Clinical Evaluation of the Relationship Between Systemic Disease and the Time of Onset of Peri-Implantitis: A Retrospective Cohort Study.

The role of systemic diseases in the development and progression of peri-implantitis remains unclear and requires discussion from various perspectives. This retrospective cohort study aimed to evaluate whether the type of systemic disease affects the onset time of peri-implantitis. The cohort consisted of patients who underwent implant maintenance evaluations between January 1998 and June 2020. Information on age, sex, history of periodontal disease, smoking habits, body mass index, systemic diseases, implant placement sites, and diagnosis of peri-implantitis were obtained. The relationships between the time of onset of peri-implantitis and the medical history of systemic diseases were determined statistically by applying the Kaplan-Meier analysis method and log-rank test. A total of 216 implants in 89 patients (34 male and 55 female) were included in this study. The average patient age was 53.9 ± 11.8 years at the first visit, and the mean duration of maintenance was 7 years and 4 months. A total of 43 patients had medical histories and were assigned to the systemic disease group. In this group, the overall prevalence of peri-implantitis was 25.4% (29 of 114 implants). The medical history of systemic diseases (odds ratio [OR], 6.87; 95% confidence interval [CI], 2.37-19.9) and dental history of periodontitis (OR, 3.64; 95% CI, 1.25-10.6) were assessed as risk factors for peri-implantitis. A significant difference in the time of onset of peri-implantitis was confirmed between patients with systemic disease and healthy patients. Diabetes mellitus, osteoporosis, and hypertension had a significant impact on the earlier onset of peri-implantitis.

Medication-Related Osteonecrosis of the Jaw Subsequent to Peri-Implantitis: A Case Report and Literature Review.

The aim of this report was to document a rare case of medication-related osteonecrosis of the jaw (MRONJ) that developed around the already osseointegrated implants in the maxillary right molar region. A 73-year-old woman presented at our university dental hospital in May 2017 with a chief complaint of discomfort near a maxillary implant. Her first visit was in 2006, and the maintenance treatment began in 2007 after the periodontal treatment. During the implant maintenance period there were no complications; however, the patient began taking alendronate sodium hydrate (Fosamac tablets, 35 mg, once weekly), an oral bisphosphonate (BP) since 2013, for treatment of osteoporosis. Eight years after starting implant maintenance, in 2016, peri-implantitis occurred, for which mechanical cleaning and antimicrobial therapy were performed. Peri-implantitis symptoms disappeared, and the medical condition improved. Nonetheless, in 2017, MRONJ developed 4 years after she commenced taking the BP. The patient underwent implant removal and sequestrectomy. There was no postoperative recurrence. Since it was such a rare case, we performed a literature review but only discovered a few similar cases. Because various triggers may lead to the development of MRONJ, even if already osseointegrated implant, it is important to note that implants in patients taking BPs should be more carefully maintained.

Prevalence and distribution of anomalies of permanent dentition in 9584 Japanese high school students.

This study investigated the prevalence and distribution of anomalies of permanent dentition in the current Japanese population by examining an unbiased sample. We conducted a survey of dental anomalies by mass dental screening at eight high schools in 2012. Participants were all students with permanent dentition. Dental anomalies were classified as hypodontia, supernumerary teeth, peg-shaped teeth, fused teeth, and talon cusps. Students with one or more dental anomalies on oral examination were given a differential diagnosis by three specialists. The final sample comprised 9584 participants (5062 boys, 4522 girls). Hypodontia was present in 372 students (3.88 %) with no significant sex difference (191 boys, 181 girls). Frequent sites were the right or left mandibular second premolar, right or left maxillary second premolar, and right or left maxillary lateral incisor. Supernumerary teeth were observed in three boys (0.06 %) and one girl (0.02 %). Peg-shaped teeth were observed in 74 students (0.77 %; 27 boys, 47 girls), differing significantly between sexes; they were most prevalent among maxillary lateral incisors. Of affected students, 18 students (0.19 %) also had hypodontia (3 boys, 15 girls). Fused teeth were present in two boys (0.04 %) and three girls (0.07 %) (gemination in one boy and fusion in the remaining four students). Sites were limited to maxillary and mandibular central and lateral incisors. Talon cusps were observed in two boys (0.04 %) and four girls (0.09 %). The present survey of a large unbiased sample can be considered to reflect the prevalence and distribution of anomalies of permanent dentition in the current Japanese population.

Use of ceria-stabilized zirconia/alumina nanocomposite for fabricating the frameworks of removable dental prostheses: A clinical report.

Ceria-stabilized zirconia/alumina nanocomposite (Ce-TZP/A) exhibits an elasticity equivalent to that of cobalt-chromium alloy and a flexural property that is superior to that of yttria-tetragonal zirconia polycrystal. Therefore, the use of Ce-TZP/A for the fabrication of removable dental prosthesis frameworks is being studied. However, the current English literature does not include any clinical report on the use of Ce-TZP/A for the fabrication of the entire framework. This clinical report describes the process and outcomes of fabricating a mandibular implant-supported overdenture and a maxillary complete denture with Ce-TZP/A as the framework material.

External versus internal abutment connection implants: a survey of opinions and decision making among experienced implant dentists in Japan.

Internal connection implants have been attracting attention in recent years leading to their being adopted for many implant systems and an increase in market share over other connections. However, internal connection implants have only been used clinically for a short period of time resulting in few clinical studies investigating outcomes and a lack of comparative clinical evidence to support their use over external hex systems at this time. Given the fact that clinical evidence is lacking regarding implant connection performance comparisons, it is important to understand what information clinicians use to choose between systems. The purpose of this study regarding implant decision-making was to ask clinicians to provide subjective evaluations of internal connection implants, in comparison with external connection implants. The survey was constructed to cover four aspects of interest; general responder information, surgical procedures and experience, prosthodontic treatments and outcomes, and implant complications. The dentists' responses indicated that internal connection implants are as user-friendly as external hex implants with respect to implant surgery, but they are favored for prosthodontic handling because impression coping and abutment placement are felt to be easier. In addition, it was revealed that dentists strongly feel that there is a lack of biological and prosthodontic evidence to support the use of internal connection implants. The findings reveal the responding clinicians recognize that they often make decisions without compelling evidence to favor one system over another. Decisions are often based on perceived ease of use or third party (colleague or manufacturer) input. For future investigations, we will seek to better understand the relative influence and validity of all forms of information used (especially third party input), as well as what barriers exist to clinicians' use of more evidence based data.

Repair of a multiple implant-supported fixed superstructure with a metal-ceramic resin-bonded fixed partial denture: a clinical report.

Even in the case of implant loss, replacement of the implant and refabrication of the superstructure are often sufficient, as long as the bone and soft tissue are in good condition. However, if implant loss accompanied by serious bone resorption occurs with a fixed implant superstructure supported by multiple implants, it is very difficult to treat. This clinical report describes the process by which multiple implant-supported fixed metal ceramic restorations were repaired with a metal ceramic resin-bonded fixed partial denture without complete refabrication after removal of one of the implants due to severe bone resorption. The 3-year follow-up indicated excellent serviceability and a well-satisfied patient.

Dental implant status in elderly individuals requiring domiciliary dental care in Japan.

BACKGROUND: The presence of implants is a significant burden not only for dentists but also for caregivers and families of elderly individuals requiring nursing and domiciliary dental care. However, few reports have assessed the status of domiciliary dental care or measures employed to deal with related issues. Hence, we aimed to evaluate the dental implant status in elderly patients requiring nursing and domiciliary dental care and to determine the suitable measures for overcoming the associated limitations. A questionnaire was mailed to 1000 dentists who provided domiciliary dental care in the Tokyo metropolitan area of Japan. The questions were classified into three categories: basic information of the dentists, actual implant status of patients requiring domiciliary dental care, and implants in an aging society. RESULTS: The response rate was 36.5%. Approximately 2% of patients requiring domiciliary dental care were implant patients. Many implant-related problems were associated with insufficiency or difficulty in cleaning around the implant, resulting in peri-implantitis. Prosthetic and more serious complications such as implant body fracture or loss were reported and frequently managed by routine follow-ups, cleaning the area around the implant, scaling and polishing, and/or pharmacological modalities. Oral care mainly involved simple toothbrushing instructions, which was not adequate. CONCLUSIONS: Our findings suggest the necessity of simplifying the oral environment and making oral care a simple task before aging individuals require nursing and domiciliary dental care.

Influence of antihypertensive medications on the clinical parameters of anodized dental implants: a retrospective cohort study.

BACKGROUND: Hypertension is a chronic medical condition in which blood pressure in the arteries is elevated. Given the large proportion of dental implant patients using antihypertensive medications, it is crucial to evaluate the effects of these drugs on the clinical parameters of osseointegrated implants. The aim of the present retrospective cohort study was to evaluate the influence of antihypertensive medications on clinical peri-implant tissue parameters. METHODS: Thirty-five patients received a total of 77 anodized dental implants. Based on the history of the use of antihypertensive medications, the patients were divided into two groups: the group taking antihypertensive medications (AH group) and the group of healthy patients (H group). Implants were followed up clinically and radiologically, with a focus on the peri-implant soft tissue parameters probing pocket depth, bleeding on probing, modified plaque index, and marginal peri-implant bone level stability. RESULTS: None of the implants were lost, and no technical failures occurred. The mean follow-up duration was 7 years and 1 month. A significant difference was observed in the probing pocket depth 3.8 ± 1.3 mm in the AH group and 3.0 ± 0.7 mm in the H group. In the AH and H groups, 26.5% (9/34) and 4.7% (2/43) of the patients were diagnosed with peri-implantitis at the implant level, respectively. CONCLUSIONS: Our findings suggest some correlations between antihypertensive medication use and clinical parameters in anodized peri-implant tissue.

Influence of lateral-oblique cyclic loading on abutment screw loosening of internal and external hexagon implants.

To date, there is no evidence that internal anti-rotation configurations are better than external ones. The purpose of this study was to evaluate the effect of eccentric cyclic loading on abutment screw loosening in internal and external hexagon implants with either of these two screw materials, titanium (Ti) alloy versus gold alloy. The reverse torque value of the abutment screw was measured before (initial preload) and after loading (post-loading). The prepared assemblies were divided into four groups (A to D). Groups A and B used internal hex implants with gold alloy and Ti alloy abutment screws respectively. Groups C and D used external hex implants with gold alloy and Ti alloy abutment screws respectively. In all the groups, post-loading preload was significantly (p<0.05) higher than initial preload. Further, two-way ANOVA indicated that the implant-abutment connection did not have an effect, but the abutment screw material did. In particular, Ti abutment screws were less likely to come loose.

Implant Treatment with 12-Year Follow-Up in a Patient with Severe Chronic Periodontitis: A Case Report and Literature Review.

Tooth loss among adults is associated with progressive periodontitis. Implant prosthetic treatment has long been utilized in periodontal patients. Even when the implants are applied, ongoing management of periodontal disease and control of inflammation is necessary to maintain a healthy oral cavity. Lack of appropriate periodontal treatment can result in recurrence of periodontal disease during a maintenance period; loss of the supportive capacity of the periodontal tissues will increase the susceptibility of residual teeth to traumatic force. For this reason, it is worthwhile to improve oral function by applying implants as a fixed device. Here, we report that implant treatment in a patient with generalized severe chronic periodontitis helped maintain the periodontal and peri-implant tissue for a long term. We propose that initial periodontal treatment and ongoing supportive therapy can help maintain implants in patients with severe periodontitis. In addition, we reviewed case reports in the English literature so far.

Ceria-Stabilized Zirconia/Alumina Nanocomposite for Fabricating the Framework of Removable Dental Prostheses: Preliminary Results from a 4-Year Follow-up.

PURPOSE: To clinically evaluate the use of ceria-stabilized zirconia/alumina nanocomposite (Ce-TZP/A) for the frameworks of removable dental prostheses (RDPs). MATERIALS AND METHODS: A total of 20 Ce-TZP/A RDPs (10 complete dentures and 10 implant-supported overdentures) were used in 16 patients, and the presence/absence of complications and patient complaints were evaluated. RESULTS: The survival rate of the RDPs during a mean follow-up period of 55.6 months was 100%, with no major complications. CONCLUSION: The patients experienced uneventful courses functionally and esthetically. In addition, there was no incidence of breakage or repair related to the Ce-TZP/A frameworks.

Marginal fit and microgaps of implant-abutment interface with internal anti-rotation configuration.

To date, there is no evidence that internal anti-rotation configurations are better than external ones. As part of a study to clarify the features and advantages of internal anti-rotation configurations, the objective of the present investigation was to compare and evaluate the marginal fit and size of microgap at the implant-abutment interface for several external and internal anti-rotation configurations. To this end, three internal connection and two external hex connection implant-abutment assemblies were examined in this study. The implant-abutment interface (I-A interface) was evaluated using three geometrical factors: vertical and horizontal discrepancies and size of microgap. Marginal fit and microgap size were measured by a scanning laser microscope. The I-A interface was also observed using a scanning electron microscope. Mean vertical discrepancy ranged from 22.6 to 62.2 microm, while horizontal discrepancy ranged from -27.1 to 16.0 microm. The microgap values of all I-A interfaces assessed in this study ranged from 2.3 to 5.6 microm. In conclusion, SEM images of I-A interface suggested no relationship between the geometrical factors and the type of anti-rotation configuration.

Reliability and validity of the patient disability-oriented diagnostic nomenclature system for prosthetic dentistry.

PURPOSE: The Japan Prosthodontic Society (JPS) has proposed a new diagnostic nomenclature system (DNS), based on pathogenesis and etiology, to facilitate and improve prosthodontic treatment. This system specifies patient disability and the causative factor (i.e. "B (disability) caused by A (causative factor)"). The purpose of this study was to examine the reliability and validity of this DNS. STUDY SELECTION: The JPS Clinical Guideline Committee assessed mock patient charts and formulated disease names using the new DNS. Fifty validators, comprising prosthodontic specialists and dental residents, made diagnoses using the same patient charts. Reliability was evaluated as the consistency of the disease names among the validators, and validity was evaluated using the concordance rate of the disease names with the reference disease names. RESULTS: Krippendorff's α was 0.378 among all validators, 0.370 among prosthodontic specialists, and 0.401 among dental hospital residents. Krippendorff's α for 10 validators (3 specialists and 7 residents) with higher concordance rates was 0.524. Two validators (1 specialist and 1 resident) with the highest concordance rates had a Krippendorff's α of 0.648. Common disease names had higher concordance rates, while uncommon disease names showed lower concordance rates. These rates did not show correlation with clinical experience of the validator or time taken to devise the disease name. CONCLUSIONS: High reliability was not found among all validators; however, validators with higher concordance rates showed better reliability. Furthermore, common disease names had higher concordance rates. These findings indicate that the new DNS for prosthodontic dentistry exhibits clinically acceptable reliability and validity.

Enhancement of antitumor effect of doxorubicin by its complexation with gamma-cyclodextrin in pegylated liposomes.

In the present study, we examined tissue distribution and the antitumor effect of doxorubicin (DOX) after intravenous injection of the pegylated liposomes entrapping the DOX complex with gamma-cyclodextrin (gamma-CyD) (complex-in-liposome) in BALB/c mice bearing colon-26 tumor cells, compared with those of DOX solution, pegylated liposomes entrapping DOX alone (DOX-in-liposome), pegylated liposomes entrapping gamma-CyD (CyD-in-liposome) and the binary system of DOX-in-liposome and CyD-in-liposome. When injected to the mice, complex-in-liposome provided the high DOX levels in plasma and solid tumors, compared with the other preparations. Reflecting the result, complex-in-liposome elicited the retardation of tumor growth and the improvement of survival rate without suppression of increase in the body weight of mice. These results suggest the potential use of pegylated liposomes entrapping the DOX complex with gamma-CyD for a promising carrier for improvement of antitumor effects of DOX.

Application of Ce-TZP/Al2O3 nanocomposite to the framework of an implant-fixed complete dental prosthesis and a complete denture.

PATIENT: A 69-year-old Japanese male visited Nihon University Dental Hospital for refabrication of his mandibular implant-supported complete fixed prosthesis (ISCFPD) and maxillary complete denture, which had been fabricated 15 years previously. In this case, Ce-TZP/Al2O3 nanocomposite (Ce-TZP/A) was applied to the framework of the mandibular ISCFPD and maxillary complete denture. Three years after deliver of the framework, no particularly notable biological or prosthetic complications were observed, and a high level of patient satisfaction had been achieved. DISCUSSION: Conventional ISCFPD frameworks were fabricated by casting gold alloys; however, with the recent advancement of CAD/CAM technology, titanium (Ti) or yttria tetragonal zirconia polycrystal (Y-TZP) frameworks have become more common. In contrast, the main fabrication method for Ti or Co-Cr frameworks of removable dental prostheses has shifted from the conventional casting method to CAD/CAM fabrication. Ce-TZP/A, which was chosen as the framework material this time, shows higher strength and greater toughness than Y-TZP. However, since it has a low light-transmitting property and exhibits an opaque white color, the range of its application in fixed prostheses, particularly in the esthetic area, is limited. CONCLUSION: We described a case in which Ce-TZP/A was applied to the frameworks of a mandibular ISCFPD and a maxillary complete denture. No particularly notable biological or prosthetic complications were observed in the mandibular ISCFPD or the maxillary complete denture, and a high level of patient satisfaction was achieved. Medium- and long-term observations with a greater number of cases are essential to obtain information concerning various phenomena related to this procedure.

Enhancement of Orthodontic Anchor Screw Stability Under Immediate Loading by Ultraviolet Photofunctionalization Technology.

PURPOSE: Ultraviolet (UV)-mediated photofunctionalization technology is intended to enhance the osseointegration capability of titanium implants. There are concerns about orthodontic anchor screws loosening under immediate loading protocols in adolescent orthodontic treatment. The purpose of this in vivo study was to evaluate the effects of photofunctionalization on the intrabony stability of orthodontic titanium anchor screws and bone-anchor screw contact under immediate loading in growing rats. MATERIALS AND METHODS: Custom-made titanium anchor screws (1.4 mm in diameter and 4.0 mm in length) with or without photofunctionalization pretreatment were placed on the proximal epiphysis of the tibial bone in 6-week-old male Sprague-Dawley rats and were loaded immediately after placement. After 2 weeks of loading, the stability of the anchor screws was evaluated using a Periotest device, and the bone-anchor screw contact ratio (BSC) was assessed by a histomorphometric analysis using field-emission scanning electron microscopy. RESULTS: In the unloaded group, Periotest values (PTVs) were ~25 for UV-untreated screws and 13 for UVtreated screws (P < .01), while in the immediate-loading group, PTVs were 28 for UV-untreated screws and 16 for UV-treated screws (P < .05). Significantly less screw mobility was observed in both UV-treated groups regardless of the loading protocol. The BSC was increased ~1.8 fold for UV-treated screws, compared with UV-untreated screws, regardless of the loading protocol. CONCLUSION: Photofunctionalization enhanced the intrabony stability of orthodontic anchor screws under immediate loading in growing rats by increasing bone-anchor screw contact.

Bone Generation Profiling Around Photofunctionalized Titanium Mesh.

PURPOSE: The aim of this study was to evaluate whether photofunctionalization of titanium mesh enhances its osteoconductive capability. MATERIALS AND METHODS: The titanium mesh (0.2 mm thickness) used in this study was made of commercially pure grade-2 titanium and had hexagonal apertures (2 mm width). Photofunctionalization was performed by treating titanium mesh with UV light for 12 minutes using a photo device immediately before use. Untreated or photofunctionalized titanium mesh was placed into rat femurs, and bone generation around titanium mesh was profiled using three-dimensional (3D) microcomputed tomography (micro-CT). A set of in vitro experiments was conducted using bone marrow-derived osteoblasts. RESULTS: Photofunctionalized titanium mesh surfaces were characterized by the regenerated hydrophilicity and significantly reduced surface carbon. Bone generation profiling at week 3 of healing showed that the hexagonal apertures in photofunctionalized mesh were 95% filled, but they were only 57% filled in untreated mesh, particularly with the center zone remaining as a gap. Bone profiling in slices parallel to the titanium surface showed that photofunctionalized titanium mesh achieved 90% bone occupancy 0 to 400 µm from the surface, compared with only 35% for untreated mesh. Bone occupancy remained as high as 55% 800 to 1,200 µm from photofunctionalized titanium mesh surfaces, compared with less than 20% for untreated mesh. In vitro, photofunctionalized titanium mesh expedited and enhanced attachment and spread of osteoblasts, and increased ALP activity and the rate of mineralization. CONCLUSION: This study may provide novel and advanced metrics describing the osteoconductive property of photofunctionalized titanium mesh. Specifically, photofunctionalization not only increased the breadth, but also the 3D range, of osteoconductivity of titanium mesh, enabling space-filling and far-reaching osteoconductivity. Further translational and clinical studies are warranted to establish photofunctionalized titanium mesh as a novel clinical tool for better bone regeneration and augmentation.

Dental implant status of patients receiving long-term nursing care in Japan.

BACKGROUND: The increase in implant patients is expected to give rise to a new problem: the changing general health status of those who have had implants placed. PURPOSE: The aim of this present study was to find out the needs of and proper measures for elderly implant patients in long-term care facilities. MATERIALS AND METHODS: A questionnaire was sent by mail to 1,591 long-term care health facilities, daycare services for people with dementia, and private nursing homes for the elderly in the Osaka area, which is in the middle area of Japan, in order to extract patients with cerebrovascular disease or dementia who were possibly at risk of inadequate oral self-care, as well as patients with implants. RESULTS: Approximately half of all facilities responded that they cannot recognize implants, and many facilities did not know anything about oral care for implant patients. Residents with implants were reported at 19% of all facilities. Also, the facilities pointed out problems with implants relating to the difference in oral care between implants and natural teeth. CONCLUSIONS: There are people with implants in some 20% of caregiving facilities, and there is a low level of understanding regarding implants and their care among nurses and care providers who are providing daily oral care.

Current status of implant prosthetics in Japan: a survey among certified dental lab technicians.

BACKGROUND: There are many implant cases in which dental technicians take initiative with regard to the design of implant prostheses, and to a certain extent, this area of care is one in which dentists do not necessarily play the leading role. Moreover, inadequate communication between dental technicians and dentists and insufficient instructions for technicians has been highlighted as issues in the past. The purpose of this questionnaire is to improve the quality of implant prostheses and thereby contribute to patient service by clarifying, among other aspects of treatment, problem areas and considerations in the fabrication of implant prostheses, conceptual-level knowledge, and awareness of prosthodontics on the part of the dentists in charge of treatment and methods for preventing prosthetic complications. METHODS: A cross-sectional survey was given to 120 certified dental technicians. To facilitate coverage of a broad range of topics, we classified the survey content into the following four categories and included detailed questions for (1) the conditions under which implant technicians work, (2) implant fixed prostheses, (3) implant overdentures, and (4) prosthetic complications. RESULTS: Out of 120 surveys sent, 74 technicians responded resulting in a response rate of 61.6%. CONCLUSIONS: This survey served to clarify the current state of implant prosthodontics, issues, and considerations in the fabrication of implant prostheses, and the state of prosthetic complications and preventive initiatives, all from a laboratory perspective. The results of this survey suggested that, to fabricate prostheses with a high level of predictability, functional utility, and aesthetic satisfaction, it is necessary to reaffirm the importance for dentists to increase their prosthetic knowledge and work together with dental technicians to develop comprehensive treatment plans, implement an organized approach to prosthesis design, and accomplish occlusal reconstruction.