Prospective cohort clinical study assessing the 5-year survival and success of anterior maxillary zirconia-based crowns with customized zirconia copings.

STATEMENT OF PROBLEM: Studies evaluating anterior zirconia-based crowns are limited. PURPOSE: The purpose of this prospective cohort clinical study was to assess the efficacy of zirconia-based anterior maxillary crowns with 0.3-mm customized copings at the cervical third and anatomical design elsewhere for up to 5 years of service. MATERIAL AND METHODS: Eighteen participants who required an anterior maxillary crown (n=20) and who had signed a consent form approved by the University of Washington Health Sciences Center Human Subjects Division were enrolled. All preparations were standardized and prepared with an occlusal reduction of 1.5 to 2 mm and an axial reduction of 1 to 1.5 mm with 10 degrees of convergence angle. All finish lines were located on the sound tooth structure. Zirconia copings (Lava; 3M ESPE) were custom designed and milled to a 0.3-mm thickness at the cervical third and with selective thickness elsewhere to support the veneering porcelain. All restorations were luted with self-etching self-adhesive composite resin cement. Recall appointments were at 2 weeks, 6 months, and 12 months, and annually thereafter for 5 years. Modified Ryge criteria were used to assess the clinical fracture measurements, esthetics, marginal discoloration, marginal adaptation, radiographic proximal recurrent caries, and periapical pathoses. Descriptive statistics and 95% confidence intervals were used to describe the number and rate of complications and self-reported satisfaction with the crowns. RESULTS: Twenty crowns with a mean follow-up of 58.7 months were evaluated. All crowns were rated as Alfa for fracture measurements (smooth surface, no fracture/chipping). Twelve crowns were rated esthetically as Romeo (no mismatch in color and shade) and 8 as Sierra (mismatch in color and shade within normal range). Twelve crowns were rated as Alfa (no visible evidence of crevice) and 8 as Bravo (visible evidence of crevice, no penetration of explorer) for marginal integrity. Nineteen were rated as Alfa (no discoloration) and 1 as Bravo (superficial discoloration) for marginal discoloration. No proximal caries or periapical pathoses were detected in 5 years. Participants were highly satisfied with their crowns after 5 years (mean ±SD: 9.8 ±0.4 on 0 to 10 scale). CONCLUSIONS: Zirconia-based anterior maxillary crowns with customized copings with 0.3-mm thickness at the cervical third and zirconia margins performed well after 5 years of service.

A comparative evaluation of the translucency of zirconias and lithium disilicate for monolithic restorations.

STATEMENT OF PROBLEM: Studies comparing the translucency of zirconias and lithium disilicates are limited. PURPOSE: The purpose of this in vitro study was to measure the translucency of recently developed translucent zirconias and compare them with lithium disilicate. MATERIAL AND METHODS: Five types of zirconia, Prettau Anterior (Zirkonzahn GmbH), BruxZir (Glidewell Laboratories), Katana HT, Katana ST, and Katana UT (Kurary Noritake Dental Inc), and 1 type of lithium disilicate, e.max CAD LT (Ivoclar Vivadent AG), were assessed. Non-colored zirconia test specimens (n=5) were prepared as rectangles with dimensions of 15×10×0.5 and 15×10×1.0 mm. The shade of lithium disilicate was B1. A spectrophotometer (Evolution 300 UV-Vis) with an integrating sphere was used to evaluate the total transmittance of light as a percentage (Tt%) at a wavelength of 555 nm for comparison among groups. The Welch robust test for equality of means was used to compare group means (α=.025) and post hoc pairwise comparisons among groups were performed with the Dunnett T3 method. RESULTS: For the 0.5 mm thickness groups, the Tt% was 31.90 ±0.49 for Prettau Anterior, 28.82 ±0.22 for BruxZir, 28.49 ±0.14 for Katana HT, 31.67 ±0.24 for Katana ST, 33.73 ±0.13 for Katana UT, and 40.32 ±0.25 for e-max CAD LT. Post hoc tests indicated that all groups were significantly different from each other, except for between BruxZir and Katana HT, and between Prettau Anterior and Katana ST. Katana UT was significantly more translucent than all other zirconias, and e-max CAD LT was significantly more translucent than all zirconias. For the 1.0 mm thickness groups, the Tt% was 22.58 ±0.41 for Prettau Anterior, 20.13 ±0.22 for BruxZir, 20.18 ±0.39 for Katana HT, 21.86 ±0.39 for Katana ST, 23.37 ±0.27 for Katana UT, and 27.05 ±0.56 for e-max CAD LT. Post hoc tests indicated that all materials were significantly different from each other, except for between BruxZir and Katana HT, and among Prettau Anterior, Katana ST and Katana UT which were significantly more translucent than all other zirconias and less translucent than e-max CAD LT. CONCLUSION: At a thickness of 0.5 mm, Katana UT was significantly more translucent than all other zirconias, and e-max CAD LT was significantly more translucent than all zirconias. At a thickness of 1.0 mm, Prettau Anterior, Katana ST, and Katana UT were significantly more translucent than all other zirconias and less than e-max CAD LT.

Clinical efficacy of polyvinyl siloxane impression materials using the one-step two-viscosity impression technique.

STATEMENT OF PROBLEM: Impression making is a challenging clinical procedure for both patients and dentists. PURPOSE: The purpose of this clinical study was to compare a recently introduced fast-setting polyvinyl siloxane (PVS) impression material with heavy body/light body (HB/LB) combination (Imprint 4; 3M ESPE) (experimental group) with a conventional PVS impression material with HB/LB combination (Imprint 3; 3M ESPE) (control group), using the 1-step 2-viscosity impression technique. MATERIAL AND METHODS: Two definitive impressions (1 of each material combination) were made of 20 crown preparations from 20 participants. The quality of impressions was rated by 3 evaluators (clinical evaluator, clinical operator, and dental technician) and by the patients for the level of comfort and taste of the impression materials. The order in which the 2 impressions were made with each material combination was randomized for each crown preparation. A paired t test for paired means and McNemar test for paired proportions were used for statistical comparisons (α=.05). RESULTS: Participants rated the comfort of the impression making with the experimental group significantly higher than that with the control group (P=.001). No significant differences were found in participants' rating for the taste of the impression materials (P=.46). The viscosity for tray material was rated as significantly better for the control group by the clinical operator (P=.004). The readability of the impression and visibility around the finish line were rated as significantly better for the experimental group than for the control group (P<.001). Except for the ease of removal of the stone (RS), the ratings for the 2 groups by the dental technician were similar. The ease of RS was rated as significantly better for the experimental group (P<.001). Eleven dies from the control and 9 from the experimental group were selected for fabrication of the definitive crowns (P=.65). CONCLUSION: Within the limitations of this clinical study, no significant differences were found in the overall clinical performance of the experimental and the control groups. Impressions made with both materials were clinically acceptable. Participants rated the comfort provided by the experimental group significantly better than that of the control group.

Biomimetic Dentin Repair: Amelogenin-Derived Peptide Guides Occlusion and Peritubular Mineralization of Human Teeth.

Exposure of dentin tubules due to loss of protective enamel (crown) and cementum (root) tissues as a result of erosion, mechanical wear, gingival recession, etc. has been the leading causes of dentin hypersensitivity. Despite being a widespread ailment, no permanent solution exists to address this oral condition. Current treatments are designed to alleviate the pain by either using desensitizers or blocking dentin tubules by deposition of minerals or solid precipitates, which often have short-lived effects. Reproducing an integrated mineral layer that occludes exposed dentin with concomitant peritubular mineralization is essential to reestablish the structural and mechanical integrity of the tooth with long-term durability. Here, we describe a biomimetic treatment that promotes dentin repair using a mineralization-directing peptide, sADP5, derived from amelogenin. The occlusion was achieved through a layer-by-layer peptide-guided remineralization process that forms an infiltrating mineral layer on dentin. The structure, composition, and nanomechanical properties of the remineralized dentin were analyzed by cross-sectional scanning electron microscopy imaging, energy dispersive X-ray spectroscopy, and nanomechanical testing. The elemental analysis provided calcium and phosphate compositions that are similar to those in hydroxyapatite. The measured average hardness and reduced elastic modulus values for the mineral layer were significantly higher than those of the demineralized and sound human dentin. The structural integration of the new mineral and underlying dentin was confirmed by thermal aging demonstrating no physical separation. These results suggest that a structurally robust and mechanically durable interface is formed between the interpenetrating mineral layer and underlying dentin that can withstand long-term mechanical and thermal stresses naturally experienced in the oral environment. The peptide-guided remineralization procedure described herein could provide a foundation for the development of highly effective oral care products leading to novel biomimetic treatments for a wide range of demineralization-related ailments and, in particular, offers a potent long-term solution for dentin hypersensitivity.

Data-driven design of a multiplexed, peptide-sensitized transistor to detect breath VOC markers of COVID-19.

Exhaled human breath contains a rich mixture of volatile organic compounds (VOCs) whose concentration can vary in response to disease or other stressors. Using simulated odorant-binding proteins (OBPs) and machine learning methods, we designed a multiplex of short VOC- and carbon-binding peptide probes that detect a characteristic "VOC fingerprint". Specifically, we target VOCs associated with COVID-19 in a compact, molecular sensor array that directly transduces vapor composition into multi-channel electrical signals. Rapidly synthesizable, chimeric VOC- and solid-binding peptides were derived from selected OBPs using multi-sequence alignment with protein database structures. Selective peptide binding to targeted VOCs and sensor surfaces was validated using surface plasmon resonance spectroscopy and quartz crystal microbalance. VOC sensing was demonstrated by peptide-sensitized, exposed-channel carbon nanotube transistors. The data-to-device pipeline enables the development of novel devices for non-invasive monitoring, diagnostics of diseases, and environmental exposure assessment.

Titanates deliver metal ions to human monocytes.

Amorphous peroxotitantes (APT) are insoluble titanium-based particles that bind a variety of metal compounds with high affinity; these particles could be sequestered locally in a solid phase to deliver metal-based drugs. Previous studies have confirmed the 'biodelivery' of metals from metal-APT complexes to fibroblasts, but not monocytes. Our goal in the current study was to use monocytic cytokine secretion to assess delivery of gold or platinum-based compounds from APT to human THP1 monocytes. Cytokine secretion was not triggered by APT alone or metal-APT complexes. In monocytes activated by lipopolysaccharide (LPS), APT alone enhanced or suppressed IL1beta or IL6 secretion, yet TNFalpha secretion was unaffected. Complexes of APT and Au(III) or cis-platin altered LPS-activated IL6 or IL1beta secretion most, TNFalpha least. Our results suggest that the APT deliver metals to monocytes.

Video-endoscopic Tension-free Groin Hernia Repair via Total Extraperitoneal Approach.

Introduction Tension-free repair of groin hernias with synthetic material by video-endoscopic surgery is a widely accepted method that is performed by various approaches. We aim to present our results of video-endoscopic tension-free repair of groin hernias via the total extraperitoneal (TEP) approach. Methods Between September 2016 and December 2018, 124 patients with groin hernias underwent tension-free repair using prolene mesh by video-endoscopic surgery via the TEP approach. This is a retrospective analysis of 110 (88.7%) male and 14 (11.3%) female patients with a mean age of 48.1 years. Groin hernia types, locations of hernias, intraoperative and postoperative complications, results of the mean 24-month follow-up, and recurrence rate were reported. Results A total of 134 hernias were repaired in 124 patients who had 53 (42.7%) right, 61 (49.2%) left, and 10 (8.1%) bilateral groin hernias. The most common hernia type was an indirect inguinal hernia in 83/134 (62%) groin hernias. A total of 119 (88.8%) and 15 (11.2%) hernias were primary and recurrent, respectively. Seroma was detected in two (1.6%) patients in the early postoperative period. The mean duration of hospital stay was 1.4 (1-3) days. During the follow-up period, hernia recurrence was determined in three (2.4%) patients. Hernia recurrence was detected among patients who were operated on during the first half of the study. Conclusion Tension-free repair of groin hernias by video-endoscopic technique via the TEP approach can be performed with very low complication and recurrence rates. The success of the TEP approach increases parallel to increasing surgical experience. The results of hernia repair via the TEP approach are highly satisfactory and encouraging, especially when attention is paid to proper patient selection during the learning curve period.

Residual Gastric Volume Relationship and Weight Loss After Laparoscopic Sleeve Gastrectomy.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has become a popular procedure for treating obesity. Excessive residual gastric volume (RGV) may be one cause of insufficient weight loss following this surgery. The purpose of this study was to investigate the relationship between weight loss and the RGV measured during surgery over a 2-year follow-up period. METHODS: All patients undergoing LSG at our university surgery department were included in this prospective observational study. During the operation, the pylorus was grasped with a laparoscopic clamp, and saline solution dyed with methylene blue was introduced using an intraluminal glass-tipped injector when the residual stomach became fully visible. The amount of fluid given when the remaining gastric tissue ceased expanding was noted. The patients were divided into three groups depending on the volume of the residual gastric tissue. Percentages of excess weight loss (EWL%) were also evaluated 6, 12, and 24 months after the LSG. RESULTS: Sixty-two patients (50 females and 12 males) with a mean age of 36 (17-56) years were included in the study. There was no significant difference between the preoperative and postoperative body mass index values (p = 0.407 and p = 0.337, respectively) or between the preoperative and postoperative weight (p = 0.081 and p = 0.517, respectively) among the groups. A comparison of the participants' weight losses and EWL% values after 6, 12, and 24 months of follow-up revealed no significant difference among the groups at any time point (p > 0.005). CONCLUSION: Greater weight loss was observed as the RGV decreased over the 24-month follow-up period. However, that weight loss was not statistically significant.

A clinical comparison of two vinyl polysiloxane impression materials using the one-step technique.

STATEMENT OF PROBLEM: Impression making remains a challenging procedure due to the potential for voids and tears, which may adversely affect the precise fabrication of indirect restorations. PURPOSE: The purpose of this study was to compare vinyl polysiloxane (VPS) impression materials using the 1-step impression technique for single and 2-unit crowns. MATERIAL AND METHODS: Twenty subjects provided informed consent, and two 1-step double-phase master impressions (1 of each material combination) were made of 25 crown preparations. A relatively new VPS material with heavy-body (HB) and light-body (LB) viscosities, which was defined as the experimental group (Imprint 3), was compared to a standard VPS with medium-body (MB) and light-body (LB) viscosities, which was defined as the control group (Aquasil Ultra). Stock trays were used to make a total of 40 master impressions. The order of impression making was randomized as related to the different groups. Impressions were rated visually by 2 evaluators (a clinician and a dental technician). The rating resulted in ordinally structured data for the outcome variables (alpha: excellent, no defects; bravo: acceptable, small defects; charlie: defects require impression to be remade; delta: unacceptable, defects at finish line). Definitive casts made of impressions rated as alpha or bravo were further rated by a dental technician, and that which was rated best was used for making the definitive crown. RESULTS: Twenty-three (92%) of the experimental and 24 (96%) of the control impressions were rated as alpha or bravo by the evaluator (P=.57; McNemar's test for clustered paired proportions using GEE). All 25 dies in the definitive casts of both groups were rated as alpha or bravo by the dental technician. Fifteen dies were selected from the control group and 10 from the experimental group for the fabrication of the definitive crowns (P=.41; 1-sample binomial test for clustered data using GEE). CONCLUSIONS: Within the limitations of this clinical study, there was no statistical difference in the clinical performance of the experimental and control VPS impression materials. (J Prosthet Dent 2009;102:179-186).

Cementation of Zirconia-Based Toothborne Restorations: A Clinical Review.

As the demand for esthetics in dentistry has increased over the years, zirconia-based restorations have been successfully used as alternatives to metal-ceramic restorations. A reliable marginal seal is among the factors that are vital to the clinical success of a dental restoration. One advantage of zirconia-based restorations is that the cementation process is generally simpler and more efficient compared to the delivery/cementation of other all-ceramic systems. This article reviews several categories of cement used for the cementation of zirconia restorations: zinc-phosphate cement, glass-ionomer cement (GIC), resin-modified GIC, and composite-resin cement.

Inverse 'D' incision technique in treatment of pilonidal sinus disease; excision with minimal tissue loss, closure without tension and lateral location of the suture line.

PURPOSE: Surgical excision is the preferred treatment modality for sacrococcygeal pilonidal sinus (PS). Notably, the desirable features of an ideal surgical intervention are excision with minimal tissue loss, closure without tension, and a lateral suture line. The present study aimed to investigate early outcomes of surgical excision through the inverse D (ᗡ) incision based on tissue loss, wound tension, and suture line location. METHODS: This prospective study was comprised of 80 patients with PS in whom excision of PS was performed through the 'ᗡ' incision to minimize tissue loss with a tensionless primary surgical wound closure. The suture line was located laterally in all patients. Early and late postoperative complications, duration of hospital stay, return to work, and recurrence rates were investigated. The mean duration of the follow-up period was 36 months. RESULTS: Sixty-three patients (78.8%) were male. PS in all patients was surgically removed by subcutaneous excision through a 'ᗡ' incision. Laterally placed surgical wounds were closed primarily with interrupted vertical mattress sutures. No general complications were encountered. Five patients (6.3%) experienced early postoperative surgical site complications. On average, the duration of hospital stay and return to work were 2.4 days and 3.8 days, respectively. Recurrence was seen in 1 case (1.3%) during the follow-up period. Satisfaction score was high in 83.8% of patients. CONCLUSION: The method of sinus excision using the 'ᗡ' incision with a primary suture facilitates excision with minimal tissue loss and closure without tension with an off-midline suture. It is both a simple and effective surgical technique for the treatment of sacrococcygeal PS.

Visual and electrophysiological identification of the external branch of superior laryngeal nerve in redo thyroid surgery compared with primary thyroid surgery.

PURPOSE: Thyroid reoperations are surgically challenging because of significant anatomical variance. Visual and functional identification of the external branch of the superior laryngeal nerve (EBSLN) were studied in 2 groups of patients who underwent primary and redo thyroid surgery. METHODS: This study was conducted on 200 patients: 100 patients with redo and 100 patients with primary thyroid surgery. In addition to visual identification, nerve branches were functionally identified by intraoperative nerve monitoring (IONM). Visual, functional, and total identification rates of the EBSLN in both primary and redo surgery were determined and compared between the 2 groups. RESULTS: We attempted to identify 138 and 170 EBSLNs at risk in redo and primary surgery, respectively. Visual identification rates were 65.3% and 30.4% (P < 0.001) in primary and redo surgery groups, respectively. In total, 164 (96.5%) and 97 EBSLNs (70.3%) were identified in primary and redo surgery, respectively (P < 0.001), including the use of IONM. In primary surgery group, 53 nonvisualized EBSLNs of 164 identified nerves (32.3%) were determined by IONM alone. In redo surgery group, 55 of 97 identified nerves (56.7%) were determined by IONM alone (P < 0.001). CONCLUSION: Both visual and total identification rates of the EBSLN are significantly decreased in reoperative thyroidectomy. IONM increases the total identification rate of the EBSLN in primary and redo thyroid surgery. Electrophysiological monitoring makes a substantial contribution to the identification of the EBSLN both in primary and especially in redo thyroid surgery.

Does pregnancy interval after laparoscopic sleeve gastrectomy affect maternal and perinatal outcomes?

Background: Obesity is a global health epidemic and is associated with many maternal and neonatal complications. Laparoscopic sleeve gastrectomy (LSG) is among the surgical treatments for obesity. The appropriate timing of pregnancy following LSG remains controversial and few studies have evaluated this public health issue. Objective: To evaluate the effect of pregnancy timing after LSG on maternal and perinatal outcomes. Study design: We performed a retrospective observational study of 23 pregnant women who underwent LSG at a tertiary hospital in Turkey. Women who became pregnant within 18 months of undergoing LSG were included in the early pregnancy after LSG group, and those who became pregnant after 18 months were included the late pregnancy after LSG group. Maternal and perinatal outcomes were evaluated, including gestational diabetes mellitus (GDM), pregnancy-associated hypertensive disorders, preterm birth, mode of delivery, small and large for gestational age births (small for gestational age (SGA), large for gestational age (LGA)), birth injury, and congenital malformations. Results: Body mass index (BMI) at conception was higher in the early pregnancy after LSG group than in the late pregnancy after LSG group (30.48 versus 27.25, respectively; p = .03). Pregnancy interval after LSG did not impact maternal-fetal complications or mode of delivery. After a 75 g oral glucose tolerance test (OGTT) for GDM, 75% (n = 6) of the early pregnancy group presented with early dumping syndrome, compared to only 13.3% (n = 2) of the late pregnancy after LSG group (p = .009). Conclusions: LSG may reduce obesity-related gestational complications, such as GDM and LGA. The interval between LSG and conception did not impact maternal or neonatal outcomes. Screening for GDM can result in dumping syndrome in pregnancies after LSG.

Ocular abnormalities in morbid obesity.

PURPOSE: Obesity is associated with eye diseases, but the underlying structural changes and pathogenic mechanisms have not been examined in detail. Here, we assessed the effects of morbid obesity on the morphometric indices of eye disease. METHODS: Morbidly obese volunteers (n=101, body mass index [BMI] ³40) and healthy individuals (n=95, BMI: 18.50-24.99) were examined by Goldman applanation tonometry, pachymetry, and spectral domain optical coherence tomography. Intraocular pressure, anterior chamber depth, axial length, central corneal thickness, retinal nerve fiber layer thickness, central foveal thickness, and choroidal thickness were compared between groups. RESULTS: Uncorrected intraocular pressure was significantly greater in the morbidly obese group than in the healthy control group (15.5 ± 2.5 vs. 14.5 ± 2.6 mmHg, p=0.009), whereas axial length, anterior chamber depth, and central corneal thickness did not differ between the groups. The mean retinal nerve fiber layer thickness at the temporal quadrant was reduced in the morbidly obese group (72.7 ± 13.6 vs. 85.05 ± 52.6 mm, p=0.024). Similarly, the mean retinal thicknesses at nasal and temporal 1500-mm locations were lower in the morbidly obese group (346.6 ± 18.2 vs. 353.7 ± 18.8 mm, p=0.008; 323.1 ± 20.3 vs. 330.0 ± 18.9 mm, p=0.001). The mean choroidal thickness was also reduced in almost all measurement locations (fovea, temporal 500 and 1000 mm, and nasal 500, 1000, and 1500 mm) of the obese group (p<0.05). Weight and BMI were negatively correlated with subfoveal choroidal thickness (r=-0.186, p=0.009; r=-0.173, p=0.015). CONCLUSION: Morbid obesity is associated with elevated uncorrected intraocular pressure and signs of neuropathy and retinopathy. Obesity may thus increase the risks of glaucoma and glaucomatous optic neuropathy.

Harvesting technique using a mucotome and modified surgical procedure for root coverage with enamel matrix derivatives with and without a connective tissue graft.

The aim of this clinical study was to evaluate the coverage of gingival recession defects with enamel matrix derivatives (EMD) with or without a connective tissue graft (CTG). Twenty-five patients (16 female, 9 male) from 16 to 58 years of age (mean: 32.2; SD: 11.2) with 92 gingival recessions (Miller Class I and II) and with at least 4.0 mm of clinical attachment loss were treated with a modified surgical technique for root coverage by CTG with EMD (45 recession defects) or EMD only (47 recession defects). Vertical recession depth, probing depth, clinical attachment level, dehiscence depth, width of keratinized gingiva (vertical), and recession coverage were recorded before surgery (baseline) and at 12 and 24 months. The average presurgical recession depth was 4.4 mm (SD: 1.3) with EMD and CTG versus 3.2 mm (SD: 1.1) with EMD only. Both treatment modalities led to a significant decrease in recession and a gain in attachment. Mean root coverage 12 months postoperatively was 92.7% (SD: 13.5) (EMD and CTG) versus 96.3% (SD: 11.5) (EMD only). Compared to the mean root coverage of recession after 24 months, the change was not significant. The results confirmed that the applied modified surgical techniques are safe and predictable, with better clinical outcomes at the donor and recipient sites.

Concepts and considerations of tooth wear: Part II--The mechanical component.

Identification of etiological factors is essential for successful management of tooth wear. In many cases, the diagnosis may be complicated because of the multiple etiologic factors which may confound the clinical appearance of tooth wear. Comprehensively addressing all of these factors is paramount to the long-term success of patient management.

Biomimetic Tooth Repair: Amelogenin-Derived Peptide Enables in Vitro Remineralization of Human Enamel.

White spot lesions (WSL) and incipient caries on enamel surfaces are the earliest clinical outcomes for demineralization and caries. If left untreated, the caries can progress and may cause complex restorative procedures or even tooth extraction which destroys soft and hard tissue architecture as a consequence of connective tissue and bone loss. Current clinical practices are insufficient in treating dental caries. A long-standing practical challenge associated with demineralization related to dental diseases is incorporating a functional mineral microlayer which is fully integrated into the molecular structure of the tooth in repairing damaged enamel. This study demonstrates that small peptide domains derived from native protein amelogenin can be utilized to construct a mineral layer on damaged human enamel in vitro. Six groups were prepared to carry out remineralization on artificially created lesions on enamel: (1) no treatment, (2) Ca2+ and PO43- only, (3) 1100 ppm fluoride (F), (4) 20 000 ppm F, (5) 1100 ppm F and peptide, and (6) peptide alone. While the 1100 ppm F sample (indicative of common F content of toothpaste for homecare) did not deliver F to the thinly deposited mineral layer, high F test sample (indicative of clinical varnish treatment) formed mainly CaF2 nanoparticles on the surface. Fluoride, however, was deposited in the presence of the peptide, which also formed a thin mineral layer which was partially crystallized as fluorapatite. Among the test groups, only the peptide-alone sample resulted in remineralization of fairly thick (10 µm) dense mineralized layer containing HAp mineral, resembling the structure of the healthy enamel. The newly formed mineralized layer exhibited integration with the underlying enamel as evident by cross-sectional imaging. The peptide-guided remineralization approach sets the foundation for future development of biomimetic products and treatments for dental health care.

Displacement of the Recurrent Laryngeal Nerve in Patients with Recurrent Goiter Undergoing Redo Thyroid Surgery.

Thyroid reoperations are surgically challenging because of scarring and disturbances in the anatomy of the recurrent laryngeal nerve (RLN). This study was conducted on 49 patients who underwent redo surgery. 61 RLNs were identified and completely exposed. Their functional integrity was evaluated using intraoperative nerve monitoring (IONM). Indications for secondary surgery, anatomical changes secondary to recurrent goiter mass and prior surgery, and results of IONM were studied. Frequent indications for redo surgery were multinodular goiter (MNG) in 19 (38.8%) and results of cytology in 14 (28.5%) patients. The mean time interval between primary and redo thyroid surgery was 23.4 years. We laterally approached 41 (67.2%) thyroid lobes between the sternocleidomastoid and sternohyoid muscles. 16 (26.2%) RLNs were found to be adherent to the lateral surface of the corresponding thyroid lobe. The functional integrity of all RLNs was confirmed by IONM. The remnant thyroid tissue can then lead to goiter recurrence requiring secondary surgery after a long period of time. The indications for redo surgery were similar to primary cases. Lateral displacement of the RLN which is adherent to the lateral surface of recurrent goiter mass is common anatomic variation. Thyroid reoperations based on awareness of anatomical disturbances can be performed safely by an experienced surgeon with support of ancillary electrophysiological technology.

Additive effects of TEGDMA and hydrogenperoxide on the cellular glutathione content of human gingival fibroblasts.

OBJECTIVES: Only few data are available about cytotoxic effects of leachable dental resin compounds in combination with hydrogen peroxide (H(2)O(2)) segregated from dental bleaching agents. Therefore, the purpose of this study was to evaluate the effects of various concentrations of triethylene-glycol dimethacrylate (TEGDMA) and H(2)O(2) on intracellular glutathione levels (GSH) and viability of human gingival fibroblasts (HGF) that are primary target cells of cytotoxic actions of these substances. METHODS: HGF were grown in 96-well plates for 24h, treated with various concentrations of TEGDMA (0.5-5.0mM) for 24h and subsequently for 90min with 0.2mM H(2)O(2) or culture medium (control). The relative intracellular GSH concentration was determined using a fluorescence assay with monobromobimane. Readings were normalized to cell numbers, which were determined by a propidium iodide assay. Data were statistically analyzed by t-test and ANOVA with Tukey's post test. A significance level of p<0.05 was used. RESULTS: Exposure to TEGDMA reduced the viability of HGF at concentrations > or =1.0mM. TEGDMA induced a decrease of the GSH pool in a concentration-dependent manner (p<0.05). The depletion of GSH was correlated with a reduction of viability (p<0.05) and the total cell number. Furthermore, a significant decrease of the intracellular GSH content was found when cells were exposed to TEGDMA in combination with H(2)O(2), compared to experiments without H(2)O(2). SIGNIFICANCE: We conclude from our findings that TEGDMA and H(2)O(2) have additive adverse effects on GSH metabolism and cell viability.

Coexistence of Right Nonrecurrent Nerve and Bifurcated Recurrent Laryngeal Nerve Pointed by Zuckerkandl's Tubercle.

The recurrent laryngeal nerve (RLN) has many anatomical variations and various relations with adjacent structures. Identification and total exposure of the cervical part of the RLN was performed during operations on the thyroid gland. An extremely rare anatomical variation of the nerve was encountered during the surgical procedure. Coexistence of both right RLN and non-RLN was observed in one patient surgically treated with total thyroidectomy. We first exposed the right RLN with an extralaryngeal terminal bifurcation at its usual position. Thereafter, we also identified an ipsilateral non-RLN joining the anterior branch of the RLN just before laryngeal entry. A Zuckerkandl's tubercle has pointed out the junction of the two nerves. In this period, the incidence of coexistence of non-RLN and RLN was 0.2% in our series. A non-recurrent course is a rare anatomical variation of the inferior laryngeal nerve. The coexistence of both non-RLN and RLN is an extremely rare anatomical finding which should be taken into account during thyroid surgery.