Purpose: The aim of this paper is to provide a concise overview about the principles of pre- implant orthodontic extrusion, describe methods and techniques available and provide the clinicians with guidelines about its application. Study selection: A number of reports describe orthodontic extrusion as a reliable method for pre-implant site enhancement. However, no standard protocols have been provided about the application of this technique. The literature database was searched for studies involving implant site enhancement by means of orthodontic extrusion. Information about the principles, indications and contraindications of this method, type of anchorage, force and time were obtained from the literature. Result: Despite that the scarce data is largely limited to case reports and case series, implant site enhancement by means of orthodontic extrusion seems to be a promising option to improve soft and hard tissue conditions prior to implant placement. Conclusion: Orthodontic extrusion is being implemented as a treatment alternative to enhance hard and soft tissue prior to implant placement. While the current literature does not provide clear guidelines, the decision making for a specific approach seems to be based on the clinician's preferences. Clinical studies are needed to verify the validity of this

Purpose: Dentists may encounter patients who present with a sense of a malocclusion but in whom no objective findings can be detected. For the patient who insists that there is occlusal discomfort, in the absence of evidence some dentists elect to perform an occlusal adjust- ment that not only fails to alleviate symptoms, and may, in fact, exacerbate the discomfort. The patient-dentist relationship is then likely compromised because of a lack of trust. Study selection: In 2011, the Clinical Practice Guidelines Committee of the Japan Prostho- dontic Society formulated guidelines for the management of occlusal discomfort. When formulating clinical practice guidelines, the committee bases their recommendations on information derived from scientific evidence. For ‘‘occlusal dysesthesia,'' however, there are an insufficient number of high-quality papers related to the subject. Therefore, a consensus meeting was convened by the Japan Prosthodontic Society to examine evidence in the Japanese- and English-language literature and generate a multi-center survey to create an appropriate appellation for this condition. Results: As a result of the consensus meeting and survey findings, this condition may be justifiably termed ‘‘occlusal discomfort syndrome.'' Conclusions: The Japan Prosthodontics Society believes that identification of an umbrella term for occlusal discomfort might serve as a useful guide to formulating clinical practice guidelines in the future. This position paper represents summary findings in the literature combined with the results of a multicenter survey focused on dental occlusal treatment and the condition of patients who present with occlusal discomfort syndrome.

Purpose: Interferon (IFN)-g is a major cytokine produced by immune cells that plays diverse roles in modulating both the immune system and bone metabolism, but its role in autoge- nous bone grafting remains unknown. Here, we present that local IFN-g administration improved the efficacy of autogenous bone graft treatment in an experimental rat model. Methods: An autogenous bone graft model was prepared with critically sized rat calvariae defects. Four weeks (w) after bone graft implantation, rats were treated locally with IFN-g or were not treated. The effect of IFN-g on bone formation was evaluated for up to 8 w with micro-computed tomography, quantitative histomorphometry, and Von Kossa staining. Osteoclastogenesis was assessed by tartrate-resistant acid phosphatase staining. Immuno- histochemistry staining or quantitative polymerase chain reactions were used to estimate the expression of osteoclast differentiation factor and inflammatory cytokines including tumor necrosis factor (TNF)-a, a well-known stimulant of osteoclastogenesis and an inhibi- tor of osteoblast activity, in defects. Results: Newly formed bone gradually replaced the autogenous bone grafts within 4 w, although severe bone resorption with osteoclastogenesis and TNF-a expression occurred after 6 w in the absence of IFN-g administration. IFN-g administration markedly attenuated bone loss, osteoclastogenesis, and TNF-a expression, while it enhanced bone formation at 8 w. Conclusion: Local IFN-g administration promoted bone formation in autogenous bone grafts possibly via regulating osteoclastogenesis and TNF-a expression. The data provide insights into the potential roles of IFN-g in autogenous bone grafting.

Purpose: The aim of this study was to reveal whether the differences in further loss of teeth and occlusal supports, and change in masticatory ability depend on the status of dentition at the age of 70 in community-dwelling elderly people. Methods: A 10-year longitudinal survey was carried out on 349 (176 females and 173 males) elderly subjects. The subjects to be analyzed were classified into four groups in accordance with the classifications of Miyachi's Triangular Classification. Zone A: subjects with ten or more occlusal supports. Zone B: those with nine to five occlusal supports. Zone D: those with four or fewer occlusal supports and 11 or more remaining teeth. Zone C: those with ten or fewer remaining teeth. The numbers of remaining teeth and occlusal supports were recorded in both examinations. Questionnaires regarding their food intake status were given to subjects. Results: Subjects in Zone B had greater numbers of teeth loss than those in Zones A and C. Subjects in Zone B and D lost greater numbers of occlusal supports than subjects in Zones A and C. The number of food items that could be chewed had significantly decreased in subjects who remained in Zone A and those who changed from Zone B to Zones D and C. Conclusions: It was shown that various states of dentition classified by Miyachi's Triangular Classification at the age of 70 resulted in different numbers of remaining teeth and occlusal supports and changes in masticatory ability 10 years later in community-dwelling elderly people.

Purpose: The aim of this preliminary study is to compare patient-reported outcomes between immediately and conventionally loaded mandibular two-implant overdentures retained by magnetic attachments. Methods: Nineteen participants with edentulous mandibles were randomly assigned into either an immediate loading group (immediate group) or a conventional loading group (conventional group). Each participant received 2 implants in the inter-foraminal region by means of flapless surgery. Prostheses in the immediate and conventional groups were loaded using magnetic attachments on the same day as implant placement or 3 months after surgery, respectively. All participants completed questionnaires (the Japanese version of the Oral Health Impact Profile for edentulous [OHIP-EDENT-J], the patient's denture assessment [PDA], and general satisfaction) before implant placement (baseline) and 1, 2, 3, 4, 5, 6, and 12 months after surgery. The median differences between baseline and each monthly score were compared using the Mann-Whitney U test. The differences in median and 95% confidence interval between two groups were analyzed. Results: The immediate group showed slightly lower OHIP-EDENT-J summary score at 1 and 3 months than the conventional group (P = 0.09). In the lower denture domain of PDA, the immediate group showed a statistically higher score at 3 months (P = 0.04). There was no statistically significant difference in general satisfaction between the two groups.Conclusions: Based on this preliminary study, immediate loading of mandibular two-implant overdentures with magnetic attachments tends to improve oral health-related quality of life and patient assessment earlier than observed with a conventional loading protocol.

Purpose: The purpose of this study was to assess the survival of mini dental implants (MDI) and to measure prosthetic maintenance needs in a dental practice-based setting. Methods: Patients with mandibular removable dentures were provided with MDI to improve denture retention. Complications and maintenance were analyzed by use of patient records and evaluated with Kaplan-Meier curves and the log rank test at a significance level of 0.05. Results: Ninety-nine MDI were placed in 25 patients (mean age: 72 years). Two MDI fractured during placement and eight implants failed during the first weeks. No more implants were lost for up to seven years, resulting in 92% survival. Implant survival differed significantly depending on whether the maxilla was provided with complete dentures (94.9%) or with partial dentures (81%). All prostheses were in use at the time of data extraction. Denture base fractures were observed in six cases, an incidence of fractures of 24%. Some minor intervention was necessary: one resin tooth fractured, retention rings were changed in five cases, and repeated relining was required for 16% of the dentures. Conclusions: After mid-term observation, survival of MDI was good. However, the incidence of denture base fractures and of minor prosthetic complications should not be under-estimated.

Purpose: A major complication associated with the use of resilient denture liners (RDLs) is a change in hardness over time. In vivo studies on the deterioration of RDLs over time are needed. We aimed to investigate the influence of patient characteristics on the hardness of acrylic-based RDLs (ARDLs) embedded in complete maxillary dentures. We hypothesized that 1 month after application of the ARDLs, the hardness would be influenced by age, saliva condition, occlusal force, smoking, drinking, denture wearing during sleeping, denture cleanser usage, and denture type. Methods: Thirty complete maxillary denture wearers were recruited after obtaining in- formed consent. One investigator measured the Shore D hardness of the commercially available ARDLs, Soften (SFT), FD Soft (FDS), and Bio Liner (BIO) using a Vesmeter¹. The salivary flow rates and pH values and the occlusal force were measured for all patients before initiation of the study. T-tests and Pearson's correlation coefficients were used for the statistical analyses. A p-value of <0.05 was considered statistically significant. Results: Smoking, wearing dentures while sleeping, use of denture cleansers, and denture type were associated with an increase in the hardness of the RDLs. The resting saliva pH only influenced the hardness of the SFT ARDLs. Conclusions: Smoking, denture wearing while sleeping, denture cleanser usage, denture type, and resting saliva pH are important predictors of the deterioration of ARDLs over time.

Purpose: The aim of this study was to compare 3-dimensional surfaces of study and working casts for edentulous jaws and to evaluate the accuracy of preliminary impressions with a view to the future application of digital dentistry for edentulous jaws. Methods: Forty edentulous volunteers were serially recruited. Nine dentists took preliminary and final impressions in a routine clinical work-up. The study and working casts were digitized using a dental 3-dimensional scanner. The two surface images were superimposed through a least-square algorithm using imaging software and compared qualitatively. Furthermore, the surface of each jaw was divided into 6 sections, and the difference between the 2 images was quantitatively evaluated. Results: Overall inspection showed that the difference around residual ridges was small and that around borders were large. The mean differences in the upper and lower jaws were 0.26 mm and 0.45 mm, respectively. The maximum values of the differences showed that the upward change mainly occurred in the anterior residual ridge, and the downward change mainly in the posterior border seal, and the labial and buccal vestibules, whereas every border of final impression was shortened in the lower jaw. The accuracy in all areas except the border, which forms the foundation, was estimated to be less than 0.25 mm. Conclusion: Using digital technology, we here showed the overall and sectional accuracy of the preliminary impression for edentulous jaws. In our clinic, preliminary impressions have been made using an alginate material while ensuring that the requisite impression area was covered.

Patients: Titanium has been considered to be a non-allergenic material. However, several studies have reported cases of metal allergy caused by titanium-containing materials. We describe a 69-year-old male for whom significant pathologic findings around dental implants had never been observed. He exhibited allergic symptoms (eczema) after ortho- pedic surgery. The titanium screws used in the orthopedic surgery that he underwent were removed 1 year later, but the eczema remained. After removal of dental implants, the eczema disappeared completely. Discussion: Titanium is used not only for medical applications such as plastic surgery and/or dental implants, but also for paints, white pigments, photocatalysts, and various types of everyday goods. Most of the usage of titanium is in the form of titanium dioxide. This rapid expansion of titanium-containing products has increased percutaneous and permucosal exposure of titanium to the population. Conclusions: In general, allergic risk of titanium material is smaller than that of other metal materials. However, we suggest that pre-implant patients should be asked about a history of hypersensitivity reactions to metals, and patch testing should be recommended to patients

Purpose: This Technical Procedure describes a novel workflow for a one-step formation of the supra-implant emergence profile in the esthetic zone - the ‘Digitally Flip Technique' (DFT). Methods: After implant placement, a post-operative intra-oral optical scan (IOS) was per- formed to capture the final three-dimensional implant position. Based on the superimposi- tion of the digitally slice-wise DICOM-segmentation of the digitally flipped (mirrored) contra-lateral tooth and the STL-file of the IOS, an individualized healing abutment was CAD/CAM-fabricated out of PMMA-based restoration material in a fully digital workflow and seated at the stage of reopening surgery. One single treatment step was necessary for final modulation of the supra-implant mucosa architecture in order to mimic the morphological emergence profile of the contra-lateral tooth within a short-span time frame of four days after insertion of the individualized healing abutment. Conclusions: The implant crown emergence profile could be shaped immediately after reopen- ing according to the three-dimensional radiographic contour of the digitally flipped contra- lateral tooth. Estimating the emergence profile or time-consuming step-by-step conditioning of the mucosa through an additionally produced implant provisional was therefore avoided.