Walker, Dylan; Villalobos, V; Rueggeberg, FA; Brenes, C; Department of Restorative Sciences, Department of General Dentistry (Augusta University, 2019)
      The purposes of this research were to apply an infrared spectroscopic analytical method to differentiate among a variety of commercial, 3D dental printable resins for their acrylate or methacrylate content, and to relate that knowledge to the intended use of the printed item: extraorally or intraorally.
    • Aesthetic improvement of a smile using minimal intervention procedures. A case report

      Cowan, Marcus; Babb, C; Romero, M; Pruett, M; Coleman, J; Department of Restorative Sciences (Augusta University, 2019)
      Tooth discoloration, particularly affecting the maxillary anterior teeth, is often an esthetic concern for dental patients.1 The most common cause of intrinsic tooth discoloration is dental fluorosis (DF),1 which is enamel hypomineralization due to long-term ingestion of high levels of fluoride during tooth mineralization.2 DF results in white opaque areas or discolorations ranging from yellow to dark brown, with porosities on the enamel surface.3 A widely-used scale for classifying the severity of DF is the Tooth Surface Index of Fluorosis (TSIF), developed by Horowitz, by which the examiner determines the extent of affected enamel by estimating the amount of DF as a fraction of the total visible enamel surface.4 Microabrasion, introduced by Croll and Cavanaugh in 1986,5 is a technique used to correct surface enamel irregularities and remove intrinsic enamel stains through the application of hydrochloric acid combined with pumice in a paste.6 When performed correctly and conservatively, the amount of enamel loss from microabrasion is clincally insignificant.7 The success of microabrasion depends upon the extent and severity of the discoloration, and occasionally a slightly yellowish appearance will result from the yellow dentin shade showing through the translucent enamel.8 The final appearance can be improved by dental bleaching, with long-lasting results.7 The following article is a clinical report of the use of microabrasion combined with nightguard bleaching with 10% carbamide peroxide to improve the appearance of teeth affected by fluorosis.
    • Case Selection Criteria for use with Resin-Infiltrative Treatment of Enamel Decalcification

      Raley, N; Clayton, Ashley; Fortson, WM; Deleon, E; Rueggeberg, FA; Department of Orthodontics, Department of Restorative Sciences (Augusta University, 2019)
      Although one of the primary aims for many orthodontic patients is to achieve improvement in their dental esthetic condition, a high percentage of these patients develop unesthetic, white spot lesions (WSL) during the course of treatment. These lesions develop due to enamel decalcification resulting from bacterial plaque accumulation around difficult to clean brackets and overlying wires and ligation devices. Acids produced locally in this retained plaque will decalcify enamel along the peripheral border of the bonded bracket. Quite often, despite repeated admonishment by the clinician to the patient to take extra care in cleansing these susceptible locations, patients return with large plaque deposits around the brackets, and evidence of the early stages of enamel decalcification: the so-called “white spot lesion” (WSL). The problem becomes obvious at the time of bracket removal, when, although the teeth may now be arranged in near-to-perfect alignment and occlusion, large, white areas of enamel decalcification are prominently displayed, denoting the exact location of where the bonded bracket used to be.
    • Correlation of Deph of Solvent Resistance with Monomer Conversion

      Keller, Elizabeth; Rueggeberg, Frederick A.; Department of Restorative Sciences (2017-03)
      In the mouth, inadequately cured dental restorative materials may lead to detrimental consequences in their longevity. As light travels through these photo-curable restorative composites, there is an exponential decrease in light penetration with depth, and therefore the extent of local polymerization is compromised. This phenomenon is termed the “Depth of Cure” issue, which restricts the thickness if increment that each restorative material can be placed and polymerized. The purpose of this research is to develop an easily performed test that provides a correlational value between visually identifiable transition zones within acetone-sonicated, sectioned, cured composite specimens and the extent to which a composite has reached maximal monomer conversion values, to ultimately determine adequacy of polymerization at the depth of cure for certain restorative materials. This test method, proven to be independent of composite type, will be submitted to the working group associated with the revision of the International Organization for Standards Organization 4049 standard, for consideration of further testing and perhaps replacement of the current method. This research provides a fulfillment of the requests from well-respected dental clinicians to provide a clinically relevant and meaningful depth of cure test.
    • Direct Composite restorations Using a Clear PVS Matrix to restore Worn Anterior Dentition to Create an Ideal Occlusal Plane

      Fowlkes, Colton; Romero, M; Urbanawiz, D; Department of Restorative Sciences (Augusta University, 2019)
      This clicnical case documents the use of a clear PVS matrix technique to restore the incisal edges of worn mandibular anterior teeth using flowable composite to provide a 20 degree template for eventual complete maxillary denture and mandibular removable partial denture frabrication.

      Fantaski, Lincoln; Mettenburg, D; Brenes, C; Rueggeberg, FA; Department of Restorative Sciences, Department of General Dentistry (Augusta University, 2019)
      Recent advances in the application of digital imaging of oral tissues and three-dimensional, additive fabrication techniques have led to a burgeoning industry in dentistry. Over a very short period of time, this technology has greatly improved in terms of level of surface detail reproducibility and dimensional accuracy of printed forms. Initially, thermoplastic extrusion of warmed filaments of various plastic material was used. However, the layer thickness was quite large, and surface feature reproduction was low. With advances in use of photocurable monomer resins and controlled application of photo-activating light wavelengths to provide polymerization of very thin slices of the form image, the reality of providing stoneless models of a patient’s dentition became a physical, and financial reality in private dental practices.

      Klein, Laura; Rueggeberg, FA; Department of Restorative Sciences (Augusta University, 2019)
      Purpose of this research: To measure and compare (1) tip-to-target distance irradiance profiles (2) tip-to-target distance at which irradiance has dropped to 50% of 0-mm value (3) irradiance value at the 50% distance.

      Patel, Mohit; Mettenburg, D; Rueggeberg, FA; Cellular and Molecular Biology, Department of Restorative Sciences (Augusta University, 2019)
      To measure and compare composite top and bottom surface microhardness values when using a multi-wave LED curing light emitting simultaneous blue and violet light, or when the sequence of wavelength applications was provided as separate exposures, of similar duration.
    • Expressions of matrix metalloproteinase-9 (MMP-9), dentin sialophosphoprotein (DSPP), and osteopontin (OPN) at histologically negative surgical margins may predict recurrence of oral squamous cell carcinoma

      Ogbureke, Kalu U.E.; Weinberger, Paul M.; Looney, Stephen W.; Li, Li; Fisher, Larry W.; College of Dental Medicine; Medical College of Georgia; College of Graduate Studies (2012-03-11)
      Up to 50% of oral squamous cell carcinomas (OSCCs) recur following surgical resections with conventional â histologically-negativeâ margins. Three members of the SIBLING (Small Integrin Binding LIgand N-linked Gylcoprotein) family of proteins: dentin sialophophoprotein (DSPP); bone sialoprotein (BSP); and osteopontin OPN are upregulated in OSCCs. In this study, we aimed to correlate the expression of DSPP, OPN and BSP as well as three SIBLING-partners, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-3 (MMP-3), and matrix metalloproteinase-9 (MMP-9), at histologically-negative margins of OSCCs with tumor recurrence. Immunohistochemical analyses of the SIBLINGs and MMP expressions at histologically-negative margins of OSCC was carried out in a retrospective study of 20 patients, and the results correlated with tumor recurrence. Each protein was dichotomized as â presentâ (â ¥10% staining) or â absentâ (< 10% staining). The Sensitivity, Specificity, Positive Predictive Value(PV+) and Negative Predictive Value (PVâ ) for recurrence was calculated for each protein, along with their overall diagnostic accuracy, calculated as: (number of true positives + number of true negatives)/ number of patients. OSCC recurred in 9 of 20 patients (45%), a ratio not significantly different from the estimated population recurrence rate of 50% (p = 0.664). Among the SIBLINGs, DSPP and OPN showed the greatest Accuracy with DSPP being more Sensitive (89%) and OPN more Specific (64%). MMP-9 showed the greatest overall Accuracy (80%), slightly less Sensitivity (67%) and more Specificity (100%), than either DSPP or OPN. MMP-9 showed a superior positive PV than either DSPP or OPN. The negative PVs of OPN and MMP-9 were almost identical, and inferior to DSPP. We conclude that DSPP, OPN, or MMP-9 expressions at histologically-negative surgical margins predict OSCC recurrence with MMP-9 being the preferred predictor. These proteins may identify patients who could benefit from more extensive resection, or from adjunct treatments such as radiotherapy.
    • In Vivo Pilot Study: Effect of Dehydration/Rehydration on Upper Anterior Tooth Color Change

      Britton, Eduardo; Nappi, A; Cao, T; Shepherd, K; Department of General Dentistry, Dental Hygiene, Department of Restorative Sciences (Augusta University Libraries, 2019)
      Isolation of tooth structure during fabrication of a bonded, direct, resin-based restoration is essential to optimizing its potential for long-term clinical success. Failure to protect etched enamel and bonding agents from contamination by saliva results in inadequate and unpredictable interfacial bonding of the restorative composite, potentially leading to marginal discoloration, open margins, recurrent decay, or ultimately to restoration loss or failure. A consequence of tooth isolation during placement of direct, esthetic restorative resins is the dehydration of enamel surfaces that will not be coated with saliva, and will, over time, lose water that has penetrated into the outer enamel layers (will dehydrate). The longer the tooth isolation time, the greater will be the subsequent loss of water from enamel. Presence of this water in enamel helps to provide for a stable tooth color. In teeth, the observed tooth color is the result of internal light penetration and interaction with tissues below the surface. Enamel is a translucent material, passing a great majority of transmitted light to fall on the more opaque and yellow-colored tissue underneath of it: dentin. In the hydrated state, enamel is more translucent than in its dehydrated state. The white opaque appearance of dehydrated enamel can be of great clinical concern, once a rubber dam has been removed, and the treated teeth with newly placed restorations are observed. Usually, because of the opaque, white nature of recently dehydrated enamel, there is an initial mismatch between an esthetic restoration just placed and its surrounding, remaining enamel. Patients are normally forwarded of this consequence, and are advised that a period of time needs to pass before the surrounding enamel becomes rehydrated, and more translucent (less opaque), before its pre-isolated color returns to a natural state. It is hoped that, at that time, the new restoration will perfectly match the color characteristics of the remaining enamel, and the recent replacement will not be visible at all, but will instead optically blend in without notice. However, prior to that time, there are definitely distinct color differences between a recently placed resin restoration and its surrounding tooth structure. To date, little-to-no information is available on the rate at which a clinician or patient can expect isolated enamel to return to its pre-isolated color, and when to expect this esthetic blending to occur.
    • Maxillary growth in patients with complete unilateral cleft lip and palate treated with Nasoalveolar molding

      Manente, M; Levy-Bercowski, D; Abreu, A; Fortson, W; Deleon, E; Yu, J; Looney, S; Department of Orthodontics; Department of Plastic Surgery; Department of Biostatistics and Data Science (Augusta University Libraries, 2019)
      In patients with cleft lip and/or palate (CLP), the nasolabial defect has a significant esthetic impact on the face and may impair psychosocial development. Nasoalveolar molding (NAM) is a pre-surgical orthopedic technique aimed to improve the alveolar and nasolabial morphology of patients with cleft lip and palate. This technique is used to facilitate and improve the future surgical correction in cleft lip and palate patients. Influences such as differences in patient age and gingivoperiosteoplasty procedures are among many that have made it difficult for conclusive results to be found and published on the impact of the NAM technique on maxillary growth in patients with complete unilateral cleft lip and palate (CUCLP).
    • A multidisciplinary approach to the management of a maxillary midline diastema: A clinical report

      Romero, Mario F.; Babb, C; Department of Restorative Sciences, Department of General Dentistry (Augusta University, 2019)
      Anterior maxillary spacing has been shown to be one of the most negative influences on self-perceived dental appearance, and a maxillary midline diastema (MMD) is commonly cited by patients as a primary concern during dental consultations. MMD has been defined as a space greater than 0.5 mm between the mesial surfaces of the 2 maxillary central incisors. An MMD greater than 2 mm in the mixed dentition is unlikely to spontaneously close. African Americans are more than twice as likely to have an MMD than whites or Hispanics. In esthetic situations, without a comprehensive smile analysis and proper planning, overtreatment and undesirable effects can occur. Tooth size especially has been emphasized as the primary element of an esthetic smile design. One method of establishing tooth size is tooth biometry as described by Chu. He reported that maxillary anterior tooth widths average 8.5 mm for central incisors, 6.5 mm for lateral incisors, and 7.5 mm for canines and that 80% of the patient population falls within ±0.5 mm of these values. Other important elements of smile analysis include the dental midline, tooth morphology, axial inclinations, and the soft tissue components of gingival health, levels, and harmony. The direct bonding technique is a straightforward, conservative method for diastema closure. However, artistic skills, a knowledge of tooth morphology, and the appropriate selection and use of composite resin materials are essential for success. According to Spear and Kokich, “some existing dentitions simply cannot be restored to a more pleasing appearance without the assistance of several different dental disciplines.” Therefore, complex esthetic dilemmas may require more than one dental discipline, for example, operative dentistry and orthodontics, to establish a functional, maintainable, and pleasant smile. This article illustrates a clinical situation in which an MMD was addressed by first completing a comprehensive smile analysis, followed by closure using limited orthodontics and direct composite resin restorations.

      Bowerman, Brielle; Rueggeberg, FA; Brenes, C; Department of Restorative Sciences, Department of General Dentistry (Augusta University Libraries, 2019)
      A variety of manufacturing techniques have been used throughout the history of dentistry, in order to fabricate indirect restorations. Formative processes (pouring or pressing items into molds) are used when making conventional dentures, or when pressing ceramics. Recently, subtractive fabrication methods have enabled clinicians to mill a wide variety of ceramic and resin-based blanks directly into final forms, fitting the oral structures with high degrees of precision. Examples of older additive techniques include wax buildups to establish missing tooth structure for fabrication of subsequent cast restorations and the manual layering of powdered porcelains for development of ceramic facings on metallic substrates, or for ceramic veneers themselves. Tremendous advancements have been made in the field of 3D digital printing for many industrially based applications. Advances in research and development have resulted in tabletop 3D printers that produce rapid prototype specimens having very high accuracy and surface feature details. Recently, these advances have resulted in the manufacture and availability of a wide variety of 3D digital printers that dental offices now use to directly fabricate a wide range of restorative appliances (denture bases and teeth, temporary restorations, splints) as well as ancillary devices (impression trays, surgical implant guides, casts, try-in set-ups, and stents). Contemporary dental 3D printing typically involves use of near or true ultraviolet radiation (405 nm & 385 nm, respectively) in order to fabricate the basic desired form from a vat of photo-polymerizable monomers. Subsequent to initial form fabrication, the specimen is alcohol-washed of excess surface monomer, and is then subjected to an additional exposure of strong near/UV light, in order to maximize the polymerization process and provide optimal physical properties, as well as to minimize cytotoxicity resulting from leaching of unreacted, residual monomer within the bulk of the as-printed item.

      Baxter, John; Brenes, C; Rueggeberg, FA; Departments of General Dentistry; Department of Restorative Sciences (Augusta University, 2019)
      Direct, tissue-borne, full denture restoration of edentulous arches has become a well accepted restoration modality for millions of people. In this methodology, the tissue-bearing surface of a polymeric material replacing the form and structure of lost alveolar bond and overlying mucosa rests directly on the residual ridge tissue. Retention of the denture is attained through capillary adhesion forces acting to wet (cover) both the oral mucosa and the polymeric denture bases that rests upon it. Good wetting by saliva is thus one of the many critical features affecting adhesion of the denture base to the oral mucosa. Measurement of the ability of a fluid to wet a surface is performed using the shape of a fluid droplet on that surface. If the fluid wets that surface, then the droplet will spread out. If the fluid does not wet that surface, it will bead up. Quantitative measurement of fluid flow on a surface is performed using measurement of the “contact angle.” In this method, a controlled volume is dispensed onto a surface, and while viewing the interaction of that fluid in silhouette, the angle formed at the tangent of that drop and the flat surface is determined. The lower the contact angle, the more a fluid wets a surface, and the higher its value, the less wetting is that fluid on a specific surface.