New technologies that facilitate solid alveolar ridge augmentation are receiving considerable attention in the field of prosthodontics because of the growing requirement for esthetic and functional reconstruction by dental implant treatments. Recently, several studies have demonstrated potential advantages for stem-cell-based therapies in regenerative treatments. Mesenchymal stem/stromal cells (MSCs) are now an excellent candidate for tissue replacement therapies, and tissue engineering approaches and chair-side cellular grafting approaches using autologous MSCs represent the clinical state of the art for stem-cell-based alveolar bone regeneration. Basic studies have revealed that crosstalk between implanted donor cells and recipient immune cells plays a key role in determining clinical success that may involve the recently observed immunomodulatory properties of MSCs. Part II of this review first overviews progress in regenerative dentistry to consider the implications of the stem cell technology in dentistry and then highlights cutting-edge stem-cell-based alveolar bone regenerative therapies. Factors that affect stem-cell-based bone regeneration as related to the local immune response are then discussed. Additionally, pre-clinical stem cell studies for the regeneration of teeth and other oral organs as well as possible applications of MSC-based immunotherapy in dentistry are outlined. Finally, the marketing of stem cell technology in dental stem cell banks with a view toward future regenerative therapies is introduced.

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Purpose: Current clinical procedures to control or regenerate bone loss due to peri-implantitis are not predictable neither accomplish complete resolution. Therefore, early detection of the onset and the active periods of bone loss are crucial for prevention of extensive peri-implant bone resorption. This study aimed to determine a possible association between the presence of collagenases (MMP-1, MMP-8 and MMP-13) in peri-implant sulcular fluid (PISF) and active periods of bone loss by annually adjusted vertical bone loss (AVBL) measurements.
Methods: Intended sample consisted of 76 consecutive patients who received oral implant treatment at the Fixed Prosthodontic Clinic of Okayama University Hospital from 1990 to 2000. Twelve subjects were lost to follow-up or refused to participate. Consequently, the actual sample consisted of 64 patients who were followed-up for at least one year. Those patients with AVBL > 0.6 mm were included in the severe peri-implantitis group, and randomly selected, age-, gender- and implantation site-matched healthy patients (AVBL < 0.3 mm) comprised the control group. PISF samples were collected from both groups and further analyzed by western blot for detection of collagenases.
Results: Four patients presented severe peri-implantitis. MMP-8 was the only collagenase detected in peri-implant sites with ongoing bone loss. PISF samples from control group showed no positive reactions to any collagenase.
Conclusion: This study showed MMP-8 as a possible marker for progressive bone loss in peri-implantitis.

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Purpose: To evaluate the stress distribution in peri-implant bone by simulating the effect of an implant with microthreads and platform switching on angled abutments through tridimensional finite element analysis. The postulated hypothesis was that the presence of microthreads and platform switching would reduce the stress concentration in the cortical bone.
Methods: Four mathematical models of a central incisor supported by an implant (5.0 mm × 13 mm) were created in which the type of thread surface in the neck portion (microthreaded or smooth) and the diameter of the angled abutment connection (5.0 and 4.1 mm) were varied. These models included the RM (regular platform and microthreads), the RS (regular platform and smooth neck surface), the SM (platform switching and microthreads), and the SS (platform switching and smooth neck). The analysis was performed using ANSYS Workbench 10.0 (Swanson Analysis System). An oblique load (100 N) was applied to the palatine surface of the central incisor. The bone/implant interface was considered to be perfectly integrated. Values for the maximum (σ_max) and minimum (σ_min) principal stress, the equivalent von Mises stress (σ_vM), and the maximum principal elastic strain (ε_max) for cortical and trabecular bone were obtained.
Results: For the cortical bone, the highest σ_max (MPa) were observed for the RM (55.1), the RS (51.0), the SM (49.5), and the SS (44.8) models. The highest σ_vM (MPa) were found for the RM (45.4), the SM (42.1), the RS (38.7), and the SS models (37). The highest values for σ_min were found for the RM, SM, RS and SS models. For the trabecular bone, the highest σ_max values (MPa) were observed in the RS model (6.55), followed by the RM (6.37), SS (5.6), and SM (5.2) models.
Conclusion: The hypothesis that the presence of microthreads and a switching platform would reduce the stress concentration in the cortical bone was partially rejected, mainly because the microthreads increased the stress concentration in cortical bone. Only platform switching reduced the stress in cortical bone.

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Purpose: The aim of this study was to evaluate the tensile strength, elongation, microhardness (MHV), composition and microstructure of two Ni–Cr based alloy, cast under different casting conditions.
Methods: Before casting, the alloy ingots were evaluated as regards composition (EDX) and microstructure (Optical microscopy, SEM and EDX). The casting conditions were as follows: electromagnetic induction in an environment controlled with argon (EWA), electromagnetic induction in an environment under vacuum (EWV), electromagnetic induction without atmosphere control (EWNC) and blowtorch (BT). For each condition, 16 specimens were obtained, each measuring 25 mm high and 2.5 mm in diameter. The ultimate tensile strength (UTS) and elongation (EL) tests were performed in a Kratos machine (1.0 mm/min). Fractured specimens were embedded in bakelite resin and polished for Vickers Microhardness analysis (1000 g/10 s) with 4 penetrations in each specimen. The UTS, EL and MHV results were evaluated for two-way ANOVA and Tukey's test (α = 0.05).
Results: The cross-product interaction was statistically significant for all properties evaluated (p < 0.0001), lower UTS, VHN and higth elongation means were observed for the Ni–Cr–Mo–Be alloy tested when cast under the induction/argon (p < 0.05). Higher UTS means were found for Ni–Cr–Mo–Ti alloy tested when cast under the induction/vacuum, and induction/air and flame/air condition (p < 0.05). The two alloys show a microstructure with a dendritic formation with the presence of eutectic presence.
Conclusion: The Ni–Cr–Mo–Ti alloy showed higth UTS, MHV and lowest EL comparaded with the tradicional Ni–Cr–Mo–Be, that show lowest UTS, MHV and higter EL when cast on induction/argon.

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Purpose: Candida-associated denture stomatitis is the most prevalent form of oral candidosis affecting 65% of denture wearers. Failure of therapy and recurrence of infection are not uncommon and the continuous use of antifungal agents may affect the surface properties of the denture material and may contribute to Candida adhesion. This study aimed to investigate surface properties of poly(methyl methacrylate) PMMA denture material before and after exposure to antifungal agents and its relation to in vitro adhesion of Candida albicans.
Methods: Four groups of acrylic specimens (20 mm × 20 mm × 2.5 mm) were prepared (25 specimens in each group). Specimens were immersed in nystatin (group 1), fluconazole (group 2), distilled water (group 3) and group 4 was not exposed. Specimens were tested for surface roughness, contact angle, surface hardness and in vitro Candida adherence to PMMA.
Results: The results showed that nystatin had no statistically significant effect on surface hardness (P > 0.05), but had a statistically significant effect on surface roughness, contact angle, and Candida adhesion to PMMA (P < 0.05). On the other hand, fluconazole had no statistically significant effect on surface hardness or roughness (P > 0.05), but had a statistically significant effect on contact angle, and Candida adhesion to PMMA (P < 0.05). Distilled water had no statistically significant effect on surface hardness, roughness, contact angle, or Candida adhesion to PMMA (P > 0.05).
Conclusions: Exposure of PMMA to nystatin may induce changes in roughness, wettability while exposure to fluconazole may affect surface free energy and therefore may increase Candida adhesion to it.

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Purpose: The aim of this study was to evaluate the change in thickness of different types of step-type mouthguard sheets after suction molding in response to heating conditions for more effective use.
Methods: Four types of mouthguard sheets (Impact Guard^®) were compared: a step-type sheet; a step-type sheet with a v-shaped groove 30 mm from the anterior end; a step-type sheet with a v-shaped groove at the inferior margin of the step portion; and a step-type sheet with a v-shaped groove at the center of the step portion. The working model was trimmed to a height of 20-mm at the incisor and 15-mm at the first molar. The thickness of sheet was measured at points defined on the incisor and molar portion. The heating condition was defined when the sheet sagged by 15-mm below the level of the clamp. Differences in the percent change in thickness from types of sheets were analyzed using Scheffé's multiple comparison test. Additionally, the sheet type of thickness change with smallest was compared between the 15-mm and 20-mm sheet-sagging condition by paired t-test.
Results: The sheet with a v-shaped groove at the center of the step portion showed smallest reduction in thickness. With this type of sheet, no significant difference in thickness was observed under heating conditions.
Conclusions: The present results demonstrate the thickness of the incisor and molar portions of a step-type mouthguard sheet can be maintained by creating a v-shaped groove at the center of the step portion, regardless of heating condition.

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Objective: The purpose of the pilot study was to determine the effect of restoring lost occlusal vertical dimension (OVD) due to attrition on maximum bite force in humans.
Methodology: A total of 124 subjects in age range of 25–40 years, with moderate to severe attrition, having full complement of teeth were screened according to inclusion and exclusion criteria. After consent, occlusal vertical dimension was assessed by employing mechanical and physiological methods in the experimental group and a maxillary canine guided hard splint was fabricated for each subjects fulfilling inclusion criteria and with positive consent (78). Bite force in experimental group was measured before, immediately after delivery of splint and subsequently at an interval of four, eight, and twelve weeks. Due loss during follow up, only 50 subjects could be available for bite force recording till 12 weeks. Bite force of age, gender, height and weight matched controls with no signs of attrition was also measured for comparison.
Results: Bite force of the experimental group was found to be significantly less than the matched controls (P = 0.000) initially. After delivery of splint, bite force values increased progressively till twelve weeks. However comparison of bite force values of experimental group with control group showed no significant difference at end of eight (P = 0.008) and twelve weeks (P = 0.162).
Conclusion: It was concluded that maximum bite force increases with restoration of lost vertical using splint therapy. A time period of 8–12 weeks is required to restore the maximum bite force value approximately similar to matched controls.

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Patient: The patient was partially edentulous, lacking both the first mandibular molars. The FBI and the conventional impression technique were used for the fabrication of implant-fixed prosthesis replacing the right and left molars, respectively. In the FBI technique, the definitive impression was made under occlusal force and functionally generated path (FGP) recording at the same time. The right and left occlusal contact areas were compared after completing the implant-fixed prosthesis rehabilitation.
Discussion: It has been suggested that accuracy of the impression and maxillomandibular registration is necessary to ensure a satisfactory long-term clinical outcome. The transfer of the exact position of the implants to the working cast is even more important because implants lack the mobility of natural teeth. There are displacement differences between implants and natural teeth under occlusal force. The FBI technique may compensate for this difference in accuracy.
Conclusion: Using the FBI technique, a precise prosthesis could be produced by completing simultaneously the maxillomandibular registration, impression and FGP.

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