Influences of Different Torques on the Size of the Microgap and Bacterial Leakage in Different Implant Systems: An In-vitro Study.

PURPOSE: To evaluate the adherence of three types of bacteria [Staphylococcus (S) aureus, Escherichia (E) coli, Pseudomonas (Ps) aeruginosa] and the size of the microgap of three different implant systems (JD, ORA, and Ankylos) under four different screw torque values. MATERIALS AND METHODS: Ten samples for each tested implant system were used under different torques to determine the width of the gaps. The abutments were connected to the fixtures using a universal digital wrench. A torque value of 10 N/cm was applied for all samples. After the assessment of the microgap, the fixture was repositioned into the Bench Vice, and the torque was increased to 20, 30, and, finally, 40 N/cm. The microgap assessment was done using a Scanning Electron Microscope. Before the torque increased to 40, eleven samples for each tested implant system were used under 30 N/cm torque to determine the leakage in the tested implants for S. aureus, E. coli, and Ps. aeruginosa. Data were analyzed with multiple one-way ANOVA, Post Hoc, and chi-square tests. RESULTS: The Ankylos system showed the widest gap under all torques (p < 0.005), whereas the JD system demonstrated the lowest (p < 0.005). Regarding the bacteria leakage, JD showed the highest adherence to the bacteria, and the adherence was mainly to the Ps. Aeruginosa, while the Ankylos system showed the lowest (p < 0.005). CONCLUSION: Within limits, the higher torque provides a higher fit to the IAI, offering more stability. Ankylos implant showed the widest gap, while JD showed the narrowest. Regarding the bacteria leakage, JD showed the highest adherence to Ps. Aeruginosa, while the ORA system showed the highest adherence to E. coli.

Prospective case series on possible effects of local factors on the development of halitosis in new complete denture wearers.

OBJECTIVES: To assess the development of halitosis in participants wearing new removable complete dentures (RCD). METHOD AND MATERIALS: Seventy-five completely edentulous patients receiving RCD were recruited. Halitosis was assessed by means of FitScan Breath Checker on the day of denture insertion (T0), as well as after 1 month (T1), and after 2 months (T2). Risk factors were studied using a validated questionnaire about oral and denture hygiene, and tongue scoring followed for each participant. A modified plaque scoring technique assessed the percentage of newly formed biofilms accumulated on all surfaces of the RCD. RESULTS: At T0, 44% of the participants revealed halitosis. This percentage insignificantly increased at T1 (66.7%) and T2 (65.6%), respectively (P > .109). At T1, halitosis was significantly lower among persons who reported tongue brushing compared to refraining participants (14.3% vs 72.6%; P = .002). At T2, halitosis was significantly higher among patients suffering from moderate to heavy tongue coatings compared to those with no or only light coatings (83.3% vs 50.0%; P = .006), those who did wear their dentures during sleeping (77.5% vs 45.8%; P = .010), and those who did not brush their tongues at all (87.5% vs 29.2%; P < .0001). With a 16-fold increased probability (95% CI 10.0 to 23.31; P < .001), the multivariate analysis revealed that non-brushing the tongue was the only variable significantly linked to halitosis at both follow-ups. CONCLUSION: Non-brushing of tongues as well as sleeping with dentures seems to be the main causes of halitosis in new RCD wearers.

Biomechanics in Removable Partial Dentures: A Literature Review of FEA-Based Studies.

The present study was aimed at reviewing the studies that used finite element analysis (FEA) to estimate the biomechanical stress arising in removable partial dentures (RPDs) and how to optimize it. A literature survey was conducted for the English full-text articles, which used only FEA to estimate the stress developed in RPDs from Jan 2000 to May 2021. In RPDs, the retaining and supporting structures are subjected to dynamic loads during insertion and removal of the prosthesis as well as during function. The majority of stresses in free-end saddle (FES) RPDs are concentrated in the shoulder of the clasp, the horizontal curvature of the gingival approaching clasp, and the part of the major connector next to terminal abutments. Clasps fabricated from flexible materials were beneficial to eliminate the stress in the abutment, while rigid materials were preferred for major connectors to eliminate the displacement of the prosthesis. In implant-assisted RPD, the implant receive the majority of the load, thereby reducing the stress on the abutment and reducing the displacement of the prosthesis. The amount of stress in the implant decreases with zero or minimal angulation, using long and wide implants, and when the implants are placed in the first molar area.

Biomechanical Stress in Obturator Prostheses: A Systematic Review of Finite Element Studies.

AIM: This systematic review is aimed at investigating the biomechanical stress that develops in the maxillofacial prostheses (MFP) and supporting structures and methods to optimize it. Design and Methods. A literature survey was conducted for full-text English articles which used FEA to examine the stress developed in conventional and implant-assisted MFPs from January 2010 to December 2020. RESULTS: 87 articles were screened to get an update on the desired information. 74 were excluded based on a complete screening, and finally, 13 articles were recruited for complete reviewing. Discussion. The MFP is subjected to stress, which is reflected in the form of compressive and tensile strengths. The stress is mainly concentrated the resection line and around the apices of roots of teeth next to the defect. Diversity of designs and techniques were introduced to optimize the stress distribution, such as modification of the clasp design, using materials with different mechanical properties for dentures base and retainer, use of dental (DI) and/or zygomatic implants (ZI), and free flap reconstruction before prosthetic rehabilitation. CONCLUSION: Using ZI in the defective side of the dentulous maxillary defect and defective and nondefective side of the edentulous maxillary defect was found more advantageous, in terms of compression and tensile stress and retention, when compared with DI and free flap reconstruction.

Influence of Weather on Hardness and Surface Roughness of Maxillofacial Elastomeric Materials.

AIMS: The purpose of this study was to assess the influence of hot and dry weather on the hardness and surface roughness of four different maxillofacial silicone elastomeric materials (MFSEM) including two room-temperature vulcanized (RTV) and two high-temperature vulcanized (HTV) materials. MATERIALS AND METHODS: Eighty test specimens were fabricated according to the manufacturer's instructions into rectangular test specimens. The hardness and surface roughness were tested, after 6 months of exposure to natural hot and dry weather. The hardness was measured through the International Rubber Hardness Degree (IRHD) scale using an automated hardness tester. The surface roughness was measured using a novel 3D optical noncontact technique using a combination of a light sectioning microscope and a computer vision system. Statistical Package for Social Sciences software SPSS/version 24 was used for analysis and a comparison between two independent variables was done using an independent t test, while more than two variables were analyzed, F test (ANOVA) to be used followed by a post hoc test to determine the level of significance between every two groups. RESULTS: The hot and dry weather statistically influenced the hardness and surface roughness of MFSEM. Cosmesil M-511 showed the least hardness in test groups while A-2000 showed the hardest material (p < 0.05). A-2000 showed significant changes from rough in case of nonweathered to become smoother in weather followed by A-2186 (p < 0.05). Cosmesil M-511 showed the roughest material. CONCLUSION: Cosmesil M-511 showed the least hard MFSEM after outdoor weathering while A-2000, the highest and least material showed hardness and surface roughness, respectively. CLINICAL IMPLICATION: A-2000 had a high IRHD scale hardness. This makes this material more suitable for the replacement of ear and nose defects. Cosmesil M-511 is soft and easily adaptable material that makes the material more appropriate for the replacement of small facial defect with undercut area to be easily inserted and removed. Whilst A-2000 is smoother and finer in test specimens after weathering, Cosmesil M-511 became rougher after weathering.

Erratum: Denture-related stomatitis in new complete denture wearers and its association with Candida species colonization: a prospective case-series Denture-related stomatitis in new complete denture wearers and its association with Candida species colonization: a prospective case-series.

The following amendments are made to the published article: Quintessence Int 2020;51(7):554-565; First published 5 June 2020; doi: 10.3290/j.qi.a44630.

Denture-related stomatitis in new complete denture wearers and its association with Candida species colonization: a prospective case-series.

OBJECTIVES: To assess the relationship between the development of denture-related stomatitis (DRS) and the identification of commonly isolated yeast species, and to evaluate various predisposing factors in Saudi participants wearing new removable dental prostheses. METHOD AND MATERIALS: A total of 75 edentulous male participants were recruited, and 64 patients finished the present case-series. All participants received new conventional complete dentures. Colonization of Candida species was assessed, and species were identified by means of the VITEK 2 (bioMérieux) laboratory components. RESULTS: The most prevalent type of Candida at baseline was C albicans, followed by non-C albicans species (C glabrata). Counts of Candida species significantly increased from the day of insertion to the first month (P < . 05), but there were no significant changes between the first and second month (P > . 05). On the day of insertion, C tropicalis, C dubliniensis, and C krusei were extracted from few subjects only, with no significant changes over the first and second month (P > .05). Patients revealing habits of sleeping with their dentures were found to frequently suffer from DRS; development of the latter was rapid, and mixed Candida biofilms (with high CFU/mL counts), along with inadequate oral and denture hygiene, turned out to be contributing factors (P < .05). CONCLUSION: DRS can develop faster than previously reported, even with new dentures; continued denture wearing and poor cleaning of dentures revealed a considerable impact on DRS onset. In the present cohort, C albicans was the most identified kind of yeast, and was followed by C glabrata infection in cases with DRS.

Musculoskeletal pain in the community.

OBJECTIVE: To estimate the prevalence of musculoskeletal (MSK) pain in Al-Qaseem province in central Saudi Arabia. METHODS: Over a period of 18 months extending from September 1993 through to the end of February 1995, a house-to-house survey was conducted in Al-Qaseem province and included 5,894 adults asking regarding musculoskeletal pain. RESULTS: We obtained a response from 5,823 (98.8%), 2,667 (45.8%) men, and 3,156 (54.2%) women. The mean age was 34.14 +/- 15.16 years. Musculoskeletal pain was reported by 1,477 (25.4%), 762 (13.1%) men and 715 (12.3%) women. Musculoskeletal pain was significantly correlated with age (r =0.454), married status (r=0.238), unemployment (r=0.122), lower educational attainment (r=0.347), frequent attendance at local doctor (r=0.703), consumption of medications for pain (r =0.551), and change in ability to work (r=0.492). We found no association with sex or body mass index. CONCLUSION: Musculoskeletal pain, although common in the community, is less prevalent than reported from Western countries, but has similar socio-medical consequences.

How common is back pain in Al-Qaseem region.

OBJECTIVE: The aim of this study was to estimate the prevalence of back pain in the adult population of Al-Qaseem Central Province, Kingdom of Saudi Arabia and to find associated features and factors. METHODS: A house-to-house survey covering 1,000 household in the towns and villages of Al-Qaseem province was carried out over a period of 18 months extending from September 1993 until the end of February 1995. A total of 5,894 adults, aged 16 years and above, were questioned by trained staff regarding back pain, and the demographic data in addition to general, medical and social history. RESULTS: A response was obtained in 5,743 (97.4%). Their mean age was 34.14 15.16 (range 16-99). Back pain was reported by 1,081 (18.8%), wherein 499 (8.8%) were men, and 574 (10%) were women. Back pain was more prevalent in married (23.3%) individuals than unmarried (6.4%). Adjusted odds ratio (OR) for back pain in married individuals was 1.88 (95% confidence intervals [CI] 1.49-2.37). Back pain was strongly correlated with age (correlation coefficient = 0.378 P < 0.01). It also showed significant correlation with weight and height, depression, family history of back pain, change in work ability, frequency of attendance at local doctor, use of medication and lower education level. The association with body mass index became evident only after comparing the heaviest 20th percentile to the lightest (OR 1.335 [95% CI, 1.279-1.402]). Certain occupational status (unemployed, farmers, professional workers and housewives) were associated with back pain. CONCLUSION: Back pain was relatively common in this largely unindustrialized community although its prevalence is lower than reported from some western countries.

Knee osteoarthritis in Al-Qaseem, Saudi Arabia.

OBJECTIVE: The aim of this study was to estimate the prevalence of clinical osteoarthritis (OA) of the knee in Al-Qaseem, a central province in the Kingdom of Saudi Arabia (KSA). METHODS: A house to house survey of randomly selected inhabitants of Al-Qaseem, KSA was conducted. A total of 10,406 persons were interviewed of whom 5,894 were above the age of 16 years. The study was carried out at King Khalid University Hospital and College of Medicine, Riyadh, KSA, from September 1993 to February 1995. They were questioned regarding musculoskeletal complaints, and those positively identified were interviewed further by a team of trained medical staff and later examined by trained doctors including rheumatologists. RESULTS: We found 766 (13%) cases of clinical OA of the knee in the 5,894 adult population (13%). The prevalence of OA increased with increasing age reaching 30.8% in those aged 46-55 years and 60.6% in the age group 66-75 years. The odds ratio (OR) for the association between clinical OA of the knee and age adjusted for sex and body mass index (BMI) was 1.0894 (95% CI, 1.08-1.09). The association of clinical OA of the knee with female sex was also significant [OR (adjused for age and BMI) was 1.261 (95% CI, 1.0456-1.5208)]. CONCLUSION: Clinical OA of the knee is common in this community, particularly in the older age groups.