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Open Access Publications from the University of California

Scholarly Works (349 results)

  • Article
  • Peer Reviewed
UC San Francisco Previously Published Works (2014)
The objective of this article is to investigate parental understanding of tooth discoloration and decay and their related care seeking for young, Mexican-American children. The research design entailed semi-structured, face-to-face interviews conducted in Spanish with a convenience sample of 37 Mexican immigrant mothers of young children in a low-income urban neighborhood. Five major color terms - white, off-white, yellow, brown, and black - were used to describe tooth discoloration, the causes of which were mainly unrecognized or attributed to poor oral hygiene and exposure to sweet substances. Mothers also described three major levels of deterioration of the structural integrity of teeth due to caries, from stains to decayed portions to entirely rotten. A trend was observed between use of darker discoloration terms and extensive carious lesions. Teeth described as both dark in color and structurally damaged resulted in seeking of professional care. The paper concludes with the finding that Spanish terms used to describe tooth discoloration and carious lesions are broad and complex. Mexican immigrant mothers' interpretations of tooth discoloration and decay may differ from dental professionals' and result in late care seeking. Increased understanding between dental practitioners and caregivers is needed to create educational messages about the early signs of tooth decay.
    Cover page: Shades of Decay: The Meanings of Tooth Discoloration and Deterioration to Mexican Immigrant Caregivers of Young Children
    • Thesis
    • Peer Reviewed
    UC San Diego Electronic Theses and Dissertations (2020)

    Brilliant white teeth is a desire for most Americans today. Currently there is different whitening products to bring this shine, however the stains themselves do not have structured origins. Throughout their life, a tooth’s shade can change due to age, unrelated impacts, a number of oral cavity diseases, and by the products which we consume. Exploring the consumption of our food products, the chemistry of the oral cavity, and the associating microbial communities in relation to tooth staining is the focus of this study. In hopes of determining the chemical compounds that are causing the staining to occur extrinsically (in the enamel) and intrinsically (in the dentin) within the coronal portion of the tooth. In addition to this goal the study aims to assess the differences between teeth that have been stained significantly over time, versus teeth that have normal natural stain occurrences throughout time. The teeth that have been stained significantly over time were artificially stained with common staining solutions. Those staining solutions include: coffee, tobacco, tea, and wine. These solutions have been index and annotated for comparison to normal naturally stained teeth. 1000 human teeth were used in this study, which were analyzed using HPLC-MS/MS. Based on the metabolomics analysis, microbial communities will be analyzed in correlation to the various staining measurements

    • 2 supplemental ZIPs
    Cover page: The Fundamentals of Tooth Staining
    • Thesis
    • Peer Reviewed
    UCLA Electronic Theses and Dissertations (2013)

    Clinical parameters for dental whitening such as peroxide concentration and treatment time have been empirically derived. However, limited quantitative analyses examine reactivity of hydrogen peroxide on in vivo tooth stains under various catalytic settings. The wide range of possible activators and stains are challenging in creating a standardized tooth model to isolate various effects for clinical applications. This study uses three model systems to determine the effects of heat, light, metal catalysts, and pH on peroxide bleaching. By first using a model chemical stain, alkaline pH levels (7.4), 35°C heat treatment, and 490nm light activation were optimal for increasing overall bleaching efficacy. When the same conditions were applied to bleaching stained bovine teeth using liquid peroxide, only 35°C heat treatment showed catalytic effect, increasing overall luminosity and decreasing yellowness. A final evaluation of the activation parameters on teeth treated with commercially used gel peroxides revealed positive catalytic activity for heat alone. These results, in conjunction with future clinical studies, can provide the basis for optimizing clinical whitening parameters and ultimately control peroxide reactivity to enhance bleaching efficacy while minimizing undesired side-effects.

      Cover page: Reaction kinetics of hydrogen peroxide in teeth for teeth whitening applications
      • Thesis
      • Peer Reviewed
      UC San Francisco Electronic Theses and Dissertations (2021)

      Alagille Syndrome is a multisystem genetic disorder characterized by chronic cholestasis,cardiovascular anomalies, ocular abnormalities, skeletal defects, and characteristic facial features. Mutations in Jagged1 (Jag1), a key ligand in the Notch signaling pathway, are associated with the majority of cases. The Notch signaling pathway plays important roles in the development and homeostasis of most, if not all tissues. However, the roles of Jag1 and the Notch signaling pathway in craniofacial and dental development remain unclear. This study aimed to elucidate the roles of Notch signaling pathway in craniofacial and dental development using a mouse model of Alagille Syndrome (Jag1Ndr/Ndr mice, which possess a missense mutation (H268Q) in Jag1). Embryonic and postnatal mouse specimens were collected at various stages from Jag1Ndr/Ndr mice. Micro-computed tomography (microCT) and three-dimensional (3D) Geometric Morphometric Analysis (GMA) were performed on adult skulls to analyze changes in craniofacial morphology. Hematoxylin and eosin (H&E) staining on histological sections was performed on control and Jag1Ndr/Ndr mice at embryonic day (E)14.5, E16.5, postnatal (P)0, and P7 to analyze tooth development. 3D GMA showed variations in the coronoid process, zygomatic process, and the area where parietal, occipital, and squamosal bones intersect in Jag1Ndr/Ndr mutant mice. In addition, mutants had more convex crania from both frontal and lateral views and a longer snout. Our histological analysis of tooth development showed defects in cell-matrix adhesion (ameloblast-enamel matrix) and cell-cell adhesion (ameloblast-stratum intermedium) at P7. MicroCT analysis of P7 and adult molars supported our histological findings and revealed changes in tooth morphology. Disruption in Notch signaling due to a missense mutation (H268Q) in Jag1 led to: 1) specific changes in craniofacial morphology; 2) defective cell-matrix and cell-cell attachments during tooth development; 3) possible changes in tooth structures due to abnormal tooth development and mineralization. Our study demonstrates for the first time that Notch signaling is essential for specific changes in craniofacial morphology and proper dental development.

        Cover page: Analysis of Craniofacial and Dental Abnormalities in a novel mouse model for Alagille Syndrome
        • Article
        • Peer Reviewed
        UC San Francisco Previously Published Works (2013)

        Introduction

        In vivo and in vitro studies have shown that high contrast images of tooth demineralization can be acquired in the near-infrared (near-IR) without the interference of stain. The purpose of this study is to compare the lesion contrast in reflectance at near-IR wavelengths coincident with high water absorption with those in the visible, the near-IR at 1,300 nm and with fluorescence measurements for early lesions in occlusal surfaces.

        Methods

        Twenty-four human molars were used in this in vitro study. Teeth were painted with an acid-resistant varnish, leaving a 4 × 4 mm window in the occlusal surface of each tooth exposed for demineralization. Artificial lesions were produced in the exposed windows after 1- and 2-day exposure to a demineralizing solution at pH 4.5. Lesions were imaged using near-IR reflectance at three wavelengths, 1,300, 1,460, and 1,600 nm using a high definition InGaAs camera. Visible light reflectance, and fluorescence with 405 nm excitation and detection at wavelengths greater than 500 nm were also used to acquire images for comparison. Crossed polarizers were used for reflectance measurements to reduce interference from specular reflectance.

        Results

        The contrast of both the 1- and 2-day lesions were significantly higher (P < 0.05) for near-IR reflectance imaging at 1,460 and 1,600 nm than it was for near-IR reflectance imaging at 1,300 nm, visible reflectance imaging, and fluorescence.

        Conclusion

        The markedly higher contrast at 1,460 and 1,600 nm wavelengths, coincident with higher water absorption, suggest that these wavelengths are better suited than 1,300 nm for imaging early/shallow demineralization on tooth surfaces.
          Cover page: High contrast reflectance imaging of simulated lesions on tooth occlusal surfaces at near‐IR wavelengths
          • Article
          • Peer Reviewed
          UC San Francisco Previously Published Works (2013)
          In vivo and in vitro studies have shown that high contrast images of tooth demineralization can be acquired in the near-IR due to the high transparency of dental enamel. The purpose of this study is to compare the lesion contrast in reflectance at near-IR wavelengths coincident with high water absorption with those in the visible, the near-IR at 1300-nm and with fluorescence measurements for early lesions in occlusal surfaces. Twenty-four human molars were used in this in vitro study. Teeth were painted with an acid-resistant varnish, leaving a 4×4 mm window in the occlusal surface of each tooth exposed for demineralization. Artificial lesions were produced in the exposed windows after 1 & 2-day exposure to a demineralizing solution at pH 4.5. Lesions were imaged using NIR reflectance at 3 wavelengths, 1310, 1460 and 1600-nm using a high definition InGaAs camera. Visible light reflectance, and fluorescence with 405-nm excitation and detection at wavelengths greater than 500-nm were also used to acquire images for comparison. Crossed polarizers were used for reflectance measurements to reduce interference from specular reflectance. The contrast of both the 24 hr and 48 hr lesions were significantly higher (P<0.05) for NIR reflectance imaging at 1460-nm and 1600-nm than it was for NIR reflectance imaging at 1300-nm, visible reflectance imaging, and fluorescence. The results of this study suggest that NIR reflectance measurements at longer near-IR wavelengths coincident with higher water absorption are better suited for imaging early caries lesions.
            Cover page: Imaging early demineralization on tooth occlusional surfaces with a high definition InGaAs camera
            • Article
            • Peer Reviewed
            UC Davis Previously Published Works (2024)
            Interceptive orthodontics may be indicated in puppies exhibiting dental malocclusion with linguoverted deciduous mandibular canine teeth to alleviate pain and prevent teeth interlock, which may affect growth and development of the mandibles. Historically extraction of deciduous mandibular canine teeth has been recommended as soon as a malocclusion is identified, often as early as 6-8 weeks of age and no later than 12 weeks of age. This early surgical intervention of deciduous teeth extractions risks potential damage to the developing permanent canine teeth resulting in enamel defects often referred to as a Turner's tooth or Turner's hypoplasia. A search of medical records from five veterinary specialty dentistry practices was conducted to identify dogs 8-12 weeks of age who (a) underwent deciduous mandibular canine extractions for management of class 1 or class 2 malocclusion with linguoverted mandibular canine teeth, and (b) were seen for at least one recheck exam to assess for enamel defects on permanent mandibular canine teeth. Furthermore, data was collected to determine the number of dogs that required additional treatment after eruption of the permanent canine teeth due to linguoversion of the permanent canine teeth. All procedures were performed by a board-certified veterinary dentist™ or a supervised veterinary dentistry resident. Seventy-four dogs fit the inclusion criteria and had a total of 143 deciduous mandibular canine teeth extracted, out of which 13 dogs exhibited enamel defects affecting 21 permanent canine teeth. The 13 affected dogs represent a 17.5% cumulative incident rate 13/74 (95%CI 11-28%). Of all extracted teeth, 14.6% (21/143) had enamel defects affecting permanent canine teeth. Twenty-eight dogs required additional treatment to prevent the permanent mandibular canine teeth from causing trauma to the hard palate and gingiva which represented 37.8% (28/74) of all dogs in the study. Age and sex of the dog at the time of extraction were not found to be associated with the likelihood of incidence of enamel defects. This is the first reported rate of enamel defects on permanent mandibular canine teeth following extraction of deciduous mandibular canine teeth and is important to consider when advising or performing extraction of deciduous teeth in dogs.
              Cover page: Incidence of enamel defects on permanent canine teeth following extraction of linguoverted mandibular deciduous canine teeth in dogs
              • Article
              • Peer Reviewed
              UC San Francisco Previously Published Works (2019)
              Most new caries lesions are found in the pits and fissures of the occlusal surface. Radiographs have extremely low sensitivity for early occlusal decay, and by the time the lesion is severe enough to appear on a radiograph, it typically has penetrated well into the dentin and surgical intervention is required. The occlusal surfaces are often heavily stained, and visual and tactile detection have poor sensitivity and specificity. Previous near-infrared imaging studies at wavelengths beyond 1300 nm have demonstrated that stains are not visible and demineralization on the occlusal surfaces can be viewed without interference from stains. The objective of our study is to determine how the contrast between sound and lesion areas on occlusal surfaces varies with wavelength from the visible to 2350 nm and determine to what degree stains interfere with that contrast. The lesion contrast for reflectance is measured in 55 extracted teeth with suspected occlusal lesions from 400 to 2350 nm employing silicon and indium gallium arsenide imaging arrays. In addition, the lesion contrast is measured on 25 extracted teeth with suspected occlusal lesions from 400 to 1600 nm in reflectance and from 830 to 1400 nm in transillumination before and after stains are removed using a ultrasonic scaler. The highest lesion contrast in reflectance is measured at wavelengths >1700  nm. Stains interfere significantly at wavelengths <1150  nm (400 to 1150) for both reflectance and transillumination measurements. Our study suggests that the optimum wavelengths for imaging decay in the occlusal surfaces are >1700  nm for reflectance (1700 to 2350 nm) and near 1300 nm (1250 to 1350 nm) for transillumination.
                Cover page: Near-infrared imaging of demineralization on the occlusal surfaces of teeth without the interference of stains
                • Article
                • Peer Reviewed
                UC Davis Previously Published Works (2024)
                Odontodysplasia is an uncommon dental developmental disorder associated with enamel, dentin, pulp abnormalities, and overall tooth morphology. The affected tooth is grossly abnormal in size and contour and is commonly associated with swelling of the affected area and failure of eruption. Histologically, the enamel and dentin are hypoplastic and hypomineralized. Odontodyplasia occurs most commonly in response to direct trauma to the developing tooth bud (enamel organ and dental follicle). Data on the prevalence and features of non-traumatic odontodysplasia are lacking. Medical records of dogs diagnosed with odontodysplasia were reviewed at the William R. Pritchard Veterinary Medical Teaching Hospital (VMTH), University of California, Davis, for 10 years (from 2013 to 2023). Dogs with a known history of facial trauma, persistent deciduous tooth or teeth over the region of odontodysplastic tooth or teeth, and endodontic disease of the persistent deciduous tooth or teeth were excluded from the study. Twenty-eight dogs were included in this retrospective study, representing an incidence of 1.4 per 100 dogs presenting over 10 years. Regional odontodysplasia (RO) was identified in twenty-two dogs, and generalized odontodysplasia (GO) was found in six dogs. Both comprehensive oral examination and diagnostic imaging were essential in diagnosing and assessing the presence of odontodysplasia. Awake oral examination failed to identify odontodysplasia in almost 70% of the RO cases. Secondary diseases or lesions in odontodysplastic teeth, such as periodontal disease, endodontal disease, and perio-endo lesions, were commonly seen and were particularly more frequently identified in strategic teeth (canine and carnassial teeth) than non-strategic ones. Similarities, such as female predilection, maxilla more commonly affected, and clinical signs, were observed between RO in dogs and those reported in people. The exact etiology of non-traumatic odontodysplasia remains elusive, and the condition may be of multifactorial causality.
                  Cover page: Clinicial-pathologic correlations of non-trauma related Odontodysplasia in 28 dogs: 2013-2023
                  • Article
                  • Peer Reviewed
                  UC San Francisco Previously Published Works (2016)
                  The purpose of this study is to show that optical clearing agents can be used to increase the visibility of deeply penetrating occlusal lesions that have reached the underlying dentin and spread laterally under the enamel. Previous studies have shown that high refractive index fluids can increase the contrast of caries lesions. Extracted teeth with natural occlusal lesions were imaged with optical coherence tomography (OCT) with and without the addition of a transparent vinyl polysiloxane impression material (VPS) currently used in vivo. The relative intensity of the reflectivity from the underlying lesion area for each sample was measured before and after application of the VPS. Lesion presence was confirmed with polarized light microscopy and microradiography. Application of VPS significantly increased (P < 0.0001) the integrated reflectivity of subsurface dentinal lesions. This study shows that optical clearing agents can be used to increase the optical penetration and the visibility of subsurface lesions and the dentinal–enamel junction under sound and demineralized enamel in OCT images.
                    Cover page: Use of an optical clearing agent to enhance the visibility of subsurface structures and lesions from tooth occlusal surfaces
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