Denture Base Resin Coated with Titanium Dioxide (TiO2): A Systematic Review

Background

The main objective of this systematic review was to evaluate the effect of coating with titanium dioxide nanoparticles (TiO2 nanoparticle) on the surface condition of removable acrylic resin prosthetic base materials.

Methods

Our review is registered in the PROSPERO database under the identification code CRD42023397170. Electronic database searches of PubMed, Scopus and Science Direct including studies from January 2009 to January 2023 were conducted and supplemented with manual searches. Research questions were generated in accordance with the PICO strategy. The modified Consolidated Standards of Reporting Trials (CONSORT) checklist was used to evaluate the quality of the selected studies.

Results

Since the included studies were variable in design, a meta-analysis was not performed. The electronic searches retrieved 29 references that met the eligibility criteria, among which 5 studies matched the inclusion criteria for this review. Significant differences were detected between the TiO2 NP-coated and uncoated groups. The available data indicate that TiO2 NP coating elicits antimicrobial activity and improves the wear resistance of polymethylmethacrylate (PMMA) surfaces. Moreover, the nanoparticles provide high levels of glossiness and decelerate the process of color change of heat-cured acrylic resin, thus increasing the lifespan of dentures.

Conclusion

The collective results clearly indicate that TiO2 nanoparticle coating induces alterations in the surface properties of pure PMMA, enhancing the mechanical, physical and biological characteristics of the denture base material. Further studies are essential to identify the optimal thickness of coating and concentrations of nanoparticles for clinical applications.

Impression techniques in Removable partial denture: epidemiological study

INTRODUCTION

Various impression techniques are used in the realization of free-end extension partial denture, one of the imperatives is to respect the compressibility and behavior of the tissue during impression making as well as during function.

AIM

To evaluate the knowledge and practices of private practitioners regarding secondary impressions made during the management of terminal edentulism with metallic removable partial denture, and to search for possible correlations between prosthetic complaints and non-compliance with the various final impression standards in terms of materials, equipment and techniques.

METHODS

The study involved a sample of dentists practicing in the Rabat-Sale-Kenitra region in the Kingdom of Morocco. The paper questionnaire was filled out in face-to-face interviews or by the dentists themselves. The computerized questionnaire was sent to the dentists by e-mail or via various social network platforms. A descriptive and analytical statistical study was carried out to treat the data.

RESULTS

Following the results of the statistical study: (57.6%) used the alginate as a secondary impression material, (66%) used individual trays, 17% used models from primary impressions for direct prosthesis fabrication, (17%) used the cast impression technique in free end mandibular edentulous. (77%) recorded the peripheral joint in Kennedy Applegate class I and II, concerning the complaints; practitioners who worked with more than one impression material or those who use solely the alginate encountered a combination of similar complaints (75%).

CONCLUSION

The practices of the dentists differ in terms of materials and techniques used in the management of edentulous terminals by removable partial denture (RPD). The complaints expressed by patients were independent of the method used in the secondary impression. The results of our survey concur with the fact that until today there is no consensus to demonstrate that a technique, or a material can be more reliable for the stability and the success of the RPD.

Maintaining occlusal stability by selecting the most appropriate occlusal scheme in complete removable prosthesis

The search of an adequate occlusal scheme that maximizes dentures’ stability and patients’ satisfaction is an ultimate objective in every complete prosthodontic treatment. Many studies compared occlusal schemes in terms of retention, comfort and masticatory performance. The purpose of this article is to review literature about different occlusal schemes related to complete dentures’ stability and edentulous patients’ satisfaction, in order to select the most appropriate occlusal scheme. Thus, an electronic search was performed from PubMed (MEDLINE), Scopus, Cochrane, Google Scholar and Sciencedirect databases. 65 articles were identified of which 56 were selected to compose the present article. Within the limitations of this review, it has been concluded that edentulous patients prefer anatomic occlusal schemes to non-anatomic teeth. Furthermore, canine guidance seems to be efficace in terms of chewing comfort and dentures’ retention, as well as lingualized occlusion. However, bilateral balanced occlusion does not confer a long-term masticatory performance and satisfaction to edentulous patients.

Toxoplasma gondii: taux de portage chez les ovins de la région de Marrakech (Mnabha)

Toxoplasma gondii is an ubiquitous parasite with a prevalence variable from country to country. In Morocco very few studies were devoted to this prevalence. To fill this gap we were interested to study the epidemiology of this parasite and to know the level of carriage by the different vectors which are the sources of contamination in humans. The study was done by directly detecting the cysts in the cerebral tissue of the 50 sheep killed and destined for consumption. The results of this preliminary study show that 30% of the cases carry the cysts of T. gondii. To confirm this result and verify the virulence, cerebral specimens were inoculated into mice. These findings are encouraging to complete this study with serological tests and to look for the parasite in cows and goats of this region.

[A giant chondroblastic osteosarcoma of the mandible. A case report]

INTRODUCTION

Osteosarcoma of the craniofacial bones location is less common, usually with low grade of malignancy; it has better prognosis when surgical excision is complete.

REPORT CASE

We report a case of a 35-year-old male diagnosed with a low-grade chondroblastic osteosarcoma of the mandible. The patient was treated with surgery alone and recovered with pectoralis major myocutaneous flap. After 48 months, the oncology's and aesthetics results are good.

DISCUSSION

We will discuss the treatment of chondroblastic osteosarcoma of the mandible.

[Vascular epulis or lobular capillary hemangioma]

Vascular epulide or Lobular capillary hemangioma is a form of epulide which is marked by an inflammatory infiltrate rich of blood vessels. Angiogenic factors seem to be responsible of the important vascular proliferation. Therapeutic implications include cautions toward hemorrhagic risk. Complete ablation is also required to avoid the risk of high recurrence.

Carcinosarcome de la peau

BACKGROUND

Carcinosarcoma of skin is a biphasic tumor composed of intimately admixed malignant epithelial and mesenchymal components. Various terms have been used to designate these tumors (metaplastic carcinoma, pseudosarcoma, spindle cell carcinoma, etc.). However, the histogenetic conception has changed and carcinosarcoma is currently regarded as authentic sarcomatoid carcinoma.

CASE REPORT

The authors report the case of a 32-year-old women initially presenting with a budding and ulcerating tumor at the site of an old cutaneous scar on the right leg. Histopathological and immunohistochemical evaluation led to a diagnosis of cutaneous carcinosarcoma. One month after treatment, the patient developed inguinal lymph node metastasis.

DISCUSSION

Our case and a review of other cases in the literature confirm the dual epithelial and sarcomatous phenotype of sarcomatoid carcinoma. Progressive transition between the cells of the two components on microscopic analysis and their positive immunostaining for anti-p53 antibody suggest a clonal origin of the tumor. The carcinomatous component seems to influence the course of the disease with the development of metastases, particularly at the lymph nodes. It thus seems advisable to combine lymphadenectomy with surgical tumor excision.

[Uterine carcinosarcoma in a teenager: report of a case macroscopically mimicking rhabdomyosarcoma]

Uterine carcinosarcoma (malignant mixed mullerian tumor) is uncommon. We report the case of a 17-year-old patient who complained of pelvic pain and abnormal genital bleeding, and had a voluminous hemorrhagic tumor protruding through the vaginal os. Hysterectomy was performed. The histopathologic and immunohistochemical evaluation led to the diagnosis of uterine carcinosarcoma. Adjuvant chemotherapy was given. In spite of the surgical treatment, the evolution was fatal with widespread metastases. From data of the literature, we discuss the diagnosis, histogenesis and treatment of this rare tumor.

[Pleuropulmonary blastoma: possible interest of neoadjuvant chemotherapy. A case report]

Pleuropulmonary blastoma is a very exceptional anatomoclinical and histological entity recently distinguished from adult pneumoblastoma. This tumor, observed in children aged less than 15, can involve the lung, the pleura, or the mediastinum and is characterized by a very poor prognosis. We report the case of a 4-year-old girl who developed pleuropulmonary blastoma which was discovered in a context of respiratory distress. Standard chest x-ray revealed an opacity covering the entire left lung. Histology and immunohistology led to the diagnosis of pleuropulmonary blastoma with several components: blastematous, malignant mesenchymatous with pluridirectional differentiation, and benign epithelial tissue. Treatment consisted in preoperative chemotherapy and radiotherapy to reduce tumor volume. This neoadjuvant treatment is not widely reported and its relatively favorable result allowed tumor resection. This approach might be useful in similar cases.

[Accuracy of intraoperative diagnosis in central nervous system tumors: report of 1315 cases]

Clinicians order neurosurgery frozen sections in order to answer three questions: is the specimen tumor tissue? is it benign or malignant? what is its histological type? We studied the diagnostic accuracy of 1 315 frozen sections of central nervous system tumors, performed between 1988 and 1999, and compared it with data in the literature. Agreement between intraoperative and paraffin-section diagnosis was 96.6% (rate of error: 3.4% for the question tumor tissue or not). The answer was concordant in 92.6% with a 7.4% rate of error for tumor malignancy or benignity. Exact histological concordance was 87.6%. The most frequent errors in histological typing concerned gliomas, hemangioblastomas and metastasis. Our results emphazise the reliability of intraoperative frozen sections in Neurosurgery and the importance of close collaboration between clinicians, radiologists and pathologists.

[Pelvic actinomycosis simulating adnexal malignant tumor]

The purpose of this report is to describe the case of a 35-year-old patient admitted to the National Oncology Institute in Rabat, Morocco for pelvic pain and deteriorating general status ongoing for 8 months. Clinical and ultrasonographic examination showed a heterogenous mass measuring 7 cm in maximum width located inferior and lateral to the inferior aspect of the right side of the uterus. These findings were suggestive of a malignant tumor of the right ovary. Ovariectomy and omentectomy were performed. Histological examination of surgical specimens demonstrated right tubo-ovarian actinomycosis associated with peritonitis. Genital tract actinomycosis is an uncommon finding in women of childbearing age. It is due to colonization by a pyogenic bacteria (Actinomyces) usually secondary to a gastrointestinal infection, e.g. ileocecum, and sometimes in association with the presence of an intrauterine device or foreign body. Based on this case report, the authors discuss abdominopelvic actinomyocosis with emphasis on tumor-like findings that can lead to misdiagnosis by clinicians and radiologists.