A 39-year-old female patient presented a fibroelastic nodule with a yellowish coloration, in the left region of the floor of mouth, measuring about 4.0 cm in its largest diameter. An incisional biopsy was performed and the main microscopic features revealed an infiltrative lesion with glandular differentiation organized in cystic spaces, where neoplastic cells secreting eosinophilic material were observed. The tumor showed immunopositivity for pancytokeratin (AE1/AE3), keratins 7 (CK7) and 14 (CK14), and negativity for p63. The proliferation level measured by Ki-67 marker was considered higher. The patient underwent radical surgical resection, but unfortunately, she developed local recurrence, lymph node mestastasis and died 1.5 year after diagnosis.

CONCLUSION

Although rare in the sublingual gland, particularly at this age, AdCaNOS can occur and early diagnosis and early treatment are essential for a better prognosis and survival rates of the patients.

Oral leukoplakia in adolescents: Report of a rare case and review of the literature

The aim of this report was to describe a rare case of leukoplakia in a young patient without any risk factors for squamous cell carcinoma. An 18-year-old male patient presented with an asymptomatic white lesion on the right lateral border of the tongue. Microscopic examination of the excisional biopsy specimen displayed hyperkeratosis and acanthosis without epithelial dysplasia, which were consistent with the clinical diagnosis of oral leukoplakia. The patient is undergoing systematic and regular evaluation, and after 28 months of follow-up, no recurrence has been observed. This report showed that, although uncommon, adolescents and/or young adults can also be affected by oral potentially malignant disorders. Therefore, dentists should be aware of this condition to establish the proper diagnosis and management.

Cephaeline is an inductor of histone H3 acetylation and inhibitor of mucoepidermoid carcinoma cancer stem cells

AIM

To evaluate the potential use of Cephaeline as a therapeutic strategy to manage mucoepidermoid carcinomas (MEC) of the salivary glands.

MATERIAL AND METHODS

UM-HMC-1, UM-HMC-2, and UM-HMC-3A MEC cell lines were used to establish the effects of Cephaeline over tumor viability determined by MTT assay. In vitro wound healing scratch assays were performed to address cellular migration while immunofluorescence staining for histone H3 lysine 9 (H3k9ac) was used to identify the acetylation status of tumor cells upon Cephaeline administration. The presence of cancer stem cells was evaluated by the identification of ALDH enzymatic activity by flow cytometry and through functional assays using in vitro tumorsphere formation.

RESULTS

A single administration of Cephaeline resulted in reduced viability of MEC cells along with the halt on tumor growth and cellular migration potential. Administration of Cephaeline resulted in chromatin histone acetylation as judged by the increased levels of H3K9ac and disruption of tumorspheres formation. Interestingly, ALDH levels were increased in UM-HMC-1 and UM-HMC-3A cell lines, while UM-HMC-2 showed a reduced enzymatic activity.

CONCLUSION

Cephaeline has shown anti-cancer properties in all MEC cell lines tested by regulating tumor cells' viability, migration, proliferation, and disrupting the ability of cancer cells to generate tumorspheres.

Antimicrobial profile of a dental implant abutment coating to prevent adhesion and migration of bacteria and screw loosening

OBJECTIVE

Failure of dental implants treatment is frequently the result of bacterial colonization of implants followed by diseases like peri-implantitis. Recent studies have been made regarding the surface treatment of implants components, namely abutments that are in the interface of the living tissue with the implant. This work aimed at evaluating the antimicrobial profile of a silane-based coating with TiO₂ adapted to an abutment screw, that was also developed as an anti-loosening agent, to prevent adhesion and migration of Gram + and Gram-bacteria, Staphylococcus aureus, and Escherichia coli, respectively.

METHODS

Direct contact antimicrobial studies were conducted on coated and uncoated samples by resazurin fluorescent assay and cytotoxicity assessment was done via MTT indirect method on days 1 and 4. Sterilizations studies by FTIR analysis were also performed to understand the ideal balance between sterilization efficacy and coating functionality subjecting the samples to ethylene oxide, gamma irradiation, and autoclave sterilization, before antimicrobial testing. The implant system as a whole was also studied for its ability to block bacterial migration and preventing microleakage as well as an assessment of initial bacterial adhesion evaluated by scanning electron microscopy.

RESULTS

Direct contact studies performed on coated samples showed a very high antimicrobial activity, while cytotoxicity assays revealed the coating to be safe and non-leachable. Sterilizations studies showed that the antimicrobial features of the coating were preserved and interchangeable regardless of the sterilization method. The implant system migration studies demonstrated that the implant system works as an efficient barrier for the studied bacteria.

SIGNIFICANCE

The acquired results clearly show that it is possible to obtain a highly functional coating with obvious and marked antimicrobial features that together with an abutment that prevents bacterial migration and versatility in sterilization methodology has a very high potential in the dental implant field.