Language：English   Publisher：(一社)歯科基礎医学会  

ポリエーテルエーテルケトン(PEEK)製の冠が有する放射線不透過の特性は、誤って嚥下・吸引してしまった時の位置の特定、および二次齲蝕の発見に利用可能なものであるか実験した。歯列模型の下顎左側第1大臼歯を支台歯とし、PEEK製、ハイブリッドレジン製、ジルコニア製、金銀パラジウム合金製の冠を製造した。これらの冠を、口腔内X線、胸部X線、コーンビームCT、マルチスライスCTの各撮像法で画像を取得した。その結果、PEEK冠の不透過特性は最も低く、2種のCT画像ではアーチファクトが大変少なくなることが示された。その一方で、PEEK冠のCT値はハイブリッドレジン冠と比較してもほとんど低下しておらず、ジルコニア冠および合金製の全部鋳造冠と比べた時は相当に低下していた。次の実験として、模型支台歯の頬側面と遠心面に模擬窩洞を作製し冠を設置した二次齲蝕モデルの口腔内X線画像を取得した。その画像から窩洞の存在を検出することは可能であった。

Language：English   Publishing type：Research paper (scientific journal)  

OBJECTIVES: There have been no reports on the radiopaque properties of new polyetheretherketone (PEEK) crowns for locating crowns during accidental ingestion or aspiration and detection of secondary caries, which is essential information for clinical application. This study aimed to investigate whether the radiopaque properties of PEEK crowns could be used to identify the site of accidental ingestion or aspiration and detect secondary caries. METHODS: Four types of crowns were fabricated: three non-metal crowns (PEEK, hybrid resin, and zirconia) and one full metal cast crown (gold-silver-palladium alloy). Initially, the images for these crowns were compared using intraoral radiography, chest radiography, cone-beam computed tomography (CBCT), and multi-detector computed tomography (MDCT); computed tomography (CT) values were calculated. Subsequently, the images for the crowns placed on the secondary caries model with two artificial cavities were compared using intraoral radiography. RESULTS: The PEEK crowns displayed the lowest radiopaque properties on radiography and very few artifacts were observed on CBCT and MDCT. On the other hand, the CT values of the PEEK crowns were a little lower than those of the hybrid resin crowns and considerably lower than the zirconia and full metal cast crowns. The cavity could be detected in the PEEK crown-placed secondary caries model through intraoral radiography. CONCLUSIONS: This simulated study of radiopaque properties with four types of crowns suggested that a radiographic imaging system can be used to identify the site of accidental ingestion and aspiration of PEEK crowns and to detect secondary caries of the abutment tooth within a PEEK crown.

DOI： 10.1016/j.job.2023.05.002

Scopus

PubMed

Language：Japanese   Publisher：(一社)日本接着歯学会  

本研究の目的は,デュアルキュア型レジンセメントで装着されたCAD/CAM用コンポジットレジンクラウンの外面より行う光照射が,初期接着強さに及ぼす光照射の影響を明らかにすることである.CAD/CAM用コンポジットレジンブロックを厚さ2mmに切断して試験片とし,被着面にリン酸処理およびシラン処理を行った.金銀パラジウム合金で製作した剪断試験用ハンドルをレジンセメントにて接着した.初期硬化後に冠外面より光照射した状況を想定し,接着の5分後に光照射を行った.試験片は90枚準備し,照射なし群,照射3秒群,照射20秒群の3群に分けた.ISO/TR 11405に則って,各群の試験片の半分(n=15)は接着操作の1時間後に剪断接着強さを測定し,各群の残り半分(n=15)は接着操作の24時間後に剪断接着強さを測定した.接着操作の1時間後における照射20秒群の接着強さは,他の2群よりも有意に高かった.接着操作の24時間後の接着強さは,すべての群間で有意差はみられなかった.20秒照射群の1時間後と全群24時間後の間に接着強さの有意差は認めなかった.このことから,CAD/CAMコンポジットレジンクラウンの装着時に十分な時間光を照射することにより,高い初期接着強さが得られることが示された.(著者抄録)

Language：Japanese   Publisher：Japan Society for Adhesive Dentistry  

<p>The purpose of this study was to evaluate the effect of light irradiation through the outer surface of a CAD/CAM composite resin crown on the initial bond strength of a dual-cure resin cement. A CAD/CAM composite resin block was cut to a thickness of 2 mm as a specimen, and the surface was treated with phosphoric acid and silane coupling agent. Adherend for the shear bond strength test made of silver-palladium-copper-gold alloy was bonded to the specimen with dual-cure resin cement. Assuming a clinical situation, the specimen was irradiated by dental curing light 5 minutes after the bonding procedure. A total of 90 specimens were divided into three groups: group without light irradiation, group with light irradiation for 3 seconds, group with light irradiation for 20 seconds. Half of the specimens in each group (n = 15) were measured for shear bond strength after 1 hour, and the remaining half (n = 15) were measured after 24 hours according to ISO/TR 11405. As a result, the bond strength of the group with light irradiation for 20 seconds was significantly higher than that of the other two groups at 1 hour after the bonding procedure. There was no significant difference in bond strength between all groups at 24 hours after the bonding procedure. There was no significant difference between the bond strength after 1 hour of the group with light irradiation for 20 seconds and the bond strength after 24 hours of all groups. It was shown that high initial bond strength can be obtained by irradiating light for a sufficient time when luting a CAD/CAM composite resin crown.</p>

DOI： 10.11297/adhesdent.41.1_2

CiNii Research

J-GLOBAL

Language：Japanese   Publishing type：Research paper (scientific journal)  

We conducted a six-month clinical follow-up on computer-aided design/computer-aided manufacturing-fabricated molar polyetheretherketone PEEK crowns to investigate their therapeutic effect. Only the PEEK crowns were examined as our study focused on short-term clinical evaluation of the new PEEK material. Twenty-three cases of PEEK crowns placed on the molars of 20 subjects (7 males and 13 females, mean age: 60.6 ± 14.2 years) were included in the study. The evaluation items were the condition of the crowns at the time of cementation and after six months, patient satisfaction, masticatory ability, and occlusal force. Mann-Whitney U tests with a significance level of 5% were used to examine the difference in glucose concentration by masticatory ability, occlusal pressure, and occlusal force, with and without PEEK crowns. The occlusion, margin fit, and contact of all 23 cases at the time of cementing were good. Six months after cementation, there was no crown desorption, fracture or crack, and prosthodontics was not needed in the 22 cases (one patient dropped out). No wear of the dental antagonist was observed. Patient satisfaction was generally high. There was no significant difference in masticatory ability between the groups with and without PEEK crowns. The subject's occlusal force was within the normal range. PEEK crowns used on molars can replace metal crowns and hold promise for an appropriate and effective treatment.

DOI： 10.1038/s41598-022-23458-5

Scopus

PubMed

Language：English  

The purpose of this study was to investigate the effect of various surface treatments on the shear bond strength between dental polyetheretherketone (PEEK) and adhesive resin cement. Two hundred and forty specimens were randomly classified into four groups: no treatment, sandblasted, sulfuric-acid-etched, and laser-grooved treatment. Each group was classified into two adhesive resin cement subgroups. Surface roughness, water contact angle, shear bond strength, and failure mode were measured; SEM and XPS results were obtained. The data were statistically analyzed using one-way or two-way analysis of variance and Tukey's honest significant difference test (α=0.05). Laser-grooved PEEK surface showed regular grooves and carbonization by thermal degradation; the surface roughness as well as water contact angle of were the highest in all groups. Shear bond strength values were significantly higher in the laser-groove-treated and sulfuric-acid-etched groups. Laser-groove-treated specimens showed cohesive failure. Laser-grooved treatment can improve shear bond strength between PEEK and adhesive resin cement.

DOI： 10.4012/dmj.2020-036

PubMed

J-GLOBAL

Language：English   Publisher：(一社)日本歯科理工学会  

歯科用ポリエーテルエーテルケトン(PEEK)材料と接着性レジンセメントの間のせん断接着強さ(SBS)に対する各種表面処理の影響を調べた。PEEK材(Vestakeep DC4450)から円板等の形状に切り出したものを検体とした。サンドブラスト、硫酸エッチング(硫酸群)、レーザー溝加工(LG群)のいずれかの表面処理を行う3群、または無処理の対照群を設定した。それらの表面特性を解析した。その結果、Nd:YVO4レーザーを使用したLG群では検体表面に精密な溝が形成され、熱分解によって炭化している様子が観察された。LG群の表面粗さと水接触角は4群の中で最も高い値となった。次に各群の検体に円柱状の検体を接着してSBS測定などを行った。接着性レジンセメントにはRelyX UltimateまたはスーパーボンドC&Bのいずれかを、接着システムにはVisio.linkを使用した。接着後は24時間水中保管し、一部の検体には1万サイクルの熱サイクルを加え、SBSを測定して破壊様式を調べた。その結果、LG群と硫酸群のSBS値は有意に上昇していることが示された。LG群の検体が示した破壊様式は凝集破壊であった。PEEKと接着性レジンセメントの間のSBSはレーザー溝加工処理によって向上させることが可能であった。

CiNii Research

CiNii Research

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.ijadhadh.2020.102746

J-GLOBAL

J-GLOBAL

J-GLOBAL

J-GLOBAL

J-GLOBAL

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