Comparison of the Fracture Resistance and Fracture Mode of Contemporary Restorative Materials to Overcome the Offset of Mandibular Implant-Supported,Cement-Retained Crowns

Background: The purpose was to compare the fracture resistance and the mode of failure of different contemporary restorative materials to restore implant supported, cement-retained mandibular molars. Methods: Two 5 × 10 mm titanium dental implants were mounted in resin blocks and prefabricated titanium and zirconia abutments were connected to each implant. Each implant received forty crowns resembling mandibular first molars. The specimens were divided into four groups (n = 10/group) for each abutment according to the type of material; Group A: porcelain fused to metal crowns; Group B: monolithic zirconia crowns; Group C: zirconia coping with ceramic veneer; Group D: all ceramic lithium disilicate crowns. Specimens were cemented to the abutments, mounted into a universal testing machine, and vertical static load was applied at a speed of 1 mm/min. The test stopped at signs of visual/audible fracture/chipping. Fracture resistance values were analyzed using ANOVA and Tukey’s tests (α ≤ 0.05). The modes of failure were visually observed. Results: A statistically significant difference (p < 0.001) of the fracture resistance values among tested groups was found. The group that showed the highest fracture resistance was Group A for both the titanium and the zirconia abutments (3.029 + 0.248 and 2.59 ± 0.39, respectively) while Group D for both abutments (1.134 + 0.289 and 1.68 ± 0.13) exhibited the least resistance. Conclusions: Fracture resistance and fracture mode varied depending on type of restorative material. For both titanium and zirconia abutments, porcelain fused to metal showed the highest fracture resistance values followed by monolithic zirconia.     

内镜下黏膜注射联合金属钛夹与两者单用治疗溃疡病出血的临床对比研究

目的内镜下黏膜注射联合金属钛夹治疗溃疡出血和单纯黏膜注射及单纯钛夹止血进行疗效比较,为临床治疗溃疡出血寻找新方法。方法选取2011年6月-2013年6月公安县人民医院收治的非静脉曲张性溃疡病出血患者75例作为研究对象,将其按照数字随机表法分为三组:钛夹止血联合黏膜注射止血组25例、钛夹止血组25例和黏膜注射止血组25例,比较三组患者治疗后的即时止血率、再出血率、止血有效率、转外科手术率及并发症发生情况,总结钛夹止血联合黏膜注射止血的临床效果。结果三组患者的即时止血率分别为:联合止血组100%、钛夹止血组80.00%、黏膜注射组76.00%,三组即时止血率行χ2检验,单纯钛夹组和单纯黏膜组均明显低于联合治疗组,差异具有统计学意义(P0.05);单纯钛夹组和单纯黏膜治疗组比较,差异无统计学意义(P0.05)。三组患者72 h后再出血发生率分别为:联合止血组4.00%、钛夹止血组16.00%、黏膜注射组12.00%,三组72 h后再出血率行χ2检验,单纯钛夹组和单纯黏膜组均明显高于联合治疗组,差异具有统计学意义(P0.05)。单纯钛夹组和单纯黏膜治疗组比较,差异无统计学意义(P0.05)。联合组有效止血率达到96.00%,明显高于单纯钛夹止血组和单纯黏膜注射组,组间行χ2检验,联合治疗组明显高于单纯钛夹组和单纯黏膜注射液组,差异均具有统计学意义(P0.05);单纯钛夹组和单纯黏膜注射组比较,差异无统计学意义(P0.05)。外科手术发生率联合治疗组为4.00%,单纯钛夹组为16.00%,单纯黏膜注射组为20.00%,组间行χ2检验,联合治疗组明显低于单纯钛夹组和单纯黏膜注射液组,差异均具有统计学意义(P0.05);单纯钛夹组和单纯黏膜注射组比较,差异无统计学意义(P0.05)。结论内镜下金属钛夹止血联合黏膜注射止血治疗溃疡病出血较单纯钛夹止血和单纯黏膜注射止血的临床效果更优,且并发症发生率和单纯注射治疗及单纯钛夹治疗无明显差异,故该治疗方案作为治疗溃疡出血可进行更深入的研究,以规范治疗方法,稳定治疗效果。     

Zirconia vs. Titanium Dental Implants: Primary Stability In-Vitro Analysis

The present experimental trial uses two types of dental implants, one made of titanium (Ti₆A_l4V) and the other one of zirconia (ZrO₂), but both of identical design, to compare their stability and micro-movements values under load. One of each type of implant (n = 42) was placed into 21 cow ribs, recording the insertion torque and the resonance frequency using a specific transducer. Subsequently, a prosthetic crown made of PMMA was screwed onto each of the implants in the sample. They were then subjected to a static compression load on the vestibular cusp of the crown. The resulting micromovements were measured. The zirconia implants obtained a higher mean of both IT and RFA when compared with those of titanium, with statistically significant differences in both cases (p = 0.0483 and p = 0.0296). However, the micromovement values when load was applied were very similar for both types, with the differences between them (p = 0.3867) not found to be statistically significant. The results show that zirconia implants have higher implant stability values than titanium implants. However, the fact that there are no differences in micromobility values implies that caution should be exercised when applying clinical protocols for zirconia based on RFA, which only has evidence for titanium.     

Effect of zirconia-modified magnesia investment on the casting of pure titanium

Several investigations have examined magnesia-based investments for pure titanium casting. However, the thermal expansion value was insufficient at low casting temperatures and high interfacial reactivity occurred at high casting temperatures. The purpose of this investigation was to modify a magnesia-based investment by adding a heat-resistant mold material, zirconia, in different ratios to produce a more accurate titanium casting. The thermal expansion value was measured using a new precise automatic laser recording machine and pure titanium was cast using an argon casting machine. The marginal accuracy was measured using a stereomicroscope and the interfacial reactivity of the titanium was evaluated using X-ray diffraction analysis. The results indicate that adding different amounts of zirconia to a magnesia-based investment can increase its thermal expansion value and decrease the interfacial reactivity of the titanium. Maximal thermal expansion in the zirconia-modified investments significantly increased by 5-6 weight % (wt%) and peaked at 1.62% expansion. Selevest with 5 wt% zirconia had the smallest mean marginal discrepancy, 21.70 microm at 750 degrees C. Analysis of variance indicates significant differences in marginal discrepancy between zirconia-modified investments (p < 0.001). Adding zirconia can also decrease the interfacial reactivity of the titanium. The data indicated that proper amounts of zirconia (5-6 wt%) added to a magnesia-based investment can produce a more accurate and less interfacial reactive pure titanium casting.     

迷宫手术保留右心耳对血浆心房钠尿肽的影响及其临床意义

为评价慢性心房颤动 (简称房颤 )施行迷宫手术时保留右心耳对心房钠尿肽 (ANP)分泌的影响 ,及其对肾脏水钠排泄功能的作用 ,选择行二尖瓣替换术和改良迷宫手术的风湿性心脏病 (简称风心病 )患者 43例 ,根据术中有无切除右心耳 ,分成切除组 (n =2 3)和保留组 (n =2 0 ) ,另选同期行二尖瓣和主动脉瓣替换术的风心病患者 2 0例作为对照组。各组分别于术前 1天、术后 1,3,7,14天采用放射免疫法测定血浆ANP的含量 ;同时记录术后 7天内每日液体的入量、尿量以及体重的变化。结果发现 ,切除组和保留组术后 1个月窦性心律的维持率无统计学差异 ;各组术后 7天内各时间点的血浆ANP含量均较术前明显降低 (P <0 .0 5 ) ,其中尤以术后第 1天下降最为明显 ;术后 3天保留组和对照组血浆ANP含量均较术后 1天明显升高 (P <0 .0 5 ) ;保留组术后第 3,7天血浆ANP含量显著高于切除组 (P <0 .0 5 ) ;术后每日液体入量、尿量、体重以及术后 7天体液的总平衡量各组间均无显著差异 (P >0 .0 5 ) ;切除组术后 7天内应用多巴胺和速尿的总量均显著高于保留组和对照组 (P <0 .0 5 )。提示保留右心耳的迷宫手术同样能达到治疗慢性房颤的目的 ,并且对ANP的分泌的影响相对较小、从而相对改善术后肾脏水钠排汇功能。     

Evaluation of Antimicrobial Efficacy and Permeability of Various Sealing Materials at the Implant–Abutment Interface—A Pilot In Vitro Study

The microenvironment of the oral cavity is altered when an implant, a biocompatible foreign body, is inserted into the mouth. Bacteria settle in the tissues in and around the implant due to the passage of microorganisms through the microgap at the connection of the implant and prosthetic abutment. To prevent colonization of the implant by microorganisms, one idea is to use sealing and antimicrobial materials to decontaminate the implant–abutment interface and close the microgap. The purpose of this study is to evaluate the antimicrobial efficacy and permeability of different types of sealing materials at the implant–abutment interface, under static conditions. Three different sealing material (GapSeal gel, Oxysafe gel and Flow.sil) were used for sealing the implant–abutment interfaces in 60 titanium dental implants, which were first contaminated with a solution containing Staphylococcus aureus and Candida albicans for 14 days under an aerobic condition. Results showed that a complete seal against bacterial infection was not formed at the implant–abutment interface, while for fungal infections, only GapSeal material helped to prevent microleakage. Findings of this in vitro study reported that application of sealing material before abutment connection may reduce peri-implant bacterial and fungal population compared with the interface without sealing material.     

STA无痛麻醉仪结合超声骨刀在抗凝血治疗老年人残根拔除术中的应用

目的探讨STA无痛麻醉仪结合超声骨刀用于长期抗凝血药物治疗老年人残根拔除的临床效果。 方法选取2018年6月至2019年9月在浙江医院行残根拔出的老年患者60例，其中30例采用STA无痛麻醉结合超声骨刀行微创拔牙（观察组），另30例采用传统卡局式注射器麻醉配合高速涡轮机与牙挺拔牙（对照组）。比较两组患者麻醉及拔牙过程中的VAS疼痛评分和麻醉前、麻醉后30 s、拔牙开始5 min、拔牙后30 min的血压和心率，以及拔牙时间、术中出血量、术后30 min的止血情况。组间计量的比较采用秩和检验、重复测量方差分析及t检验，率的比较采用χ²检验。 结果两组患者残根均完整拔除。观察组麻醉VAS评分明显低于对照组（z=-2.462，P<0.05），拔牙VAS评分的差异无统计学意义（z=-1.802，P>0.05）。两组患者各时点收缩压、舒张压及心率的差异均无统计学意义（F=2.500、0.014、3.001，均P>0.05），但观察组拔牙时间及术中出血量均明少于对照组（t=2.553、-6.368，P<0.05或0.01）。两组患者拔牙30 min后，观察组止血效果亦明显优于对照组（χ²=5.450，P<0.05）。 结论对于长期抗凝血治疗的老年人，采用STA无痛麻醉仪配合超声骨刀进行拔牙术，可明显减轻术中疼痛程度和血压波动，且术中、术后止血情况良好。     

Bone Response to Conventional Titanium Implants and New Zirconia Implants Produced by Additive Manufacturing

The aim of the present study was to evaluate the in vivo bone response to an additively manufactured zirconia surface compared to osseointegration into titanium (Ti) surfaces. Scanning electron microscopy, confocal laser scanning microscopy, and electron spectroscopy for chemical analysis were performed to assess the surface characteristics of implant specimens. For the in vivo evaluation, eight Ti implants and eight 3D-printed zirconia implants were used. The surface of four Ti implants was sandblasted, large-grit, and acid-etched (Ti-SLA group), while those of the other four Ti implants were left untreated (Ti-turned group). The zirconia implants had no further surface modification. Implants were placed into the tibiae of four rabbits; two received the Ti-SLA and zirconia implants and the other two received Ti-turned and zirconia implants. The experimental animals were sacrificed after four weeks of surgery, and the undecalcified microscopic slides were prepared. The bone–implant interface was analyzed by histomorphometry to evaluate the bone response. The degree of surface roughness showed that Ti-SLA was the highest, followed by zirconia and Ti-turned surfaces. The 3D-printed zirconia surface showed similar bone-to-implant contact to the Ti-turned surface, and Ti-SLA had the most bone-to-implant contact. The additively manufactured zirconia implant surface is biocompatible with respect to osseointegration compared to the commercially pure Ti surface.     

Group A streptococcal brain abscess: a case report and a review of the literature since 1988

Brain abscesses caused by group A Streptococcus (GAS) are rare infectious diseases. In this report we present a case of brain abscess due to GAS infection occurring after milk tooth extraction in a healthy child. A literature review of previously reported cases is presented.     

A possible defensive mechanism in the basal region of gastric mucosa and the healing of erosions

A possible defensive mechanism in the basal region of the gastric mucosa was hypothesized in the present study. In vivo microscopy was performed to observe the basal region after thermal injury to the back skin of rats. A donor of nitric oxide, 3-morpholinosydnonimine hydrochloride (SIN-1), or a serine protease inhibitor, camostat mesilate, was administered. Anti-vascular endothelial growth factor (VEGF) neutralizing antibody was administered 5 hours after thermal injury (anti-VEGF group). Post-capillary venules could be observed in the basal region of the gastric mucosa (PV-BGM). The PV-BGM was dilated 5 hours after thermal injury, and it was reduced by the administration of SIN-1 or pre-treatment with camostat mesilate. In the control group, the erosions did not reach the basal region of the gastric mucosa. Most of the erosions healed within 72 hours. Delayed healing was observed in the anti-VEGF group. In this group, exudation and congestion in the basal region were observed at 24 hours, and ulcer formation was observed at 72 hours after thermal injury. It is thus hypothesized that blood flow of the PV-BGM increases when superficial mucosal circulation is disturbed. The PV-BGM can contribute to defensive mechanisms in the basal region of gastric mucosa. The abnormal healing process may disturb the defensive mechanism at the base of the gastric mucosa, thereby resulting in ulcer formation.     

Periodontal disease and implant-supported prostheses

Periodontal disease is one of the most common dental pathologies which is found in more than 80% of the Japanese adult population. It is also one of the major causes of tooth loss where more than 50% of the tooth are lost due to the periodontal disease. To reconstruct the dental defects, and re-establish the lost functions due to the periodontal disease are very important aspects of the clinical dentistry. Because of the aging society, these services will become even more critical. To lose a tooth not only means a compromised masticatory efficiency, but it has a profound effect on the patient's QOL and ADL. That is why the rehabilitation of the dental function becomes so important. There are two major clinical procedures for the reconstruction of the lost dental functions. They are (1) bridge or partial denture, and (2) implant-supported prostheses. Among other problems, the crown-root ratio of the periodontally involved teeth are less than adequate to serve as an abutment tooth for a bridge, or a clasped tooth for a partial denture. Their prognosis is questionable because of an excessive load over the diseased tooth. Implant-supported prostheses, in contrast, have an excellent long term prognosis because the prosthetic appliances are directly supported by the jaw bone.     

Effect of cardiac rehabilitation on muscle mass,muscle strength,and exercise tolerance in diabetic patients after coronary artery bypass grafting

BackgroundThe effects of cardiac rehabilitation (CR) on muscle mass, muscle strength, and exercise tolerance in patients with diabetes mellitus (DM) who received CR after coronary artery bypass grafting (CABG) have not been fully elucidated.MethodsWe enrolled 78 consecutive patients who completed a supervised CR for 6 months after CABG (DM group, n = 37; non-DM group, n = 41). We measured mid-upper arm muscle area (MAMA), handgrip power (HGP), muscle strength of the knee extensor (Ext) and flexor (Flex), and exercise tolerance at the beginning and end of CR.ResultsNo significant differences in confounding factors, including age, gender, ejection fraction, or number of CR sessions, were observed between the two groups. At the beginning of CR, the levels of Ext muscle strength and peak VO₂ were significantly lower in the DM group than in the non-DM group. At the end of CR, significant improvement in the levels of muscle strength, HGP, and exercise tolerance was observed in both groups. However, the levels of Ext muscle strength, HGP, peak VO₂, thigh circumference, and MAMA were significantly lower in the DM group than in the non-DM group. In addition, no significant improvement in thigh circumference and MAMA was observed in the DM group. At the end of CR, the levels of thigh circumference and MAMA correlated with Ext and Flex muscle strength as well as with HGP. Percent changes in the levels of Ext muscle strength were significantly correlated with those of MAMA and hemoglobin A1c.ConclusionsThese data suggest that improvement in muscle strength may be influenced by changes in muscle mass and high glucose levels in DM patients undergoing CR after CABG. A CR program, including muscle mass intervention and blood glucose control, may improve deterioration in exercise tolerance in DM patients after CABG.     

386例老年人缺牙及修复情况分析

目的了解老年人缺牙及修复情况。方法依据一例一卡制的问诊和口腔检查资料,分析在天津市环湖医院和河北区口腔病防治所就诊的３８６例老年人缺牙、缺牙病因及义齿修复情况。结果３８６例中,缺牙者３６７例,缺牙率９５．１％,主要病因是龋病和牙周病;修复者２０２例,修复率５５．０％,修复体２５４件,其中不洁修复体３２件（１２．６％）,不良修复体５９件（２３．２％）,不良修复体主要为局部托牙（４９件）,不良修复的主要原因为义齿设计不当。结论应积极开展老年人口腔卫生保健和缺牙后修复必要性的宣传,提高义齿修复率,修复体要适应老年人口腔特点,修复后要定期复查,以提高义齿合格率。     

氧化锆全瓷冠与全锆冠后牙固定修复的临床研究

目的比较氧化锆全瓷冠与全锆冠在后牙固定修复中的临床综合修复效果。方法36例后牙缺失需修复的患者,其中19例66颗牙行氧化锆全瓷冠桥修复,17例60颗牙行氧化锆全锆冠桥修复。追踪观察1～3年,由修复科医师对义齿的边缘适合性、牙龈健康情况、牙冠外形、色泽、是否崩瓷、破裂等进行评价。结果两组病例修复效果在所检查的指标中比较差异均无统计学意义（ P＞0.05）。结论氧化锆全瓷冠与全锆冠在边缘密合性、美观性及抗折强度方面,均能满足临床要求。但在合龈距离较短的病例中,全锆冠的修复更具优势。     

树脂与烤瓷贴面治疗氟斑牙的临床观察

目的 观察树脂与烤瓷贴面修复氟斑牙的临床改变,为氟斑牙的修复提供依据.方法 2005-2008年,在哈尔滨医科大学附属口腔医学院口腔修复科,将56名重度氟斑牙患者分为烤瓷组和树脂组,烤瓷组应用烤瓷贴面法修复,共25人,162颗牙;树脂组以复合树脂贴面修复,共31人,201颗牙.在修复完成时应用Easyshade电脑比色仪检测2种贴面的颜色;在修复后18个月,除用电脑比色仪检测贴面颜色外,还检查贴面的边缘密合度、固位、基牙继发龋情况,并按颜色、外形、功能、感觉对临床效果进行综合评价.结果 烤瓷组、树脂组在修复完成时色差值分别为0.27±0.20、0.21±0.15,18个月后分别为0.28±0.21、0.77±0.68.树脂组修复完成时的色差值低于修复后18个月(t=-13.55,P<0.01);18个月后,烤瓷组的色差值低于树脂组(t=-12.60,P<0.01).烤瓷组修复后18个月,牙齿密合度A级百分比[100%(162/162)]高于树脂组[91.04%(183/201),χ2=15.26,P<0.01].烤瓷组的临床效果分别为优、一般、失败的牙齿数分别为158、4、0,树脂组分别为148、56、4,烤瓷组的临床效果优于树脂组(χ2=44.24,P<0.01).结论 烤瓷贴面颜色比树脂贴面持久性好;烤瓷贴面的边缘密合度和临床效果优于树脂贴面,但两种修复方法的远期疗效,尤其是树脂贴面有待进一步研究.     

Impact of diabetes on muscle mass, muscle strength, and exercise tolerance in patients after coronary artery bypass grafting

Background

The impact of diabetes mellitus (DM) on muscle mass, muscle strength, and exercise tolerance in patients who had undergone coronary artery bypass grafting (CABG) has not been fully elucidated.

Methods

We enrolled 329 consecutive patients who received cardiac rehabilitation (CR) after CABG (DM group, n = 178; non-DM group, n = 151) and measured lean body weight, mid-upper arm muscle area (MAMA), and handgrip power (HGP) at the beginning of CR. We also performed an isokinetic strength test of the knee extensor (Ext) and flexor (Flex) muscles and a cardiopulmonary exercise testing at the same time.

Results

No significant differences in risk factors, including age, gender, number of diseased vessels, or ejection fraction were observed between the 2 groups. The levels of Ext muscle strength, peak oxygen uptake, and anaerobic threshold were significantly lower in the DM group than in the non-DM group (all p < 0.05). Both peak oxygen uptake and MAMA correlated with Ext and Flex muscle strength as well as HGP (all p < 0.005). The MAMA, HGP, and Ext muscle strength were lower in patients who received insulin therapy than in those who did not. Interestingly, fasting glucose levels significantly and negatively correlated with Ext muscle strength.

Conclusions

These data suggest that DM patients had a lower muscle strength and exercise tolerance than non-DM patients. Moreover, a high glucose level may affect these deteriorations in DM patients after CABG.     

Clinical experience with fibrin glue in cardiac surgery

Cardiac surgery is often associated with hemostatic abnormalities leading to severe bleeding. Special problems are to be expected, if prosthetic material has to be implanted. Preclotting of Dacron prostheses with blood is well established but failures are sometimes encountered. Several years ago a new hemostatic sealing system (fibrin glue) was introduced into therapy. Since 1978 fibrin glue has been applied in 176 patients. The indications were: 1. sealing of woven Dacron prostheses, 2. bleeding from suture-holes (Gore-Tex), 3. diffuse myocardial bleeding and 4. prevention of kinking of coronary artery grafts. In 32 patients with an aortoventriculoplasty operation using Dacron the "blood preclotting" and "fibrin sealing" methods were compared. In the fibrin glue group there was a significant reduction in postoperative blood loss as well as a shortening of the operation time (period of protamin administration to skin closure). No fibrinolytic dissolution of the fibrin layer on the prostheses was observed.     

Hard Tissue Volume Stability Effect beyond the Bony Envelope of a Three-Dimensional Preformed Titanium Mesh with Two Different Collagen Barrier Membranes on Peri-Implant Dehiscence Defects in the Anterior Maxilla: A Randomized Clinical Trial

This single-blinded, randomized, controlled study aimed to clinically and radiographically evaluate hard tissue volume stability beyond the bony envelope using three-dimensional preformed titanium mesh (3D-PFTM) for peri-implant dehiscence defects in the anterior maxilla. A total of 28 patients who wished to undergo implant surgery combined with guided bone regeneration (GBR) after extraction of a single maxillary anterior tooth were randomly assigned to two groups depending on the type of collagen membrane used, additionally with the 3D-PFTM—test (n = 14, cross-linked collagen membrane; CCM) and control (n = 14, non-cross-linked collagen membrane; NCCM) groups. Each implant was evaluated radiographically using CBCT at baseline, immediately after surgery, and at 6 months postoperatively. The relative position and distances from the bony envelope to the outlines of the augmented ridge were further determined immediately after GBR and 6 months after healing. At the platform level, the mean horizontal hard tissue gain (HG) at all the sites was 2.35 ± 0.68 mm at 6 months postoperatively. The mean HG rate was 84.25% ± 14.19% in the CCM group and 82.56% ± 13.04% in the NCCM group, but the difference was not significant between the groups. In all cases, HG was maintained beyond the bony envelope even after 6 months of GBR. This study suggests that 3D-PFTM should be considered a valuable option for GBR for peri-implant dehiscence defects in the anterior maxilla. In addition, 3D-PFTM may confer predictable hard tissue volume stability even after the healing period of hard tissue augmented outside the bony envelope by GBR.     

Accuracy of the Intra- and Extra-Oral Scanning Technique for Transferring the Intaglio Surface of a Pontic of Provisional Restorations to Definitive Restorations

When taking the final impression for a three-unit fixed partial denture (FPD), the intaglio surface of the pontic of provisional restoration cannot be transferred accurately to that of definitive restoration. The intra- and extra-oral scanning (IEOS) technique, a method for accurately reproducing the submucosal morphology of the superstructure of an implant, has been reported using an intraoral scanner. In the present study, we evaluated the difference between the conventional impression method using impression material and the IEOS technique in reproducing the morphology of the surface of the pontic of a definitive FPD. There was a significant difference in the trueness of the intaglio surface morphology of the pontic between the conventional method and the IEOS technique; however, no significant difference in precision was observed. As a result, the intaglio surface of the pontic of the three-unit FPD could be transferred to definitive restorations more accurately with the IEOS technique than with the conventional method. These results suggest that the IEOS technique can duplicate the intaglio surface of the pontic more reproducibly to the definitive restorations compared with the conventional method.     

Hydrothermal Ageing and Its Effect on Fracture Load of Zirconia Dental Implants

Due to growing demand for metal-free dental restorations, dental ceramics, especially dental zirconia, represent an increasing share of the dental implants market. They may offer mechanical performances of the same range as titanium ones. However, their use is still restricted by a lack of confidence in their durability and, in particular, in their ability to resist hydrothermal ageing. In the present study, the ageing kinetics of commercial zirconia dental implants are characterized by X-ray diffraction after accelerated ageing in an autoclave at different temperatures, enabling their extrapolation to body temperature. Measurements of the fracture loads show no effect of hydrothermal ageing even after ageing treatments simulated a 90-year implantation.