Group 3 ITI Consensus Report: Materials and antiresorptive drug-associated outcomes in implant dentistry.

OBJECTIVES: The aim of Working Group 3 was to address the influence of both material- and anti-resorptive drug- related factors on clinical and biological outcomes and complications in implant dentistry. Focused questions were addressed on (a) implant materials other than titanium (alloy)s, (b) transmucosal abutment materials and (c) medications affecting bone metabolism were addressed. MATERIALS AND METHODS: Three systematic reviews formed the basis for discussion in Group 3. Consensus statements and clinical recommendations were formulated by group consensus based on the findings of the systematic reviews. Patient perspectives and recommendations for future research were also conveyed. These were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Zirconia is a valid alternative to titanium as material for implant and transmucosal components, allowing soft and hard tissue integration with clinical outcomes-identified by implant survival, marginal bone loss and peri-implant probing depths-up to 5-years comparable to titatnium. However, most of the evidence for zirconia implants is based on 1-piece implants limiting the indication range. Furthermore, based on expert opinion, zirconia transmucosal components might be preferred in the esthetic zone. In patients receiving low-dose bisphosphonate therapy, the rate of early implant failure is not increased, while the long-term effects remain poorly studied. Although it has not been sufficiently addressed, similar outcomes can be expected with low-dose denosumab. A drug holiday is not recommended when considering implant placement in patients treated with low-dose ARD. However, the specific therapeutic window, the cumulative dose and the administration time should be considered. Access to peri-implant supportive care is mandatory to prevent peri-implantitis-related medication-related osteonecrosis of the jaw (MRONJ) or implant-related sequestra (IRS). In patients receiving low-dose anti-resorptive drugs (ARD) therapy, the risk of complications related to implant placement is high, and implant procedures in this specific population should be strictly treated in a comprehensive multidisciplinary center. Finally, healthy dental implants should not be removed before low or high-dose ARD. CONCLUSIONS: Zirconia implants can be an alternative to titanium implants in selected indications. However, the current state of evidence remains limited, especially for 2-piece implant designs. Administration of low-dose ARD did not show any negative impact on early implant outcomes, but careful follow-up and supportive care is recommended in order to prevent peri-implant MRONJ and IRS. Implant placement in high-dose patients must be strictly considered in a comprehensive multidisciplinary center.

A 3D printing replication technique for fabricating digital dentures.

Digitally fabricated dentures allow clinicians to provide new prostheses for edentulous patients in an efficient manner. One approach uses a replication technique where a prosthesis in need of minor alterations is used as a basis for the definitive prosthesis. Compared with conventional duplication techniques, this method allows for the predictable fabrication of accurate dentures in less time and with increased quality. In this clinical report, interim treatment dentures were scanned and 3D printed to make a replication denture for fabrication of a digital prosthesis with the replication technique.

A comparative study of the effects of 4-META/MMA-TBB resin and cyanoacrylate on wound healing of skin defects.

The purpose of this study was to investigate the healing process of wounded skin following the application of cyanoacrylate or a 4-(2-methacryloxyethyl) trimellitic anhydride/methyl methacrylate-tributylborane resin (4-META resin). Those materials were applied to skin wound areas in rats, and the regenerating tissues were biopsied and examined at days 1, 3, 5, 7, and 14. Paraffin-embedded specimens were sectioned and stained with hematoxylin and eosin or with Azan-Mallory stain. Sections were also immunohistochemically stained with Pan-cytokeratin and CD68 antibodies. In cyanoacrylate-treated wounds, CD68-positive cells were observed in the connective tissue and their number increased up to day 5. The wound surface was completely covered by epithelial tissue at day 14. In 4-META resin-treated wounds, CD68-positive cells appeared in the soft-tissue hybrid layer (STHL) and epithelial tissue had migrated under the STHL by day 5. The wound surface was completely covered by epithelial tissue at day 7. CD68-positive cells were distributed over the entire area of the cyanoacrylate-treated wounds, but accumulated under the STHL in the 4-META resin-treated wounds. In conclusion, the results suggest that covering skin defects with a 4-META resin is an effective strategy to promote wound healing compared to cyanoacrylate.

The Effect of Concentrated Growth Factor on Rat Bone Marrow Cells In Vitro and on Calvarial Bone Healing In Vivo.

PURPOSE: Concentrated growth factor (CGF) is an autologous leukocyte- and platelet-rich fibrin biomaterial that has recently been used for bone healing therapy. Previous studies used fibrin membrane or CGF extract without fibrin without soluble factors in vitro. This study investigated the effects of CGF that contained soluble factors on cultured rat bone marrow (RBM) cells in vitro. Furthermore, the effects of CGF implanted in rat calvarial bone defects in vivo were also investigated. MATERIALS AND METHODS: CGF and platelet-poor plasma (PPP) gel, which both have fibrin networks, were prepared from rat blood. For the in vitro study, CGF and PPP gel were frozen, and thin sections approximately 30 µm thick were cut and coated onto the surfaces of cell disks. RBM cells were then harvested and cultured on the coated disks in serum-free medium. For the in vivo study, rat calvarial bone defects (3.8 mm in diameter) were created and implanted with CGF, PPP gel, or left unfilled. RESULTS: In vitro, the actin stress fibers of RBM cells cultured on disks coated with CGF or PPP gel tended to extend more than cells cultured on uncoated disks. However, no significant difference was observed in terms of cell morphology between RBM cells cultured on CGF- and PPP gel-coated disks. Cell proliferation and osteoblastic differentiation were significantly higher in cells cultured on the CGF-coated disks than on the PPP gel-coated disks. In vivo, more new bone had formed in defects treated with CGF than in defects treated with PPP gel. CONCLUSION: In this preliminary study, fibrin and soluble factors in CGF promoted initial cell stretching, proliferation, and osteoblastic differentiation of RBM cells in vitro and bone regeneration in rat calvarial bone defects in vivo.

Inflammatory pseudotumor of the choroid plexus. Case report.

The authors report a case of inflammatory pseudotumor that developed in the choroid plexus of the lateral ventricle. The patient was a 73-year-old man who had undergone surgery for rectal cancer at another hospital 5 years earlier. He was referred to the authors' department, with his chief symptoms consisting of disorientation, right hemiparesis, and gait disorder that had gradually developed during the preceding month. On computed tomography and magnetic resonance imaging, a well-demarcated and homogeneously contrasted tumorous lesion was noted in the region from the trigone to the medial wall of the inferior horn of the left lateral ventricle. Expansion of the inferior horn was also evident. Intraoperative findings showed that the tumor originated from the choroid plexus of the lateral ventricle, and the histopathological diagnosis was inflammatory pseudotumor. There are only 4 previously reported cases of inflammatory pseudotumor that developed in the choroid plexus; the authors review the literature and discuss the clinicopathological characteristics of the condition.

Endodermal cyst ventral to the lower brain stem.

A 28-year-old woman presented with a rare case of endodermal cyst located ventral to the lower brain stem manifesting as recurrent aseptic meningitis. Computed tomography and magnetic resonance imaging demonstrated a cystic mass located ventral to the lower brain stem and extending from the prepontine to the upper cervical (C-2) cistern. The lesion was totally removed through a retrosigmoid craniotomy and C1-2 hemilaminectomy. Histological and immunohistochemical examination showed the cyst was derived from the endoderm. The histological diagnosis was endodermal cyst. Early diagnosis and surgical removal are important for patients with these cysts.

Evaluation of combined nedaplatin and docetaxel therapy for human head and neck cancer in vivo.

BACKGROUND: Nedaplatin (NDP) was developed as a second-generation platinum complex. The antitumor efficacy of the combination of NDP with docetaxel (TXT) was evaluated against human head and neck carcinoma. The antitumor activity of NDP plus TXT was compared with that of some other platinum compounds, cisplatin (CDDP) and carboplatin (CBDCA) plus TXT. MATERIALS AND METHODS: Mice implanted with HNC-3 or KB3-1, human head and neck carcinoma were administered i.v. NDP, CDDP or CBDCA plus TXT. RESULTS: The antitumor efficacy was enhanced significantly by the combination of NDP with TXT. Combined NDP plus TXT treatment exerted antitumor efficacy comparable to that of combined CDDP plus TXT treatment. Thrombocytopenia induced by NDP was not enhanced by the combination of NDP and TXT. CONCLUSION: The results suggest that combined NDP and TXT can alleviate thrombocytopenia caused by NDP and that this combination may have significant potential in clinical use.

[Micro-tourniquet method: a substitute or supporting technique for aneurysm clipping].

The micro-tourniquet method is designed as a substitute and/or supporting technique for obliterating aneurysms that are difficult to operate on using the conventional clipping technique. This method is useful for squeezing the aneurysm neck and making a detour around the neck to spare the branching vessels. These micro-tourniquet instruments are a ligature with both ends attached to a ligature guide, a guide holder, a silastic sheath, and a hemostatic clip or a small aneurysm clip set. The ligature is a 20cm long GORE-TEX suture CV-3, and is attached on both ends to a ligature guide. These ligature guides are made of 7mm wire, and are malleable enough to be bent intentionally during surgery. However, they are also rigid enough to be used as a micro dissector. The silastic sheath is made of a 20G infusion needle, and is cut to a length of 2cm. After branching vessels and perforators are dissected and spared with the aid of the ligature guide, the ligature is passed around the aneurysm neck, both ends of the ligature are passed through the sheath, the aneurysm neck is squeezed, and a clip is applied as a stopper on the ligatures adjacent to the distal end of the sheath. By gently displacing the distal end of the sheath, a conventional aneurysm clip is applied on the aneurysm neck just distal or proximal to the ligature on the neck. Then, the ligature is removed. Two demonstrable cases are presented and the usefulness of the micro-tourniquet method is discussed.

Preclinical combination chemotherapy of nedaplatin with gemcitabine against gemcitabine-refractory human lung cancer.

The antitumor efficacy of the combination of nedaplatin (NDP) with gemcitabine (GEM) was evaluated against Ma44/GEM, a GEM-refractory subline of Ma44 human lung cancer, which was established by serial in vitro passage of Ma44 cells in the presence of GEM.Ma44/GEM showed less sensitivity to GEM and cytosine arabinoside with resistance factors of 7.7 and 8.3, respectively, but not to Taxol, Irinotecan, Mitomycin C and NDP. Flow cytometry analysis demonstrated that membrane transporter molecules such as multidrug-resistant, multidrug-resistant related protein or lung resistant protein were not induced in Ma44/GEM cells. In vivo experiments confirmed the less sensitivity of Ma44/GEM to GEM. The resistant factor of Ma44/GEM to GEM in vivo was estimated to be 6.7 in terms of ED(50).MA44/GEM-implanted athymic mice were treated with GEM i.v. once followed by i.v. injection of NDP at an interval of approximately 30 min. The mice were treated again with GEM after 3 or 4 days. The combined dosing of NDP with GEM resulted in synergistically enhanced inhibition of tumor growth against Ma44/GEM. The antitumor efficacy of the combination of NDP and GEM was superior to the best effect of either monotherapy. These results demonstrate the effectiveness of the combination of NDP with GEM against the GEM-refractory human lung cancer model.