Mechanical Properties of Additively Manufactured and Milled Interim 3-Unit Fixed Dental Prostheses.

PURPOSE: To investigate the survival and mechanical properties of 3-unit interim fixed dental prostheses (FDPs) made with additive manufacturing (AM) technology compared to milled and conventional manual fabrication. MATERIALS AND METHODS: Sixty 3-unit interim FDPs replacing the first left mandibular molar were divided in 6 groups (n = 10): manual (Man) (Protemp 4), milled (Mil) (Telio-CAD Multi), and 4 additive manufacturing (AM) groups were subdivided into 4 AM technology subgroups: direct light positioning (DLP) (Rapidshape P30 [RS]), and stereolitography (SLA) (Formlabs 2 [FL]) and the type of printed interim polymer (P Pro C&B [St] and SHERAprint-cb [Sh]) (RS-St, RS-Sh, FL-St, and FL-Sh). Survival and complications were assessed after thermomechanical aging. The surviving samples were tested for fracture resistance. Kaplan-Meier test followed by log-rank test to show differences between groups was used to calculate the survival and complication rates. For fracture strength, one-way ANOVA and Tukey-b post hoc test were used to compare groups. Descriptive statistics was used for failure modes and Pearson chi-square to compare groups (α = 0.05). RESULTS: Survival rates among groups varied from 100% (Man, Mil and FL-Sh), 70% (FL-St), 50% (RS-Sh), and 20% (RS-Sh) (p < 0.001), respectively. Additional events were observed in 50% to 80% in FL-St, RS-St, and RS-Sh groups (p < 0.001). Man, FL-St, and RS-S showed lower mean static load resistance (p < 0.001). Fracture through the connector between tooth 35 and the pontic was the most prevalent type of failure. CONCLUSION: The manufacturing method, type of resin, and the printing mode had a significant influence on the mechanical properties of AM interim 3-unit FDPs.

Accuracy of Additively Manufactured and Milled Interim 3-Unit Fixed Dental Prostheses.

PURPOSE: To investigate the accuracy of additive manufacturing (AM) by means of internal fit of fixed dental prostheses (FDPs) fabricated with two AM technologies using different resins and printing modes (validated vs nonvalidated) compared to milling and direct manual methods. MATERIAL AND METHODS: Sixty 3-unit interim FDPs replacing the first mandibular molar were divided into 6 groups (n = 10): manual (Protemp 4), milled (Telio-CAD), and AM groups were subdivided based on AM technology (direct light processing (Rapidshape P30 [RS]) and stereolithography (FormLabs 2 [FL])) and the polymer type (P-Pro-C&B [St] and SHERAprint-cb [Sh]) (RS-St, RS-Sh, FL-St, FL-Sh). Validated (RS-Sh and RS-St) or nonvalidated (FL-St and FL-Sh) modes were adopted for AM. The specimens were scanned to 3D align (GOM inspect) according to the triple scan method. The internal space between the FDPs and preparation surfaces in four sites (marginal, axial, occlusal, and total) was measured using equidistant surface points (GOM Inspect). Statistical analysis was done using Kruskal Wallis and Dunn post-hoc tests. (α = 0.05). RESULTS: One AM group (FL-Sh) and milling exhibited better adaptation compared to manual and RS-St at molar site (p < 0.05). FDPs with St resin (FL-St and RS-St) displayed bigger marginal space than milled, FL-Sh, and RS-Sh. The nonvalidated printing mode showed better mean space results (p < 0.05) with higher predictability and repeatability (p < 0.001). CONCLUSIONS: The AM interim FDPs tested provided valid alternatives to the milled ones in regard to their accuracy results. The printing mode, resin, and the AM technology used significantly influenced the manufacturing accuracy of interim FDPs, particularly at the marginal area. The nonvalidated printing mode with lower-cost 3D printers is a promising solution for clinical applications.

The 3D-printed prototype: a new protocol for the evaluation and potential adaptation of monolithic all-ceramic restorations before finalization.

The prototyping protocol to evaluate and make the potential adjustments prior to finalization of the monolithic restorations was described by two clinical situations. In the first case report, following the digital impressions using an intraoral scanner (3Shape Trios, 3Shape) for an implant-supported four-unit fixed dental prosthesis, a digital design (3Shape Dental System, 3Shape) was performed and a prototype using subtractive CAM (milling) (PMMA, Telio CAD, Ivoclar Vivadent) was fabricated. The second case highlights the 3D-printed prototyping (additive CAM) (Sheraprint Model Plus UV, Shera) following digital impressions using an intraoral scanner and digital design in a patient requiring two opposing open-end three-unit fixed dental prostheses. By means of prototyping, the esthetic, fitting, and functional properties could be tested and the adjustments were completed on the prototypes. It is suggested that prototyping is an efficient tool that minimizes the clinical adjustment need for the final restoration while improving the communication between the dental practitioner and the technician.

Perianal versus endoanal application of glyceryl trinitrate 0.4% ointment in the treatment of chronic anal fissure: results of a randomized controlled trial. Is this the solution to the headaches?

BACKGROUND: Application of nitroglycerin (glyceryl trinitrate) ointment with perianal administration is a widely used treatment for chronic anal fissure. However, headache occurs after application in 20% to 70% patients and leads to withdrawal in 10% of patients. OBJECTIVE: The aim of the study was to investigate whether endoanal application of the ointment may lower the frequency of headaches without sacrificing effectiveness. compare the effects of perianal versus endoanal administration of nitroglycerin ointment on frequency of headache and rate of healing in the treatment of chronic anal fissure. DESIGN: This was a prospective randomized clinical trial (ClinicalTrial.gov, NCT01132391). SETTINGS AND PATIENTS: Study participants were consecutive patients with a diagnosis of chronic anal fissure treated at a university teaching hospital in Elche, Alicante, Spain. INTERVENTION: Patients were randomly assigned to receive perianal (n = 26) or endoanal (n = 26) administration of 0.4% nitroglycerin ointment (375 mg of ointment containing 1.5 mg of glyceryl trinitrate), applied every 12 hours over an 8-week period. MAIN OUTCOME MEASURES: The primary endpoint of the study was the number of patients with headache within 3 hours after application of the ointment, analyzed with the intention-to-treat principle. Intensity of headache pain was rated on a 10-point visual analog scale. Secondary endpoints included frequencies of fissure healing, anorectal pain, rectal bleeding, pruritus, and incontinence. RESULTS: Headaches were reported in 14 (54%) patients with perianal treatment and in 6 patients (23%) with anorectal treatment (p = 0.003). The median headache pain score was 6 (range, 0-10) in the perianal group and 4.5 (range, 0-10) in the endoanal group (p = 0.03). Disabling headaches led to crossover from perianal to endoanal treatment in 4 patients (15%), and from endoanal to perianal treatment in 1 patient (4%) (p = 0.004). Of the 4 patients who switched from perianal to endoanal treatment, 2 reported improvement in headaches and 2 stopped treatment. The patient who switched from endoanal to perianal treatment also showed no improvement and stopped treatment. The healing rate at 24-week follow-up was 62% (16 patients) with perianal treatment and 77% (20 patients) with endoanal treatment (p < 0.05). LIMITATIONS: Effects on sphincter pressure were not evaluated because manometric measurements were not available. CONCLUSIONS: Endoanal application significantly reduces the frequency of headaches due to treatment with 0.4% nitroglycerin ointment and results in a higher healing rate compared with perianal administration. However, roughly 1 in 4 patients still experiences headaches. Our data suggest that endoanal application may be a better option for treatment of anal fissure with nitroglycerin ointment.

[Acute renal failure and chronic diarrhea: McKittrick-Wheelock syndrome]. / Insuficiencia renal aguda y diarrea crónica: síndrome de McKittrick-Wheelock.

In 1954, McKittrick and Wheelock described for the first time a syndrome presenting chronic lost of fluid and electrolytes secondary to chronic diarrhea, associated to large rectal villous adenomas. We report a case of a 75-year-old female who presented chronic diarrhea (3 to 4 depositions per day in the last year), accompanied by acute renal failure. In the rectal tact, we objective the presence of a mass of soft consistency with an irregular surface, occupying approximately two thirds of the circumference, at about 3 cm from the anal margin. It was confirmed by the colonoscopy and the patology was informed as villous adenoma, producing chronic diarrhea or McKittrick-Wheelock syndrome. We decide the surgical approach after the normalization of patient's general status and a proctectomy with coloanal anastomosis was performed. We conclude that we must think about this syndrome in aged patients with chronic diarrhea, alterations of the electrolyte balance and presence of renal failure. Surgery treatment after the replacement of water and electrolytes is the unique curative treatment. The absence of this can cause the death of these patients.

Fistulotomy and sphincter reconstruction in the treatment of complex fistula-in-ano: long-term clinical and manometric results.

OBJECTIVE: To evaluate the long-term clinical and manometric results of fistulotomy and sphincter reconstruction for the treatment of complex fistula-in-ano. BACKGROUND: Complex fistula-in-ano is difficult to treat due to the occurrence of postoperative anal incontinence and the high rate of recurrence. METHODS: Seventy patients who were diagnosed with complex fistula-in-ano and underwent fistulotomy and sphincter reconstruction between October 2000 and October 2006 were analyzed in the present study. Preoperative assessment included physical examination, anorectal manometry, and anal endosonography. Appointments were scheduled every 6 months during the first and second year of treatment and every 2 years thereafter. Recurrence and incontinence were evaluated during each visit. Continence was assessed according to the Wexner continence grading scale. Anal manometry was performed 3 and 12 months after treatment and every 2 years thereafter. Anal endosonography was conducted 6 months after treatment. RESULTS: Fistulas were classified as medium-high trans-sphincteric in 64 patients (91.42%) and were recurrent in 22 patients (32%). Before surgery, 22 patients (32%) reported fecal incontinence, which improved after surgery in 15 cases (70%), from 6.75 to 1.88 (P < 0.005) on the Wexner Scale. Eight preoperative continent patients (16.6%) reported postoperative incontinence (Wexner Score < 3), and 6 patients (8.5%) had recurrent incontinence. Among these patients, 2 developed recurrent incontinence 6 months after treatment, 2 developed recurrent incontinence 1 year after treatment, 1 developed recurrent incontinence 2 years after treatment, and 1 developed incontinence 5 years after treatment. CONCLUSIONS: Fistulotomy with sphincter reconstruction is an effective technique for the treatment of complex fistula-in-ano. Continence and anal manometry results were improved in incontinent patients and were not jeopardized in continent ones. Fistulotomy with sphincter reconstruction is an especially suitable technique for incontinent patients with recurrent fistulas.

Long-term clinical results of double-pursestring stapled hemorrhoidopexy in a selected group of patients for the treatment of chronic hemorrhoids.

BACKGROUND AND OBJECTIVE: The aim of this prospective controlled trial was to evaluate the long-term clinical and manometric results of stapled hemorrhoidopexy performed by expert surgeons in a selected group of patients for the treatment of chronic hemorrhoids. SETTINGS: This study took place in the outpatient clinic and at the Day Surgery Unit attached to the University Hospital of Elche. PATIENTS: From March 2003 to May 2005, 200 consecutive patients with third-degree hemorrhoids and treated with double-pursestring stapled hemorrhoidopexy with a PPH33-03 stapler were included in the study. MAIN OUTCOME MEASURES: Demographic, manometric, and clinical features were analyzed, as well as the variables related to surgery, postoperative course, and follow-up. Manometry was repeated at the 6-month, 1-year, and 5-year follow-up. RESULTS: Median follow-up was 110 months. Four patients (2%) reported daily rectal bleeding. One patient with active rectal bleeding was taken for reoperation within the first 12 postoperative hours. Seventy percent of patients reported pain ≤ 2 on the first postoperative day, 85% on the fourth postoperative day, and 95% on the seventh postoperative day. Pain was measured with a linear analog scale from 0 to 10 (0 = no pain; 10 = unbearable pain). Seventeen patients (8.5%) reported tenesmus during the first week. Eight patients (4%) reported persistent pain: in 5 patients, the pain resolved within the next 6 months; 2 patients presented with anal fissure; and 1 patient required the removal of the staples. Two patients (1%) reported residual soiling at the 5-year revision. Fourteen patients (7%) experienced recurrence with symptomatic prolapse. Six (3%) underwent further surgery: stapled hemorrhoidopexy was indicated again in 2 patients, and 4 patients underwent a Milligan-Morgan open hemorrhoidectomy, because they did not have a uniform prolapse. Six patients required treatment with rubber band ligation. There were no statistically significant differences between preoperative and postoperative manometric values. CONCLUSIONS: The new PPH33-03 stapler, the learning process of the modified surgical procedure, and the correct selection of patients will overcome the main objections to stapled hemorrhoidopexy.

Bazo errante en paciente asintomática / Wandering spleen in an asymptomatic patient

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