Optical technology has provided a paradigm shift in implant dentistry. However, there is little information about the use of optical technology in implant dentistry, since this technology is ...relatively new and has been evolving under the current conditions. In the present narrative literature review, the effects of intraoral scanners (IOSs) use on accuracy and the operating time, as well as safety and patient perception, in implant dentistry were evaluated from the clinical perspective. The accuracy of digital scans with IOSs was comparable to the conventional impression techniques for single or partial prostheses, and the digital scans with IOSs are time efficient when taking impressions for single- or double-abutments. However, the accuracy and time efficiency are decreased for multiple implant scans or large-area scans with IOSs use. Patient satisfaction with and preference for IOSs scans are generally superior to those with conventional impression procedures.
Antiresorptive agents such as bisphosphonates and denosumab, as well as angiogenesis inhibitors, may induce medication-related osteonecrosis of the jaw (MRONJ). However, the exact mechanisms of MRONJ ...are unclear and definitive treatment strategies have not yet been developed. Moreover, the aging population requiring antiresorptive agents and angiogenesis inhibitors has been increasing worldwide. Therefore, the aim of this literature review was to introduce the latest information on MRONJ. The epidemiology, triggering factors, risk factors, drug holiday, pathoetiology and treatment strategies for each drug-induced ONJ were investigated by conducting a PubMed search.
The prevalence and incidence of ONJ were very low. Some mechanisms of ONJ have been identified, although they were not definitive. Novel treatment strategies have been proposed in basic and clinical research. Several factors, including age and the administration duration of bisphosphonates, are risks for the development of bisphosphonate-related ONJ (BRONJ). Dental implant therapy and peri-implantitis could become risk factors of BRONJ, regardless of the onset timing of bisphosphonates. No reliable information about ONJ induced by denosumab and angiogenesis inhibitors was found.
Caution should be taken when dental treatment including implant therapy is performed in patients receiving bisphosphonates, denosumab, and angiogenesis inhibitors. There is limited scientific evidence regarding the relationship between MRONJ and older age. Further ONJ-related research on the aging population is required to manage the treatment of such diseases in older people in the future.
Background
Medication-related osteonecrosis of the jaw (MRONJ), which was first reported as bisphosphonate-related osteonecrosis of the jaw (BRONJ) in bisphosphonate users, is a rare but severe soft ...and hard tissue disease induced by several types of medications. There has been a deluge of information about MRONJ, such as epidemiology, risk factors, clinical recommendations for dental treatment to prevent it, and treatment strategies in medication-prescribed users. The aim of this study was to comprehensively review recent articles and provide the current scientific information about MRONJ, especially clinical considerations or recommendations for dental treatment to prevent its occurrence.
Materials and methods
The current literature review was mainly based on 14 systematic reviews with or without meta-analysis, 4 position papers, 1 consensus statement, 1 clinical guideline, and 2 clinical reviews regarding MRONJ after a PubMed database and manual searches according to inclusion and exclusion criteria. Moreover, 53 articles were selected by manual search in regard to all references from selected articles and other articles identified on the PubMed search, irrespective of publication date, and inclusion and exclusion criteria.
Results
The incidence and prevalence of MRONJ are relatively low, although they are clearly higher in cancer patients receiving high-dose antiresorptive agents or angiogenesis inhibitors rather than osteoporosis patients receiving oral bisphosphonates or denosumab. There are many types of local, systemic, and other risk factors for the development of MRONJ. Clinical recommendations are provided for each clinical situation of patients to prevent MRONJ. There are also treatment strategies for MRONJ in each stage.
Conclusions
General dentists should perform appropriate dental treatment to prevent MRONJ in the patients prior to or when receiving medications that could induce MRONJ. Moreover, there are treatment strategies for MRONJ in each stage that oral surgeons could follow. Adequate and updated clinical information regarding MRONJ based on scientific data is required whenever possible.
The pathophysiology, histopathology, and immunopathology of bisphosphonate-related osteonecrosis of the jaw (BRONJ)
Stage 0
remain unclear. The aim of this study was to investigate the effects of ...high-dose bisphosphonates on tooth extraction socket healing by creating a murine model of BRONJ
Stage 0
-like lesions using 8-week-old female C57BL/6J mice. Zoledronic acid (Zol) was administered subcutaneously twice a week for 7 weeks at doses of 0.1 mg/kg/week (moderate dose; Zol-M), 0.5 mg/kg/week (high dose; Zol-H1), and 1.0 mg/kg/week (higher dose; Zol-H2). Saline was used as a control (VC). Both maxillary first molars were extracted 3 weeks after drug treatment. Maxillae, long bones, and sera were collected 4 weeks post-extraction (
n
= 7 mice/group). Microcomputed tomography, histological, immunohistochemical, and ELISA analyses were performed. A ceiling effect for Zol was noted at the Zol-H1 dose. Osseous healing of extraction sites was significantly impaired with increased necrotic bone and the number of empty lacunae in a Zol dose-dependent manner. Zol significantly decreased epithelial thickness, due to a decrease in thickness of the stratum spinosum, in both Zol-H1 and Zol-H2. Both Zol-H1 and Zol-H2 significantly suppressed the distribution of F4/80
+
macrophages in the connective tissue of tooth extraction sockets, although gross healing appeared to be normal. Intriguingly, both Zol-H1 and Zol-H2 significantly increased the numbers of TRAP
+
mononuclear cells and detached osteoclasts in the connective tissue and bone marrow of extraction sites compared to VC and Zol-M, correlated with serum TRAcP5b levels. The created murine model of BRONJ
Stage 0
-like lesions becoming more severe in a dose-dependent manner may help to understand the pathophysiology and histopathology of BRONJ
Stage 0
in humans.
Dental implant treatment in patients prescribed medications is associated with bisphosphonate-related osteonecrosis of the jaw (BRONJ) around the implants. However, there is no scientific information ...on how bisphosphonate and/or steroid therapies affect wound healing around implants after implant placement. The aim of this study was to histopathologically and immunopathologically investigate the effects of bisphosphonate and/or steroid therapy on the early stages of soft and hard tissue wound healing around implants in rat maxillae. Eight-week-old female Wistar rats were used. Alendronate (ALN) monotherapy, dexamethasone (DEX) monotherapy, and ALN/DEX combination therapy were started 4 weeks after tooth extraction of right maxillary first molars. Saline was used as a control (n = 14/group). Implant placement was carried out after grossly and manually confirming no open wounds at 16 weeks post-extraction. Euthanasia was performed at 18 weeks post-extraction. Microcomputed tomography, histological stains and immunostaining to detect blood vessels and macrophages were performed to quantitatively analyze wound healing around implants. ALN/DEX combination therapy significantly increased necrotic bone with more empty lacunae and polymorphonuclear cell infiltration with open wounds when compared with all other therapy groups. Necrotic bone was broadly distributed from the crestal bone to the lower area near the apex of the implants in the ALN/DEX group. Interestingly, both ALN/DEX combination therapy and DEX monotherapy significantly increased the number of CD68
NG2
macrophages, whereas only ALN/DEX combination therapy, not DEX monotherapy, significantly shifted the M1/M2 ratio to M1 by significant increases in M1 macrophages and unchanged M2 macrophages in the connective tissue around implants. Within the limitations of this study, these findings may contribute to understanding the early stages of the histopathology and immunopathology of BRONJ-like lesions around dental implants. Continuous accumulation of M1 macrophages without alteration of M2 macrophages may be associated with developing BRONJ around implants.
Objectives
This study aimed to investigate the effects of early loads on bone quality and quantity around implants and to compare the effects of early loads on bone quality and quantity with the ...effects of conventional loads.
Materials and Methods
Grade IV‐titanium implants with buttress threads were placed in rat maxillary bone 4 weeks after extraction of first molars. A controlled mechanical load (10 N, 3 Hz, 1800 cycles, 2 days/week) was started via the implants 1 and 3 weeks after implant placement for 2 weeks (early and conventional loads, respectively). Bone quality, defined as distribution of bone cells, types and orientation of collagen fibers, and production of semaphorin3A, its receptor neuropilin‐1, and sclerostin, were quantitatively evaluated.
Results
Early loads substantially and positively affected bone quality by changing the preferential alignment of collagen fibers with increased production of type I and III collagens, semaphorin3A, and neuropilin‐1, increased osteoblast numbers, decreased production of sclerostin, and decreased osteoclast numbers both inside and outside the implant threads, when compared with non‐loaded conditions. Conventional loads changed bone quality around implants slightly. Interestingly, early loads had significantly stronger effects on bone quality and quantity based on the evaluation parameters than conventional loads.
Conclusions
This is the first report to provide scientific evidence for load initiation time based on both bone quality and quantity around implants. These new findings show that implants with buttress threads transmitted early loads optimally to bone tissue by improving bone quality and quantity inside and outside the implant threads.
Bisphosphonate-related osteonecrosis of the jaw (BRONJ) worsens oral health-related quality of life. Most BRONJ occurs in multiple myeloma or metastatic breast cancer patients treated with ...bisphosphonate/chemotherapeutic combination therapies. Cyclophosphamide (CY), an alkylating chemotherapeutic drug, is used to treat multiple myeloma, although its use has been recently reduced. The aim of this study was to clarify the effects of CY dose on tooth extraction socket healing when CY is used with or without bisphosphonate in mice. Low-dose CY (50 mg/kg; CY-L), moderate-dose CY (100 mg/kg; CY-M), high-dose CY (150 mg/kg; CY-H), and bisphosphonate Zometa (ZA): 0.05 mg/kg were administered for 7 weeks. Each dose of CY and ZA in combination was also administered for 7 weeks. Both maxillary first molars were extracted at 3 weeks after the initiation of drug administration. Euthanasia was performed at 4 weeks post-extraction. Gross wound healing, microcomputed tomography analysis, histomorphometry, and immunohistochemistry were used to quantitatively evaluate osseous and soft tissue wound healing of tooth extraction sockets. ZA monotherapy induced no BRONJ-like lesions in mice. CY monotherapy rarely induced open wounds, though delayed osseous wound healing occurred in a CY dose-dependent manner. In contrast, CY/ZA combination therapy prevalently induced BRONJ-like lesions with compromised osseous and soft tissue healing in a CY dose-dependent manner. Interestingly, anti-angiogenesis was noted regardless of CY dose and ZA administration, even though only CY-M/ZA and CY-H/ZA combination therapies induced BRONJ-like lesions. Our findings suggest that high-dose CY may be associated with the development of BRONJ following tooth extraction only when CY is used together with ZA. In addition to anti-angiogenesis, other factors may contribute to the pathoetiology of BRONJ.
•Impaired tooth socket healing rarely occurred with cyclophosphamide (CY) monotherapy.•Bisphosphonate (ZA) monotherapy did not induce BRONJ-like lesions in mice.•High-dose CY in combination with ZA and tooth extraction induced BRONJ-like lesions in mice.•BRONJ-like lesions prevalently increased in a CY dose-dependent manner.
The purpose of the present study was to evaluate the wear of four different ceramics and human enamel. The ceramics used were lithium disilicate glass (e.max Press), leucite‐reinforced glass ...(GN‐Ceram), yttria‐stabilized zirconia (Aadva Zr), and feldspathic porcelain (Porcelain AAA). Hemispherical styli were fabricated with these ceramics and with tooth enamel. Flattened enamel was used for antagonistic specimens. After 100,000 wear cycles of a two‐body wear test, the height and volume losses of the styli and enamel antagonists were determined. The mean and standard deviation for eight specimens were calculated and statistically analyzed using a non‐parametric (Steel–Dwass) test (α = 0.05). GN‐Ceram exhibited greater stylus height and volume losses than did Porcelain AAA. E.max Press, Porcelain AAA, and enamel styli showed no significant differences, and Aadva Zr exhibited the smallest stylus height and volume losses. The wear of the enamel antagonist was not significantly different among GN‐Ceram, e.max Press, Porcelain AAA, and enamel styli. Aadva Zr resulted in significantly lower wear values of the enamel antagonist than did GN‐Ceram, Porcelain AAA, and enamel styli. In conclusion, leucite‐reinforced glass, lithium disilicate glass, and feldspathic porcelain showed wear values closer to those for human enamel than did yttria‐stabilized zirconia.
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The aim of this systematic review and meta-analysis was to evaluate the effect of surface conditioning methods on the bond strength of industrial indirect composite blocks (ICs).
...Based on the PICOS strategy, the Medline via PubMed, Embase and Web of Science (ISI – Web of Knowledge) electronic databases were searched for peer-reviewed articles in both English and Chinese, with no publication year limit. In vitro studies evaluating the effects of surface conditioning on the bond strength of ICs were selected. The meta-analysis was conducted to calculate the mean difference between surface-conditioned ICs and unconditioned controls. Subgroup analysis was performed to evaluate the different surface conditioning methods, separately for polymer-infiltrated ceramic network (PICN) material and the ICs with dispersed fillers (ICDFs). Meta-analyses were performed with a random-effects model at a significance level of 0.05.
From 802 relevant studies, 25 were selected for full-text analysis. Nineteen studies were eligible for inclusion in this systematic review, whereas 9 studies were included in the meta-analysis. A manual search of the principal periodicals specific to the area resulted in no additional articles. The meta-analysis indicated a significant difference in bond strength between the surface-conditioned ICs and controls under both non-aged and aged conditions. The combination of mechanical and chemical conditioning yielded the highest bond strength of ICs. This meta-analysis suggests that chemical etching followed by a universal primer and alumina air abrasion followed by a silane coupling agent could be considered the best strategy for optimizing the bond strength of PICN materials and ICDFs under aged conditions, respectively.
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