Purpose: The aim of the study was to assess microbial adherence on maxillary complete denture carried by different fabrication techniques; the conventional and CAD/CAM (computer-aided design and computer-aided manufacturing) techniques. Material and methods: Ten completely edentulous patients were selected and divided into randomly two equal groups: group I, patients received maxillary and mandibular complete dentures made of conventional heat-cured acrylic resin and group II, patients received maxillary CAD/CAM complete denture and mandibular conventional complete denture. Assessment of the microbial colonization of maxillary dentures for both groups was carried out after 3, 6 and 9 months after denture insertion. The tested microorganisms are Candida albicans (C. albicans), Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans) and Escherichia coli (E. coli). results: Comparison of microbial colonization count represented in colony forming unit per ml (CFU/ml). Change between group I and group II revealed that, group II has statistically significant lower CFU/ml than group I for all the tested microorganisms during the study period (P-value <0.05) except for E. coli after 3 months the difference between both groups was statistically non significant (p = 0.139). And there was a gradual increase in the microbial count during the time of using both types of dentures. Conclusion: CAD/CAM dentures showed less microbial colonization than conventional heat cure acrylic resin dentures. Further short-term and long-term clinical studies are needed to validate CAD/CAM technology in complete denture prosthodontics. IntroduCtIon Poor oral health can adversely affect the mental, social, physical and general systemic health of denture wearers (1). The condition of oral and denture hygiene is very important in controlling microorganisms

Aim of study: was to evaluate and compare the effect of occlusal reactive versus thermoplastic partial denture bases on the supporting alveolar structure of mandibular distal extension partial dentures cases. Materials and methods: Ten partially edentulous patients were precisely selected to avoid factors that may adversely affect the results of this study. Removable partial dentures were constructed for all patients following the same procedures and the same design. According to denture base material the selected patients were randomly divided into two equal groups: Group I: five patients received cobalt-chromium partial denture with thermoplastic denture base. Group II: five patients received cobalt-chromium partial denture with occlusal reactive base. The patients were evaluated both clinically and radiographically, clinical assessment of the abutment was carried out through measuring its pocket depth, while radiographic assessment was done by recording bone height change distal to abutment teeth and bone high change of the residual ridge. Results: The results of this study showed that there were a significant differences between flexible and occlusal reactive bases on their effect on supporting structures. Conclusion: The occlusal reactive base exhibited better effect than flexible base regarding bone resorption in abutment as well as residual ridge.

Objectives: This study was designed to evaluate the antimicrobial effect of alternative disinfection methods of heat cured acrylic resin and thermoplastic resin denture base materials and to investigate the porosity resulting from disinfection by these methods. Material and Methods: Disc specimens of heat cured acrylic resin and thermoplastic resin were fabricated and divided into four groups for each denture base material according to the disinfection method. The specimens were contaminated in vitro by standardized suspensions of Candida albicans (C. albicans).The following test agents were used: distilled water (as a control group), 5% sodium hypochlorite (NaOCl), 100% white vinegar and 650 W microwave (MW) energy. After the disinfection procedure, the number of viable microbial cells was counted in CFU/ml. Porosities of acrylic resin and thermoplastic resin specimens were evaluated with Scanning Electron Microscope (SEM) after one month of daily exposure to disinfection. Results: ANOVA test showed that, there was a statistical significant difference among the tested treatment agents against C. albicans in each denture base material(P≤ 0.05). Post Hoc test showed a statistical significant difference between the control samples and the other disinfected samples in the microbial count, however, there was no statistical significant difference among the tested methods of disinfection (P>0.05).Regarding porosity area percentage, there was a statistical significant difference among the tested methods of disinfection (P≤ 0.05), where, 100% white vinegar showed the highest porosities followed by NaOCl then the MW disinfection and the least is the control group. Regarding comparison between the two denture base materials, thermoplastic resin showed statistically significant lower microbial adherence as well as lower porosity area percentage than heat cured acrylic resin(P≤ 0.05). Conclusion: All the tested disinfection methods shown to be efficient against C. albicans. Thermoplastic resin demonstrated lower microbial adherence than heat cured acrylic resin and lower porosity area percentages.

Purpose: Was to compare between tracing method and Cone Beam imaging for recording Bennett movement and lateral condylar angle. Material and methods: Ten completely edentulous patients were selected with ages ranged from 50-60 years, with average age 55years. Each patient received complete denture and teeth were arranged according to balanced occlusion concept. The lateral condylar angle was measured by Gothic arch tracer and with Cone Beam imaging for each side. The Immediate Bennett shift was measured using condylar tracing and the Cone Beam imaging for each condyle during its lateral shift. results: The result of this study showed that there was no significant difference between the Bennett angle measured by Gothic arch and the angle that get from Cone Beam and also there is no significant difference between the reading of immediate Bennett shift recorded by condylar tracer or Cone Beam. Conclusion:Within the limitation of this study, it can be concluded that, the Cone Beam recording can replace tracing method for recording Bennett angle and Bennett shift. IntroduCtIonThe purpose of the guidelines for good occlusal practice is to reduce the risk of damage that might occur to the related tissues of the masticatory system, leading to increase the chances of a healthy function. This will reduce the liability to supporting tissue disease, mechanical failure of the denture and TMJ dysfunction or pain. Dentists can positively influence these factors as part of their care (1) .

Purpose: The purpose of this study was to compare between two different impression techniques in ball and socket attachments supported complete implant overdentures on electromyographic activity. Material and Methods: Ten fully edentulous patients were chosen from the patient clinic of removable prosthodontics department, Patients were divided into 2 groups according to the type of impression technique Group 1: The patients received the denture with the open impression tray technique then a washing period of two weeks elapsed and then switched to the other denture with closed impression tray technique. Group 2: The patients received the denture with the closed impression tray technique then washing period of two weeks elapsed and then switched to the other denture with open tray impression technique. Electromyographic activity measurements were made when the patient in each group wear dentures for one month then a wash out period for two weeks and once more measurements were made when the patient wear the other denture respectively. Masticatory efficiency and electromyographic activity were tested. Results: Patients received dentures made with closed tray impression techniques showed higher masticatory efficiency and lower electromyographic activity than patients received dentures with open tray impression techniques during chewing hard food so significant difference between two techniques were calculated. Conclusions: From the findings of this study; it was concluded that: 1-Masticatory efficiency improved and also the electromyographic activity decreased in patients using closed tray impression technique than that with open tray impression technique during chewing hard food.

Purpose: was to evaluate the effect of different thickness of two types of soft liner (silicone based soft liner and acrylic plasticizer soft liner) on retention and electromyography of complete denture. Material and Methods: Ten patients were selected Age ranging from 50-70 year. Patients were randomly divided into two groups (five patients each group). Group(I) : Each patient received maxillary and * Paper extracted from master thesis entitled "The Effect of Different Thickness of Two Types of Softn Liner on Retention and Electromyography of Complete Denture"

Purpose: was to evaluate the effect of using two different types of overdenture attachment systems (ball and socket and magnet attachments) in single implant retained mandibular overdentures by measuring electromyographic activity and masticatory efficiency of the patient's masseter and temporalis muscles. Materials and methods: Ten completely edentulous patients with ages ranged from 55-65 years. Each patient received overdentures retained by midline implant with two different types of attachments; ball and socket attachment (group A) and magnet attachment (group B). The masticatory efficiency and the electromyographic activity of the masseter and temporalis muscles were evaluated after one month and three months from attachment connection for both groups. Results: The results of this study showed that there were significant decrease in the measurement of masticatory efficiency and electromyographic activity of the masseter and temporalis muscles after one month from using ball and socket attachments. While, there were insignificant differences in the measurements of masticatory efficiency and electromyographic activity of the masseter and temporalis muscles after three months from delivery for both ball and socket and magnet attachments. Conclusion: The masticatory efficiency and electromyographic activity were more improved after using ball and socket attachments compared to magnet attachments.

Purpose:The aim of this study was to compare between the effects of using two different designs of extra coronal precision attachments on supporting structures of the abutment teeth in unilateral free end saddle partial denture. Material and Methods: Ten Kennedy class II partially edentulous patients with the last second premolar which is lasting abutment tooth were selected. The patients were divided into two groups (each group five patients), group I; patients were received unilateral partial denture retained by OT unilateral extra coronal attachment, group II; patients were received partial denture retained by OT cap extra coronal attachment with bilateral cross arch stabilization. Clinical evaluation including pocket depth measurements at four sides of last abutment tooth and radiographic evaluation using cone beam computed tomography (CBCT) was done at time of partial denture delivery, after 6, 9 and 12 months. Results: Inspection of radiographic evaluation revealed non-statistical significant difference between the two groups at the time of insertion, 6 and 9 months while after 12 months group II showed more bone loss than group I. Regarding the clinical evaluation showed non-statistical significant difference in pocket depth between two groups at time of insertion, 6 and 9 months and more pocket depth in group II at 12 months. Conclusions: Using special design of extra coronal castable precision attachment (OT unilateral) exerts less stresses on the abutments and their supporting structures in comparison with OT cap attachment, in addition to it is simple and more comfortable to the patients.