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By correctly repositioning teeth, orthodontic therapy improves both the function and appearance of an occlusion. The relationship between teeth and the tissues that surround and support them significantly influences these alterations. With ever more adults seeking orthodontic care, orthodontists are increasingly seeing patients with periodontal issues. Concerns about the patient's appearance, such as uneven gingival margins or functional issues caused by inflammatory periodontal diseases, should be accounted for when designing orthodontic treatment plans. Furthermore, orthodontics may increase the chances of saving and recovering a degraded dentition in cases of severe periodontitis. Today, general dentists, dontists, and orthodontists play integrative roles that enable them to achieve the best possible results for their patients. This review will improve the results of interdisciplinary treatments and increase cooperation between dental specialists by drawing attention to the essential connection between orthodontics and periodontics in regular clinical practice.

Placing antimicrobial treatments directly in periodontal pockets is an example of the local administration of antimicrobial drugs to treat periodontitis. This method of therapy is advantageous since the drug concentration after application far surpasses the minimum inhibitory concentration (MIC) and lasts for a number of weeks. As a result, numerous local drug delivery systems (LDDSs) utilizing various antibiotics or antiseptics have been created. There is constant effort to develop novel formulations for the localized administration of periodontitis treatments, some of which have failed to show any efficacy while others show promise. Thus, future research should focus on the way LDDSs can be personalized in order to optimize future clinical protocols in periodontal therapy.

Background and Objectives : Acrylic resins remain the materials of choice for removable prosthesis due to their indisputable qualities. The continuous evolution in the field of dental materials offers practitioners today a multitude of therapeutic options. With the development of digital technologies, including both subtractive and additive methods, workflow has been considerably reduced and the precision of prosthetic devices has increased. The superiority of prostheses made by digital methods compared to conventional prostheses is much debated in the literature. Our study's objective was to compare the mechanical and surface properties of three types of resins used in conventional, subtractive, and additive technologies and to determine the optimal material and the most appropriate technology to obtain removable dentures with the highest mechanical longevity over time. Materials and Methods : For the mechanical tests, 90 samples were fabricated using the conventional method (heat curing), CAD/CAM milling, and 3D printing technology. The samples were analyzed for hardness, roughness, and tensile tests, and the data were statistically compared using Stata 16.1 software (StataCorp, College Station, TX, USA). A finite element method was used to show the behavior of the experimental samples in terms of the crack shape and its direction of propagation. For this assessment the materials had to be designed inside simulation software that has similar mechanical properties to those used for obtaining specimens for tensile tests. Results : The results of this study suggested that CAD/CAM milled samples showed superior surface characteristics and mechanical properties, comparable with conventional heat-cured resin samples. The propagation direction predicted by the finite element analysis (FEA) software was similar to that observed in a real-life specimen subjected to a tensile test. Conclusions : Removable dentures made from heat-cured resins remain a clinically acceptable option due to their surface quality, mechanical properties, and affordability. Three-dimensional printing technology can be successfully used as a provisional or emergency therapeutic solution. CAD/CAM milled resins exhibit the best mechanical properties with great surface finishes compared to the other two processing methods.

(1) Background: Early diagnosis and treatment of peri-implant mucositis may reduce inflammatory markers and halt the progression of the condition to peri-implantitis. Adjunctive laser treatment may have therapeutic benefits that are not yet well known. The aim of this study was to determine the advantages and limitations of laser therapy as an adjuvant in the treatment of peri-implant mucositis. (2) Methods: A total of 42 patients with at least 2 implants situated in different hemiarches were included in this study and divided into two groups: G1 (received laser therapy) and G2 (no laser therapy). Periodontal health status indices were recorded at the initial moment (T0), and all patients underwent non-surgical debridement therapy accompanied by oral hygiene training. In patients from group G1, one implant site received adjuvant laser therapy (subgroup IL), and the other one did not receive active laser light (IC). The plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) values recorded after 3 months (T1) and 6 months (T2) were analyzed and compared with those at T0. (3) Results: PI values considerably reduced at moment T1 and T2 for both G1 and G2 ( p = 0.0031). PPD was also reduced, but the difference between the groups and the three recording moments was not statistically significant. Statistically significant differences were found when comparing the BOP values between G1 IL and G1 IC for T0/T1 ( p = 0.0182) and T1/T2 ( p < 0.0001), but there was no significant difference between G2 and G1 IL or G1 IC. (4) Conclusions: Laser therapy as an adjunct to conventional treatment of peri-implant mucositis leads to a statistically significant reduction in bleeding on probing at 3-month and 6-month re-evaluations. Moreover, it leads to an evident reduction in probing depth but with no statistical significance. These results should be interpreted with caution, and more in-depth research should be performed to create a complete laser therapy protocol for peri-implant mucositis.

Significant changes in the microstructure of the brain cause dementia and other mental declines associated with aging and disease. Although research has established a connection between oral health and dementia, the underlying pathologic mechanisms are still unknown., Aim: Our aim was to evaluate dentures' impact on the cognitive state of geriatric patients., Material and Methods: A total of 108 individuals seeking treatment at the Faculty of Dental Medicine in Iasi, Romania, participated in the study, which ran from May 2022 to October 2022. Cognitive dysfunction was assessed using the Mini-Mental State Examination. The acquired data were analyzed with IBM SPSS 26.0, and the p -value was set at 0.05., Results: The average value of the MMSE score was 21.81 ± 3.872. Differences between groups of wearer/non-wearer subjects were statistically significant for most of the questions in the questionnaire. Linear regression analysis showed that individuals with a high MMSE score have prosthodontic treatment. A decrease in the MMSE score is associated with a decrease in masticatory efficiency (B = 1.513, p = 0.268)., Conclusions: This study provides further evidence that tooth loss is associated with worse cognitive performance. It is thus conceivable that the necessary effects can be achieved by increasing the efforts dedicated to preventing tooth loss in the adult population.

Light is an emerging treatment approach that is being used to treat many diseases and conditions such as pain, inflammation, and wound healing. The light used in dental therapy generally lies in visible and invisible spectral regions. Despite many positive results in the treatment of different conditions, this therapy still faces some skepticism, which has prevented its widespread adoption in clinics. The main reason for this skepticism is the lack of comprehensive information about the molecular, cellular, and tissular mechanisms of action, which underpin the positive effects of phototherapy. However, there is currently promising evidence in support of the use of light therapy across a spectrum of oral hard and soft tissues, as well as in a variety of important dental subspecialties, such as endodontics, periodontics, orthodontics, and maxillofacial surgery. The merging of diagnostic and therapeutic light procedures is also seen as a promising area for future expansion. In the next decade, several light technologies are foreseen as becoming integral parts of modern dentistry practice.

Background and Objectives: Study models are essential tools used in the dental teaching process. The aim of the present study was to compare the values obtained by manual and digital orthodontic measurements on physical and digital case study models. Materials and Methods: The physical experimental models were obtained by traditional pouring (improved stone-type IV gypsum products) and by additive manufacturing (resins). The digital experimental models were created by scanning the physical ones, using a white light-emitting diode (LED) source and an L-shaped dental scanner—Swing DOF (DOF, Seoul, Korea). The physical study models were first measured using a digital caliper, and then, they were scanned and evaluated using the DentalCad 3.0 Galway software (exocad GmbH, Darmstadt, Germany). The Pont, Linder−Harth, and Bolton indices, which are used in orthodontics for training students, were derived using the available data. Results: When comparing the linear measurement mean ranks taken on physical study models to those of digital models, no statistically significant differences (p > 0.05) were found. A similar result was also shown when the dentoalveolar growth indicators were analyzed. Conclusions: It can be concluded that dental study models made by direct light processing (DLP) and pouring type IV class gypsum are both acceptable for orthodontic teaching purposes.

Background and Objectives: The surface condition of the materials that are used for temporary prostheses influences their microbial colonization, with a direct impact on the oral tissues. This study aims at a comparative analysis of three types of resins for temporary bridges using conventional and digital technologies. The attention was focused on the analysis of the surface characteristics and mechanical strength of these materials. Materials and Methods: The surface condition was assessed for three distinct materials both before and after polishing- heat-curing resin Superpont C + B (SpofaDental, Jicin, Czech Republic) used unconventional technology, Zotion dental milling polymethyl methacrylate (PMMA) block (Zotion, Chongqing, China) for provisional crowns/bridges used in digital subtractive technologies and Freeprint Temp (Detax GmbH & Co. KG, Ettlingen, Germany) resin for temporary crowns and bridges that are used in 3D printing technologies. The two-way ANOVA analysis indicated that polishing leads to a statistically significant increase in roughness coefficients for all the three resins that were tested (p < 0.001). While the highest roughness coefficients were displayed in the 3D cured sample, the largest decrease was reported by the milled sample Results: The results revealed that surface roughness was significantly influenced by both the type of resin that was used (p < 0.001) and the treatment that was induced by finishing and polishing (p < 0.001). Similar p-values were obtained for each of the three resins. Conclusions: The results demonstrated a significant optimization of the surfaces after finishing and polishing and statistically significant differences between the surface parameters and the mechanical properties of the samples. The low values of the roughness and the acceptable values of the mechanical resistance for the conventional samples indicate these materials for the long-term temporary bridge’s realization, allowing the correct restoration of the functions and the rehabilitation at the oral level.

Dentists and dental staff have an increased risk of airborne infection with pathogens such as SARS-CoV-2 since they are exposed to high levels of droplets and aerosols produced during specific dental procedures. Hence, new guidelines such as patient screening and temperature control, air purification, space, surface and hand sanitizing and the use of protective equipment and physical barriers have been successfully implemented. In addition, the use of teledentistry has expanded considerably in pediatric dentistry, orthodontics, oral medicine and periodontics in order to address oral and dental health issues during the COVID-19 pandemic while minimizing virus transmission. Thus, teleconsultation, telediagnosis, teletriage, teletreatment and telemonitoring have emerged as valuable tools not only in the delivery of care, but also in the academic and research training of dental health professionals. This narrative review summarizes the current literature on the impact of the pandemic on dental care, dental staff and dental education, with an emphasis on how newly emerging protocols and technologies can be successfully utilized as integral parts of various branches of the dental practice and their future implications without compromising patient care.

Physiological/normal tooth mobility may be defined as the slight displacement of the clinical crown of a tooth, which is allowed by the resilience of an intact and healthy periodontium, under the application of a moderate force. The factors influencing the success and longevity of dental splinting are the type of material used for the splint, the type of composite resin, the number and location of the dental units included for splinting (maxillary or mandibular arch). In periodontology, the term 'splint' is defined as the joining of two or more teeth into a rigid unit through restorations or fixed or removable devices. The purpose of using periodontal splints for tooth immobilization is to provide a period of rest in the areas where the healing process has begun and to allow normal functioning there where the tissues alone would not be able to withstand occlusal forces. The aim of the present study was to evaluate comparatively, by means of energy dispersive electron spectrometry (EDX), the chemical composition in the case of in vitro samples that structurally reproduce direct periodontal immobilization systems using fiberglass strips and fluid composite resins. The differences in the chemical composition of the investigated materials can influence their physiochemical properties, but also their biological and toxicological reliability. Elements such as C, O, Al, Si and Ba were identified as common elements among the resins tested in the present study. The only difference in terms of the component elements was found in the case of the fluid composite Clearfil Majesty ES Flow, which, apart from the elements mentioned, also presented Co in its structure., Competing Interests: The authors declare that they have no competing interests, and none of the authors have any affiliations with GC Corporation, Voco and Kuraray Noritake Dental., (Copyright: © Goriuc et al.)

Fixed prosthodontic dental restorations can potentially affect the periodontal tissues and vice versa, the periodontium can influence the longevity and esthetic appearance of dental restorations. We proposed an investigation on total bacterial load, specific periodontal pathogens, and periodontal clinical parameters in patients with dental fixed prosthesis and different degrees of periodontal tissue loss that followed photoactivation therapy (PDT) adjunctive to scaling and root planing. The study was conducted on 160 subjects, which were randomly assigned to scaling and root planing (SRP) alone (52 subjects, 256 sites), SRP and chlorhexidine rinsing (58 subjects, 276 sites), and SRP plus PDT (50 subjects, 318 sites). Periodontal parameters (plaque index, bleeding on probing, probing depth, and clinical attachment loss), followed by total bacterial load and specific periodontal pathogens ( Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola ) were examined in each patient at baseline, one and six months after. PDT exerted significant improvements both in clinical and microbiological load after one month, and these results were maintained 6 months after when compared to chlorhexidine rinsing or SRP alone, especially in severe periodontitis cases. Photoactivation therapy as an adjunctive periodontal therapeutic method was efficient in offering supplementary periodontal improvements in the clinical and microbiological parameters of patients with fixed dental prosthesis, particularly in severe periodontitis cases.

Periodontitis is one of the most common immune-mediated inflammatory conditions resulting in progressive destruction of periodontium. Metalloproteinase-9 (MMP-9), an enzyme that is involved in the degradation of gelatin and collagen and present in the gingival crevicular fluid, is markedly increased in periodontitis. The aim of the study is to evaluate the effects of periodontal treatment either alone or in combination with orthodontic treatment on MMP-9 levels. In this study, 60 individuals were subjected to periodontal treatment (PD) or periodontal treatment combined with orthodontic treatment (POD). Both periodontal and periodontal plus orthodontic treatments significantly improved clinical parameters and lowered MMP-9 levels compared to control group. However, the combination of periodontal with orthodontic treatment further improved clinical parameters and enhanced the lowering effect on MMP-9 levels compared to periodontal or control groups alone. Finally, the degree of malocclusion significantly affected the effect of the treatment on MPP-9 levels with PD treatment having the most pronounced effect. We concluded that salivary MMP-9 can serve to accurately predict the level of inflammation in affected periodontal tissues during orthodontic treatment that is also associated with the type of malocclusion, making it a viable diagnosis tool in monitoring the progression of the periodontium during orthodontic treatment.

Chemotherapy often presents side effects, including oral adverse effects that may interfere with the completion of the oncology treatment, threatening the outcome of the treatment and significantly affecting the quality of life of the patient. The aim of the present study was to evaluate two antiseptic, antimicrobial and antifungal substances that may be used in order to achieve improved oral hygiene and to lower the prevalence of side effects during chemotherapy. Patients were randomly divided into three groups: Placebo, oral rinse with cetrimide and mouth coating with a pharmacy-made compound (nystatin, neomycin and metronidazole). Their oral hygiene and periodontal parameters were determined at baseline and 14 days of use. It was revealed that the most effective clinical results were achieved in the group that used cetrimide mouth rinse that highlighted the best improvements of parameter values, whereas the control and coating-using group did not obtain statistically significant improvements. Cetrimide oral rinse was demonstrated to be an efficient adjunct method in achieving better oral hygiene and improved periodontal parameters in chemotherapy patients. The present study offers an alternative to the commonly used compounds that may present unwanted side effects in patients during chemotherapy, it promotes the importance of good oral hygiene in the prevention of chemotherapy-induced oral adverse effects and improves the quality of life of the patient., (Copyright: © Kappenberg-Niţescu et al.)

With the progress of dental materials and techniques, CAD/CAM system currently allows the manufacture of high precision prosthetic restorations. Zirconia is an ideal base for porcelain because the bonding process between the zirconia and the porcelain is stronger than it is with porcelain and metal. This means that the porcelain is less likely to fracture away from a zirconia base. Zirconia can also be colored to match teeth and it is translucent, mimicking the natural look of teeth far better than any crown with a metal base could. The aim of this article is to describe a case of oral rehabilitation, involving CAD/ CAM technology for full dental crowns, using zirconia as framework.

Aim: This baseline study aims to find out the young patients' perception on different surgical management of the disto-oclusal gingival operculum in second mandibular molars:the conventional technique and the laser assisted one., Material and Methods: The current study included a batch of 20 patients who needed surgical bilateral removal of the disto-oclusal operculum in second mandibular molars order for them to receive conservative treatment. Each patient benefited of two different surgical techniques (laser assisted and conventional). Patients' perception towards these procedures was evaluated with a simple questionnaire., Results: The questionnaires were evaluated by a specialized team and the results were illustrated in the specific charts. On one hand the conventional technique wasn't perceived as very comfortable and on the other hand the laser assisted technique was very well perceived by the patients., Conclusions: The overall perception of young patients towards laser assisted periodontal surgery was very high and this is a means of reducing operating time and anxiety caused by the surgery itself.

Aim: This baseline study aims to find out the young patients' perception on different surgical management of the disto-oclusal gingival operculum in second mandibular molars: the conventional technique and the laser assisted one., Material and Methods: The current study included a batch of 20 patients who needed surgical bilateral removal of the disto-oclusal operculum in second mandibular molars order for them to receive conservative treatment. Each patient benefited of two different surgical techniques (laser assisted and conventional). Patients' perception towards these procedures was evaluated with a simple questionnaire., Results: The questionnaires were evaluated by a specialized team and the results were illustrated in the specific charts. On one hand the conventional technique wasn't perceived as very comfortable and on the other hand the laser assisted technique was very well perceived by the patients., Conclusions: The overall perception of young patients towards laser assisted periodontal surgery was very high and this is a means of reducing operating time and anxiety caused by the surgery itself.

Aim: To evaluate the efficiency of laser therapy in healing, regeneration and repair processes located in the superficial periodontium after gingivectomy procedures., Materials and Methods: The study group consisted of 38 patients without any systemic diseases presenting with gingival hypertrophy developed exclusively within the clinical context of gingivitis and/or periodontitis. All patients were included in the study based on their informed consent. All patients required several surgical interventions at the level of the superficial periodontium. Subgroup 1 (17 patients) was treated only through gingivectomy procedures. For subgroup 2 (21 patients), the gingivectomy was associated with laser therapy, applied every day for seven days. Gingival mucosa fragments were taken on day 1 (curative gingivectomy) and on day 21 (clinical control and corrective gingivectomy), and routinely processed for the microscopic exam, using Hematoxylin-Eosin and special stains (trichrome Szekely and Periodic Acid-Schiff)., Results and Discussion: The comparison between the morphological pictures characterizing the healing process associated or not with laser therapy, allowed the identification of some features supporting the benefits of laser therapy. We believe that the decrease in the inflammatory infiltrate located in the lamina propria is the critical morphological trait for the control of a healing process as near to restitutio ad integrum as possible. The diminished number of lymphocytes and macrophages will implicitly determine a lower production of chemical mediators interfering with the sequences of the healing process., Conclusions: The morphological differences identified at the gingival epithelium level and subjacent lamina propria support the value of laser therapy, stimulating an improved healing of the damaged tissues.

This paper presents the case of a 37 years old female patient who needed a reconstruction of an endodontic treated' second maxillary premolar. The patient presented large areas of occlusal abrasion caused by bruxism, therefore the solution consisted of a reconstruction with a non-metallic post reinforced with glass fibers. In such cases, the excessive occlusal forces developed by bruxism can produce a radicular fracture if the tooth would be reconstructed with a rigid metallic post. The glass-fiber reinforced post has some important qualities, which render it more suitable in most clinical cases: it is easy to use; has the ability to bond with restorative resins; decreases the risk of tooth fracture and provides better esthetics.

Aim: The determination of the influence of non-metallic posts on the stress distribution to the supporting tissues., Method: Two 3D models were created: one intact maxillary incisor and one reconstructed with post (ceramic, carbon fiber and glass fiber). The compressive load (30daN) was applied to an angle of 45 degrees on the palatal surface of the crown. The Algor software computed the stress for each model comparing the maximum registered intensity, localization and concentration into the dento-periodontal complex., Results: The fiber reinforced posts induced lower stress peak inside the root, the von Mises stress in the teeth reconstructed with carbon and glass fiber post being similar to that recorded in a tooth without post. The ceramic post produced the greatest stress concentration in the middle third of the root, this behavior supporting the potential risk of the vertical root fractures registered "in vivo"., Conclusions: The fiber reinforced posts are more suitable for the clinical longevity of the tooth, representing the best choice to reconstruct an endodontically treated tooth.

We present a 29 years old female patient treated with an all ceramic inlay. The IPS Empress system has been used to make an optimal, esthetic and morpho-functional restoration. An inlay restoration is a biological prosthetic solution that is indicated as a proper treatment possibility for the young patients. The IPS Empress inlays are characterized by a good biomechanical behavior, law abrasion rate and perfect chromatic integration.

The study evaluated the influence of atenolol/nifedipine on the local anaesthesia with lidocaine in 64 patients with essential arterial hypertension following dietetic regimen and divided in: control group (21 patients), atenolol-treated group (21 patients with atenolol therapy) and nifedipine-treated group (22 patients with nifedipine therapy). Atenolol/nifedipine was administrated three hours before anaesthesia (1.5 mg lidocaine/kg body weight) applied on Spix Spina. The atenolol/nifedipine influence on the anaesthetic intensity was evaluated both by the patient and dentist using scales for the appreciation of pain intensity (Visual Analogue Scale, Numerical Rating Scale) at 0 minutes (before anaesthesia), 5, 10, 20, 30, 60 minutes (moments for the determination of lidocaine plasmatic concentrations). There were no statistically significant differences between the values appreciated by the patient and dentist. Our data demonstrated a significant decrease of pain intensity in patients treated with atenolol/nifedipine. Very good inverse correlation was found between lidocaine concentrations and pain intensity.

The design conception and the technological achievement of every gnato-prosthetic device are conditioned by a minute evaluation of the biological and morphological individualities of each case, the social level of the patient, corroborated with the technological supply. In our study we evaluated different modalities of dento-stomato-facial rehabilitation of young patients with partially reduced maxillary or mandibular dentition. The study was carried out on a group of 12 young patients, 5 males and 7 females, aged between 16-24 years, who presented at the clinic for the treatment of complex functional disorders that occurred as a consequence of the dentition. The fixed mixed gnatoprosthetic therapy for the young patients and teenagers has to be adapted to the surveyed clinical individuality. The success of the therapy is assured by the accurate application of the gnatoprosthetic principles, the accurate achievement of the technological steps, the use of compatible biomaterials according to the dento-stomato-facial features of this age category.

The local anaesthetic domain, very often implicated in the dental practice, it's in to a continuously progress from two points of view: the development of the products proposal and the improvement of the pharmacokinetic parameters. In our study we presented: new classifications of local anaesthetics, their characteristics and structure, the pharmacokinetic and pharmacodynamic parameters of local anaesthetics used in dental practice. An interesting remark of last years is represented by the fact that the local anaesthetics could also have an antibacterial effect which is often helpful in dental practice.

Partial removable prosthesis is the most frequently therapeutical solution applied to patients aged more than forty years and which were diagnosed with extended partial edentations. The purpose of our study is to estimate oral tissues diseases installment to subjects having partial removable prosthesis, this patients being exposed on contacting stomatopaties. We developed this study on the clinical examination of a group of forty subjects partial removable prostheded, three or four year ago, respectively 23 woman and 17 men aged between 40 and 75 years. The oral hygiene, caries incidence, clasps fractures were evaluated, it was registered the aspect of the acrylic resin of the base, and also the inflammation degrees of the oral mucousa. A high level of oral hygiene statement diminuates the installment of the whole series of post-prothetical involvements, also decreasing the stomatopathies appearance frequently.

To reach a good link between the metallic framework and the ceramic element of a bridge represents one of the most important aim of the clinical and technical steps of the dental treatment for partial edentulous patients. The purpose of this study was represented by the analysis of the electrodeposition method in enhancing of the metalo-ceramic link. We used an electrogalvanic bath inside which we introduced a metallic framework which has been improved by electrodeposition of a thin layer of gold. The results showed a stronger and more stable link between the metallic framework and the ceramic element.

Moiré effect is an optical phenomenon that occurs when two similar arrays of alternately opaque and transparent lines or dots are superimposed upon each other. Superimposition of two such similar, but slightly different, line arrays causes interference between the arrays; the interference results in the formation of moiré fringes. There is a definite relationship between the pitches of the two arrays and the spacing of the fringes. Therefore, given the pitch of one of the arrays and the distance between the moiré fringes, the pitch of the other array can be calculated. The moiré effect can be used to determine the development of cutaneous tumors in a very short time-frame and to assess the measurement of dental eruption within 20 minutes. The 3-D facial, palatal and dental morphology can thus be evaluated very accurately. The CAD/CAM dental technology is actually possible due to the moiré effect.

The preservation of the natural dental roots represents a big advantage for the overdenture prosthetic appliances. The realization of an overdenture needs a perfect correlation of all the clinical and technological factors, in all the prosthetics steps. Another important aspect is represented by the possibility of a correct treatment of the remaining roots. The remaining roots will be correctly endodontically treated. The root section will be prepared with two inclines bucally and orally located. A metallic cup will cover the root section. On the inner surface of the overdenture the dental technician will realize specific preparations corresponding to this cups. This kind of prosthetic treatment is indicated only for patients with a very good oral hygiene and a good general health.

The stress quantification in dento-periodontal structures is an important concept, as stress in the tissue and in surrounding structures. A number of clinical studies have suggested figures for such an optimal stress strange. The clinical experiments can be completed with mathematical analysing methods as finite element method. Once the basics of biomechanics understood laws the treatment goes clearly defined, the computer aided design improve the optimal restorative prosthetic or orthodontic appliance. The finite element method (FEM) makes possible the numerical simulation of different clinical situations. Based upon mathematical modelling and extrapolation from experimental studies, practical conclusions can be drawn concerning the different types of forces and their subsequent induced relationship to the stresses. Clinical and histological experiments confirm the mathematical prediction offered by the FEM.

In modern CAD/CAM technology of dental prosthetics, the "optical impression" taken by special video cameras deploying 3D-recording of the oral situation (Cerec 1, Cerec 2) initiates the computer-generated production of a digital model. The computer receives and renders the digital data obtained through "optical impression" i.e. data acquisition not as a "negative" of the oral situation but as a "positive" copy of it, namely as a digital model in a virtual environment which can be displayed on the screen and be further used in the fabrication of dental prostheses by means of a computer-assisted device (CAM or CIM).

The surface of dental alloys in contact with well conducting electricity solutions are electrochemically corroded. This phenomenon is determined by a proper electric wave generated by electrochemical phenomena present at the limit between the two phases. Because during dental treatments similar conditions with the generation of corrosion waves are present, we decided to study the electrochemical behaviour of the most commonly used dental alloys. The method used in our study is based on the anodic and catodic reactions developed simultaneously, represented by the global curve of polarization that gives informations on the intensity of corrosion waves. We have also studied the influence of corrosion products on the excitable tissues. The results demonstrate the significant influence of metallic ions on the excitable tissues.

In the laryngeal surgical pathology area, the application of a cannula with temporary or long term indications is necessary for ensuring the respiratory function troubled by various causes (inflammatory, tumor or traumatic) that obstruction the respiratory tract. The most frequently used standard cannula is rigid and does not show proper adaptation for every clinical situation, thus leading to local troubles. In this paper, the realization technique of a rigid/flexible and individual cannula applied after the tracheotomy is presented. In order to carry out the cannula, a rigid material is utilized (acrylic resin) for maintaining the shape and dimensions of the laryngeal stoma. It is also utilized an elastically material (acrylic resin with a retard plug--Simpa) that ensures the optimal adaptation, tight close and tissue protection around the stoma. In co-operation with the ORL Clinic--Recuperation Hospital, these cannulae were applied to fifteen patients pursuing their evolution in time.

The aim of this study was to quantify the stress induced in the periodontal ligaments by the orthodontic appliances. A finite element model of an orthodontic system, applied on a lower premolar, was developed in different loading conditions. The maximum stress values depend on the location, direction and the magnitude of force application.

The loss of anterior teeth may be transient solved by temporary adhesive bridges (Oslo bridge, Rochette, Ellmann, Neumann, Tschemitscheck, Armatron systems). Provisional crowns and bridges could be used for Brackets fixing. Anterior bridge with subocclusal connector permits transversal expansion. When a successful orthodontic treatment is followed by a prosthetic treatment, it is not important to change the achieved occlusion, by the occlusal framework morphology. The framework design of the metal component can contribute to the improvement of the aesthetic aspect and reduce the cost by using a small quantity of expensive alloy. Cytocompatibility of the used Cr-Co alloy is confirmed by cell culture test.