PURPOSEThis in vitro study investigated and compared the durability and retention of three types of attachments.MATERIALS AND METHODSThree commercially available attachments were investigated: Clix®, Dalbo-Plus® and Locator®. In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37℃. The abutments were placed at angulations of 0°, 10° and 20°. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles.RESULTSThe results revealed that there were significant differences in the average values of the insertion/removal force due to angulation (F (2.48) = 343619, P<.05) and the type of attachment (F (7.48) = 23.220, P<.05).CONCLUSIONGreater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.

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PURPOSEThe aim of this study was to compare the durability and retention of 4 types of attachments placed over computer aided design/computer aided manufacturing (CAD/CAM) titanium bars when subjected to different pH conditions.MATERIALS AND METHODSFour commercially available attachments were investigated: Hader Yellow, Hader Red, Ackerman Gold and Ackerman Stainless Steel. These attachments and Ackerman CAD/CAM titanium bars were placed in 2 vessels containing different artificial saliva solutions (pH 7/pH 4) at 37℃ for one month to simulate corrosion conditions, and they were then subjected to mechanical testing (5400 cycles of insertion and removal).RESULTSThe results revealed that there were significant differences in the average values of insertion/removal force due to the pH (F (1, 24)=9.207, P<.05) and the type of attachment (F (3, 24)=11.742, P<.05).CONCLUSIONMore acidic pH values were found to have a negative influence on the retention capacity of the attachments.

This study aimed to review clinical publications involving anterior-region resin-bonded fixed partial dentures to evaluate their survival rates vis-à-vis their materials and design. An electronic search was conducted using PubMed/MEDLINE to identify articles that reported on the longevity of anterior resin-bonded fixed dental prostheses published between 2000 and 2020. Only primary clinical studies that involved a follow-up after at least 3 years were included in this review. A statistical analysis was performed to evaluate resin-bonded fixed dental prostheses’ survival rates in relation to their materials and design. This review ultimately included 23 clinical publications, comprising prospective studies, retrospective studies, and randomized controlled trials. Its statistical analysis estimated the studied prostheses’ 5-year survival rate at 86.2% for metal-framed prostheses, 87.9% for zirconia prostheses, 93.3% for alumina prostheses, 100% for glass or ceramic prostheses, and 81.7% for fiber-reinforced composite restorations. Failure rates did not significantly differ between the different material groups or between the single- and double-retainer groups. Resin-bonded fixed dental prostheses present excellent 5-year clinical longevity in the anterior sector and a favorable benefit/risk/cost ratio. Currently, no consensus has been established on an ideal material for these restorations. Cantilever design tends to limit constraints on the prostheses’ retainers and, thus, increases their survival time. All-ceramic cantilever fixed partial dentures can be considered as a definitive therapy, given their high success and survival rates. They are an optimal solution for adolescents or young adults facing potentially continuous growth.

(1) Introduction: Denture adhesives (DAs) promote stability, chewing ability, and quality of life. The objective of this study was to compare the effectiveness of original brand DAs and white brands in their retention of conventional complete dentures. (2) Methods: This study followed the recommendations of the international standard ISO 10873. Three original brands of DA (Corega® Fixação 3D, GlaxoSmithKline®, Stafford Miller Ltd., Dungarvan Co. Waterford, Ireland), KuKident® Pro Procter & Gamble Technical Centres®, Ltd., Whitehal Lane, Germany and Elgydium® Fix, Laboratórios URGO® SL, Florida, Spain) were compared to three white brands (Fixação Extra Forte Pingo Doce®, Laboratórios Cosmodent®, Cantabria, Spain), Fixador de Próteses (Continente®, Propack®,Gmbh, Ladenburg, Germany) and Creme Fixador de Próteses (Auchan®, Ellipse®, Roubaix, France). Their retention capacities were analyzed using a mechanical test device. (3) Results: The mean retentive ability of original brand adhesives (M = 11.16, SD = 5.27) was significantly higher (t(298) = 11.88; p < 0.001) than that of the white brands (M = 5.92, SD = 1.18). When comparing all brands, statistically significant differences were also observed, F(5.294) = 707.68 (p < 0.001). The generic adhesive results were more homogeneous. The generic brands from Continente® (M = 5.24, SD = 0.94) and Auchan® (M = 5.80, SD = 0.79) were not significantly different, while the Pingo Doce® brand obtained significantly higher mean retention results (M = 6.71, SD = 1.28). (4) Conclusions: The original brands of DA have a significantly higher retentive ability than the white brands. Elygidim® Fix had the worst result of the three original brands, and the product from Pingo Doce® had the best result among the three white brands.

Micromovements of the implant–abutment connection influence peri-implant bone preservation. This study evaluates and quantifies the maximal torque after a cycle of implant prosthetic screws tightening using original components. A total of 40 samples were tested: Megagen®—Daegu, South Korea; Dentium®—Gangnam-Gu, Seoul, Korea; BIOMET 3i®—West Palm Beach, FL, USA and BTI®—Álava, Spain. Screws from each manufacturer were subjected to maximal stress force until they fractured. The fracture points were recorded and compared among all samples. To compare the mean values of fracture torques, the reference values associated with each brand and the sample results were used in t-tests. ANOVA (analysis of variance) was used to compare the maximal resistance limit between brands, complemented with Tukey’s multiple-comparison test. The maximal considered level of significance was 5%. The average fracture force for the brands was 40.07 Ncm for Megagen®, 53.39 Ncm for Dentium®, 39.74 Ncm for Biomet 3i®, and 68.84 Ncm for BTI®. BTI® screws showed the most resistance to fracture. According to the protocol that was applied, the implant–abutment connection demonstrated good resistance and a precise fit between these interfaces; therefore, in some cases, the presented values showed a lack of quality control and low fracture resistance.

Temporary restorations play a fundamental role in oral rehabilitation. They can be used on teeth or implants for a variable period of time during the period prior to rehabilitation with definitive restorations. Temporary or provisional restorations manufactured via CAD/CAM methods are becoming increasingly used in the intermediate phase of the treatment of complex cases. The main objective of this study was to compare the fracture resistance of three materials used in the creation of provisional crowns on implants: polymethyl methacrylate (PMMA), composite resin, and polyether ether ketone (PEEK). Fracture resistance in PMMA (Zirkonzahn Temp Basic® , Gais, South Tyrol, Italy) ranged from 1216.0 N to 1461.2 N, with a mean of 1300.4 N (SD = 97.09). In the composite material (3M Lava Ultimate®, Minnesota, USA), fracture resistance varied between 1343.5 N and 1490.6 N, with a mean of 1425.9 N (SD = 49.03). Lastly, in PEEK (Tecno Med Mineral®, Zirkonzahn®, Gais, South Tyrol, Italy), fracture resistance ranged from 2294.8 N to 2451.7 N, with a mean of 2359.5 (SD = 50.01). The crowns made with the PEEK Tecno Med Mineral® (Zirkonzahn®, Tyrol, Italy) material presented the best fracture resistance, followed by the crowns made with the Lava Ultimate® (3M® ESPE, Minnesota, USA) composite resin material and, finally, those made with the PMMA Temp Basic® (Zirkonzahn®, Tyrol, Italy) material.

Abstract. Gastric cancer is a disease in which the main treatment is surgical extirpation. The modifications introduced in the surgical treatment over the last decades were accompanied by a clear increase of survival, which reaches global values of 61% at 5 years in Japan. One of the reasons that contribute to this improvement is early diagnosis of the lesions. In the period between January 1, 1990 and December 31, 1999 662 patients with gastric adenocarcinoma were treated in the Service of Surgery 1 of our hospital; 110 were refused surgical treatment. Of the resected patients, 91 (21.4%) were classified as early gastric cancer according to the definition of the Japanese Society of Digestive Endoscopy. There were 30 women and 61 men, with a median age of 60.2 ؎ 15 years; 3 patients had a preoperative diagnosis of gastric ulcer; 2 others were operated without recent histology; and 1 patient was urgently resected for a bleeding ulcer. In all the remaining patients biopsy confirmed the presence of cancer (89%) or serious dysplasia (4.6%). The lesions had been distributed essentially in the medium 1/3 (48.3%) and distal 1/3 of the stomach.Subtotal gastrectomy was accomplished in 48 patients, total gastrectomy in 40, total desgastrogastrectomy in 3, and in 9 patients the surgery involved the spleen (8 patients) and the spleen and tail of the pancreas in 1 patient. Lymphadenectomy was not performed in 5 patients, lymph nodes by the first lymph node barrier were removed in 25 patients and by the second barrier in 61 patients (67%). Median tumor size was 26 ؎ 1.8 mm. The lesion reached the mucosa in 46 patients and the mucosa and submucosa in 45. In 6 patients the removed lymph nodes were microscopically invaded (6.7%). Five patients died (5.7%). The median follow-up of the patients is 41 ؎ 26 months; 7 patients died (8.1%) during this period; 4 died unequivocally of disease progression. The median survival of patients was 85% at 5 years and 80% at 10 years. In our series, survival was affected by the presence of invaded lymph nodes, not by the penetration in depth of the lesion or the size of the tumor.Modifications in the surgical treatment of gastric cancer introduced in the last decades brought a clear increase of 5-year survival. This effect became particularly visible in Japan, whose surgeons present survival rates at 5 years of 61% in comparison to Western authors, whose results are approximately 40%, considering only radical surgery [1,2]. One of the reasons that also contribute to this survival increase is early diagnosis, which allows the detection of more carcinomas in initial phases. In Japan this subgroup constitutes 50%-55% of all operated patients, being a common clinical entity, but the same does not happen in Europe [3] and in the United States [4], where the frequency of early diagnosis does not surpass 15%.