Uptake of Nanotitania by Gingival Epithelial Cells Promotes Inflammatory Response and Is Accelerated by Porphyromonas gingivalis Lipopolysaccharide: An In Vitro Study.

Titanium is often used in the medical field and in dental implants due to its biocompatibility, but it has a high rate of leading to peri-implantitis, which progresses faster than periodontitis. Therefore, in the present study, the expression of cytokines from gingival epithelial cells by nanotitania was investigated, which is derived from titanium in the oral cavity, and the additional effect of Porphyromonasgingivalis (periodontopathic bacteria) lipopolysaccharide (PgLPS) was investigated. Ca9-22 cells were used as a gingival epithelial cell model and were cultured with nanotitania alone or with PgLPS. Cytokine expression was examined by reverse transcription-quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. In addition, cellular uptake of nanotitania was observed in scanning electron microscopy images. The expression of interleukin (IL)-6 and IL-8 significantly increased in Ca9-22 cells by nanotitania treatment alone, and the expression was further increased by the presence of PgLPS. Nanotitania was observed to phagocytose Ca9-22 cells in a dose- and time-dependent manner. Furthermore, when the expression of IL-11, related to bone resorption, was investigated, a significant increase was confirmed by stimulation with nanotitania alone. Therefore, nanotitania could be associated with the onset and exacerbation of peri-implantitis, and the presence of periodontal pathogens may worsen the condition. Further clinical reports are needed to confirm these preliminary results.

Knowledge and Practice of Oral Cancer Screening in Teaching Faculty-Comparison of Specialty and Year of Clinical Experience.

The purpose of this study was to assess the knowledge, practice, confidence, and perceived barriers to oral cancer screening among teaching faculty in Japan. Results were compared by specialist as well as years of clinical experience. A 25-question survey was used to assess the oral cancer screening practices of faculty dentists at Iwate Medical University, School of Dental Medicine, the only dental school located in the northeast (Tohoku) region of Japan. The study was approved by the Institutional Review Board of Iwate Medical University. The response rate was 83% (n = 110, 71.8% were male). This survey revealed that only 43.6% of the dentists performed oral cancer screening frequently (always or usually) at the initial appointment, and there was no significant differences between specialists and clinical experience. Visual inspection of the oral cavity was the primary screening method, but the frequency and content of the examination (TMJ and tonsil) was significantly different between specialties. A history of cancer and tobacco use motivated providers to perform an examination and was significantly different between various specialists and clinically experienced providers. In contrast, HPV and alcohol consumption were a weak motivator. The confidence level of providers on their examination knowledge/skills was poor, especially among junior faculty. More than 80% of junior faculty indicated a lack of knowledge/skills as a major barrier.

Quantitative analysis of change in bone volume 5 years after sinus floor elevation using plate-shaped bone substitutes: a prospective observational study.

PURPOSE: Tricalcium phosphate (TCP) has osteoconductive ability and reportedly offers similar clinical results as autogenous bone grafts in dental implant treatment. However, few reports quantify temporal changes in augmented bone volume after sinus augmentation. We aimed to establish a three-dimensional (3D) quantification method to assess bone volume after sinus augmentation and to evaluate biocompatibility of the TCP plate. METHODS: Maxillary sinus floor augmentation was performed employing the lateral window technique, and plate-shaped ß-TCP (TCP plate) was used instead of granular bone grafting materials. After lifting the sinus membrane, the TCP plate was inserted and supported by dental implants or micro-screws. The changes in bone volumes in the maxillary sinus before and after surgery were recorded using cone-beam computed tomography, saved as Digital Imaging and Communications in Medicine-formatted files, and transformed to Standard Triangle Language (STL)-formatted files. Pre- and post-operative STL data of bone volume were superimposed, and the augmented bone volume was calculated. Moreover, changes in bone volumes, TCP plate resorption rates, and bone heights surrounding the implants were three dimensionally quantified. RESULTS: Fifteen implants in nine subjects were included in this study. TCP plates secured long-term space making, with results similar to those of granular bone substitutes. Newly formed bone was identified around the implant without bone graft material. TCP plate was absorbed and gradually disappeared. CONCLUSIONS: A novel 3D quantification method was established to evaluate changes in bone volume. Clinical application of TCP plate in sinus augmentation could be a better procedure in terms of prognosis and safety.

Current complications and issues of implant superstructure.

The purpose of this review is to search for complications of dental implant superstructures and consider the issues involved. This narrative review was performed by searching through PubMed databases and review articles that were published after 1990. Misfitting of the superstructure can result in loosening of screws, reduced preload, and in some cases, significant stress around the implant. External connection modalities and single implant prostheses have been reported to have more loose or broken abutment screws. In addition, when zirconia abutment was used for platform shifting, the rate of fracture of the abutment was considered to be high. Additionally, it was reported that men were significantly at an increased risk of abutment fracture. As for the retention mechanism of implant overdenture, stud attachment (Locator type) should receive more attention to wear and damage of retention parts than other attachments. The causes of the complications of implant superstructures have not been clarified in some cases, and further verification is required. Verification of complications is considered important to obtain a long-term prognosis for superstructures of implants. It will be necessary to further verify complications of implants in the future.

In vitro comparative analysis of scanning accuracy of intraoral and laboratory scanners in measuring the distance between multiple implants.

BACKGROUND: The purpose of this study was to evaluate the accuracy of intraoral scanners by comparing the trueness and precision of several types of scanners in measuring the distance between the ball abutments on pairs of multiple implants. METHODS: Seven implants were placed on a fully edentulous upper jaw model. After ball abutments were attached to the implants on the master model, the three-dimensional (3D) shape of the model was evaluated using a computer numerical control 3D coordinate-measuring machine. Subsequently, the 3D shape-related data of the model were obtained using two types of intraoral scanners (3M True Definition Scanner [TDS] and 3Shape Trios3 [TR3]) and two types of laboratory scanners (KaVo ARCTICA Auto Scan [KA] and Identica Hybrid [IH]). Using the obtained 3D shape-related data, the trueness and precision in measuring the distance between the balls within seven pairs of ball abutments were compared among the scanners using 3D analysis software. RESULTS: Intraoral scanners produced significantly greater errors in trueness and precision than laboratory scanners in measuring the distances between the ball abutments in all the dental regions. Between the intraoral scanners, powder-requiring TDS produced significantly lower errors at inflection points than powder-free TR3. CONCLUSIONS: These results indicate that an optical impression technique using an intraoral scanner is suitable for dental implant treatment in patients with a few missing teeth.

Bone Regeneration of Critical-Size Calvarial Defects in Rats Using Highly Pressed Nano-Apatite/Collagen Composites.

Osteo-conductive bone substitute materials are required in dentistry. In this study, highly pressed nano-hydroxyapatite/collagen (P-nHAP/COL) composites were formed by a hydraulic press. Critical-size bone defects (Φ = 6 mm) were made in the cranial bones of 10-week-old Wistar rats, in which P-nHAP/COL and pressed collagen (P-COL) specimens were implanted. Defect-only samples (DEF) were also prepared. After the rats had been nourished for 3 days, 4 weeks, or 8 weeks, ossification of the cranial defects of the rats was evaluated by micro-computed tomography (micro-CT) (n = 6 each). Animals were sacrificed at 8 weeks, followed by histological examination. On micro-CT, the opacity of the defect significantly increased with time after P-nHAP/COL implantation (between 3 days and 8 weeks, p < 0.05) due to active bone regeneration. In contrast, with P-COL and DEF, the opacity increased only slightly with time after implantation, indicating sluggish bone regeneration. Histological inspections of the defect zone implanted with P-nHAP/COL indicated the adherence of multinucleated giant cells (osteoclasts) to the implant with phagocytosis and fragmentation of P-nHAP/COL, whereas active bone formation occurred nearby. Fluorescent double staining indicated dynamic bone-formation activities. P-nHAP/COL is strongly osteo-conductive and could serve as a useful novel bone substitute material for future dental implant treatments.

Characterization of Five Collagenous Biomaterials by SEM Observations, TG-DTA, Collagenase Dissolution Tests and Subcutaneous Implantation Tests.

Collagenous biomaterials that are clinically applied in dentistry have dermis-type and membrane-type, both of which are materials for promoting bone and soft tissue formation. The properties of materials supplied with different types could affect their biodegradation periods. The purpose of this study was to characterize five of these products by four different methods: scanning electron microscopy (SEM) observation, thermogravimetry-differential thermal analysis (TG-DTA), 0.01 wt% collagenase dissolution test, and subcutaneous implantation test in vivo. SEM micrographs revealed that both dermis and membranous materials were fibrous and porous. The membranous materials had higher specific derivative thermal gravimetry (DTG) peak temperatures in TG-DTA at around 320 °C, longer collagenase dissolution time ranging from about 300 to 500 min, and more longevity in mice exceeding 9 weeks than the dermis materials. There existed a correlation between the peak temperature in TG-DTA and the collagenase dissolution time. It was considered that higher cross-link degree among collagen fibrils of the membrane-type collagenous materials might account for these phenomena. The experimental protocol and numerical results obtained could be helpful for selection and future development of fibrous collagenous biomaterials in clinical use.

Surface attrition of zirconia and hybrid composite resin superstructure during implant therapy.

PURPOSE: The purpose of this study was to examine morphological changes in the superstructure of implants in relation to the degree of attrition of the implant superstructure and its antagonists. METHODS: Thirty-three patients participated. The implant superstructures of the first molar and its antagonists were scanned with an intraoral scanner every 3 months. The amount of attrition was calculated in relation to the various materials used for the superstructure, and differences were analyzed statistically (P < 0.05). RESULTS: Attrition of the implant superstructure was 110 ± 30 µm for monolithic zirconia and 105 ± 27 µm for resin-veneered metal after 12 months. No statistically significant difference was found between the two groups. In contrast, attrition of the antagonists was 75 ± 25 µm for zirconia and 105 ± 20 µm for resin-veneered metal after 12 months. A statistically significant difference in the attrition levels between the two groups was observed after 9 and 12 months. CONCLUSION: During the 12-month observation period, there was no difference in superstructure attrition between zirconia and resin-veneered metal. Attrition of the antagonists was higher for hybrid composite resin-veneered metal than for zirconia, suggesting that surface roughness affected the degree of attrition.

Titanium nanoparticles potentially affect gingival tissue through IL-13α2 receptor expression.

PURPOSE: To determine the effects of titanium nanoparticles, that may have been scattered after dental implant placement, on gene and promoter expression, and gingival tissue. METHODS: Ca9-22 cell lines were used as gingival epithelial cells to assess the effects of titanium dioxide nanomaterials as titanium nanoparticles. Cells were cocultured with or without titanium dioxide nanomaterials prior to gene and promoter expression analysis. Expression of interleukin-13α2 receptor was investigated using real-time quantitative reverse-transcription polymerase chain reaction and immunofluorescence staining. Additionally, the enhanced messenger ribonucleic acid (mRNA) expression of transforming growth factor ß1 was analyzed using the same method. RESULTS: Titanium dioxide nanomaterials affected gene and promoter expression in Ca9-22 cells: among the 160 upregulated genes, the upregulation of IL13RA2, which encodes interleukin-13α2 receptor, was the highest (8.625 log2 fold change). Immunofluorescence staining confirmed the increased expression of interleukin-13α2 receptor, which enhanced transforming growth factor ß1 expression by stimulation with interleukin-13. CONCLUSION: Titanium dioxide nanomaterials applied on the gingival epithelium around the dental implant may increase interleukin-13α2 receptor expression. In turn, this can enhance the secretion of transforming growth factor ß1, which is known to promote the differentiation of osteoclasts involved in bone resorption, and potentially affect gingival tissue.

Increase in masseter muscle activity by newly fabricated complete dentures improved brain function.

Purpose To reveal effects of improvement of masseter muscle activity on brain function in elderly people wearing complete dentures.Methods Subjects were 14 edentulous patients with a chief complaint of the inconvenience of their complete dentures. The surface electromyographic (EMG) activity of the masseter muscles was measured. Brain activities were analyzed with functional magnetic resonance imaging (fMRI), employing chewing gum as the task program. Cognitive functions were evaluated with Trail Making Test Part A (TMT-A), Rey Auditory Verbal Learning Test (RAVLT) and Rey-Osterrieth Complex Figure Test (R-OCFT). Those evaluations were performed in which subjects wore their old dentures (OD) or newly fabricated dentures (ND).Results We compared ND condition with OD condition. The masseter muscle activity significantly increased in ND condition (p < 0.05, Wilcoxon signed rank test). The brain activity increased significantly in the superior frontal gyrus, precentral gyrus, putamen, inferior parietal lobule, cerebellum, inferior frontal lobe, and middle frontal gyrus under the ND condition than under the OD condition (p < 0.01, uncorrected, cluster size > 10 voxels). Results of TMT-A, RAVLT, and R-OCFT were also significantly improved (p < 0.05, Wilcoxon signed rank test).Conclusions In the edentulous elderly, the brain activity was increased following the improvement of the masseter muscle activity. Consequently, it is possible that the improvement of the masseter muscle activity might influence on the attention, verbal skills, and visual memory.

Applications of three-dimensional printers in prosthetic dentistry.

This narrative review aims to provide an overview of recent studies and case reports on three-dimensional (3D) printing, and to verify the applicability of 3D printers in the field of dental prostheses. This review was performed by conducting a search of PubMed. The clinical application of fabricating a prosthesis made with cobalt-chromium is considered possible depending on the material and hardware of the 3D printer. However, it is currently difficult to assess the clinical use of 3D-printed zirconia crowns. Further research is required, such as verification of materials used, margin morphology, and hardware. Clinically acceptable results have been reported for patterns using 3D printers. Interim restorations made using a 3D printer have been reported with good results that are considered clinically usable. Dentures made with 3D printers need further verification in terms of strength and deformation. Custom trays made with 3D printers are clinically useful, however, issues remain with design time and effort. Although several studies have reported the usefulness of 3D printers, further verification is required since 3D printers are still considered new technology.

A review of the recent literature on maxillary overdenture with dental implants.

The recent literature on maxillary implant overdenture (IOD) was reviewed in order to clarify its predictability and establish treatment guidelines. Electronic searches were performed using PubMed, and articles about maxillary IOD written after 1990 were reviewed, focusing on the following items: I. implant survival rate, II. maxillary IOD survival rate, III. number of implants, IV. attachment type, V. follow-up period, VI. implant system, and VII. opposing dentition. The review revealed an implant survival rate of 61-100% and an overdenture survival rate of 72.4-100%. The attachments used included bars, balls, locators, and telescope crowns. The minimum and maximum observation periods were 12 months and 120 months, respectively, and the number of implants used for supporting IOD ranged from 2 to 8. At present, there is no strong evidence to indicate that maxillary IOD is clearly superior for all the items examined. However, the existing data indicate that maxillary IOD has almost the same therapeutic effect as fixed implant superstructures, and is a treatment option that can be actively adopted for patients in whom fixed superstructures cannot be applied for various reasons.

Oral mucosa pressure caused by mandibular implant overdenture with different types of attachments.

PURPOSE: To determine the appropriate attachment and design of a denture base for mandibular implant overdenture (IOD), the oral mucosa pressure caused by mandibular implant overdentures was measured using edentulous jaw models with various attachments. METHODS: An experimental edentulous mandibular model with a 1.5-mm thick artificial oral mucosa was used. Two implants were placed at the area equivalent to the bilateral canines of an experimental jaw model. Locator attachments (LA), ball attachments (BA), magnetic attachments (MA), and round-bar attachments (R-BA) were fabricated. Six miniature pressure sensors were placed at the bilateral buccal premolar regions, bilateral buccal shelves, and bilateral lingual molar regions. A precision universal testing machine was used to apply dynamic repetitive loads of 50N. The load points were the center of the model, which should represent bilateral mastication on both sides (bilateral load), and were equivalent to the left first molar, which should represent unilateral mastication (unilateral load). Statistical analysis was performed using one-way analysis of variance. Multiple comparisons were then performed using the Bonferroni post hoc test. P<0.05 was considered statistically significant. RESULTS: Under the bilateral load condition, the lower oral mucosa pressure value with BA was measured, compared to other attachments at all measurement sites. Under the unilateral load condition, the oral mucosa pressure value of BA was smaller than the other attachments at the measurement site on the loading side. CONCLUSIONS: BA has exerted the greatest effects on support and bracing, suggesting that, BA is suitable for reducing oral mucosa pressure during mastication.

Sinus floor elevation using tricalcium phosphate plate.

When the sinus is enlarged, it may be necessary to elevate the floor of the maxillary sinus using the crestal or lateral approach. This report presents a case where sinus floor elevation was performed using tricalcium phosphate (TCP) plates supported by implant bodies, and only the blood clot was present around the implant bodies. Cone-beam computed tomography images, taken one year after the lateral approach, revealed the presence of a TCP-like radio-opacity, which almost disappeared after two years. About seven years after the surgery, the patient's superstructure and occlusion were stable. Furthermore, the grafted TCP was completely absorbed, and the implant body appeared to be in good condition, with no signs of bone resorption around the implant.

Accuracy and practicality of intraoral scanner in dentistry: A literature review.

PURPOSE: The digitization of the dental field has been vigorously promoted in recent years. An impression using an intraoral scanner is considered to significantly change future dental treatment. The purpose of this review is to evaluate accuracy and practicality of various intraoral scanners and verification method of intraoral scanners. STUDY SELECTION: This review was based on articles searched through the MEDLINE and PubMed databases. The main keywords that were employed during the search were "Oral Scanner, Intraoral Scanners, Desktop Scanner, and Digital Impression". RESULT: It was reported that illuminance and color temperature affected trueness and precision of intraoral scanners. The repeatability of intraoral scanners indicated the possibility of producing fixed prostheses within the range of being partially edentulous. It is considered difficult to use intraoral scanners in fabricating cross-arch fixed prostheses. However, with intraoral scanners, it may be considered possible to fabricate mouth guards and dentures equivalent to those of desktop scanners. Current intraoral scanner scans are considered more comfortable than traditional impressions that use irreversible hydrocolloid and elastomeric impression materials. CONCLUSION: Since the intraoral scanner is an evolving device, further improvement in accuracy is expected in the future. In addition, verification of the accuracy of intraoral scanners must be conducted accordingly.

Effects of the combination with alpha-tricalcium phosphate and simvastatin on bone regeneration.

BACKGROUND: Although local application of statins stimulates bone formation, high dose of simvastatin induces inflammation. OBJECTIVE: A study was conducted to test the hypothesis that maximum bone regeneration with less inflammation would be achieved by combining an optimal dose of simvastatin with alpha-tricalcium phosphate (alpha-TCP), which is an osteoconductive biomaterial capable of releasing the drug gradually. MATERIAL AND METHODS: Bilateral 5-mm-diameter calvarial defects were created in adult Wistar rats and filled with preparations of different doses of simvastatin (0, 0.01, 0.1, 0.25 and 0.5 mg) combined with alpha-TCP particles or left empty. The animals were sacrificed at 2, 4 and 8 weeks and analyzed radiologically and histologically. Half of the animals of 4 and 8 weeks were labeled with fluorescence dyes and histomorphometrically analyzed. RESULTS: Simvastatin doses of 0.25 and 0.5 mg caused inflammation of the soft tissue at the graft site whereas control and other doses did not. The micro-CT analysis revealed that the alpha-TCP with 0.1 mg simvastatin (TCP-0.1) group yielded significantly higher bone volumes than untreated control group at all three time points (249%, 227% and 266% at 2, 4 and 8 weeks, respectively). The percentage of defect closure, bone mineral content and bone mineral density were also higher in the TCP-0.1 group than in the other groups. CONCLUSION: When combined with alpha-TCP particles, 0.1 mg simvastatin is the optimal dose for stimulation of the maximum bone regeneration in rat calvarial defects without inducing inflammation and it could be applied as an effective bone graft material.

[Implant placement on restricted mesiodistal space with simulation software and guiding system: a case report].

A surgical guiding system with simulation software has recently been used for safe implant treatment. We report a clinical case in which we successfully used this system for implant treatment of a congenital tooth missing region with severely restricted mesiodistal space. The patient was a 19-year-old female whose mandibular right deciduous canine was wobbling without a successional permanent tooth and who desired implant treatment. CT images showed that this site was narrow buccal-lingually and only five millimeters in mesiodistal width. The implant position was planned using simulation software (SimPlant : Materialise Dental) based on CT data and a surgical guide template (SurgiGuide : Materialise Dental) was fabricated prior to the implant surgery. During the implant surgery, the deciduous canine was extracted under local anesthesia. The implant bed was prepared with the surgical guide template and an implant was installed. One month after surgery, the position of the implant was examined with a cone-beam CT, which demonstrated that the implant position was exactly the same as planned. At 5 months, a provisional prosthesis was delivered and optimal soft-tissue condition was formed by modifying the provisional prosthesis. Then, the final impression was taken and a ceramo-metal implant-supported crown was delivered. In this case of a congenital tooth missing region with narrow space, implant treatment with simulation software and the surgical guide system provided excellent clinical results.

A comparison of diagnosis of early stage interproximal caries with bitewing radiographs and periapical images using consensus reference.

OBJECTIVES:: The purpose of this study was to assess the diagnostic property of intraoral bitewing radiographs (BTW) for early stage interproximal caries, and to compare them with periapical radiographs (PA) at different levels of caries progression. METHODS:: A total of 241 interproximal surfaces of BTW and corresponding PAs were used. Seven teaching faculty consisting of three oral and maxillofacial radiologists, two operative faculty, and two prosthodontists evaluated the images. The observers graded images as either "intact", "enamel caries <1/2 width", "enamel caries >1/2 width", or "caries into dentin". The gold-standard was established by consensus of two experienced faculty with 35 years and 27 years of experience. Specificity, sensitivity, positive-predictive value, and negative-predictive value were calculated for the different level of caries progression. Furthermore, receiver operating curves) of BTW and PAs of each evaluator were made and the area under the curve of BTW and PAs were compared. RESULTS:: There was no significant difference in the specificity of BTW and PAs. BTW showed significantly higher sensitivity than PAs in all levels of caries progression (p<0.01). Positive-predictive value and negative-predictive value of BTWs were also significantly higher than PAs. One-way ANOVA and Tukey HSD test showed a significant difference in sensitivity with different levels of caries progression. The average area under the curve was significantly higher for BTWs than PAs (p<0.01). CONCLUSIONS:: BTWs offer a significant advantage over PAs in the diagnoses of early stages of interproximal carious lesions.

Epithelial cell adhesion efficacy of a novel peptide identified by panning on a smooth titanium surface.

Epithelial attachment via the basal lamina on the tooth surface provides an important structural defence mechanism against bacterial invasion in combating periodontal disease. However, when considering dental implants, strong epithelial attachment does not exist throughout the titanium-soft tissue interface, making soft tissues more susceptible to peri-implant disease. This study introduced a novel synthetic peptide (A10) to enhance epithelial attachment. A10 was identified from a bacterial peptide display library and synthesized. A10 and protease-activated receptor 4-activating peptide (PAR4-AP, positive control) were immobilized on commercially pure titanium. The peptide-treated titanium showed high epithelial cell migration ability during incubation in platelet-rich plasma. We confirmed the development of dense and expanded BL (stained by Ln5) with pericellular junctions (stained by ZO1) on the peptide-treated titanium surface. In an adhesion assay of epithelial cells on A10-treated titanium, PAR4-AP-treated titanium, bovine root and non-treated titanium, A10-treated titanium and PAR4-AP-treated titanium showed significantly stronger adhesion than non-treated titanium. PAR4-AP-treated titanium showed significantly higher inflammatory cytokine release than non-treated titanium. There was no significant difference in inflammatory cytokine release between A10-treated and non-treated titanium. These results indicated that A10 could induce the adhesion and migration of epithelial cells with low inflammatory cytokine release. This novel peptide has a potentially useful application that could improve clinical outcomes with titanium implants and abutments by reducing or preventing peri-implant disease.

A Survey of Dental Implant Instruction in Predoctoral Dental Curricula in North America.

The aim of this study was to investigate the extent and forms of predoctoral implant dentistry instruction in North American dental schools and to identify future directions and challenges. The survey collected data on curriculum content, departmental oversight, techniques, and materials, as well as current problems to be solved. The 30-question survey was sent in 2012 to the dean or administrator in charge of the predoctoral curriculum of all 73 dental schools in the U.S. and Canada at the time; four reminders were sent. Forty-seven schools responded, for a response rate of 64%. Of the 47 responding schools, 46 (98%) offered didactic instruction (mean of 17 hours); 87% had a laboratory component (mean of 14.46 hours); and 57% had a clinical requirement. In the responding schools, students had an average of 1.85 implant restorative cases and 0.61 surgical cases. Forty-two of the schools (89%) had implemented observation of implant surgery and/or assisting with implant surgery in their curricula. Major challenges reported in implementing a comprehensive predoctoral implant curriculum included expense of implant systems to the schools and to patients, shortage of predoctoral cases, and lack of curriculum time and trained faculty. These results show that implant education for predoctoral dental students continues to expand, with a trend towards more preclinical exercises and clinical experiences and fewer didactic courses.