Dentistry School Theses and Dissertations
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Item Effect of Toothbrushing on a Monolithic Dental Zirconia Submitted to an Accelerated Hydrothermal Aging(2022) Almajed, Norah; Sochacki, Sabrina Feitosa; Cook, Norman Blaine; Capin, Oriana ReisItem Distal and Proximal Influences on Self-Reported Oral Pain and Self Rated Oral Health Status in Saudi Arabia, 2017(2022-08) Abogazalah, Naif Nabel F.; Martinez Mier, Esperanza Angeles; Yepes, Juan Fernando; Yiannoutsos, Constantin T.; Bindayel, Naif A.; Soto Rojas, Armando ErnestoAlthough complex phenomena such as oral diseases can be studied using generalizable conceptual frameworks, the differences in the underlying influences across countries necessitate adaptation of existing oral health frameworks to the specific conditions in each country. The aim of this dissertation was to investigate distal (indirect) and proximal (direct) influences of oral health and their interactions with both self-reported oral pain (OP) and self-rated oral health status (SROH) in Saudi Arabia (SA). Two secondary data analyses were conducted utilizing data from the national demographic and health survey (DHS) of SA in 2017. The objective of the first study was to describe the study design, and the distal and proximal influences reported in the 2017 SA DHS. The objective of second study was to explore associations between proximal and distal factors that affect OP and SROH, using the adapted framework. Path analysis modeling was used to estimate direct, indirect, and total effects. The 2017 SA DHS used an innovative multistage stratified random-sampling technique to select the population sample by using primary health care centers’ catchment areas as the primary sampling unit. The final analysis included 29,274 adults, 9910 adolescents, and 11653 children. OP in the past year was experienced in 39% in children and, 48.5% for the adolescents, and 47.1% in adults. The proportion of respondents who reported good, very good, or excellent self-rated oral health status was 92.9 % in children, 87.1% in both adolescents and adults. In children group, OP was linked to less tooth brushing, more dental visits and less dental routine examination, while less favorable SROH was linked to less tooth brushing, more dental visits and sweets consumption. In adolescents and adults groups, OP and less favorable SROH were linked to more dental visits, complaint dental visits, less tooth brushing. Many distal influences showed significant effects (direct, indirect, and total) on OP and SROH; however, differences existed among the three age groups. The studies suggest that future investigations should focus on why Saudi residents perceive their oral health positively while the prevalence of negative oral health influences and OP was high.Item The Effect of Silver Diamine Fluoride on Caries Lesion Remineralization as a Function of Lesion Baseline Mineral Distribution(2022) AlMady, Fahad; Lippert, Frank; Hara, Anderson; Al Dehailan, Laila; Capin, OrianaPurpose: The primary objective of this laboratory study was to investigate whether the ability of SDF to remineralize caries lesion is modulated by their baseline mineral distribution. The exploratory objective was to determine whether the staining caused by SDF is modulated by lesion mineral distribution. Materials and methods: This in vitro study utilized bovine permanent enamel specimens. SDF was compared to the clinical reference standard, 5% sodium fluoride varnish (FV), and deionized water (DIW) was the negative control. By utilizing three lesion creation protocols (methylcellulose [MeC], hydroxyethylcellulose [HEC], Carbopol [C907]), artificial caries lesions with different mineral distributions (n=20 per subgroup) were created in the enamel specimens Interventions were applied and the lesions remineralized using artificial saliva. Changes in mineral loss, lesion depth, mineral density of the surface zone, and lesion mineral distribution were determined using transverse microradiography. Throughout the study, color of the lesion and changes thereof were measured using a spectrophotometer. Data were analyzed by using two-way ANOVA. Pair-wise comparisons were performed using Fisher’s Protected Least Significant Differences to control the overall significance level at 5%. Results: For changes in mineral loss, DIW in MeC showed significantly greater change (more remineralization) than both SDF (p<0.01) and FV (p=0.01), which were not different from one another (p=0.13). There were no statistically significant differences between SDF and FV in the other lesions (C907 – p=0.18; HEC – p=0.56). For changes in lesion depth, there was no statistically significant interaction between study factors lesion protocol and treatments (p=0.23) as well as the individual factors lesion protocols (p=0.08) and treatments (p=0.82). For changes in surface zone mineral density, SDF showed significant change in mineral density compared to FV (p=0.02); however, SDF was not different from with DIW (p=0.25). For lesion mineral distribution, MeC exhibited the greater mineral loss in the lesion body and lowest mineral density at the surface zone. HEC lesions were the deepest but exhibited modest differences in mineral loss between the lesion body and the surface zone. C907 lesions were somewhat between MeC and HEC. SDF in MeC had the highest mineral gain in the surface zone, while DIW resulted in the highest mineral gain in the lesion body. SDF in HEC showed the highest mineral gain in the surface area compared to FV and DIW, with all treatments resulting in the largest mineral gain to a similar extent in the lesion body. In C907, SDF showed the most mineral gain in the lesion body compared to DIW and FV, while differences in the surface zone between treatments were less pronounced. For color changes post intervention, SDF showed more darkening in C907 and HEC lesions compared to MeC (p<0.01) and compared to FV and DIW. For post remineralization, SDF treated C907 lesions became significantly whiter (p<0.01) compared to SDF in MeC and HEC which continued to get darker. Conclusion: SDF did exhibit different remineralization abilities and behaviors and the modulation was based on lesion baseline mineral distribution. Staining resulting from SDF treatment varied significantly based on lesion mineral distribution.Item EGCG-Encapsulated Halloysite Nanotube Modified-Adhesive for Longer-Lasting Dentin-Resin Interfaces(2022-07) Alhijji, Saleh Mohammed; Windsor, L. Jack; Platt, Jeffrey A.; Bottino, Marco C.; Manicke, Nicholas; Sochacki, Sabrina FeitosaThe degradation of the resin-dentin interface after restoration placement is multifactorial and can be attributed in part to matrix metalloproteinases (MMPs) enzymes associated with recurrent and secondary caries progression. This dissertation aimed to synthesize and characterize the effects of Epigallocatechin-3-gallate (EGCG) from green tea extract as an MMP-inhibitor loaded into a dental adhesive using slow therapeutic compound release nanotubes as a reservoir to allow sustained and slow release. Loading efficiency and drug release were evaluated using a UV-vis spectrometer. The effects on the degree of conversion (DC), polymerization conversion (PC), and Vickers Micro-Hardness (VHN) tests were performed. MMP mediated β-casein (bCN) cleavage rate was used to determine the potency of the eluates contained EGCG to inhibit MMP-9 activity. The results indicated that HNTs could hold about 21.35% (±4.2%) of the EGCG used in the encapsulation process. The addition of 7.5% HNT or 7.5% EGCG-encapsulated HNT adhesive groups did not alter the curing efficiency indicated by the degree of conversion, polymerization conversion, and surface hardness results compared to the control group (p> 0.05). A statistically significant influence of adding HNTs was found to slow down the EGCG release measured up to 8 weeks (p< 0.05). There was a significant decrease in the degradation of β-casein mediated by pre-activated MMP-9 exposed to eluates from EGCG adhesives compared to non-EGCG adhesive groups (p< 0.05). The results suggested that using HNTs for EGCG encapsulating can remedy the negative impact of EGCG on the adhesive’s polymerization and still have the MMP-inhibitory effect and longer release period. Dentin adhesive containing EGCG-encapsulated HNT may contribute to the long-term preservation of restorations through slow and controlled release to maintain the dentin-resin interface's integrity by inhibiting MMP activity.Item Survival Analysis of Endodontically Treated Teeth in Patients with Diabetes and Hypertension within National Dental PBRN Practices(2022-06) Crosby, William Justin; Spolnik, Kenneth; Thyvalikakath, Thankam Paul; Ehrlich, Ygal; Warner, NedIntroduction: The prevalence of diabetes mellitus (DM) is rapidly increasing among the aging United States population. This poses a challenge to dental providers since DM and multiple oral conditions have been identified as comorbidities. Hypertension (HTN) is associated with more poorly controlled DM and has been identified as contributing to RCT tooth loss in prior studies. Links have also been established between DM and the survival rate of root canal treated teeth, however, previous research has focused on institutional settings despite the majority of RCT being performed in private dental practices. This study will use data from private dental practices to evaluate the survival rate of RCT teeth in patients with DM and HTN. Materials and Methods: This retrospective study evaluated the survival rate of endodontic treated teeth among patients with DM and HTN using National Dental PBRN Practice data. Electronic dental records from 42 private dental practices in the United States over a period of 15 years with a minimum 2-year follow-up comprising 11,532 root canal treated teeth were analyzed. Kaplan-Meier survival curves were used to demonstrate the effects of HTN and DM on RCT tooth survival and Cox proportional hazards survival analysis was used to evaluate the DM and HTN effects after accounting for age, gender, insurance, year of treatment, tooth type, and crown and filling placement as covariates. Results: Patients with HTN only had significantly lower risk of failure than patients with both HTN and DM (p=0.003). Patients with neither HTN nor DM had significantly lower risk of failure than patients with both HTN and DM (p=0.020). Patients with DM only did not have significantly different risk of failure than patients with both HTN and DM (p=0.223). Patients with DM only did not have significantly different risk of failure than patients with HTN only (p=0.361). Patients with neither HTN nor DM did not have significantly different risk of failure than patients with HTN only (p=0.121) or patients with DM only (p=0.800). Conclusions: Patients with both DM and HTN have an increased chance of root canal treated tooth failure while patients with only DM or only HTN do not. Evaluation of severity of DM may be more important in determining RCT failure and studies utilizing laboratory values should be considered for future research.Item Performance of Multiple Emission Peak Light Emitting Diode Light Curing Unit: Degree of Conversion and Microhardness of Resin-Based Pit and Fissure Sealant(2022-07) Ba Armah, Ibrahim; Soto, Armando E.; Platt, Jeffrey A.; Al Dehailan, Laila A.Background: The light-cured resin-based pit and fissure sealants success and longevity are enhanced by sufficient curing. Multiple emission peak Light Emitting Diode Light Curing Units offer a wider range of wavelengths and different levels of irradiances to ensure sufficient curing.The irradiance is considered a main curing factor that can affect the material properties. Purpose: The aim of this study was to assess the effect of different settings of a multiwave LED LCU on the degree of conversion and microhardness of a pit and fissure sealant comparing the irradiance of 1000 mW/cm2 to 1400 mW/cm2 and 3200 mW/cm2 irradiances of the LCU using manufacturer’s guidelines for curing times at 2, 4 and, 6 mm distances. Methods: A multiwave LED light curing unit was evaluated on three different irradiance levels 1000 mW/cm2 (S), 1400 mW/cm2 (H), and 3200 mW/cm2 (X). A total of 90 samples made from the fissure sealant were fabricated and divided into eighteen groups (n=5/group). Samples were cured following manufacturer’s guidelines of curing times for each curing mode at 2, 4, or 6 mm distance between the light tip and top of samples. The DC was measured using (ATR-FTIR) spectroscopy. The KHN test was performed on five different locations of each specimen using a hardness tester (Leco LM247AT, MI, USA, software; Confident V 2.5.2). Results: The top DC for H-8 was significantly higher than S-10 at 2 and 4mm, H-20 DC was significantly lower than S-30 at only 2mm. The bottom DC for H-8 was significantly higher than S-10 at 2mm only, H-20 DC was significantly lower than S-30 at 4 and 6mm only. H-8 KHN at top surface was significantly lower than S-10 at 2mm only, H-20 was significantly lower than S-30 at 2 and 6mm only. H-8 KHN at bottom surface was significantly lower than S-10 at 4 and 6mm but significantly higher at 2mm. H-20 was significantly lower than S-30 at 2mm but significantly higher at 4 and 6mm. The top DC for X-3 was significantly lower than S-10 at all curing distances with no significant difference at all curing distances between X-9 and S-30. The bottom DC for X-3 was significantly higher than S-10 at all curing distances with no significant difference between X-9 and S-30. X-3 KHN at top surface was significantly lower than S-10s at all curing distances. X-9 was significantly lower than S-30 at 6mm only. X-3 KHN at bottom surface was significantly lower than S-10 at 2 and 4mm only with no significant difference at all curing distances between X-9 and S-30. Conclusions: Using a multiwave LED LCU to polymerize Delton Opaque resin-based fissure sealants will result in an optimal DC and KHN values for any irradiance level if the curing distance is kept at 4 mm or less and with at least two cycles of the shortest curing time recommended by the manufacturer. Using a multiwave LED LCU with 1000, 1400 or 3200 mW/cm2 irradiance levels with shortest curing times recommended resulted in unsatisfactory DC and KHN levels. LED LCU with high and extra high irradiance levels (1400 and 3200 mW/cm2) can result in high DC and KHN levels when used adequately. Xtra Power mode (3200 mW/cm2) used on shortest curing time (3 seconds) resulted in significantly lower mechanical properties and for that reason it is not recommended to be used.Item Differentiation and Activity of Murine Derived Stromal Osteoblasts After Electromagnetic Wave Stimulation(2022) Wu, Jennifer L.; Spolnik, Kenneth; Bruzzaniti, Angela; Ehrlich, Ygal; Warner, NedIntroduction: Elimination of bacteria and active infection within an infected root canal system is one of the primary objectives of nonsurgical root canal treatment. One of the measures of successful root canal treatment is subsequent bone healing of periapical lesions caused by previous infection. A previous study by Yumoto et al. showed that electromagnetic wave stimulation can increase proliferation of osteoblastic cells with no cytotoxicity, and it can also up-regulate growth factors such as vascular endothelial growth factor and platelet-derived growth factor.18 They also showed increased proliferation of an immortalized osteoblastic MC3T3-E1 cell line 3 days following electromagnetic stimulation (EMS).18 Previously, Pauly et al. found increased alkaline phosphatase (ALP) activity with 10 mA EMS application to primary murine calvaria-derived osteoblastic cells with 5 pulses at 1 second per pulse, but no significant differences were found for MTS proliferation nor mineral deposition compared to a negative control group.82 Optimization of the different variables including post-treatment incubation time, current delivery, and number of pulses per treatment may be necessary to improve osteogenic activity. The use of mesenchymal stem cells from murine bone marrow may also offer a physiologically relevant model for osteoblastic regeneration of periapical lesions. Objectives: The goal of this study was to investigate and optimize the effects of electromagnetic wave stimulation (EMS) on murine bone marrow mesenchymal stem cells (MSCs) by evaluating the proliferation and differentiation of the cells after exposure to different EMS treatment regimens. Materials and Methods: 5 x104 stromal osteoblasts (SOBs) were cultured in 24-well plates in α-MEM containing 10% fetal bovine serum. Cells were then subjected to pulsed EMS treatments of 1 mA, 10 mA, and 50 mA. EMS was generated using an electromagnetic apical treatment (EMAT) device created by J. Morita MFG Corp. Proliferation was assessed via MTS assay 1 days after treatment. For osteogenic differentiation, ascorbic acid and β-glycerol phosphate were added to the culture media, and SOBs were cultured for 14 days. Afterwards, alkaline phosphatase (ALP) activity and Alizarin-red S mineral deposition were quantified as measures of osteoblast activity. Cells grown in osteogenic media without EMS treatment served as the negative control. Results: Although MSC proliferation was unaffected by different EMS treatment regimens, 50 mA EMS resulted in a decrease in ALP activity and mineral deposition by osteoblasts. Conclusions: Our findings suggest bone healing by EMS may involve a different cellular mechanism, that is not reproduced in vitro in our studies. Utilizing different amperage and EMS regimens may improve osteogenic differentiation.Item Buffered vs. Unbuffered Local Anesthesia in Mandibular Molars Diagnosed with Symptomatic Irreversible Pulpitis: A Controlled, Randomized, Double-Blind Study(2022) Alena, Peter; Spolnik, Kenneth; Ehrlich, Ygal; Warner, NedIntroduction: Profound pulpal anesthesia is not always adequate in mandibular teeth after the administration of local anesthesia, especially in the presence of irreversible pulpitis. Failure to achieve anesthesia has been seen in 30–80% of patients in teeth with a diagnosis of irreversible pulpitis. Onpharma™ developed an FDA-approved device that uses sodium bicarbonate to buffer a standard local anesthetic (LA) solution so that its pH may become closer to its pKa. Claims have been made that buffering a local anesthetic increases the anesthetic’s effect. Previous studies on the anesthetic efficacy of Onpharma’s Onset buffering system were inconclusive and may be dependent on the techniques used. Objectives: The aim of this study is to determine whether a buffered local anesthetic can lead to more profound and faster pulpal anesthesia in mandibular molars diagnosed with symptomatic irreversible pulpitis as compared to a standard, unbuffered local anesthetic. Materials and Methods: 40 total subjects completed the study. Screened and eligible subjects with a mandibular molar diagnosed with symptomatic irreversible pulpitis were randomly allocated into 2 groups so 1 group received a total of 3 cartridges of a standard, unbuffered 2% lidocaine with 1:100,000 epinephrine via inferior alveolar nerve block (IANB) followed by supplemental buccal and lingual infiltrations, while the other received the equivalent yet buffered formulation. An electronic pulp tester (EPT) was used to objectively determine baseline pulpal status of the affected tooth, followed by 2-minute interval testing following the administration of all local anesthesia. The onset of pulpal anesthesia was defined by the first of 2 consecutive EPT=80 readings, and the endodontic treatment could begin. Profound pulpal anesthesia was ultimately determined if the patient reported a comfortable pulpotomy as reflected on the Wong-Baker FACES Visual Analog Scale. Null Hypothesis 1: Subjects possessing mandibular molars diagnosed with symptomatic irreversible pulpitis will not achieve pulpal anesthesia more profoundly using buffered 2% lidocaine w/ 1:100,000 epinephrine in comparison to the standard, unbuffered anesthetic formulation. Null hypothesis 2: Subjects possessing mandibular molars diagnosed with symptomatic irreversible pulpitis will not achieve pulpal anesthesia faster using buffered 2% lidocaine w/ 1:100,000 epinephrine in comparison to the standard, unbuffered anesthetic formulation. Results: We observed a local anesthetic success rate of 45% in the buffered group, 70% in the unbuffered group, and ultimately 57.5% between both groups. The findings further indicate that the VAS scores after pulpotomy is significantly different between the 2 groups (p=0.019), with the unbuffered group having a more profound mean VAS score of 1.2 (as opposed to a buffered mean of 3.1). Regarding the time of onset for pulpal anesthesia, there was no statistically significant difference noted between the buffered and unbuffered groups. Conclusion: Based on the findings of this study, the null hypothesis 1 cannot be rejected since unbuffered 2% lidocaine with 1:100,000 epinephrine had a statistically significant increase in profound pulpal anesthesia compared to the buffered equivalent. The null hypothesis 2 cannot be rejected since there was no evidence of a significant difference in the time to pulpal anesthesia between the buffered and unbuffered groups.Item Incisal Endodontics Access vs Traditional Palatal Access to Negotiate Simulated Obliterated Canals Using Guided Endodontic Techniques(2022-06) Gohil, Arjun A.; Spolnik, Kenneth J.; Dutra, Vinicius; Ehrlich, Ygal; Warner, NedIntroduction: Endodontic treatment in teeth with pulp canal obliteration (PCO) is challenging. Guided Endodontic Access (GEA) combines information from a cone-beam computed tomography (CBCT) scan with an intra-oral scan to create a stent that can be used as a guide to treat teeth with PCO. GEA stents designed with traditional palatal accesses were shown to be successful in accurately negotiating these 3D printed teeth with simulated PCO, however, the difference in accuracy between the traditional palatal access compared to a conservative incisal access is not yet known. Objective: This in vitro study compares GEA stents designed with an incisal access approach to GEA stents designed with a traditional palatal access approach. The effect on the overall degree of deviation of the designed access path from the prepared path is evaluated by measuring the degree of angle of deviation and amount of deviation in millimeters. Materials and Methods: A 3-D printed maxillary model of an anonymous patient was used. PCO was simulated in a 3D printed natural #8 using the coDiagnostiX software tooth at two levels: coronal and mid-root. A GEA stent that extended from tooth #3 to tooth #14 with a guide sleeve over the simulated tooth #8 was accessed with a dedicated 1.0 mm diameter and 20 mm length drill that is designed to fit the access sleeve. 15 GEA stents had guides utilized for the incisal access approach, and 15 GEA stents had guides utilized for the traditional palatal access approach. Results: Angle, mesio-distal (base), and mesio-distal (tip) deviations were significantly lower for the incisal access compared to the traditional access. Inciso-apical (base) deviation was significantly more negative for incisal access compared to the traditional access. Bucco-lingual (base) deviation was significantly more negative for traditional access compared to the incisal access, while incisal and traditional accesses were not significantly different for bucco-lingual (tip) deviation. Coronal 1/3 calcification groups had significantly more mesio-distal (base) deviation than the middle 1/3 and no PCO groups. The no PCO group had significantly more negative inciso--apical (base) deviation than the coronal 1/3 calcification and middle 1/3 calcification groups, and the coronal 1/3 calcification group was significantly more negative than the middle 1/3 calcification group. The coronal 1/3 calcification group had significantly more mesio-distal (tip) deviation than the no PCO group. PCO level did not have a significant effect on angle, bucco-lingual (base), or bucco-lingual (tip) deviations. Conclusion: The utilization GEA via incisal access resulted in less degree and amount of drill deviation compared to the traditional access at all levels of calcification, however, the level of PCO did not influence the degree and amount of drill deviation between the incisal and traditional access approaches. It can be concluded that the use of a GEA stent that utilizes an incisal access approach in teeth with PCO will result in a more predictable outcome.Item Impact of Toothbrush Head Configuration and Dentifrice Abrasivity on Non-Carious Cervical Lesions Development In-Vitro(2022) Alzahrani, Lina; Hara, Anderson T.; Lippert, Frank; Al Dehailan, Laila