Localized juvenile spongiotic gingival hyperplasia possibly originates from the junctional gingival epithelium-an immunohistochemical study.

AIMS: To immunohistochemically evaluate the cytokeratin (CK) pattern of expression in localized juvenile spongiotic gingival hyperplasia (LJSGH) as compared with the gingival epithelium (GE). METHODS AND RESULTS: Ten cases of LJSGH were semiquantitatively evaluated for the immunohistochemical pattern of CK1/10, CK4, CK8/18, and CK19. GE controls were taken from 10 cases of reactive gingival fibroepithelial hyperplasia. GEs showed mean positivity rates of 80% for both CK1/10 and CK4, and 5% for both CK8/18 and CK19. LJSGHs showed mean positivity rates of 65% for CK19, 60% for CK8/18, 30% for CK4, and 5% for CK1/10. The differences between LJSGHs and GEs were statistically significant (P < 0.01). CONCLUSIONS: The LJSGH pattern of CK expression is reminiscent of the profile described in the literature for the junctional epithelium (JE). Possibly, JE exteriorized from the gingival sulcus would be more prone to irritation from a variety of sources, resulting in inflammation and hyperplasia, with the subsequent development of LJSGH.

Flapless cortical bone damage has no effect on medullary bone mesial to teeth being moved.

INTRODUCTION: In this study, we evaluated the effects of bone awl-induced damage to bone surrounding a tooth that was moved. METHODS: A randomized split-mouth design with 7 foxhounds was performed to evaluate protraction of the mandibular third premolars for 56 days with 200 g of orthodontic force. Before initiating tooth movements, a bone awl was used on the experimental side to create 60 buccal and lingual microfracture injuries to the cortical bone without a periosteal flap. Tooth movements were performed on the control and experimental sides. Microcomputed tomography and histology were used to assess bone morphology and modeling. Radiographic and caliper measures were used to assess tooth movements. RESULTS: The awl-induced injuries produced significant damage and microfractures (95 mm(3)). Buccal and lingual cortical bone volume fractions and densities were significantly less and cortical modeling was significantly greater on the experimental sides than on the control sides. Bone volume fractions and densities mesial to the third premolars were the same on the experimental and control sides. Experimental side tooth movements (1.40 ± 0.25 mm) were statistically the same as the control side tooth movements (1.57 ± 0.45 mm). CONCLUSIONS: The effects of flapless, bone awl-induced damage were limited to the cortical bone. Because there was no effect on the medullary bone mesial to the tooth being moved, no differences in tooth movements were produced.

Effects of pilot holes on longitudinal miniscrew stability and bony adaptation.

INTRODUCTION: The purposes of this study were to longitudinally evaluate the effects of pilot holes on miniscrew implant (MSI) stability and to determine whether the effects can be attributed to the quality or the quantity of bone surrounding the MSI. METHODS: Using a randomized split-mouth design in 6 skeletally mature female foxhound-mix dogs, 17 MSIs (1.6 mm outer diameter) placed with pilot holes (1.1 mm) were compared with 17 identical MSIs placed without pilot holes. Implant stability quotient measurements of MSI stability were taken weekly for 7 weeks. Using microcomputed tomography with an isotropic resolution of 6 µm, bone volume fractions were measured for 3 layers of bone (6-24, 24-42, and 42-60 µm) surrounding the MSIs. RESULTS: At placement, the MSIs with pilot holes showed significantly (P <0.05) higher implant stability quotient values than did the MSIs placed without pilot holes (48.3 vs 47.5). Over time, the implant stability quotient values decreased significantly more for the MSIs placed with pilot holes than for those placed without pilot holes. After 7 weeks, the most coronal aspect of the 6- to 24-µm layer of cortical bone and the most coronal aspects of all 3 layers of trabecular bone showed significantly larger bone volume fractions for the MSIs placed without pilot holes than for those placed with pilot holes. CONCLUSIONS: MSIs placed with pilot holes show greater primary stability, but greater decreases in stability over time, due primarily to having less trabecular bone surrounding them.

Bony adaptation after expansion with light-to-moderate continuous forces.

INTRODUCTION: The purpose of this study was to evaluate the biologic response of dentoalveolar bone to archwire expansion with light-to-moderate continuous forces. METHODS: With a split-mouth experimental design, the maxillary right second premolars of 7 adult male dogs were expanded for 9 weeks using passive self-ligating brackets (Damon Q; Ormco, Orange, Calif) and 2 sequential archwires (0.016 × 0.022-in copper-nickel-titanium alloy, followed by 0.019 × 0.025-in copper-nickel-titanium alloy). Intraoral and radiographic measurements were made to evaluate tooth movements and tipping associated with expansion; archwire forces were measured using a force gauge. Microcomputed tomography was used to compare buccal bone height, total tooth height, total root height, and buccal bone thickness. Bone formation was evaluated histologically using tetracycline and calcein fluorescent labels and hematoxylin and eosin stains. RESULTS: Buccal expansion was produced by forces between 73 and 178 g. Compared with the control side, which showed no tooth movement, the experimental second premolars were expanded by 3.5 ± 0.9 mm and tipped by 15.8°. Buccal bone thickness was significantly thinner (about 0.2 mm) in the coronal aspects and significantly thicker (about 0.9 mm) in the apical aspects over the mesial roots. The tipping and expansion significantly (P <0.05) reduced buccal bone height (ie, caused dehiscences) at the mesial (about 2.9 mm) and distal (about 1.2 mm) roots. Bony apposition occurred on the trailing edges of tooth movement and on the leading edges of the second premolar apices. The axial microcomputed tomography slices indicated, and the bone histomorphometry and histology demonstrated, newly laid-down bone on the periosteal side of the buccal cortical surfaces. Ordered osteoblast aggregation was also evident on the periosteal surfaces of buccal bone, just cervical to the apparent center of rotation of the tooth. Tooth and root heights showed no significant differences between the experimental and control second premolars. CONCLUSIONS: Buccal expansion with light-to-moderate continuous forces produced 3.5 mm of tooth movement, uncontrolled tipping, and bone dehiscence, but no root resorption. Bone formation on the periosteal surfaces of cortical bone indicates that apposition is possible on the leading edge of tooth movements.

Effects of iodine in microbial control of dental treatment water.

OBJECTIVE: To determine the effects of low levels of iodine constantly present in the dental unit water system on microbial control of dental treatment water and biofilm control. MATERIALS AND METHODS: This study used a dental unit water system simulator with eight dental unit waterline systems built to scale and function, each controlled via computer. Each of the eight units was operated independently, four units supplied with self-contained water reservoirs and four units supplied with municipal water. Four units were precleaned to remove biofilm buildup. The study had a well-balanced design with equal representation (variables) of presence/absence of biofilms, selfcontained reservoirs for introduction of treatment water, source water directly connected to municipal water source and iodinated cartridges within the self-contained reservoirs and between municipal water and dental unit. Point-of-use iodinated resin cartridges (IRC) were retrofitted proximal to handpiece and air/ water syringe tip lines in four units, and iodinated resin water cartridges (IRSWC) were fitted to the other four units at the source water output. Heterotrophic plate counts were performed at baseline and twice weekly for a period of 6 weeks. One representative waterline sample was taken from each group at baseline and end-of-study to analyze changes in biofilm status using scanning electron microscopy. RESULTS: Waterlines not previously contaminated with biofilms did not show organization of biofilm matrix in units equipped with IRSWC. Constantly present low levels of iodine, demonstrated some disruption of biofilms in waterlines already contaminated with mature biofilms. All groups showed contamination levels < 500 cfu/ml (colony forming units per milliliter) consistent with the CDC and ADA guidelines. CONCLUSION: In this 6 weeks study, IRSWC equipped waterlines showed disruption of established biofilms, controlled formation of new biofilms in clean lines and rendered the dental treatment water < 500 cfu/ml. Point-of-use iodinated resin cartridges were also effective in controlling contamination in the dental treatment water. CLINICAL SIGNIFICANCE: Dental unit water systems that are in use get contaminated with microbes and biofilms in weeks of being put into use. These biofilms contaminate the treatment water thereby putting patients and staff at risk of infection by predominantly gram-negative microbes. Biofilms in the water systems must be cleaned periodically with a strong decontaminant and the dental treatment source water needs to be modified with a low-grade antimicrobial that can preserve the water quality yet safe to humans. In this translational research study, we evaluate the effects of elemental iodine dissolved in water flowing through an iodine containing cartridge in controlling biofilm and dental treatment water contamination using a dental unit water system simulator, prior to clinical utilization.

Effect of phosphate treatment of Acid-etched implants on mineral apposition rates near implants in a dog model.

PURPOSE: This study evaluated the effects of phosphate coating of acid-etched titanium on the mineral apposition rate (MAR) and new bone-to-implant contact (BIC) in a canine model. MATERIALS AND METHODS: Titanium implants (2.2 3 4 mm) with acid-etched surfaces that were electrolytically phosphated or not were placed in 48 mandibular sites in six foxhounds. Tetracycline and calcein dyes were administered 1 week after implant placement and 1 week before sacrifice. At 12 weeks after implant placement, the animals were sacrificed. MAR and BIC were evaluated using fluorescence microscopy. Light microscopic and histologic evaluations were performed on undecalcified sections. RESULTS: Microscopic evaluation showed the presence of healthy osteoblasts lining bone surfaces near implants. Similar BIC was observed in phosphated and nonphosphated titanium implant sites. MAR was significantly higher around the nonphosphated titanium implant surfaces than around the phosphated titanium samples. No significant differences were found between dogs or implant sites. CONCLUSION: Acid-etched implants showed significantly higher MARs compared to acid-etched, phosphate-coated implants. Int J Maxillofac Implants 2010;25:278-286.

Effects of intentional damage of the roots and surrounding structures with miniscrew implants.

INTRODUCTION: The purposes of the study were to evaluate the immediate damage to roots and periodontal structures after initial miniscrew implant (MSI) placement and the short- and long-term damage after MSIs were left in situ. METHODS: The roots of the maxillary second, third, and fourth premolars of 7 mature beagle dogs were randomly assigned to undergo immediate, short-term (left for 6 weeks), or long-term (left for 12 weeks) damage. Intentional damage was inflicted with self-tapping screws (1.8 x 8 mm) placed with a stent. Alternating tetracycline and calcein labels were administered at 6-week intervals. Undecalcified sections were stained and evaluated histologically to determine the extent of damage; healing was evaluated by using fluorescence labels. RESULTS: Histology showed damage to 73.8% of the teeth, ranging from displacement of bone into the periodontal ligament to invasion of the pulp chamber. Displacement of bone into the periodontal ligament and direct damage to the periodontal ligament occurred in 3 (7.2%) instances. Damage was isolated to the cementum of 8 (19.0%) teeth, whereas damage occurred in the dentin of 11 (26.2%) teeth. Loss of bone in the furcation was evident in 3 (7.2%) teeth, and severe damage into the pulp occurred in 6 (14.2%) teeth. No differences in the amounts of damage were evident between the immediate, short-, and long-term groups. Healing often occurred with cementum around the unloaded MSIs. CONCLUSIONS: Extensive damage can be caused by MSIs, with little to no differences evident over time. Unloaded MSIs that remain in contact with roots of teeth can show varying degrees of healing.

Healing of the roots and surrounding structures after intentional damage with miniscrew implants.

INTRODUCTION: In this study, we evaluated the healing potential of the roots and surrounding periodontium (cementum, periodontal ligament [PDL], and bone) after intentional damage during miniscrew implant (MSI) placement. METHODS: A randomized split-mouth design was used to evaluate healing 6 and 12 weeks after intentional root damage. Seven skeletally mature male beagle dogs had MSIs placed into the roots of 8 mandibular teeth (6 premolars, 2 first molars). After root contact had been verified by using insertion torques and radiographs, the MSIs were immediately removed, and the sites were allowed to heal for 6 or 12 weeks. Sequential point labeling was performed at 6-week intervals with tetracycline and calcein. Demineralized and undemineralized sections were stained, and healing was histologically evaluated. RESULTS: The placement torque was twice as high with root contact than without contact (23.8 vs 50.7 Ncm). Damage to the roots and periodontium ranged from cementum interruption to pulp invasion. New bone, PDL, and cementum were observed in 64.3% of the teeth, with significant (P <0.05) increases in the percentages of cementum over time. Sequential labeling confirmed healing at both 6 and 12 weeks. Abnormal healing was found in 35.7% of teeth; it included lack of PDL and bone regeneration, bone degeneration in the furcation area, ankylosis, and no healing associated with inflammatory infiltrate or pulpal invasion. CONCLUSIONS: Under favorable conditions (no inflammatory infiltrate or pulpal invasion), healing can occur when root damage caused by MSIs is limited to the cementum or the dentin. Increased resistance should be used as an indicator of possible root contact during MSI placement.

Integrating Diverse Disciplines to Enhance Interprofessional Competency in Healthcare Delivery.

Interprofessional education (IPE) typically involves clinical simulation exercises with students from medical and nursing schools. Yet, healthcare requires patient-centered teams that include diverse disciplines. Students from public health and informatics are rarely incorporated into IPE, signaling a gap in current educational practices. In this study, we integrated students from administrative and non-clinical disciplines into traditional clinical simulations and measured the effect on communication and teamwork. From July 2017-July 2018, 408 students from five schools (medicine, nursing, dentistry, public health, and informatics) participated in one of eight three-hour IPE clinical simulations with Standardized Patients and electronic health record technologies. Data were gathered using a pre-test-post-test interventional Interprofessional Collaborative Competency Attainment Survey (ICCAS) and through qualitative evaluations from Standardized Patients. Of the total 408 students, 386 (94.6%) had matched pre- and post-test results from the surveys. There was a 15.9% improvement in collaboration overall between the pre- and post-tests. ICCAS competencies showed improvements in teamwork, communication, collaboration, and conflict management, with an average change from 5.26 to 6.10 (t = 35.16; p < 0.001). We found by creating new clinical simulations with additional roles for non-clinical professionals, student learners were able to observe and learn interprofessional teamwork from each other and from faculty role models.

The efficacy of IntraFlow intraosseous injection as a primary anesthesia technique.

The purpose of this study was to compare the efficacy of intraosseous injection and inferior alveolar (IA) nerve block in anesthetizing mandibular posterior teeth with irreversible pulpitis. Thirty human subjects were randomly assigned to receive either intraosseous injection using the IntraFlow system (Pro-Dex Inc, Santa Ana, CA) or IA block as the primary anesthesia method. Pulpal anesthesia was evaluated via electric pulp testing at 4-minute intervals for 20 minutes. Two consecutive 80/80 readings were considered successful pulpal anesthesia. Anesthesia success or failure was recorded and groups compared. Intraosseous injection provided successful anesthesia in 13 of 15 subjects (87%). The IA block provided successful anesthesia in 9 of 15 subjects (60%). Although this difference was not statistically significant (p = 0.2148), the results of this preliminary study indicate that the IntraFlow system can be used as the primary anesthesia method in teeth with irreversible pulpitis to achieve predictable pulpal anesthesia.

Bone regeneration around implants in the canine mandible with cultured fibroblasts in polyglactin mesh.

BACKGROUND: Human fibroblast-derived dermal substitute (HFDDS) is a tissue-engineered material that consists of polyglactin mesh seeded with cultured fibroblasts. Cultured fibroblasts are not as differentiated as tissue fibroblasts and retain the ability to differentiate into other cells types. HFDDS also is capable of stimulating angiogenesis and wound healing. The purpose of this study was to attempt to evaluate the effects of HFDDS on guided bone regeneration at sites with 1.5-mm peri-implant defects in the canine mandible. METHODS: Fifty sand-blasted acid-etched test implants were placed into the edentulous areas of mandibular ridges of five American foxhounds. Each site had a standardized 1.5-mm circumferential peri-implant defect in the coronal half of the implant, created by a specialized drill at the time of osteotomy. In each canine two implants received no treatment of the defects, four implants were treated with polyglactin mesh (carrier only) wrapped around the circumference of the defect wall, and four implants were treated with HFDDS placed in a similar fashion to the mesh. Implant sites healed submerged for 10 weeks, at which time sacrifice took place and sections were prepared, processed, and analyzed histomorphometrically. RESULTS: The mean distance from the top of the fixture to the first point of bone-implant contact was 2.20 mm, 2.25 mm, and 2.60 mm for the HFDDS, carrier, and control sites, respectively (P = 0.202). Overall mean percentage of bone-to-implant contact (BIC) in the defects was 32.8%, 31.0%, and 22.8% for the HFDDS, carrier, and control groups, respectively. These differences were not statistically significant, but approached statistical significance for the control group compared to HFDDS and carrier (P = 0.057). Overall mean bone fill in the defects calculated histometrically was 36.0%, 35.8%, and 33.9% for the HFDDS, carrier, and control groups, respectively. These differences were not statistically significant. Sites with dehiscence at the time of implant placement had significantly greater distance to first bone-implant contact (P = 0.002), a smaller percentage of BIC (P = 0.006), and significantly less bone fill (P = 0.006) in the defects. It was consistently found that when dehiscence occurred on the buccal side of the implant, the outcomes for all parameters measured were significantly inferior on the lingual side as well. Factorial analysis, which grouped outcomes by dehiscence categories (none, partial, or full dehiscence), revealed that with intact defects without dehiscence, HFDDS had less bone fill compared to the carrier. However, in defects with partial or full dehiscence, HFDDS had more bone fill compared to carrier sites. These differences were statistically significant (P = 0.034). CONCLUSIONS: In intact sites without dehiscence, the presence of cultured fibroblasts in 1.5-mm-wide peri-implant defects did not significantly enhance bone regeneration compared to the carrier, polyglactin mesh. However, sites with partial or full dehiscence treated with HFDDS had significantly greater bone fill compared to the carrier (P = 0.034). When dehiscence occurs during immediate implant placement on narrow ridges without the use of membranes, bone regeneration tends to be inferior on the side of the dehiscence as well as the opposite side of the implant.

Effects of phosphated titanium and enamel matrix derivatives on osteoblast behavior in vitro.

PURPOSE: The purpose of this study was to evaluate the effects of phosphated titanium and enamel matrix derivatives (EMD) on osteoblast function. MATERIALS AND METHODS: Primary rat osteoblasts were cultured on disks of either phosphated or nonphosphated titanium. In half of the samples 180 microg of EMD was immediately added. The medium was changed every 2 days for 28 days and then analyzed using transforming growth factor-beta1 (TGF-beta1) and interleukin-1beta (IL-1beta) enzyme-linked immunosorbent assays (ELISAs). Scanning electron microscopy and light microscopy were used to evaluate nodule formation and mineralization. RESULTS: Microscopic evaluation revealed no differences in osteoblast attachment between the 4 groups. Osteoblast nodule formation was observed in all groups. In the absence of mineralizing media, nodules on the nonphosphated titanium samples showed no evidence of mineralization. All nodules on the phosphated titanium had evidence of mineralization. ELISA revealed no significant differences in IL-1beta production between any of the groups. The EMD-treated osteoblasts produced significantly more TGF-beta1 than non-EMD-treated cells for up to 8 days, and osteoblasts on phosphated titanium produced significantly more TGF-beta1 at 8 days. DISCUSSION AND CONCLUSION: Osteoblast attachment appeared unaffected by surface treatment. EMD initiated early TGF-beta1 production, but production decreased to control levels within 10 days. Phosphated titanium increased TGF-beta1 production at 8 days and induced nodule mineralization even in the absence of mineralizing medium.

Efficacy of retreatment techniques for a resin-based root canal obturation material.

Resilon/Epiphany obturation system is emerging as an alternative to gutta-percha (GP). The efficacy of retreatment techniques for Resilon removal has not been determined. The purpose of this study was to evaluate two commonly used retreatment techniques in the removal of Resilon. Sixty single-canal teeth were instrumented and obturated with either Resilon/Epiphany or GP/AH Plus. Each canal was randomly allocated to receive one of the two retreatment techniques-ProFile 0.06 rotary files combined with heat or chloroform. The time required to remove the obturation material was recorded and the cleanliness of canal walls was determined by stereomicroscope and electron microscopy. The results demonstrated that chloroform combined with rotary files was more efficient in material removal compared to heat (p < 0.05). Resilon was faster to remove than GP. Both techniques resulted in cleaner canal walls in the apical third of the teeth obturated with Resilon when compared to GP (p < 0.05).

Increased Tgf-beta1 production by rat osteoblasts in the presence of PepGen P-15 in vitro.

Bone grafting materials may enhance tissue regeneration after endodontic, periodontal, or implant surgery. The differences in physical and biological properties between products may result in different osteoblastic responses. This study was designed to determine whether interleukin-1beta and Tgf-beta1 production by primary cultures of rat osteoblasts differed when cells were exposed to three grafting materials: BioOss, OsteoGraf N-300, and PepGen P-15. Cells were exposed to materials for 24, 48, and 72 h and were characterized by mineralized nodule formation. Supernatants were collected for Lowry and enzyme-linked immunosorbent assays to assess cytokine production. All groups produced mineralized nodules after 14 days. Statistical analysis revealed no difference in interleukin-1beta production between groups, but a significant increase in Tgf-beta1 production was noted in the PepGen P-15 group. These results indicate that PepGen P-15 stimulates osteoblasts to express Tgf-beta1, which may accelerate repair of bone defects created during periradicular or dental implant surgeries.

Cultured primary osteoblast viability and apoptosis in the presence of root canal sealers.

This study was designed to test the hypothesis that Roekoseal is less cytotoxic than eugenol-based Sealapex or calcium hydroxide-based Kerr's Pulp Canal Sealer. Embryonic, day-19, rat calvarial osteoblasts were cultured at 4 x 10(5) cells/well. The concentration of conditioned medium from each sealer producing 50% surviving cells (ED50) was determined and long-term viability and apoptosis of cells assessed after exposure to the ED50 of each sealer. Low concentrations of Kerr's Pulp Canal Sealer (190 mm(2)/1 ml) and high concentrations of Sealapex and Roekoseal (190 mm(2)/300 microl) produced the ED50. ED50 challenged osteoblasts had fewer viable cells at 72 h than at 24 h, with significantly more viable cells in the Roekoseal group. There was significantly less apoptotic activity in cells exposed to Roekoseal ED50 than in cells exposed to Kerr's Pulp Canal Sealer (p < 0.05) ED50. Roekoseal may be less cytotoxic than Kerr's Pulp Canal Sealer, but further studies of this new sealer are required.

Comparison of particle morphology between commercial- and research-grade calcium hydroxide in endodontics.

Ca(OH)2 aqueous slurry is widely used as an inter-appointment antimicrobial dressing in root canal treatment. The aim of this study was to quantify the particle size and shape of commercial-grade UltraCal XS (UC) and to compare it with that of research-grade Ca(OH)2 (RG) using a flow particle image analyzer (FPIA). The morphology and penetration inside the dentin tubules of the UC and RG particles were examined using a scanning electron microscope (SEM). UC and RG (10 mg) were mixed with 15 mL of alcohol, and were sonicated. Five milliliters of the dispersion was subjected to FPIA, and particle length, width, perimeter and aspect ratio were analyzed. In addition, UC paste and RG aqueous slurry were agitated on dentin discs and were prepared for SEM examination. There were significant differences between UC and RG with regard to the frequency of different length groups (P < 0.0001). UC contained smaller particles than RG (P < 0.0001). Under SEM, the agitated UC and RG particles occluded the opening of dentin tubules and penetrated inside the dentin tubules. The size of UC particles is smaller than those of RG. Both UC and RG particles were able to penetrate into open dentin tubules.

Influence of powder composition and morphology on penetration of Gray and White ProRoot mineral trioxide aggregate and calcium hydroxide into dentin tubules.

This study examined the influence of powder composition and morphology on the penetration of Gray and White ProRoot mineral trioxide aggregate (GMTA, WMTA) and calcium hydroxide (CH) into open dentin tubules. GMTA, WMTA, and CH particle dimensions were analyzed by flow particle image analysis (FPIA). Penetration of open dentin tubules into dentin discs was studied by scanning electron microscopy. Five samples of each material were randomly selected and prepared for this study. The GMTA averages for length (µm), width (µm), perimeter (µm), and aspect ratio were 1.94 ± 1.65, 1.43 ± 1.19, 5.61 ± 4.27, and 0.76 ± 0.14, respectively. Corresponding averages for WMTA were 2.04 ± 1.87, 1.49 ± 1.33, 5.88 ± 4.81, and 0.76 ± 0.14, and for CH were 2.26 ± 1.99, 1.62 ± 1.46, 6.70 ± 5.60, and 0.74 ± 0.15, respectively. The rank order of the averages for particle length, width and perimeter from the largest to the smallest material was CH > WMTA > GMTA. The rank order of the averaged aspect ratios was GMTA > WMTA > CH. SEM showed that all three materials, when deposited and agitated on dentin discs, penetrated the open dentin tubules. Tubule occlusion occurred as particle surface concentrations increased. Significant differences in particle length, width, perimeter, and aspect ratio were observed for GMTA, WMTA, and CH (P < 0.0001 in all cases). All particle types penetrated into open tubules when agitated on dentin discs; all tubules were eventually occluded as particle concentrations grew. (J Oral Sci 56, 287-293, 2014).

AEGD programs: why now, why more?

With an increased number of dental schools graduating more dentists, along with the opening of new dental schools throughout the United States, more graduating dental students are considering utilizing Advanced Education in General Dentistry (AEGD) programs as a means to increase their understanding of the complexity of modern dentistry and to gain additional training and experience before heading into practice. This position paper describes how these programs can aid in transforming the face of dental education to address the needs of graduates and best educate the next generation of dental professionals. Its purpose is to examine reasons why dental students are choosing to participate in AEGD programs and to support a call for additional programs. An online survey of current AEGD residents was conducted to investigate reasons why they chose to enter this specific postgraduate opportunity. This position paper will also discuss how AEGD programs can be an effective training mechanism to address problematic issues such as access to care and dental licensure. Interest in AEGD programs will continue to rise, and this paper provides support for the expansion of such programs.