Surgical obturator duplicating original tissue-form restores esthetics and function in oral cancer

Oral cancer treatment primarily focused on the surgical removal of cancer tissues followed by surgical/prosthetic reconstruction. Restoration of the missing structures immediately after surgery shortens recovery time and allows patient to return to community as a functioning member. The most practiced surgical obturators are simple resin prosthetic bases without incorporation of the teeth. This article highlights a technique to fabricate a surgical obturator that duplicates patient’s original tissue form including teeth, alveolus and palatal tissues. The obturator is placed immediately after surgery and make patient feel unaware of surgical deformity. The obturator prosthesis fabricated with this technique supports soft tissues and minimizes the scar contracture. We have clinically tried this technique in 11 patients. Patients’ satisfaction level was recorded on visual analogue scale (VAS) and it ranges between 74% and 94% (with average of 87%). Four different prosthodontists have visually evaluated facial asymmetry of patients at 6 mo recall and their average perception on VAS varies between 71% and 93% (with average of 84%).

Effects of different root canal preparation methods on root fracture resistance: A systematic review of the literature

AIM: To study the root fracture resistance after root canal preparation with Ni-Ti rotary instruments and stainless hand instruments by means of meta-analysis.

METHODS: Literature was researched in CNKI and CBMDisc, PubMed, CALIS, Proquest, Web of Science and 11 kinds of Chinese or English dentistry journals. Retrieval time on Internet was in all years and hand retrieval time was from January 2013 to October 2013. The literatures were selected through reading abstracts and full texts by two reviewers independently and Revman 5 software was used to analysize the literature.

RESULTS: Six articles met the inclusion criteria. According to Meta-analysis of tooth root bending properties, total standardized mean difference (SMD) was 0.63 (95%CI: -0.24-1.50, P > 0.05). That indicated there was no statistically significant between the two groups. Subgroup analysis was carried out. SMD were 2.22 (95%CI: 0.23-4.20, P < 0.05) and -0.61 (95%CI: -1.05- -0.17, P < 0.05) when the premolar teeth with a single canal or the mesiobuccal roots of molars were used as the materials for tests to compare the effects of different root canal preparation methods on root fracture resistance. That only indicated that there were statistically significant in two subgroups.

CONCLUSION: In vitro experiments, the effects on the fracture resistance of root had no statistical difference with Ni-Ti rotary instruments and stainless steel hand instruments in root canal preparation.

Subconscious temporomandibular dysfunction therapy: A new therapeutic approach for temporomandibular disorders

AIM: To evaluate a new therapeutic approach that may permanently address excessive involuntary muscle activity which causes temporomandibular disorders (TMD).

METHODS: A cohort of 69 TMD patients (33 men and 36 women, age range 14-71 years) was treated with Subconscious Temporomandibular Dysfunction (STeDy) therapy. A thick awareness splint assisted patients to gradually recognize the interdependence between psychological pressure and subconscious muscle activity. The STeDy therapy lasted for one year and involved three stages: (1) data collection including medical history, clinical examination and psychological evaluation; (2) application of the awareness splint and consultation on a monthly basis; and (3) final evaluation.

RESULTS: About 10% of patients (3 men and 4 women) quit the STeDy therapy within the first 3-6 mo due to severe health problems or psychosocial reasons. Based on the absence of objective and subjective clinical symptoms as well as on radiographic findings, the temporomandibular dysfunction treatment was successful in all remaining 62 patients that completed the year-long therapy. Symptoms, including recurrent headache, morning fatigue, clicking sound or painful temporomandibular joint disorders, were eliminated in all patients within the first six months. By completion of the STeDy therapy, all patients had learned to recognize stressful conditions and cognitively avoided displaying excessive bruxism or other subconscious activity of the stomatognathic muscles. A follow-up after at least one year indicated the permanent nature of the cognitive treatment in all patients, illustrating the fact that subconscious muscle activity due to stress plays a principal role in the great majority of TMD, at least in adults.

CONCLUSION: The STeDy therapy successfully and permanently resolved TMD problems of all patients that completed the year-long treatment.

Molar incisor hypomineralization and pre-eruptive intracoronal lesions in dentistry-diagnosis and treatment planning

The aim of this study is to report the diagnostic features, prevalence, mineral content, clinical significance and treatment options of molar incisor hypomineralization (MIH) and pre-eruptive intracoronal lesions (PEIR), in order to minimize miss-treatment of primary and permanent teeth in young children. MIH was defined as the occurrence of hypomineralization of one up to four permanent first molars from a systemic origin and frequently associated with affected incisors. PEIR are lesions that are located in the occlusal portion of the crown of unerupted permanent or primary teeth. The prevalence of MIH was reported between 2.5%-40% in the permanent first molars and 0%-21.8% in primary second molars. PEIR was observed in 2%-8% of children, mainly in mandibular second premolars and second and third permanent molars. A number of possible causes for MIH were mentioned, including environmental changes, diet and genetics in prenatal and postnatal periods, but all are questionable. In PEIR, the resorption of the intracoronal dentine begins only after crown development is complete and is caused by giant cells resembling osteoclast observed histologically on the dentine surface close to the pulp. The mineral content in MIH is reduced in comparison to normal enamel and dependent on the severity of the lesion. In PEIR the resorbed surface of enamel showed less mineral content. The hypomineralized enamel in MIH is not suitable for restorations with amalgam or composite materials, and the best material should be based on remineralization material like glass-ionomers. Similar, the resorbed dentin surface in PEIR should be covered by the biocompatible and re-mineralizing glass-ionomer cement.

Melkersson-Rosenthal syndrome

Melkersson-Rosenthal syndrome (MRS) is a rare, non-caseating granulomatous disorder of unknown etiology and undefined diagnostic criteria. The classical triad of recurrent orofacial edema, relapsing facial paralysis, and fissured tongue, is not frequently seen in its complete form, and many patients remain misdiagnosed or undiagnosed for years. The purpose of this study is to review the findings in the literature describing the Melkersson-Rosenthal syndrome with aim to identify its clinical and histopathological characteristics and correlate them with definitive diagnostic criteria and effective treatment modalities. A systematic review and analysis of more than 100 publications met eligibility criteria performed by the authors. Orofacial edema of unknown etiology is the most typical clinical feature of the Melkersson-Rosenthal syndrome. Its coexistence with of facial nerve palsy or fissured tongue could be characterized as an oligosymptomatic MRS. Many investigators suggest cheilitis granulomatosa as a monosymptomatic form of MRS, while patients with facial palsy and fissured tongue, without orofacial edema, should not be considered having MRS. Histological evidence is not necessary. Corticosteroids are generally accepted as the mainstay treatment.

Tissue restoration after improper laser gingivectomy: A case report

We report the case of 27-year-old female patient applied to our clinic with several pain at her upper teeth and weakness complaints. Anamnesis revealed that she experienced laser gingivectomy to have remarkable teeth. Clinical examination showed that maxillar alveolar bone was partially uncovered with gingivae and periosteum. Interproximal necrosed area was observed. She had sensitivity at her maxillar anterior teeth. Furthermore, she was so anxious and depressed. In order to ensure more blood supply and clot formation, perforations on uncovered cortical bone was prepared. Avoiding from infection antibiotic, antiseptic gel and for epithelization vitamin E gel were prescribed. During one month she was recalled every third day. Recall times diminished periodically, as new tissue evolves. Although laser’s irreversible photothermal effects on soft and hard tissue, after a year all denuded areas were covered with healthy tissues without any surgical procedures. Histopathologic comparing showed severe lymphocyte infiltration and increased fibrosis and kollagenization in restored gingiva, additionally epithelial loss was observed. Since there is not a case report about the complications of laser gingivectomy in literature, we tried to represent a treatment plan that may be elucidative for clinicians.

Quantitative scintigraphic analysis of the apical seal in Thermafil/Topseal and RealSeal 1/Realseal filled root canals

AIM: To investigate the microleakage of two different root canal obturation systems, using the nuclear medicine approach.

METHODS: Twenty-six single-rooted extracted teeth were selected. The crowns were sectioned to obtain 15-mm long root segments and each tooth was prepared using rotary ProFile^® instruments. The roots were divided into 2 experimental groups using RealSeal 1 and RealSeal sealer or Thermafil and TopSeal sealer as well as two control groups. On the 7^th and the 28^th day the apices were submersed in a solution of ^99mTc-Pertechnetate during 3 h. The radioactivity was counted using a γ camera.

RESULTS: The present study showed that none of the root canal-filled teeth was leakage free. The statistical analyses were made using Kruskal-Wallis and statistical significance was assessed using α = 0.05. Although apical leakage measured in counts per minute (cpm) in the Thermafil/TopSeal group was lower than in the RealSeal/RealSeal group (363 916 ± 180 707.7 cpm vs 533 427 ± 414 020.6 cpm) on 7^th day and (1 678 200 ± 567 217.4 cpm vs 2 240 518 ± 383 356.7 cpm) on 28^th day, there was no statistical difference (P > 0.05). In the Thermafil/TopSeal group and RealSeal 1/RealSeal group it was found that over time, the number of counts increased between 7 d and 28 d (363 916 ± 180 707.7 cpm vs 1 678 200 ± 567 217.4 cpm) and (533 427 ± 414 020.6 cpm vs 2 240 518 ± 383 356.7 cpm), respectively, with statistically significant differences (Thermafil/TopSeal group, P = 0.015 and RealSeal 1/RealSeal group, P = 0.036).

CONCLUSION: Both carrier-based Realseal 1 and Thermafil techniques showed a similar sealing effect, but none of the materials was leakage free.

Molecular biomarkers of cell proliferation in ameloblastomas

Cell proliferation is a vital biological process that is important for all living organisms because of its role in growth and the maintenance of tissue homeostasis. The control of this important process differs greatly among benign and malignant neoplasms, and the evaluation of cell proliferation in neoplasms has become a common tool used by pathologists to provide useful information pertaining to diagnosis, clinical behavior, and treatment. The usefulness of information regarding cell proliferation has led to numerous studies on the value of these methods for diagnosing different types of tumors and for clinical decision making. Ameloblastomas are no exception. This review discusses the use of several classical molecular proliferation markers, including Ki-67, proliferating cell nuclear antigen, cyclin D1 and DNA topoisomerase II alpha, to characterize ameloblastomas and proposes the use of new proliferation markers used previously to characterize other neoplasms. The use of these biomarkers offers valuable opportunities to evaluate the biological behavior of this type of odontogenic tumor.

Unusual aggressive behavior of central giant cell granuloma following tooth extraction

Central giant cell granuloma (CGCG) is found exclusively in jaws. Its etiopathogenesis is unclear; however it is suggested that it can arise as a reactive response to trauma. This report describes an aggressive variety of CGCG which raises a question; can extraction of tooth modify the behavior of CGCG? A 46 years old male had reported with a rapidly increasing intraoral and extraoral swelling of lower jaw following tooth extraction. Radiographic examination revealed a large multilocular lesion involving the body and ramus of mandible which had been proved to be aggressive CGCG on histopathological examination. The importance of radiographic examination prior to extraction of teeth and importance of inclusion of CGCG in jaw swellings associated with mobility of teeth or failure of healing sockets is emphasized.

Periosteal pedicle graft for the treatment of gingival recession: A viable alternative to sub-epithelial connective tissue graft

Treating gingival recessions is important to satisfy the functional and aesthetic needs of the patients. Among various available techniques to treat gingival recessions, the subepithelial connective tissue graft technique is still considered to be the best despite its inherent disadvantages. The recent innovation utilising periosteum as a pedicle graft to treat gingival recession defects has drawn considerable attention and may provide a viable alternative to subepithelial connective tissue graft.

Autotransplantation of a premolar to the maxillary anterior region in young children - how long should the donor root be? A case report

Autotransplantation of premolars to anterior region after incisor loss due to trauma is accepted as the best restoration procedure with very long follow-ups. There are two main protocols: Premolars with only two thirds of the root or premolars with complete root development. Premolars with two thirds of the root completed remain vital and show complete pulp obliteration while premolars with closed apex require root canal treatment. The problem arises when the child is very young and the root of the donor premolar is developed for only one third. This case report describes the outcome of an autotransplantation of a lower first premolar with only a third of developed root to the anterior region. The donor tooth was extracted with his follicle and placed instead of tooth No. 21. For the first month esthetics was restored with a glass-fibers ribbon attached to tooth No. 11 and composite material. After a month, the crown erupted and was reshaped to mimic an incisor with composite. Orthodontic movement was performed after 5 mo, in order to alleviate the gingival contour. The final restoration was performed after 15 mo. Follow up showed full root development with normal mobility, continuous periodontal ligament and complete pulp obliteration. A multidisciplinary approach and meticulous preparation are necessary for a positive result in autotransplantation of premolars with only a third of root development to the anterior region and this case report show that this method can be performed in very young children.

Stomatological management of head and neck cancer patients treated with chemotherapy and radiotherapy

Treatment of head and neck cancer with radiotherapy and/or chemotherapy can cause oral damage. Long-term treatment can damage the salivary glands, the oral mucosa, and the maxilla, leading to altered production of saliva and to multiple infections. These lesions can be prevented, limited or avoided by thorough evaluation prior to treatment and by therapeutic follow-up and preventive measures. The dentist must have strong medical knowledge of the possible short-, medium-, and long-term oral complications of the cancer treatment, and must have knowledge of the protocols for oral management of cancer patients. The availability of a multidisciplinary medical team together with a dentist to attend to the patient prior to the cancer treatment, as well as close communication between team members during and after treatment, is crucial. The aim of the present study was review the stomatological management of head and neck cancer patients treated with chemotherapy and radiotherapy and summarizing current treatments, therapeutic innovation and tissue regeneration perspectives.

Laser assisted periodontics: A review of the literature

Over the years, the use of the laser within health field and more particularly dentistry has been increasing and improving. The application of laser in the periodontal treatment takes part of a non-surgical and surgical approaches, is used for the decontamination of periodontal pockets due to its bactericidal effect, and the removal of granulation tissues, inflamed and diseased epithelium lining, bacterial deposits and subgingival calculus. However in spite of all the marketing surrounding, the use of laser highlighting its beneficial effect, the capacity of laser to replace the conventional treatment for chronic periodontitis is still debatable. In fact there is no evidence that any laser system adds substantial clinical value above conventional treatments of chronic periodontitis. Some studies showed a significant positive effect on clinical attachment level gain and probing depth reduction. In the other hand, several articles demonstrated no evidence of the superior effectiveness of laser therapy compared to root planing and scaling. Our aims is to review the literature on the capacity of erbium:Yttrium-aluminum-garnet and neodymium:Yttrium-aluminium-garnet laser to either replace or complete conventional mechanical/surgical periodontal treatments.

Unraveling the role of epidermal growth factor receptor in oral lesions: Key to non surgical treatment modes

Epidermal growth factor receptor (EGFR) is a transmembrane receptor with tyrosine kinase activity, mediating actions of various growth factors including EGF, transforming growth factor-α, and neuregulins. Protein binding to ligand induces receptor modification, tyrosine autophosphorylation leading to cell signaling resulting in cellular proliferation. This receptor plays diverse roles in maintaining homeostasis and recent molecular advances identify that EGFR mutations are linked to several carcinomas. EGFR plays important roles in the development and maintenance of various oral structures, tooth development, eruption and morphogenesis. EGFR expression has also been studied in diverse oral pathologies like squamous cell carcinomas, potentially malignant lesions, lichen planus, salivary gland tumors and odontogenic cysts and tumours. The present review delves into the various general features of EGFR with an insight into its physiological and pathological role in the oral cavity. The clinical implications and upcoming role of EGFR inhibitors in the nonsurgical treatment of oral lesions has also been discussed.

Accuracy of linear vs spiral tomography: Alveolar crest to sinus/nasal floor height

AIM: To determine the accuracy of tomography in the linear measurement of alveolar bone at maxillary sinus/nose location.

METHODS: Two dry skulls each marked with 10 pairs of guttaperchas placed on buccal and lingual sides of the maxillary ridge were used in this in vitro study. The distance between the alveolar crest and the sinus/nasal floor was measured on tomographic views, prepared by linear and spiral techniques. The ridges were then sectioned so that each section would include one pair of buccal and lingual guttaperchas. The actual distances directly measured on the sections were compared to those of the equivalent tomographic sections (the magnification co-efficient was applied). Paired t-test was used to statistically analyze the data.

RESULTS: The measurement error with the application of linear tomography and spiral tomography was shown to be 0.455 ± 0.838 mm (P = 0.029) and 0.17 ± 0.78 mm (P = 0.347), respectively. There was a statistically significant difference between the liner tomography values and actual values (P = 0.029). This difference was representative of underestimation. McNamara’s test was used to assess the ± 1 mm error; 73.7% of the linear values and 84.2% of the spiral values were within the ± 1 mm error limit. McNamara’s test did not show any significant differences between the 2 methods in this regard (P = 0.625). The linear values were significantly different to the actual values (P = 0.029) but not to the spiral values (P = 0.185).

CONCLUSION: Spiral tomography has enough accuracy for the measurement of alveolar ridge height. Although linear tomography somewhat underestimates the actual values it provides satisfactory accuracy.

Oral graft vs host disease: An immune system disorder in hematopoietic cell transplantation

Graft vs host disease (GVHD) is a complication of patients who are treated by hematopoietic cell transplantation. National Institutes of Health in 2005 by Working Group on Diagnosis and Staging Consensus Development Project on Criteria for Clinical Trials in Chronic GVHD (cGVHD) established 2 principal categories of oral GVHD, acute and chronic. The oral mucosa may be the first site of manifestation of the disease. Clinical diagnosis needs to be confirmed by a biopsy of oral mucosa and minor salivary glands. Microscopic results have played a major role in the diagnosis and management of acute and chronic oral GVHD. Development of second malignancies is the greatest risk of oral cGVHD patients, mostly regarding squamous cell carcinoma. The focus of oral GVHD therapy is to improve symptoms and maintain oral function. The aim of this review article is to update the information on the oral GVHD in its clinical, microscopic features and their complications.

Pharmacogenomics in oral diseases

The availability of newer technologies for identification and characterization of the human genome has enabled our understanding of the genetic variations in a majority of human diseases. Human genomic sequence varies in less than 1% among the different population group and these differences known as gene polymorphisms are the primary reasons for differences in individuals’ response to various drug therapy. Also understanding the genetic changes may enable implementation of targeted therapy, thus providing for effective treatment strategies and minimizing the adverse side effects. Pharmacogenomics is a recent development in the field of personalized medicine which focuses on the genetic determinants of drug response at the levels of entire human genome. It primarily deals with tailoring of drug therapy for every individual based on their genetic make-up and identifying new target in various diseases for drug therapy. While the application of pharmacogenomics in systemic illness is well researched, its role in oral diseases needs documentation. Identifying specific targets in periodontitis, head and neck cancer, infections and genetic disorders can be beneficial in discovery of new drugs. This editorial provides an overview of basics of pharmacogenomics, its current role in disease management and its potential role in various head and neck diseases.

Management of missile injuries to the maxillofacial region: A case series

AIM: To assess our management of patients suffering from missile injuries to the maxillofacial region.

METHODS: From December 2009 to September 2012, 40 patients with missile injuries (high velocity gunshot and bullet wounds, explosive injuries and shrapnel etc.) affecting the maxillofacial region were treated. All except for 2 patients were males. All had soft tissue injuries with or without bone injuries. These patients were referred to the plastic and maxillofacial surgery ward of our hospital. The patients were 19 to 65 years of age (mean 45 years). In 19 cases, there were missile injuries to other parts of the body, especially the lower extremities. All of the patients were managed by early soft tissue debridement, comprehensive reconstruction and antibiotics. This retrospective study was approved by the IRB and ethical committees.

RESULTS: The majority of injuries were caused by high velocity projectiles (88%) and the remaining by car explosions or dynamite blasts (12%). 40 patients were treated surgically. Thirty patients had soft tissue loss (75%) and 20 patients (50%) had bone loss; there was combined soft tissue and bone loss in 10 (25%) patients. Facial fractures were in the orbital bones in 10 cases, maxillary in 7, nasal in 5 and the mandible in 3 cases. We used primary repair in the majority of soft tissue defects (25 of 40 cases). Bone repair was done primarily at the same stage using miniplates, titanium screws or wires. In some cases with a bone defect, iliac bone grafts were used simultaneously or in the later stages (mandibular defects). There was no failure of bone reconstruction in our cases. Infections occurred in two cases and were treated with systemic antibiotics and dressing changes, without any long term sequelae.

CONCLUSION: Our principles for soft tissue reconstructions were according to the reconstructive ladder and included primary repair, local flaps, skin grafts and regional flaps depending on the extent of damage. Primary repair in facial missile defects was not associated with increased morbidity or complications in this series. We recommend this approach when feasible.

Controversy of silver amalgam as a restorative material

Silver amalgam contains mercury leading to concerns about the potential toxic effects of amalgam on the health of dental patients. The debate over the toxicity of silver amalgam restorations has divided the dental profession for over a century. The use of amalgam restorations for anterior teeth have been declining worldwide due to patient’s safety concerns and preference for tooth colored restorations. Nevertheless, amalgam has served the dental profession for decades and benefited hundreds of millions of patients because of its longevity as a dental restorative material. Amalgam is still the World’s most widely used restorative material for posterior teeth.

Retrieving dental instruments through endoscopy: A literature review

Clinical accidents involving dental instruments and materials inside the oral cavity are reported in the medical literature. Specifically, ingestion and aspiration of foreign bodies have greater prevalence in the routine of medicine and dentistry. Despite being less harmful than aspirations, the accidental ingestion of dental instruments does not always culminate in favorable prognoses. Mostly, complex conditions require medical intervention through endoscopy or surgical approaches. The present research aims to review the literature pointing out the specialties of dentistry most involved with accidental ingestion of dental instruments, highlighting the important role of endoscopy for accurately locating and retrieving foreign bodies. Prosthodontics, operative dentistry, orthodontics, and maxillofacial surgery arose as the specialties in which these accidents are more prevalent. Based on that, general dentists and specialists must be aware for the essential care to avoid such clinical accidents, as well as to know the available tools, such as endoscopy, to overcome these situations in the routine of dentistry.

When will RNA-based tests similar to Oncotype DX be used for oral cancer?

Methods for detection, diagnosis and predicting treatment outcomes for oral squamous cell carcinoma (OSCC) have not changed in decades. Information from studies about molecular changes that occur with these tumors are not useful in the clinic. This is in contrast to breast cancer where global gene expression analysis in the form of the Oncotype DX and Mammaprint tests are used routinely to determine ideal treatment for a large subset of breast tumors. While the first large scale studies of gene expression in both cancer types were done over a dozen years ago, research on OSCC has not led to gene expression profiles that are useful in the clinic. Global gene expression data for well over a thousand breast tumors linked to clinical outcomes has been available online for nearly ten years. This accelerated the development and validation of multiple RNA classifiers used to predict breast cancer treatment outcomes. Molecular characterization of oral and head and neck cancer research has been handicapped primarily due to low sample numbers. The recent release from The Cancer Genome Atlas of global gene expression analyses of over 500 head and neck tumors, including 308 oral tumor samples, obtained by standardized methods, along with linked clinical outcome data, should change this. It makes the vision of including gene expression analysis in OSCC treatment planning an obvious and attainable goal that could occur in the next five years.

Pierre Robin sequence from orthodontic and surgical perspective

Pierre Robin sequence (PRS) is a triad of micrognathia, glossoptosis, and cleft palate that results in an obstruction of the airway on inspiration and impeding feeding. The tongue of infants with PRS fall back toward the posterior pharyngeal wall (glossoptosis) due to receding chin produced by mandibular micrognathia (small jaw) or retrognathia. This causes a serious condition with potentially severe, life-threatening airway obstruction. If untreated, this problem can lead to exhaustion, cardiac failure, and ultimately death, especially during the early months of life. Actually, in the majority of PRS infants, these symptoms can be managed by placing the infant in the prone position until adequate growth of the jaw occurs. If this type of treatment fails, the infant then should be considered for other conservative therapies or surgical interventions. This paper reviews surgical interventions such as tongue-lip adhesion, mandibular traction, mandibular distraction, tracheotomy and conservative orthodontic approaches, and presents a baby treated successfully with an orthodontic appliance.

Cytotoxicity of a silorane-based dental composite on human gingival fibroblasts

AIM: To evaluate the direct and indirect biocompatibility of Filtek Silorane on human gingival fibroblastic cells.

METHODS: Sixty-three standardized cylindrical specimens (8 mm diameter and 2 mm thickness) of restorative material were prepared using a light emitting diode-curing unit. The sample were built up in one increment and divided in 2 groups. In the first group, 21 samples (unpolished samples) were left without a specific polishing procedure; in the second one, 42 samples (polished samples) were polished with 4 different grains of discs. Fibroblast cultures, obtained from gingiva of 2 subjects without systemic and oral disease, were used to assess the direct and indirect biocompatibility. Cells cultured for 48 h in normal culture medium were used as a control.

RESULTS: The scanning electron microscope observations of fibroblasts cultured on the silorane samples, either polished or unpolished, confirmed the good biocompatibility of the material, favouring the cellular spreading. 3-dimethylthiazol-2, 5-diphenyltetrazolium bromide tests showed a significant reduction (P < 0.01) of gingival fibroblasts viability cultured both in polished samples (90.05% ± 19.00%) and unpolished samples (78.15% ± 11.00%) compared with the control. Cells growth in medium conditioned with the samples for 1 wk showed a significant viability reduction (P < 0.01) compared to the control. A reduction of cell viability was observed even in the groups containing the material for 3 wk (polished: 89.45% ± 10.00%; unpolished: 65.97% ± 10.00%), even if the cytotoxicity was reduced after this long time exposure.

CONCLUSION: Although the poor chromatic availability of this material remains a big limit that restricts its use to posterior sectors, the silorane-based material can be considered an option to perform restorations when aesthetic demands are not the priority, such as the class II restorations