Ahmad A. Alnazzawi

Mechanical Properties and Simulated Aging of Silicone Maxillofacial Elastomers: Advancements in the Past 45 Years

PURPOSE To identify and discuss the findings of publications on mechanical behavior of maxillofacial prosthetic materials published since 1969. METHODS Original experimental articles reporting on mechanical properties of maxillofacial prosthetic materials were included. A two-stage search of the literature, electronic and hand search, identified relevant published studies up to May 2015. An extensive electronic search was conducted of databases including PubMed, Embase, Scopus, and Google Scholar. Included primary studies (n = 63) reported on tensile strength, tear strength, and hardness of maxillofacial prosthetic materials at baseline and after aging. RESULTS The search revealed 63 papers, with more than 28 papers being published in the past 10 years, which shows an increased number of publications when compared to only 6 papers published in the 1970s. The increase is linear with significant correlation (r = 0.85). Such an increase reflects great awareness and continued developments and warrants more research in the field of maxillofacial prosthetic materials properties; however, it is difficult to directly compare results, as studies varied in maxillofacial prosthetic materials tested with various silicone elastomers being heavily investigated, standards followed in preparing test specimens, experimental testing protocols, and parameters used in setting simulated aging conditionings. CONCLUSION It is imperative to overcome the existing variability by establishing unified national or international standards/specifications for maxillofacial prosthetic materials. Standardization organizations or bodies, the scientific community, and academia need to be coordinated to achieve this goal. In the meantime and despite all of these theoretically significant alternatives, clinical practice still faces problems with serviceability of maxillofacial prostheses.

Surface characteristics and biocompatibility of cranioplasty titanium implants following different surface treatments

OBJECTIVE Surface and mechanical properties of titanium alloys are integral for their use in restoring bone defects of skull and face regions. These properties are affected by the method of constructing and surface treatment of the titanium implant. This study aimed to investigate the effects of titanium finishing protocols on the surface morphology, hardness and biocompatibility of TiAl6V4. METHODS Square shaped TiAl6V4 specimens (ASTM F68) (10×10×0.5mm) were divided into seven groups of different surface treatments (n=10). The treatments included mechanical polishing, sandblasting with AL2O3 (50μm), immersion in different acids, and/or electro-chemical anodization. Weight loss %; 3D micro-roughness; Knoop micro-hardness, and osteoblast cell attachment and proliferation (after 3 days) were determined for each specimen. Data was analysed using one way ANOVA and Dunett T3 post-hoc tests, and t-test (p<0.05). RESULTS Weight loss % was in the range of 1.70-5.60 as mechanical polishing produced the highest weight loss, followed by sandblasting, and combined protocol of mechanical polishing and acid treatment (p<0.05). Micro-roughness values (μm) were in the range of 2.81-16.68. It was the highest for control specimens (p<0.05), and smoothest surfaces after combined mechanical polishing and acid treatment; or after electro-chemical treatment (p<0.05). Micro-hardness values (MPa) ranged 170.90-442.15 as sandblasting with/without acid treatment caused statically significantly the highest values (p<0.05) while control and mechanically polished specimens had the lowest values (p<0.05). All treatments produced equally biocompatible surfaces (p>0.05) after 1h or 3 days. Furthermore, osteoblast cell proliferation statistically significantly increased after 3days among each surface treatment (p<0.05). SIGNIFICANCE Different finishing treatments have variable effect on cranioplasty titanium surface loss, micro-roughness and micro-hardness but constant improved biocompatibility effect. Electro-chemical treatment caused less material loss and produced biocompatible smoothest surface of comparable hardness; hence it can be suitable for cranioplasty titanium surface finishing.

A randomized control trial comparing the visual and verbal communication methods for reducing fear and anxiety during tooth extraction

Purpose To evaluate the value of using the visual information for reducing the level of dental fear and anxiety in patients undergoing teeth extraction under LA. Methods A total of 64 patients were indiscriminately allotted to solitary of the study groups following reading the information sheet and signing the formal consent. If patient was in the control group, only verbal information and routine warnings were provided. If patient was in the study group, tooth extraction video was showed. The level of dental fear and anxiety was detailed by the patients on customary 100 mm visual analog scales (VAS), with “no dental fear and anxiety” (0 mm) and “severe dental distress and unease” (100 mm). Evaluation of dental apprehension and fretfulness was made pre-operatively, following visual/verbal information and post-extraction. Results There was a substantial variance among the mean dental fear and anxiety scores for both groups post-extraction (p-value < 0.05). Patients in tooth extraction video group were more comfortable after dental extraction than verbal information and routine warning group. For tooth extraction video group there were major decreases in dental distress and anxiety scores between the pre-operative and either post video information scores or postoperative scores (p-values < 0.05). Younger patients recorded higher dental fear and anxiety scores than older ones (P < 0.05). Conclusion Dental fear and anxiety associated with dental extractions under local anesthesia can be reduced by showing a tooth extraction video to the patients preoperatively.

Comparison of onset anesthesia time and injection discomfort of 4% articaine and 2% mepivacaine during teeth extractions

Objective: To investigate the speed of action and injection discomfort of 4% articaine and 2% mepivacaine for upper teeth extractions. Materials and Methods: Forty-five patients were included in the articaine 4% group, and 45 in the mepivacaine 2% control group. After all injections, soft and hard tissue numbness was objectively gauged by dental probe at intervals of 15 s. Furthermore, the discomfort of the injections were recorded by the patients after each treatment on standard 100 mm visual analog scales, tagged at the endpoints with “no pain” (0 mm) and “unbearable pain” (100 mm). Results: There were significant differences in the meantime of first numbness to associated palatal mucosa and tooth of patients between mepivacaine and articaine buccal infiltration (BI) groups P = 0.01 and 0.01. Patients in the articaine group recorded earlier palatal mucosa and teeth numbness than those in the mepivacaine group. With regards to the discomfort of the needle injections, palatal injection was significantly more painful than BI (t-test: P< 0.001). Articaine buccal injection was significantly more painful than mepivacaine buccal injection (t-test: P<0.001). However, articaine palatal injection was less painful than articaine BI. Clinically, anesthesia onset time was faster in anterior upper teeth than upper middle and posterior teeth. Conclusions: BIs with 4% articaine was faster in achieving palate and teeth anesthesia than 2% mepivacaine for extraction of upper maxillary teeth. Patients in mepivacaine BI and articaine palatal injection groups reported less pain with needle injection. Failure of anesthesia was noticeable with maxillary multiple-rooted teeth.

Waterpipe Tobacco Smoking Among Dental Practitioners: Prevalence and Health Perceptions

Background Waterpipe tobacco smoking prevalence, practice, and the associated health perceptions among dental practitioners have not been previously reported. This study aims to determine the prevalence of waterpipe smoking among dental practitioners and to evaluate their awareness of health hazards of waterpipe smoking, particularly the adverse effects on oral health. Methods This was a cross-sectional questionnaire-based survey among dental practitioners. Surveyed dental practitioners practiced dentistry in the holy city of Al-Madinah Al-Munawarah, a city in the Central-Western Region of Saudi Arabia, and the study was conducted during March 2015. The questionnaire consisted of questions on demographic data, history and practices of tobacco use, and perceptions toward the health hazards of smoking. Dentists were approached at their work places and invited to participate. Descriptive statistics were used to describe the samples demographic and smoking characteristics, while cross-tabulation and chi-square test were used to determine the statistical significance of association between the groups (P ≤ 0.05). Results One hundred dental practitioners participated in the survey, with 55 males and 45 females. Twenty-six percent indicated that they were water-pipe smokers. Male gender and cigarette smoking were the only factors to be significantly associated with waterpipe smoking (P = 0.008 and P = 0.000, respectively). Most participants stated that waterpipe smoking is harmful to health, and the most commonly reported health hazard was respiratory disease, which was reported by 81% of participants. Conclusions Prevalence of waterpipe smoking among dental practitioners is comparable to adult populations but lower than younger populations of university students. Health awareness of dental practitioners regarding waterpipe smoking was judged to be insufficient.

Antibiotic Self-Medication for Oral Conditions: Characteristics and Associated Factors

Objective: To investigate the prevalence and contributing factors of antibiotic self-medication for oral conditions in dental patients. Material and Methods: A questionnaire was distributed to 501 patients attending Taibah University Dental College and Hospital, Al Madinah, Saudi Arabia during late 2016. Questions were on socio-demographic characteristics, and pattern of antibiotic self-medication for oral disease. Statistical analysis was performed using IBM SPSS software version 21. Statistical significance level was set at p ≤.05. Results: Age range was 15-64 years (29.08±9.32 years) with 297 females (59.3%) and 204 males (40.7%). 135 patients (27%) self-medicated with antibiotics for oral disease. This practice was statistically significantly associated with the older adults (p=0.001), lack of medical or dental insurance (p=0.014 and 0.007, respectively), and poor dental attendance (p=0.021). A number of 26 (25.7%) perceived analgesics as antibiotics. Amoxicillin-clavulanic acid was the most commonly cited antibiotic by 18 patients (17.8%). Dental pain was the most frequently reported oral condition. Pharmacists were the most common source for antibiotic prescription cited by 58 (57.4%). Conclusion: Antibiotic self-medication for oral disease is associated with the use of broad-spectrum antibiotics for non-indicated clinical oral conditions. The practice was encouraged by lenient behavior of pharmacists, lack of health insurance, and poor dental attendance.

The efficacy of retreatment and new reciprocating systems in removing a gutta-percha-based filling material

Objectives To investigate the efficacy of retreatment and reciprocating rotary systems in removing gutta-percha filling material from root-canal systems. Methods A total of 90 single-canal human teeth were instrumented using a F3 ProTaper file and obturated with gutta-percha and the Tubliseal sealer using the lateral-compaction technique. They were divided into five groups according to the rotary system used to remove the filling material: Reciproc, which used the Reciproc-R25 file; WaveOne, which used the WaveOne-Primary file; S1, which used the S1 (25/.06) file; ProTaper-R, which used the ProTaper-Retreatment system; and Mtwo-R, which used the Mtwo®-Retreatment system. The time required to remove the filling material (min) and the associated instrument separation, if any, were recorded. Teeth were cleaved longitudinally and photographed with a high-resolution camera. Images were imported to the AutoCAD application to measure the remaining filling material and the root-canal space. Data were analysed using the one-way analysis of variance and Chi-squared tests. Results The Mtwo-R group showed the highest mean remaining filling material (51%) (p < 0.001), with no significant differences among the other groups. The ProTaper group required the least time for filling-material removal (4.95 min), with significant differences compared to the other groups (p < 0.05), except the WaveOne group (5.83 min; p = 1.000). Overall, 13 instruments (15.9%) were used for filling-material removal, with a significantly greater proportion in the Mtwo-R group (33.3%) compared to the other groups (p = 0.009). Conclusions Within the limitations of this in vitro study, reciprocating rotary systems were as effective as retreatment rotary systems in removing root-canal filling material. The Mtwo-R system showed the poorest performance with respect to removal effectiveness and instrument separation.

Effect of fixed metallic oral appliances on oral health

There is a substantial proportion of the population using fixed metallic oral appliances, such as crowns and bridges, which are composed of various dental alloys. These restorations may be associated with a number of effects on oral health with variable degrees of severity, to review potential effects of using fixed metallic oral appliances, fabricated from various alloys. The MEDLINE/PubMed database was searched using certain combinations of keywords related to the topic. The search revealed that burning mouth syndrome, oral pigmentation, hypersensitivity and lichenoid reactions, and genotoxic and cytotoxic effects are the major potential oral health changes associated with fixed prosthodontic appliances. Certain oral disorders are associated with the use of fixed metallic oral appliances. Patch test is the most reliable method that can be applied for identifying metal allergy, and the simultaneous use of different alloys in the mouth is discouraged.

Oral diseases associated with fixed prosthodontic restorations

[No Abstract Available].

Survey of Ocular Prosthetics Rehabilitation in the United Kingdom, Part 2: Anophthalmic Patients’ Satisfaction and Acceptance

Aim: Ocular prostheses are integral for anophthalmic patients. Part 1 of this study reported that patients’ aetiology, opinions, and attitudes significantly affected their prosthetic eyes experience. Part 2 investigates the patient satisfaction and acceptance in light of some of the aetiological demographics reported in Part 1. Methodology: One hundred sixty questionnaires were delivered to anophthalmic patients attending oculoplastic clinic. Etiological aspects presented in the questionnaire were disseminated in part 1. Patient satisfaction was assessed through 8 closed-end statements reflecting aspects concerning patients views on prosthesis comfort and appearance; patients expectations, self-esteem, and perception; and cooperation with ocularist. Each statement had 3 categories as agree, moderately agree, and disagree. A total of 126 questionnaires were returned (response rate was 78.8%). Data was analyzed using SPSS software. Association coefficients and correlations between variables were also analyzed. Results: Total number of responses for the 8 statements was 888, averaging of 111 (expected 126) respondent per statement. Overall, 95.4% of our patients agreed with all satisfaction statements presented echoing very high satisfaction rate with their ocular prosthetics. Having an eye replacement that covers the defect is associated with high satisfaction among patients regardless of ocular prosthetic type. Patient acceptance of prosthesis in relation to employment status was high but not the same among the different categories (P > 0.05). High satisfaction with ocular prosthetics was prevalent among both genders, but there were no statistically significant differences in percentages of agreement in all statements (P > 0.05). Satisfaction and acceptance with ocular prosthetics was the same among all age groups of 12 to 85 years old (P > 0.05). Conclusions: The patient satisfaction is associated with the interplay of different variables that is related to ocular prosthesis design and its ability to disguise disfigurement (ie, prosthesis shape, resemblance to existing contra-lateral eye, etc.); patients themselves (ie, gender, age, occupation, marital status, etc); and psychological well-being and social support provided. Anophthalmic patients of the north west of England are significantly happy with their ocular prosthetic rehabilitation and support they receive from their regional hospital. Ocular prosthetics enhances their psychological well-being and social interaction and factors like patients’ sex, age, employment status, and type of ocular prosthesis have no effect on their acceptance and satisfaction.