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Background: Dental implants are considered the first option to replace missing teeth. Alveolar bone resorption gradually progresses following tooth extraction leading to loss of vertical bone dimension for implant placement. The lateral window approach is the most commonly used procedure to treat vertical bone loss. Objectives: The aim of the present study is to evaluate the lateral wall thickness (LWT) of the maxillary sinus and determine the influence of gender and side on maxillary LWT. Methods: This study involved a cross sectional retrospective study. Cone- beam computed tomography data were collected from 99 patients with a total of 198 maxillary sinuses that met the inclusion criteria. The patient age ranged between 18 to 35 years. On the selected sagittal section, the points of measurement are determined by a perpendicular line at 5 mm from the lowest point of the sinus floor. Measurements were taken at four different areas; first premolar (P1), second premolar (P2), first molar (M1), and second molar (M2). Descriptive statistics were used to calculate mean lateral wall thickness for each tooth, and student’s t-test was used to test the effect of gender and side on maxillary LWT. Results: The greatest mean LWT was observed around the left first maxillary molar (2.43±0.82), while the lowest mean LWT was observed around the right second maxillary premolar (1.62±0.61). There was no significant difference in the LWT around any tooth (M1 p=0.56, M2 p=0.92, P1 p=0.14, P2 p=0.19). Conclusion: There was no significant difference in both males and females of the lateral wall thickness in the left and right side of maxillary sinus.

Objectives Peri-implantitis is a destructive inflammatory process that affects the soft and hard tissues around dental implants. porphyromonas gingivalis, an anaerobic gram-negative bacterium, appears to be the main culprit. Since there is no efficient and specific vaccine to treat peri-implantitis, the goal of our research has been to develop a multi-epitope vaccination utilizing an immunoinformatics approach that targeted P. gingivalis type I fim A. Materials and methods P. gingivalis peptides 6JKZ and 6KMF are suitable for vaccine development. B- and T-cell epitopes from 6KMF and 6JKZ were detected and evaluated based on critical factors to produce a multi-epitope vaccine construct. It was assessed based on allergenicity, antigenicity, stability. The vaccine's dual major histocompatibility complex (MHC-I and MHC-II) binding epitopes allowed it to reach a larger population. P. gingivalis fimbriae induce immune subversion through TLR -CXCR4 receptor complex pathway. The ClusPro 2.0 server was used to do the molecular docking using TLR2 - CXCR4 and vaccine epitopes as receptor and ligand respectively. Results The designed vaccine was non-allergenic and had a high antigenicity, solubility, and stability. The 3D structure of the vaccine revealed strong interaction with CXCR4(TLR2) using molecular docking. The vaccine-CXCR4 interface was more consistent, possibly because the vaccination has a higher affinity for the CXCR4-TLR2 complex. Conclusion This study details the vaccine's distinct and sustained interaction with the CXCR4(TLR2) immunological receptor and its consistent and effective utterance in the bacterial system. As a result, our vaccine formulation will evoke a significant memory response and induce an adaptive immune response against P. gingivalis.

Aim: To assess the relations between the divergence angle of the maxillary molar roots and their proximity to the maxillary sinus floor using CBCT. Method: This study comprised CBCT scans of the maxilla, including at least the inferior one-third of the maxillary sinus and at least one molar present in any quadrant with complete eruption and root formation. Evaluation included the vertical relations between the maxillary molar root apices and the maxillary sinus floor (MSF), and the root divergence was measured from the root apices to the floor of the pulp chamber. The chi-square test was used for the associations between the study parameters. For the correlation between root divergence angles and MSF vertical relationship types, the Spearman test was used. A P-value 45⁰ angle groups, and a higher prevalence of the Type I relationship was found in the 21-45⁰ angle group. For the distobuccal-palatal angle groups, higher percentages of the MSF Type II relationship were found in the three angle groups. For all teeth, there was a significant positive correlation between the MSF vertical relationship and the mesiobuccal-palatal angle (r = 0.116; P = 0.039). Conclusion: There was a positive correlation between the divergence angle of the roots and their vertical relationship with the MSF. Clinicians should assess the divergence between the roots before performing extraction or endodontic treatments.

Background: Recently, implants have been widely considered as an option for replacing missing teeth. There are several biological conditions that must be considered for the success of an implant. Failure to satisfy any of these factors may result in complications, such as peri-implantitis or failure of the implant. Aim: The aim of this study was to evaluate the general dentist's attitude towards the management of peri-implant diseases in Saudi Arabia. Methods: A multicenter cross-sectional electronic-based questionnaire was formulated based on the validated questionnaire from a previous study. It was targeted towards the general dental practitioners in Saudi Arabia. The study sample consisted of 721 general dental practitioners. The questionnaire consisted of 17 questions divided into five sections. Pearson's chi-square test was used for inferential statistical analysis with Holm's correction, for adjusted p-value, the alpha at 95% confidence interval was 0.05, and all values below alpha were considered statistically significant. Results: The majority of participants had attended an implant training course (51.2%) while the rest had not (48.7%). The majority of the participants (67.3%) thought they need special instruments for the detection of peri-implantitis but only 29.5% thought they do not need any special instruments for the intended purpose. Most participants (79.3%) said they can identify and differentiate between normal and abnormal soft tissue around an implant, while 6.5% of the respondents could not. More than half of the participants (54.8%) could differentiate between peri-implant mucositis and peri-implantitis, and 19.4% had no idea about this. Amoxicillin & metronidazole was considered as the best and most effective antibiotic by the majority of respondents (76%), while only (5%) of dentists selected ciprofloxacin. Conclusion: This study concludes by suggesting that most of the participants have adequate knowledge about peri-implant soft tissue assessment, mechanism of periodontitis and peri-implantitis, its initiation and progression along with its management. Most of the participants found the training courses on peri-implantitis to be efficient. It is recommended to conduct more courses and studies that would aim at understanding the pathogenesis, etiology, diagnosis, and treatment of peri-implant diseases so as to increase awareness among general dentists.

To assess and equate the efficacy of different disinfection protocols autoclave, chlorhexidine (CHX), PDT utilizing Rose Bengal (RB), chitosan, and Er, Yag laser and their effect on fracture strength of PMMA denture-based polymer (DBP) colonized with C. Albicans, S. aureus, S.mutans, and E.coli.A total of 50 (n = 10) PMMA DBP were manufactured and adulterated with the American Type Culture Collection (ATCC) of diverse microbial colonies inhabited by C. Albicans, S. aureus, S.mutans, and E.coli. The specimens were subjected to different denture disinfection approaches by randomly distributing in into five groups i.e., Er, Yag laser, RB, autoclave, CHX, and Chitosan, respectively for appraising antimicrobial effectiveness. PMMA fracture load was also assessed and statistical analysis was performed for CFU/mL (log10) of exposed C. Albicans, S. aureus, S.mutans, and E.coli by one-way ANOVA and Tukey's multiple comparison test at a significance level of p 0.05.Intergroup comparison disclosed that denture disinfection with Er, Yag laser, autoclave, Chitosan, and CHX (control) validated comparable antimicrobial efficacy to denture against all inspected CFU/mL (log10) (p0.05). The intragroup comparison revealed that DBP sanitization with Er, Yag laser, autoclave, Chitosan, RB, and CHX substantiated equivalent effective antimicrobial efficacy in plummeting CFU/mL (log10) of S. mutans and E. coli (p0.05) but in consideration to S.aureus and C.albicans, all groups resulted in declining their count except 5µm RB activated by PDT(p 0.05). No significant difference was perceived in fracture load of PMMA denture base among Er, Yag laser, RB, chitosan, and CHX (control) (p 0.05) except autoclave decontamination procedure that indicated the least fracture strength of DBP when disinfected (p 0.05).Er, Yag laser, and Chitosan activated by PDT have the potential to be used as an alternative to chlorhexidine for disinfecting Polymethyl methacrylate denture base as they demonstrated the highest antimicrobial efficacy against E. coli, C. Albicans, S aureus, and S. mutans with optimal fracture load.

الملخص: التشنج الفكي أو ما يعرف بالضزز هو أحد مضاعفات العلاج الإشعاعي التي تصيب الناجين من أورام الرأس والعنق. يُعرّف الضزز بأنه انخفاض في القدرة على فتح الفم إلى أقل من ٣٥ ملم بسبب التهاب العضلات الرافعة للفك السفلي نتيجة للعلاج الإشعاعي المؤين. بسبب الطبيعة التقدمية للضزز، يُعد التدخل المبكر أمرا بالغ الأهمية لمنع المزيد من الضرر وضعف العضلات الرافعة للفك السفلي. تناقش هذه الورقة العلمية حالة مريضة تبلغ من العمر ٤٠ عاما، تم تشخيصها بورم الخلايا الحرشفية في الجزء الأيمن من الفك العلوي. حيث تمت عملية استئصال جراحية للجزء الأيمن من الفك العلوي متبوعة ب ٣٣ دورة من العلاج الإشعاعي. بعد خمسة أشهر من العلاج الإشعاعي، أبدت المريضة اهتماما باستبدال أسنانها المفقودة لاستعادة وظائفها الفموية وتحسين الشكل الجمالي للوجه. خلال زيارتها بعد العلاج الإشعاعي في العيادة التخصصية للأسنان، وُجد أن فتحة الفم محدودة بمقدار ١٢ ملم. واشتملت الخطة العلاجية على استخدام جهاز خاص لزيادة قدرة المريضة على فتح الفم تدريجيا بالتناوب مع مثبطات اللسان الخشبية. بعد مرور ستة أسابيع من العلاج تحسن مقدار فتحة الفم إلى ٢٠ ملم. ونتيجة لذلك، أمكن علاجها بتركيبة تعويضية صناعية للجزء المفقود من الفك والأسنان وذلك باستخدام تقنيات التصميم والتصنيع بمساعدة الحاسوب. تشير هذه الحالة إلى أن استخدام الجهاز الخاص لزيادة ارتفاع فتحة الفم ومثبطات اللسان الخشبية يسهمان في تحسين قدرة المريض على فتح الفم بشكل ملحوظ إذا استخدما بالتناوب. Abstract: Trismus is a post-radiotherapy complication that affects survivors of head and neck cancers. It is described as the reduction of mouth opening to less than 35 mm. The condition is a progressive process; hence early intervention is crucial to prevent further damage and weakness to the elevator muscles of the mandible. Here, we report a 40-year-old woman with known squamous cell carcinoma of the maxillary sinus in stage T3N0M0 who had undergone upper right partial maxillectomy with subsequent 33 fractions of radiotherapy (66 Gy; intensity-modulating radiotherapy). Five months post-radiotherapy, the patient showed interest in replacing her missing teeth to restore her oral functions and facial appearance. At her post-radiotherapy visit in the dental assessment clinic, she showed a mouth opening of 12 mm. The TheraBite® Jaw Motion Rehabilitation System™ and wooden tongue depressors were alternatively used for 6 weeks (4–5 stretches/day; each stretch held for 15 s). Mouth opening gradually increased to 20 mm. Consequently, a definitive obturator prosthesis was fabricated using computer-aided design and computer-aided manufacturing technologies with the 3Shape D900 model scanner. These were challenging and time-consuming steps, but acceptable facial appearance and mouth opening were restored for the patient. This case suggests that Therabite® Jaw Motion Rehabilitation SystemTM and wooden tongue depressors help to increase mouth opening significantly if used together and alternatively.

Objective: The aim of the study is to assess knowledge, attitude and practices of dental implants among dental interns in Saudi Arabia Materials and Methods: A self-designed, close-ended questionnaire was distributed among 205 interns chosen by stratified random sampling technique. The questionnaire consisted of 28 items pertaining to demographic characteristics, knowledge and practices of dental implants. Responses were coded and entered into spreadsheet software (Microsoft Excel 16.0.) and analyzed using Statistical Package for Social Sciences (SPSS, IBM Version 22.0) and contingency tables and chi-square test (χ2). Results: The majority of the participants were males (64.4%), between 24-26 years of age (64%) and had a GPA between 4-5 (63.4%). The majority of the participants gained knowledge of dental implants through theoretical lectures (98.5%), and most of them (80%) knew, what material, an implant was made up of. Almost all participants (91.7%) knew that dental implants had surface modifications. Most (64.4%) believed that case selection is the most important criteria for the success of dental implant therapy, and this differed significantly among participants with respect to GPA (p=0.03). Many participants (60%) believed that the most important advantage of dental implants over fixed prosthesis is that reduction of adjacent tooth is not needed, and this differed significantly between males and females (p=0.026). There was a significant difference (p Conclusion: Knowledge of dental implants among dental interns is satisfactory, but this study reveals that participants lack practical experience and would like to acquire more clinical skills. Limitations: The response rate of participants from each university was low, which made comparisons between different universities difficult because sample size from some universities was very small, which could not produce statistically accurate results.

Conventional osteotomy techniques can, in some cases, induce higher stress on bone during implant insertion as a result of higher torque. The aim of the present study was to evaluate and compare the stress exerted on the underlying osseous tissues during the insertion of a tapered implant using different osteotomy techniques through a dynamic finite element analysis which has been widely applied to study biomedical problems through computer-aided software. In three different types of osteotomy techniques, namely conventional (B1), bone tap (B2), and countersink (B3), five models and implants designed per technique were prepared, implant insertion was simulated, and stress exerted by the implant during each was evaluated. Comparison of stress scores on the cortical and cancellous bone at different time points and time intervals from initiation of insertion to the final placement of the implant was made. There was a highly statistically significant difference between B1 and B2 (p = 0.0001) and B2 and B3 (p = 0.0001) groups. In contrast, there was no statistically significant difference in the stress scores between B1 and B3 (p = 0.3080) groups at all time points of implant placement. Overall, a highly significant difference was observed between the stresses exerted in each technique. Within the limitations of our study, bone tap significantly exerted lesser stresses on the entire bone than conventional and countersink type of osteotomy procedures. Considering the stress distribution at the crestal region, the countersink showed lower values in comparison to others.

The aim of the study was to assess the color matching ability and color stability of a single-shade resin-based composite (Omnichroma—OM) in comparison to a conventional dental composite. One hundred and sixty lower molar acrylic teeth in four different shades (B1, B2, A3, and C3) were prepared with class I cavities. Eighty teeth were divided into two groups based on the two resin composite materials (OM and Filtek Z-350 (FT)) for cavity restoration. Three groups were included in the color matching assessment, namely Gp 1-FT, Gp 2-OM-light cured (C), and Gp 3-OM-uncured (UC) groups. The color assessment was performed prior to cavity restoration and after cavity filling and before and after light curing to detect color matching. The 80 remaining teeth were restored with OM (n = 40) and FT (n = 40), half (n = 40) were submerged in coffee and the other half (n = 40) were submerged in cola for 2 weeks. The color stability was assessed by calculating material color (spectrophotometry) changes (∆E) before and after staining in immersion medium. The means and standard deviations of the ∆E values relating to color matching and color stability (stain resistance) among the study groups were analyzed using ANOVA and Tukey’s post hoc test. FT showed significantly better color matching (lower ΔE) in comparison to OM-UC specimens for shades B1, B2, and A3 (p &lt, 0.01). Regarding the color stability in cola, the FT samples showed significantly lower ΔE values (indicating better color stability) compared to OM samples for all four shades (p &lt, 0.01). The ΔE values of OM and FT samples in coffee were comparable (p &gt, 0.01), showing comparable color stability. The color matching ability of the single-shade resin composite (OM) was influenced by the tooth color. The conventional resin composite showed better color matching than the single-shade composite (OM). The color stability of the single-shade resin composite (OM) was dependent on the staining medium. The OM composite showed more compromised color stability than the conventional resin composite in cola and comparable color stability to conventional resin composite in coffee.

The study aimed to assess the effect of in-vitro chlorhexidine and antimicrobial photodynamic therapy (aPDT) disinfection protocols against acrylic resin specimens colonized with S. mutans, S. aureus, E. coli, and C. albicans.Reference strains of S. mutans, S. aureus, E. coli, and C. albicans were tested. Sixteen blocks of acrylic specimens were prepared by heat-cure acrylic resin and contaminated by in-vitro biofilm growth. Specimens in group 1, group 2 and group 3 were treated with Rose Bengal (RB), methylene blue (MB) 500 mg/L and porphyrin derivative (PD) 5 ml respectively, for the sensitization of biofilms. All photosensitizers (PS) were activated by LED at different wavelength. CHX was prepared in sterile distilled water and applied for 60 s. Each contaminated specimen was sprayed on all its surfaces with the aforementioned photosensitizers and control CHX. One-way analysis of variance (ANOVA) model was used to test the effect of the treatments and Tukey multiple comparison tests to compare means OF CFU/mL (log10) for exposed E. coli, C. albicans, S aureus, and S. mutans RESULTS: Specimens treated with 0.12% CHX (control) demonstrated a significant reduction in CFU/mL (log10) for exposed E. coli; 2.04±0.07 CFU/mL, C. albicans; 2.09±0.85 CFU/mL, S aureus; 3.04±0.11 CFU/mL, and S. mutans; 2.54±0.91 CFU/mL. The intragroup comparison revealed E.coli did not exhibit a decrease in reduction CFU/mL (log10) when acrylic resin irradiated with RB 5 µm. Whereas, CFU/mL (log10) values of S.aureus; 3.62±0.68 and S.mutans; 3.41±0.13 plummeted (p0.05). Intergroup comparison showed E.coli values to display comparable reduction when disinfected with MB 500 mg/L and 0.12% CHX; 3.16±0.34 and 2.04±0.07 CFU/mL (log10) (p0.05).Photosensitizers (RB, MB, PD) are selective in reducing bacterial count on acrylic resin blocks. CHX was found to be effective against all bacteria E.coli, C.albicans, S.aureus, and S.mutans at a concentration of 0.12%.

Objective The aim was to compare Photodynamic therapy (PDT) as an adjunct to NaOCl and EDTA on the extrusion bond strength (EBS) of AH Plus (AH), Sealapex (SA) and MTA Fillapex (MF) root canal sealers. Materials and method Root canal treatment for human teeth (n = 60) using protaper universal system was performed followed by irrigation with NaOCl/ EDTA. Samples were divided (n = 30) based on disinfection technique, NaOCl/EDTA and NaOCl/EDTA with PDT (Curcumin-PS-CP) as an adjunct. Specimens were divided in three subgroups (n = 10) based on sealers used (Gp 1-Na-E-AH, Gp 2-Na-E-PDT-AH, Gp 3-Na-E-SA, Gp 4-Na-E-PDT-SA, Gp 5-Na-E-MF & Gp 6-Na-E-PDT-MF). Canals were dried and obturated followed by sectioning at coronal and middle third. EBS testing was performed using a universal testing machine (UTM) and modes of failure were assessed. Analysis of variance (ANOVA) and Tukey multiple comparison tests were used to compare the means of EBS. (p Results Sealers showed a significant influence on EBS, as Gp 1 (Co: 9.21 ± 0.62, Mid: 8.54 ± 0.55) and Gp 2 (Co: 7.11 ± 0.68, Mid: 7.30 ± 0.37) showed higher EBS than Gp 3 (Co: 5.21 ± 0.63, Mid: 4.36 ± 0.83) and Gp 4 (Co: 5.39 ± 0.72, Mid: 4.46 ± 0.74). Gp 5 (Co: 9.04 ± 0.13, Mid: 8.14 ± 0.91) and Gp 6 (Co: 8.67 ± 0.42, Mid: 8.07 ± 0.07) exhibited higher EBS than Gp 3 and Gp 4 specimens. Adjunctive use of PDT for AH sealer (Gp 2) showed decreased EBS compared to Gp 1 specimens. EBS remained comparable for both MTA-Fillapex and Sealapex with and without PDT. Conclusion AH Plus (Gp 1 and 2) and MTA-Fillapex (Gp 5 and 6) sealers displayed better EBS compared to Sealapex (Group 3 and 4). Adjunctive Application of PDT (CP) did not show a significant improvement in bond strength of sealers to root dentin.

Aim: This study aimed to investigate an association between dental caries status and anthropometric measures in primary school children. Methods and Materials: An analytical cross-sectional study (n = 376) was conducted among primary school children (age range = 6–9 years) registered in private schools. Non-clinical data was gathered from parents of participating children through a self-administered structured questionnaire as well as from the children through an interviewer-administered questionnaire. Clinical data included the examination of dental caries using dmft/DMFT index and anthropometric measures including calculated z-scores of height-for-age (HAZ), weight-for-age (WAZ), BMI-for-age (BAZ), and physical examination. Inferential statistics included Kruskal Wallis and linear regression for univariate and multivariate analysis respectively. Results: The proportion of dental caries in primary and secondary dentition was 67.6 % and 8.2% respectively. A significant association was observed between dental caries status and HAZ, WAZ, and BAZ (p &lt, 0.001). An inverse relation was found between low, medium, and high dental caries categories and anthropometric measures. Conclusions: In the primary dentition, dental caries were significantly and inversely related to weight-for-age, height-for-age, and BMI-for-age. Hence, it can be concluded that among the low-income population dental caries is associated with lower anthropometric outcomes in children and therefore caries management should be considered an approach impacting overall health and quality of life.

Dental laboratories (LABs) are integral to the performance of a dentist in providing successful oral rehabilitation. The aim of this study was to compare the adaptation, contour, contacts, and shade matching of different government and commercial dental LABs in the fabrication of porcelain fused to metal (PFM) crowns. Thirty-two dental LABs were selected to fabricate PFM crowns (one PFM crown each). Marginal adaptation, contour, proximal contacts, and shade matching were evaluated. Evaluation of the crowns’ quality was performed following modified USPHS/FDI criteria. Visual and colorimeter assessments were employed to evaluate shade matching. Differences between groups were examined by Pearson’s Chi-square and Fisher’s exact test. The quality of marginal adaptation of crowns was good in 81.25%, however the quality of contours, contacts, and shade matching was compromised in 43.75%, 59.38%, and 39% of all LABs, respectively. Visual and colorimeter shade matching was acceptable in 62.5% and 80% of LABs in the cervical third and middle third regions of crowns, respectively, however in the incisal third the shade matching was unacceptable in nearly 60% of LABs. Commercial laboratories showed significantly better contours and shade matching, but not marginal adaptation. However, no significant differences were found in comparison of proximal contacts between the groups.

To assess the effectiveness of chemical, ultrasonic and photodynamic therapy (PDT) mediated disinfection against in-vitro biofilms colonized with C. albicans, S. oralis, and S. aureus on surfaces of PMMA (polymethylmethacrylate) denture base material.Fifty plates of PMMA were prepared with two different surface topography (rough and polished) analyzed by profilometry. Provenance culture (ATCC) of C. albicans, S. oralis, and S. aureus were inoculated on specimens and exposed to disinfection. The disinfection included Rosebengal (RB) 5 μM activated by a red LED, 2% glutaraldehyde, 70% Isopropyl alcohol, ultrasonic disinfection, and saline solution as a control. The antimicrobial efficacy was assessed by subsequently calculating viable counts after disinfection. The data were analyzed using analysis of variance (ANOVA) and Tukey's Post Hoc test.The unpolished surface demonstrated the highest average surface roughness As 5.32±0.36 (μm) and root mean square roughness Rr 7.22±0.81 (μm) compared to the polished surface. Intergroup comparison demonstrated polished and rough PMMA plate disinfected with rose bengal, glutaraldehyde and alcohol-based disinfection exhibited comparable reduction against C. albicans and S. oralis CFU/mL (log10) (p0.05). Whereas, this reduction was significantly higher on the rough and polished surface of PMMA when disinfected using ultrasounds for 30 sec (p0.05). Rose Bengal was the most effective method of disinfection against S. aureus both on polished (0.17±0.13) and rough (0.44±0.22) denture plates (p0.05).The ultrasonic disinfection was most effective in reducing viable microbial counts. RB mediated PDT exhibited a more substantial reduction of the colonies of S.aureus.

Aim The present study aimed to evaluate the effect of different cleansers and photodynamic therapy (PDT) on disinfection of Co/Cr removable partial denture colonized with C. albicans, S.aureus and S.mutans. Material and Methods Twenty-five Co/Cr removable partial dentures were constructed. and inoculated by American Type Culture Collection (ATCC) of Candida albicans, S.aureus, and S.mutans in an in-vitro setup. Co/Cr removable partial dentures were randomly allocated into five groups and framework was immersed in 15 mL of contaminated culture medium broth. Based on the cleansing method, disinfected dentures in group 1 were cleansed with porphyrin derivative; group 2 was exposed to 0.12% chlorhexidine digluconate; samples in group 3 and group 4 were subjected to sodium perborate enzyme and citric acid respectively. Through a surface analyzer, the surface roughness of Co/Cr and methacrylate resin was measured in 3 different zones in micrometers before and after disinfection. Two-way ANOVA and Tukey's test was used to analyze the data. Levene test was used to assess the normal distribution of data. Significance level p Results The results of metal roughness displayed that Co/Cr used as an alloy did not exhibit significant difference when exposed to different chemical disinfectants and photosensitizer (p > 0.05). Similarly, surface roughness (Ra) of heat polymerized acrylic resin using cleansers and PDT demonstrated no significant difference. Intergroup comparison showed that, hematoporphyrin derivative displayed comparable cleansing property against S. aureus, C.albicans, and S. mutans compared to to 0.12% CHX digluconate (p>0.05). The intragroup comparison showed hematoporphyrin derivative and CHX were equally effective against all bacteria (p>0.05). Conclusion CHX digluconate and hematoporphyrin derivative demonstrated high antimicrobial activity against S.aureus, S.mutans, and C.albicans with minimum Ra of an acrylic denture and Co/Cr metallic framework.

Aim: The aim of the study was to investigate whether the surface geometry or topography of implant abutments affects the retentive strength of prosthesis cemented with zinc phosphate on standard machined, sandblasted, and grooved implant abutments and to compare the results between them. Materials and Methods: Fifteen similarly shaped implant abutments (MDcpk61; MIS Implant Technologies Ltd.,) (height 6.0 mm and 6-degree taper) were divided into three groups (n = 05): Group I – standard machined abutments without grooves, Group II – sandblasted abutments (same as Group I but sandblasted with 50 μ aluminum oxide), and Group III – abutment with prefabricated circumferential grooves. Further in these groups of 15 abutments, 5 abutments each are to be taken to check the retentive force of zinc phosphate cement. Fifteen identical cast copings was prepared to fit all 15 abutments. The castings will be cemented to each group of abutments with an above-mentioned luting agent. After thermal cycling and storage for 6 days in a water bath, a retention test is to be done with a tensile testing machine (Instron) (5 mm/min) and retentive forces will be recorded. Data will be subjected to one-way ANOVA test and Student's t-test. Results: For zinc phosphate cement, F = 30.53 (>3.59 for P = 0.05) shows a statistically significant difference between all the three groups. Conclusion: Circumferential grooves on implant abutments give better retention when compared with standard machined (plain) and sandblasted abutments despite marked difference. Clinical Significance: Retention of restoration depends on the surface of the abutment as well as the luting agents used. Incorporation of retentive grooves can enhance retention of prosthesis, especially in situation of short abutments.