Search

This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience. MATERIALS AND METHODS. Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05). RESULTS. There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists' groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists (P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists (P < .05). CONCLUSION. CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits. [ABSTRACT FROM AUTHOR]

Purpose: This in vitro study evaluated the reliability of a surgical guide with regard to different levels of operator surgical experience and implant site.Materials and Methods: A stereolithographic surgical guide for epoxy resin mandibles with three edentulous molar sites was produced using a computer-aided design/computer-assisted manufacture (CAD/CAM) system. Two surgeons with and two surgeons without implant surgery experience placed implants in a model either using or not using the CAD/CAM surgical guide. Four groups were created: inexperienced surgeon without the guide (group 1); experienced surgeon without the guide (group 2); inexperienced surgeon with the guide (group 3); and experienced surgeon with the guide (group 4). Planned implants and placed implants were superimposed using digital software, and deviation parameters were calculated.Results: There were no significant differences in any of the deviation parameters between the groups when using the surgical guide. With respect to the implant sites, there were no significant differences among the groups in any parameter.Conclusion: Use of the CAD/CAM surgical guide reduced discrepancies among operators performing implant surgery regardless of their level of experience. Whether or not the guide was used, differences in the anterior-posterior implant site in the molar area did not affect the accuracy of implant placement. [ABSTRACT FROM AUTHOR]

PURPOSE. The marginal bone loss of implants with laser treated surface was investigated after six weeks of loading after implant installation to the mandible molar area. MATERIALS AND METHODS. A total of 23 implants were placed in the edentulous molar area of the mandible: 13 implants were immediately loaded and 10 implants were early loaded. The implants used were made of titanium grade 23, screw shaped, 4.2 mm in diameter, and 10 mm in length. Patients were evaluated with resonance frequency analysis at implant fixture installation and 1, 2 (final prosthesis installation), 3, 5, 8, and 14 months later. X-rays were taken at 2 months after fixture installation and 1, 2, 3 years after to measure the marginal bone loss. RESULTS. The mean ISQ value measured at the implant installation was over 70 at all-time points. The average of marginal bone loss was average 0.33 mm. CONCLUSION. Immediate implant loading for laser treated implants would be possible. [ABSTRACT FROM AUTHOR]

PURPOSE. The aim of this study was to investigate dental arch dimensions and to classify arch shape in Korean young adults. MATERIALS AND METHODS. The sample included 50 Koreans with age ranging from 24 to 32 years. Maxillary and mandibular casts were fabricated using irreversible hydrocolloid and type III dental stones. Incisor-canine distance, incisor-1st molar distance, incisor-2nd molar distance, intercanine distance, inter-1st molar distance, and inter-2nd molar distance in both the maxillary and mandibular arch were measured using a threedimensional measuring device. The dental arch was classified into three groups using five ratios from the measured values by the K-means clustering method. The data were analyzed with one-way analysis of variance. RESULTS. Arch lengths (IM2D, incisal-2nd molar distance) were 44.13 mm in the maxilla and 40.40 mm in the mandible. Arch widths (M2W, inter 2nd molar width) were 64.12 mm in the maxilla and 56.37 mm in the mandible. Distribution of the dental arch form was mostly ovoid shape (maxilla 52% and mandible 56%), followed by the V-shape and the U-shape. The arch width for the U-shape was broader than for the other forms. CONCLUSION. This study establishes new reference data for dental arch dimensions for young Korean adults. The most common arch form is the ovoid type in the maxilla and mandible of Koreans. Clinicians should be aware of these references and classify arch type before and during their dental treatment for effective and harmonized results in Koreans. [ABSTRACT FROM AUTHOR]

PURPOSE. The aim of this investigation was to analyze the dimensions of clinical crowns and to classify the crown and the gingival type in the anterior teeth in Korean young adults. MATERIALS AND METHODS. Casts were obtained from 50 subjects ranging in age from 24 to 32. Measurements of length and width were made on the casts using a pair of digital calipers on the entire dentition. Crown thickness and papilla height were also measured and MDW/CL (mesiodistal width to clinical length) and CW/CL (cervical width to clinical length) ratios of the maxillary anterior teeth were calculated. The K-clustering method was used for CW/CL to classify the anterior tooth shape into three groups (tapered, ovoid, and square), and one-way analysis of variance and Duncan's post-hoc comparison were used to evaluate statistical significance between the groups. Pearson's correlation analysis was performed between tooth shape and papillary height (PH) to demonstrate the correlation between tooth shape and gingival morphological characteristics. RESULTS. The average length of the maxillary central incisors was 9.89 mm; the mesio-distal width was 8.54 mm; and the ratio of width/length was 0.86 in Korean young adults. The average bucco-palatal thickness of the central incisor was 3.14 mm at the incisal 1/3 aspect. Ovoid type was the most common tooth shape (48%), followed by square type (29%) and taper type (23%) in the central incisors of Korean young adults. Tooth shape and gingival type were correlated with each other. CONCLUSION. New reference data were established for tooth size in Korean young adults and the data show several patterns of tooth shape and gingival type. Clinicians should diagnose and treat based on these characteristics for better results in the Korean population. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to investigate the effects of static magnetic fields ( SMFs) on bone regeneration around titanium implants by μ CT, histologic analysis, microarrays, and quantitative real-time PCR ( qRT- PCR). Materials and methods Neodymium magnets provided the source of SMFs, the specimens were grade 5 titanium implants, and the animals were twenty-seven adult male New Zealand white rabbits. These implants were divided into six groups according to the presence of a magnet and predetermined healing period (1, 4, and 8 weeks). Each group comprised six specimens for μ CT ( n = 6) and histologic examination, and three specimens ( n = 3) for microarrays and qRT- PCR, yielding a total of 54 specimens. Results The μ CT data showed that SMFs increased bone volume fraction (bone volume/total volume, BV/ TV), trabecular number (Tb.N), and trabecular thickness (Tb.Th). Histologic observation indicated that SMFs promoted new bone formation and direct bony contact with implants. Microarray analysis identified 293 genes upregulated (>twofold) in response to SMFs. The upregulated genes included extracellular matrix ( ECM)-related genes ( COL10A1, COL9A1, and COL12A1) and growth factor ( GF)-related genes ( CTGF and PDGFD), and the upregulation was confirmed by qRT- PCR. Gene Ontology ( GO) and pathway analysis revealed the involvement of the mitogen-activated protein kinase ( MAPK), Wnt, and PPAR-gamma signaling pathways in implant healing. Conclusions μ CT, histology, microarrays, and real-time PCR indicate that SMFs could be an effective approach to improving bone regeneration around dental implants. [ABSTRACT FROM AUTHOR]

PURPOSE. To determine the effect of fibronectin (FN)-conjugated, microgrooved titanium (Ti) on osteoblast differentiation and gene expression in human bone marrow--derived mesenchymal stem cells (MSCs). MATERIALS AND METHODS. Photolithography was used to fabricate the microgrooved Ti, and amine functionalization (silanization) was used to immobilize fibronectin on the titanium surfaces. Osteoblast differentiation and osteoblast marker gene expression were analyzed by means of alkaline phosphatase activity assay, extracellular calcium deposition assay, and quantitative real-time PCR. RESULTS. The conjugation of fibronectin on Ti significantly increased osteoblast differentiation in MSCs compared with non-conjugated Ti substrates. On the extracellular calcium deposition assays of MSCs at 21 days, an approximately two-fold increase in calcium concentration was observed on the etched 60-µm-wide/10-µm-deep microgrooved surface with fibronectin (E60/10FN) compared with the same surface without fibronectin (E60/10), and a more than four-fold increase in calcium concentration was observed on E60/10FN compared with the non-etched control (NE0) and etched control (E0) surfaces. Through a series of analyses to determine the expression of osteoblast marker genes, a significant increase in all the marker genes except type I collagen α1 mRNA was seen with E60/10FN more than with any of the other groups, as compared with NE0. CONCLUSION. The FN-conjugated, microgrooved Ti substrate can provide an effective surface to promote osteoblast differentiation and osteoblast marker gene expression in MSCs. [ABSTRACT FROM AUTHOR]

PURPOSE. The purpose of this study was to find out the effect of immediate dentin sealing (IDS) on bond strength of ceramic restoration under various thermocycling periods with DBA (dentin bonding agent system). MATERIALS AND METHODS. Fifty freshly extracted human mandibular third molars were divided into 5 groups (1 control and 4 experimental groups) of 10 teeth. We removed enamel layer of sound teeth and embedded them which will proceed to be IDS, using All Bond II. A thermocycling was applied to experimental groups for 1, 2, 7, 14 days respectively and was not applied to control group. IPS Empress II for ceramic was acid-etched with ceramic etchant (9.5% HF) and silane was applied. Each ceramic disc was bonded to specimens with Duo-link, dual curable resin cement by means of light curing for 100 seconds. After the cementation procedures, shear bond strength measurement and SEM analysis of the fractured surface were done. The data were analyzed with a one-way ANOVA and Tukey multiple comparison test (α=.05). RESULTS. There were no statistically significant differences between 4 experimental groups and control group, however the mean value started to decrease in group 7d, and group 14d showed the lowest mean bond strength in all groups. Also, group 7d and 14d showed distinct exposed dentin and collapsed hybrid layer was observed in SEM analysis. CONCLUSION. In the present study, it can be concluded that ceramic restorations like a laminate veneer restoration should be bonded using resin cement within one week after IDS procedure. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the bone formation around commercial sandblasted, large-grit, acid-etched (SLA)-treated titanium implants with or without a neodymium magnet in a rabbit tibia through histomorphometric analysis. Commercial SLA-treated implants with or without neodymium magnets were placed in 10 rabbits. After incising the flat part of the rabbit's tibia and installation of the specimens of titanium implants, the nonmagnet group was stitched without magnet insertion. On the other hand, the magnet group was inserted with neodymium magnet, fixed with pattern resin, and stitched. At 3 and 6 weeks after surgery, the animals were sacrificed, and the specimens were obtained. Undecalcified specimens were prepared for histomorphometric analysis of the bone-to-implant contact ratio (BIC) and bone volume (BV). The histomorphometric findings of the cortical bone showed that the mean BVs of the magnet group (3 weeks, 75.99%; 6 weeks, 82.94%) were higher than those of the nonmagnet group (3 weeks, 74.58%; 6 weeks, 78.75%), but there were no significant differences between the 2 groups (P > .05). In the marrow bone, the mean BICs of the magnet group (3 weeks, 10.36%; 6 weeks, 10.41%) were higher than those of the nonmagnet group (3 weeks, 6.41%; 6 weeks, 7.36%). After 3 weeks of installation, there was a significant difference between the 2 groups (P < .0.5). In rabbit tibia, the SLA-treated titanium implants with a neodymium magnet can trigger faster early peri-implant bone formation than those without a magnet. [ABSTRACT FROM AUTHOR]

Surface microgrooves and acid etching on titanium (Ti) have been proposed to enhance various cell behaviors. In this study, surface hydrophilicity, protein adsorption, and alkaline phosphatase activity of osteoblasts were analyzed and compared between microgrooved Ti, Ti with microgrooves and further acid etching, smooth Ti, and acid-etched smooth Ti. Correlations between the results of each experiment were analyzed using Pearson's correlation analysis, and the influential factor on alkaline phosphatase activity was determined using multiple stepwise regression analysis. Among groups, the Ti substrata with microgrooves and subsequent acid etching showed significantly greater surface hydrophilicity and alkaline phosphatase activity compared with smooth Ti, whereas the Ti substrata with only microgrooves showed the greatest protein adsorption. Multiple stepwise regression analysis determined the surface hydrophilicity of Ti as the influential factor on alkaline phosphatase activity. This study indicates that surface microgrooves and acid etching on Ti substrata enhance surface hydrophilicity, leading to increased alkaline phosphatase activity. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the histomorphometric and biomechanical comparison of small-diameter implants with different designs. These implants can be placed surgically in narrow bone spaces, such as the lower incisor region, that have low occlusal loading. Specimens of screw-shaped pin implants were designed for the study. These specimen implants were divided into 6 groups: group 1, machined implants; group 2, resorbable blast media (RBM)-treated implants; group 3, machined implants with a long vertical groove; group 4, RBM-treated implants with a long vertical groove; group 5, RBM-treated implants with a vertical groove on the upper thread; and group 6, RBM-treated implants with a vertical groove on the lower trunk. The specimen implants were placed surgically on the medial side of the rabbit tibia. Animals were sacrificed 2, 4, and 8 weeks after surgery. The removal torque was measured and tissues were prepared for histologic and histomorphometric analysis. The bone-to-implant contact and the percentage of the bone area inside the threads were measured. RBM-treated implants with vertical groove groups showed significantly higher values of removal torque, bone-implant contact, and bone area rate than the ones of machined surface groups. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience., Materials and Methods: Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05)., Results: There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists' groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists ( P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists ( P < .05)., Conclusion: CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits., (© 2023 The Korean Academy of Prosthodontics.)

Objectives: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed., Materials and Methods: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted., Results: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent., Conclusions: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care., (© 2018 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.)

Purpose: The aim of this study was to investigate dental arch dimensions and to classify arch shape in Korean young adults., Materials and Methods: The sample included 50 Koreans with age ranging from 24 to 32 years. Maxillary and mandibular casts were fabricated using irreversible hydrocolloid and type III dental stones. Incisor-canine distance, incisor-1 st molar distance, incisor-2 nd molar distance, intercanine distance, inter-1 st molar distance, and inter-2 nd molar distance in both the maxillary and mandibular arch were measured using a three-dimensional measuring device. The dental arch was classified into three groups using five ratios from the measured values by the K-means clustering method. The data were analyzed with one-way analysis of variance., Results: Arch lengths (IM2D, incisal-2 nd molar distance) were 44.13 mm in the maxilla and 40.40 mm in the mandible. Arch widths (M2W, inter 2 nd molar width) were 64.12 mm in the maxilla and 56.37 mm in the mandible. Distribution of the dental arch form was mostly ovoid shape (maxilla 52% and mandible 56%), followed by the V-shape and the U-shape. The arch width for the U-shape was broader than for the other forms., Conclusion: This study establishes new reference data for dental arch dimensions for young Korean adults. The most common arch form is the ovoid type in the maxilla and mandible of Koreans. Clinicians should be aware of these references and classify arch type before and during their dental treatment for effective and harmonized results in Koreans.

Purpose: The aim of this investigation was to analyze the dimensions of clinical crowns and to classify the crown and the gingival type in the anterior teeth in Korean young adults., Materials and Methods: Casts were obtained from 50 subjects ranging in age from 24 to 32. Measurements of length and width were made on the casts using a pair of digital calipers on the entire dentition. Crown thickness and papilla height were also measured and MDW/CL (mesiodistal width to clinical length) and CW/CL (cervical width to clinical length) ratios of the maxillary anterior teeth were calculated. The K-clustering method was used for CW/CL to classify the anterior tooth shape into three groups (tapered, ovoid, and square), and one-way analysis of variance and Duncan's post-hoc comparison were used to evaluate statistical significance between the groups. Pearson's correlation analysis was performed between tooth shape and papillary height (PH) to demonstrate the correlation between tooth shape and gingival morphological characteristics., Results: The average length of the maxillary central incisors was 9.89 mm; the mesio-distal width was 8.54 mm; and the ratio of width/length was 0.86 in Korean young adults. The average bucco-palatal thickness of the central incisor was 3.14 mm at the incisal 1/3 aspect. Ovoid type was the most common tooth shape (48%), followed by square type (29%) and taper type (23%) in the central incisors of Korean young adults. Tooth shape and gingival type were correlated with each other., Conclusion: New reference data were established for tooth size in Korean young adults and the data show several patterns of tooth shape and gingival type. Clinicians should diagnose and treat based on these characteristics for better results in the Korean population.

Purpose: This in vitro study evaluated the reliability of a surgical guide with regard to different levels of operator surgical experience and implant site., Materials and Methods: A stereolithographic surgical guide for epoxy resin mandibles with three edentulous molar sites was produced using a computer-aided design/computer-assisted manufacture (CAD/CAM) system. Two surgeons with and two surgeons without implant surgery experience placed implants in a model either using or not using the CAD/CAM surgical guide. Four groups were created: inexperienced surgeon without the guide (group 1); experienced surgeon without the guide (group 2); inexperienced surgeon with the guide (group 3); and experienced surgeon with the guide (group 4). Planned implants and placed implants were superimposed using digital software, and deviation parameters were calculated., Results: There were no significant differences in any of the deviation parameters between the groups when using the surgical guide. With respect to the implant sites, there were no significant differences among the groups in any parameter., Conclusion: Use of the CAD/CAM surgical guide reduced discrepancies among operators performing implant surgery regardless of their level of experience. Whether or not the guide was used, differences in the anterior-posterior implant site in the molar area did not affect the accuracy of implant placement.

Purpose: The purpose of this study was to evaluate the resistance to deformation under static overloading by measuring yield and fracture strength, and to analyze the failure characteristics of implant assemblies made of different titanium grades and connections., Materials and Methods: Six groups of implant assemblies were fabricated according to ISO 14801 (n=10). These consisted of the combinations of 3 platform connections (external, internal, and morse tapered) and 2 materials (titanium grade 2 and titanium grade 4). Yield strength and fracture strength were evaluated with a computer-controlled Universal Testing Machine, and failed implant assemblies were classified and analyzed by optical microscopy. The data were analyzed using the One-way analysis of variance (ANOVA) and Student's t-test with the level of significance at P =.05., Results: The group IT4 S had the significantly highest values and group IT2 the lowest, for both yield strength and fracture strength. Groups IT4 N and ET4 had similar yield and fracture strengths despite having different connection designs. Group MT2 and group IT2 had significant differences in yield and fracture strength although they were made by the same material as titanium grade 2. The implant system of the similar fixture-abutment interfaces and the same materials showed the similar characteristics of deformation., Conclusion: A longer internal connection and titanium grade 4 of the implant system is advantageous for static overloading condition. However, it is not only the connection design that affects the stability. The strength of the titanium grade as material is also important since it affects the implant stability. When using the implant system made of titanium grade 2, a larger diameter fixture should be selected in order to provide enough strength to withstand overloading., Competing Interests: None of the authors have conflicts of interest related to this study.

We demonstrate that a composite surface of microgroove titanium (Ti) with immobilized fibronectin (FN) or bone sialoprotein II (BSP2) promotes osteoblastic differentiation and osteogenic transcription factor expression in human bone marrow-derived mesenchymal stem cells (MSCs). Comparisons made between smooth microgrooves, microgrooves with silanization and microgrooves with matrix protein (FN or BSP2)-immobilization Ti surfaces revealed a significant promotion of in vitro osteogenic activity and osteoblastic differentiation at various timelines of culture. An even more significant increase was verified on microgrooves with a matrix protein-immobilization Ti surface in 28 d time-dependent gene expression of the main osteogenic transcription factors, such as ARF4, FRA1, RUNX2, and OSX. As a result, a synergestic effect regarding the promotion of osteogenic transcription factor expression and osteoblastic differentiation in the matrix protein-microgroove Ti composite surface was confirmed. From a multiple regression analysis using various timelines of osteogenic culture as independent variables, day 13 was verified as the most prominent influential timeline for the promotion of osteoblastic differentiation induced by the matrix protein-microgroove Ti composite surface. The FN- or BSP2-microgroove Ti composite surface resulting from silanization can strongly induce the promotion of osteoblastic differentiation in human MSCs. The proposed surface is expected to be useful in the development of a variety of osteogenic biomaterial surfaces.

Purpose: To determine the effect of fibronectin (FN)-conjugated, microgrooved titanium (Ti) on osteoblast differentiation and gene expression in human bone marrow-derived mesenchymal stem cells (MSCs)., Materials and Methods: Photolithography was used to fabricate the microgrooved Ti, and amine functionalization (silanization) was used to immobilize fibronectin on the titanium surfaces. Osteoblast differentiation and osteoblast marker gene expression were analyzed by means of alkaline phosphatase activity assay, extracellular calcium deposition assay, and quantitative real-time PCR., Results: The conjugation of fibronectin on Ti significantly increased osteoblast differentiation in MSCs compared with non-conjugated Ti substrates. On the extracellular calcium deposition assays of MSCs at 21 days, an approximately two-fold increase in calcium concentration was observed on the etched 60-µm-wide/10-µm-deep microgrooved surface with fibronectin (E60/10FN) compared with the same surface without fibronectin (E60/10), and a more than four-fold increase in calcium concentration was observed on E60/10FN compared with the non-etched control (NE0) and etched control (E0) surfaces. Through a series of analyses to determine the expression of osteoblast marker genes, a significant increase in all the marker genes except type I collagen α1 mRNA was seen with E60/10FN more than with any of the other groups, as compared with NE0., Conclusion: The FN-conjugated, microgrooved Ti substrate can provide an effective surface to promote osteoblast differentiation and osteoblast marker gene expression in MSCs.

Surface microgrooves and acid etching on titanium (Ti) have been proposed to enhance various cell behaviors. In this study, surface hydrophilicity, protein adsorption, and alkaline phosphatase activity of osteoblasts were analyzed and compared between microgrooved Ti, Ti with microgrooves and further acid etching, smooth Ti, and acid-etched smooth Ti. Correlations between the results of each experiment were analyzed using Pearson's correlation analysis, and the influential factor on alkaline phosphatase activity was determined using multiple stepwise regression analysis. Among groups, the Ti substrata with microgrooves and subsequent acid etching showed significantly greater surface hydrophilicity and alkaline phosphatase activity compared with smooth Ti, whereas the Ti substrata with only microgrooves showed the greatest protein adsorption. Multiple stepwise regression analysis determined the surface hydrophilicity of Ti as the influential factor on alkaline phosphatase activity. This study indicates that surface microgrooves and acid etching on Ti substrata enhance surface hydrophilicity, leading to increased alkaline phosphatase activity.

Purpose: The aim of this pilot study was to investigate the effect of etched microgrooves on the hydrophilicity of Ti and osteoblast responses., Material and Methods: Microgrooves were applied on Ti to have 15 and 60 µm width, and 3.5 and 10 µm depth by photolithography, respectively. Further acid etching was applied to create Ti surfaces with etched microgrooves. Both smooth- and acid-etched Ti were used as the controls. The hydrophilicity of Ti was analyzed by determining contact angles. Cell proliferation and osteogenic activity of MC3T3 mouse preosteoblasts were analyzed by bromodeoxyuridine assay and alkaline phosphatase (ALP) activity test, respectively. One-way ANOVA, Pearson's correlation analysis and multiple regression analysis were used for statistics., Results: Etched microgrooves significantly increased the hydrophilicity of Ti compared to the smooth Ti. 60 µm-wide etched microgrooves significantly enhanced cell proliferation, whereas the osteogenic activity showed statistically non-significant differences between groups. Result of the osteogenic activity significantly correlated with those of hydrophilicity and cell proliferation. Hydrophilicity was determined to be an influential factor on osteogenic activity., Conclusion: This study indicates that increase in hydrophilicity of Ti caused by etched microgrooves acts as an influential factor on osteogenic activity. However, statistically non-significant increase in the ALP activity suggests further investigation.

This study was designed to investigate the histomorphometric and biomechanical comparison of small-diameter implants with different designs. These implants can be placed surgically in narrow bone spaces, such as the lower incisor region, that have low occlusal loading. Specimens of screw-shaped pin implants were designed for the study. These specimen implants were divided into 6 groups: group 1, machined implants; group 2, resorbable blast media (RBM)-treated implants; group 3, machined implants with a long vertical groove; group 4, RBM-treated implants with a long vertical groove; group 5, RBM-treated implants with a vertical groove on the upper thread; and group 6, RBM-treated implants with a vertical groove on the lower trunk. The specimen implants were placed surgically on the medial side of the rabbit tibia. Animals were sacrificed 2, 4, and 8 weeks after surgery. The removal torque was measured and tissues were prepared for histologic and histomorphometric analysis. The bone-to-implant contact and the percentage of the bone area inside the threads were measured. RBM-treated implants with vertical groove groups showed significantly higher values of removal torque, bone-implant contact, and bone area rate than the ones of machined surface groups.