Carbon monoxide inhibition on acidogenic glucose fermentation and aceticlastic methanogenesis.

Syngas and CO-rich off-gases are key chemical platforms to produce biofuels and bioproducts. From the perspective of optimizing and up-scaling CO co-digestion with organic waste streams, this study aims at assessing and quantifying the inhibitory effects of CO on acidogenic glucose fermentation and aceticlastic methanogenesis. Mesophilic cultures were fed in two sets of batch assays, respectively, with glucose and acetate while being exposed to dissolved CO in equilibrium with partial pressures in the range of 0.25-1.00 atm. Cumulative methane production and microbial monitoring revealed that aceticlastic methanogenic archaea were significantly inhibited (2-20 % of the methane production of CO non-exposed cultures). The acidogenic glucose degrading community was also inhibited by CO, although, thanks to its functional redundancy, shifted its metabolism towards propionate production. Future work should assess the sensitivity of hereby estimated CO inhibition parameters, e.g., on the simulation output of a continuous syngas co-digestion process with organic substrates.

Cryopreservation and fast recovery of enriched syngas-converting microbial communities.

Over the last decades, the use of mixed microbial communities has attracted increasing scientific attention due to their potential biotechnological applications in several emerging technological platforms such as the carboxylate, bioplastic, syngas and bio-electrochemical synthesis platforms. However, this increasing interest has not been accompanied by a parallel development of suitable cryopreservation techniques for microbial communities. While cryopreservation methods for the long-term storage of axenic cultures are well established, their effectiveness in preserving the microbial diversity and functionality of microbial communities has rarely been studied. In this study, the effect of the addition of different cryopreservation agents on the long-term storage of microbial communities at -80 °C was studied using a stable enrichment culture converting syngas into acetate and ethanol. The cryopreservation agents considered in the study were glycerol, dimethylsulfoxide, polyvinylpyrrolidone, Tween 80 and yeast extract, as well as with no addition of cryopreservation agent. Their effectiveness was evaluated based on the microbial activity recovery and the maintenance of the microbial diversity and community structure upon revival of the microbial community. The results showed that the commonly used glycerol and no addition of cryopreservation agent were the least recommendable methods for the long-term frozen storage of microbial communities, while Tween 80 and polyvinylpyrrolidone were overall the most effective. Among the cryoprotectants studied, polyvinylpyrrolidone and especially Tween 80 were the only ones assuring reproducible results in terms of microbial activity recovery and microbial community structure preservation.

Stability of the gingival margin after an aesthetic crown lengthening procedure in the anterior region by means of a replaced flap and buccal osseous surgery: a prospective study.

OBJECTIVES: The main objective of this study was to assess changes in the position of the gingival margin (GM) after performing an aesthetic crown lengthening (ACLP) by means of submarginal incisions, buccal osseous surgery, and a replaced flap after a healing period of 6 months. METHODS: Twenty-one patients who needed a surgical crown lengthening in the maxillary anterior teeth were included. An individual stent was fabricated to record changes in the position of the GM. Clinical measurements were recorded pre-surgically; immediately post-surgically (baseline); and at 42, 90, and 180 days. RESULTS: After the ACLP, the GM displacement did not change significantly after 42, 90, and 180 days (4.32 ± 1.17 mm, 4.29 ± 1.14 mm, and 4.26 ± 1.11 mm, respectively). Tissue rebound seems to be related to the distance from the GM to the alveolar bone (AB) at the time of suturing (GM-AB(X)). When GM-AB(X) was ≤ 2 mm, 3 mm, and ≥ 4 mm, the GM rebound at 6 months was 0.94 ± 0.53 mm, 0.10 ± 0.28 mm, and - 0.26 ± 0.40 mm, respectively. These differences were statistically significant (P < 0.001). CONCLUSIONS: An ACLP releasing the flap up to the mucogingival junction, with a ≥ 3-mm distance from the bone crest to the gingival margin can lead to a stable GM position at 42, 90, and 180 days. CLINICAL RELEVANCE: This article focuses on variables affecting the stability of the GM, which is a critical factor that may compromise the biological and aesthetic long-term outcomes.

Correlation between type 2 diabetes, dry eye and Meibomian glands dysfunction / Correlación entre diabetes tipo 2, ojo seco y disfunción de las glándulas de Meibomio

PURPOSE: To assess the Meibomian glands, ocular surface and tear function in patients with type 2 diabetes, and study the correlation between these conditions. METHODS: Prospective study of 76 males, 37 with type 2 diabetes with an average of duration between 7 ± 5 years, and 36 males from control group. After completing an ocular surface disease index (OSDI) questionnaire, the non-invasive tear film break-up time (NIBUT) and the tear lipid layer pattern was performed using interferometry system and tear meniscus height/TMH. Ocular surface was studied with lissamine green staining and morphology of the glands with evaluation of Marx's line (lid margin abnormalities); meibomian secretion was expressed and was also assessed the quality. The results were analyzed using the statistical Kruskal-Wallis and Mann-Whitney, and correlations by Spearman Rho. RESULTS: The mean age was 59 ± 8 years; 71% of participants presented MGD (76% diabetics and 67% controls). OSDI were significantly higher (p = 0.01) in the diabetic group. A positive correlation was found between glycemia and symptoms (p = 0.0005) and strong correlation between Hb1Ac and OSDI in MGD. NIBUT was lower in the control group (2.47 ± 1.2s) than for the diabetic group (2.9 ± 1.2s), with a significant inverse correlation (52.22%) with MG inflammation. CONCLUSIONS: MGD in type 2 diabetic patients is more severe compared with nondiabetic patients. Longer duration of diabetes is associated with major symptoms and changes in MG. Diabetic group showed major changes in lids and tear function, accounting for evaporative dry eye and presenting a high degree of correlation with MG inflammation and obstruction

OBJETIVO: Evaluar las glándulas de Meibomio, la superficie ocular y la función de la lágrima en pacientes con diabetes tipo 2, y estudiar la correlación entre estas situaciones. MÉTODOS: Estudio prospectivo de 76 varones, 37 de ellos con diabetes tipo 2, con una media de duración de entre 7 ± 5 años, y 36 mujeres como grupo control. Tras completar el cuestionario del índice de enfermedad de la superficie ocular (OSDI), se obtuvieron el tiempo de ruptura lagrimal no invasivo (NIBUT) y el patrón de la capa lipídica de la lágrima utilizando interferometría y altura del menisco lagrimal/AML. Se estudió la superficie ocular con tinción verde de lisamina y la morfología de las glándulas con evaluación de la línea de Marx (anomalías del margen del párpado); se expresó la secreción de las glándulas de Meibomio, así como su calidad. Los resultados se analizaron utilizando la pruebas estadísticas Kruskal-Wallis y Mann-Witney, y las correlaciones con Rho de Spearman. RESULTADOS: La edad media fue de 59 ± 8 años; el 71% de los participantes presentaron DGM (76% diabéticos y 67% controles). OSDI fue significativamente superior (p = 0,01) en el grupo diabético. Se encontró una correlación positiva entre glucemia y síntomas (p = 0,0005), y una fuerte correlación entre Hb1Ac y OSDI en DGM. NIBUT fue inferior en el grupo control (2,47 ± 1,2 s) que en el grupo diabético (2,9 ± 1,2 s), con una correlación inversa significativa (52,22%) con la irregularidad del borde palbebral y queratinización del OM. CONCLUSIONES: DGM en los pacientes con diabetes tipo 2 es más grave, en comparación con los pacientes no diabéticos. La mayor duración de la diabetes se asocia a síntomas mayores y cambios en la GM. El grupo diabético reflejó cambios mayores en los párpados y la función de la lágrima, lo cual supone ojo seco evaporativo, y un alto grado de correlación con irregularidad del margen palpebral y obstrucción de la GM

Atención sanitaria e impacto económico / Healthcare and economic impact

En este capítulo se revisa el modelo actual de atención a los pacientes con VIH y su impacto económico. Existen diferencias geográficas y clínicas en los cuidados que reciben los pacientes con VIH. Se detecta la necesidad de elaborar nuevos modelos de atención integral de la enfermedad por VIH. La infección por VIH en España es un problema de salud pública relevante y costoso. Los principales costes se deben al tratamiento antirretroviral, los costes indirectos y los costes de hospitalización, consultas y pruebas diagnósticas. Se pone de manifiesto una fuerte asociación entre gravedad y costes. Los pacientes con diagnóstico tardío presentan peor evolución clínica y mayor mortalidad, y emplean más recursos médicos y terapéuticos. La detección precoz de la enfermedad mejora considerablemente la evolución clínica de los pacientes. El incremento de los pacientes en tratamiento y su envejecimiento progresivo aumentarán los costes de la atención al VIH en los próximos años

This chapter reviews the current model of HIV patient care and its economic impact. There are clinical and geographical differences in the care HIV patients receive and a need to develop new models of comprehen-sive HIV care has been identified. HIV infection in Spain is an important and expensive public health problem. The main costs are due to an-tiretroviral therapy, indirect costs and the cost of admission, consultation and diagnostic testing. A strong correlation between severity and cost has been identified. Patients diagnosed late have a poorer clinical course, increased mortality and require more medical and therapeutic resources. Early detection of the disease significantly improves the clinical outcomes of patients. The increased number of patients receiving treatment and their progressive ageing will increase costs of HIV healthcare in the coming years

Situación de la investigación sobre el VIH en España / Current situation of HIV research in Spain

Prevención, detección temprana, abordaje clínico, organización y gestión son elementos clave en los desafíos planteados por la infección por el VIH-1 en España. Sin embargo, existe otra categoría de intervención de carácter transversal que tiene gran importancia en la respuesta científica a la infección por VIH: la investigación. En este artículo se analiza la evolución de la investigación sobre el VIH/sida en España, sus principales hitos históricos y las estructuras de investigación que han permitido su desarrollo. Estos datos se enmarcan en el contexto general de la situación de la I+D en España y el impacto que sobre el sistema de ciencia español han tenido la crisis económica y los recortes presupuestarios. Por último se analizan las perspectivas de futuro de la investigación en VIH/sida en el contexto global

Prevention, early detection, clinical follow-up, organisation and management are key elements in the chal-lenges to be addressed in the field of HIV infection in Spain. In addition to these aspects, research repre-sents a transversal element that is highly relevant for building up a comprehensive response against HIV infection. The evolution of HIV/AIDS research in Spain, major milestones and the development of scientific structures are analysed. An economic description of HIV/AIDS research funding in the context of the whole Spanish R&D system is made. In particular, the impact of the economic crisis and budget restrictions and their con-sequences on medical research are considered. Finally, different perspectives on the future of HIV/AIDS research in the global scientific situation are discussed

Healthcare and economic impact. / Atención sanitaria e impacto económico.

This chapter reviews the current model of HIV patient care and its economic impact. There are clinical and geographical differences in the care HIV patients receive and a need to develop new models of comprehen-sive HIV care has been identified. HIV infection in Spain is an important and expensive public health problem. The main costs are due to an-tiretroviral therapy, indirect costs and the cost of admission, consultation and diagnostic testing. A strong correlation between severity and cost has been identified. Patients diagnosed late have a poorer clinical course, increased mortality and require more medical and therapeutic resources. Early detection of the disease significantly improves the clinical outcomes of patients. The increased number of patients receiving treatment and their progressive ageing will increase costs of HIV healthcare in the coming years.

Current situation of HIV research in Spain. / Situación de la investigación sobre el VIH en España.

Prevention, early detection, clinical follow-up, organisation and management are key elements in the chal-lenges to be addressed in the field of HIV infection in Spain. In addition to these aspects, research repre-sents a transversal element that is highly relevant for building up a comprehensive response against HIV infection. The evolution of HIV/AIDS research in Spain, major milestones and the development of scientific structures are analysed. An economic description of HIV/AIDS research funding in the context of the whole Spanish R&D system is made. In particular, the impact of the economic crisis and budget restrictions and their con-sequences on medical research are considered. Finally, different perspectives on the future of HIV/AIDS research in the global scientific situation are discussed.

Enrichment of syngas-converting mixed microbial consortia for ethanol production and thermodynamics-based design of enrichment strategies.

BACKGROUND: The production of ethanol through the biochemical conversion of syngas, a mixture of H2, CO and CO2, has been typically studied using pure cultures. However, mixed microbial consortia may offer a series of benefits such as higher resilience and adaptive capacity, and non-sterile operation, all of which contribute to reducing the utility consumption when compared to pure culture-based processes. This work focuses on the study of strategies for the enrichment of mixed microbial consortia with high ethanologenic potential, investigating the effect of the operational conditions (pH and yeast extract addition) on both the ethanol yield and evolution of the microbial community along the enrichment process. The pH was selected as the main driver of the enrichment as it was expected to be a crucial parameter for the selection of carboxydotrophic bacteria with high ethanologenic potential. Additionally, a thermodynamic analysis of the network of biochemical reactions carried out by syngas-converting microbial consortia was performed and the potential of using thermodynamics as a basis for the selection of operational parameters favoring a specific microbial activity was evaluated. RESULTS: All enriched consortia were dominated by the genus Clostridium with variable microbial diversity and species composition as a function of the enrichment conditions. The ethanologenic potential of the enriched consortia was observed to increase as the initial pH was lowered, achieving an ethanol yield of 59.2 ± 0.2% of the theoretical maximum in the enrichment at pH 5. On the other hand, yeast extract addition did not affect the ethanol yield, but triggered the production of medium-chain fatty acids and alcohols. The thermodynamic analysis of the occurring biochemical reactions allowed a qualitative prediction of the activity of microbial consortia, thus enabling a more rational design of the enrichment strategies targeting specific activities. Using this approach, an improvement of 22.5% over the maximum ethanol yield previously obtained was achieved, reaching an ethanol yield of 72.4 ± 2.1% of the theoretical maximum by increasing the initial acetate concentration in the fermentation broth. CONCLUSIONS: This study demonstrated high product selectivity towards ethanol using mixed microbial consortia. The thermodynamic analysis carried out proved to be a valuable tool for interpreting the metabolic network of microbial consortia-driven processes and designing microbial-enrichment strategies targeting specific biotransformations.

Soft tissue volume gain around dental implants using autogenous subepithelial connective tissue grafts harvested from the lateral palate or tuberosity area. A randomized controlled clinical study.

AIM: To compare the soft tissue volume gain (VG) around single tooth implants with subepithelial connective tissue graft (SCTG) from either the lateral palate (LP) or from the tuberosity area (TA). METHODS: Thirty-two patients with 36 implants with buccal volume deficiencies were randomly assigned to receive SCTG from LP (control group/CG) or TA (test group/TG). Clinical parameters were recorded. VG was evaluated by stereolithography (STL) image superimposition of two intraoral scans (baseline/BL and 3 months after surgery/FU-3). Descriptive analysis was performed for both groups, and for comparisons, Mann-Whitney U test was used. RESULTS: In terms of VG values, no statistically significant differences were observed except for values at 6 and 7 mm apically to the healing abutment which favoured the TG. Mean values were 0.69 ± 0.23 mm for CG while TG obtained 0.79 ± 0.10 mm (p = .64). Regarding Keratinized tissue (KT) width statistical significant differences were found favouring TG, which obtained a gain of 0.83 ± 0.61 mm compared with 0.22 ± 0.48 mm for CG (p = .009). Pink esthetic scores resulted in mean values of 10.07 ± 2.19 for the CG, while TG obtained 9.15 ± 2.34. CONCLUSIONS: Both procedures were effective in increasing soft tissue volume with no statistically significant differences. A longer follow-up is needed to confirm or refute these results.

Efficacy of Adjunctive Er, Cr:YSGG Laser Application Following Scaling and Root Planing in Periodontally Diseased Patients.

The application of laser as a monotherapy has been shown to reduce probing pocket depths and increase clinical attachment levels after treatment of patients suffering from chronic periodontitis. Its controversial use as an adjunct to scaling and root planing (SRP) is discussed. The present study aimed to evaluate the efficacy of adjunctive Er, Cr:YSGG laser application following conventional SRP. A total of 30 patients with chronic periodontitis were enrolled in the study. The quadrants of each patient were allocated to either SRP or SRP + laser. A total of 3,654 sites with pocket depths ≥ 4 mm were treated and evaluated at 6 weeks and 6 months postoperatively with respect to attachment gain. Both therapies resulted in improved probing pocket depths and clinical attachment levels. The adjunctive application of Er, Cr:YSGG laser following SRP did not improve probing pocket depth or attachment level compared with SRP alone.

In vitro evaluation of the root surface microtopography following the use of two polishing systems by Confocal Microscopy (CFM) and Scanning Electron Microscope (SEM).

OBJECTIVES: To compare and evaluate the root surface roughness after using two polishing instruments for root planing. MATERIALS AND METHODS: This comparative study was carried out on a sample of ten extracted human teeth with twenty interproximal root surfaces. Control group 1 and 2: (n=20 root surface): Gracey Curettes, 15 vertical strokes. Test group 1 (n=10): control group 1 + Termination Diamond Curettes (TDC), 15 strokes. Test group 2 (n=10): control group 2 + Termination Diamond Burs -15 µm (TDB), with irrigation for 15 seconds at 3000 rpm. The root surface was planed with the polishing instruments and test measurements were obtained with Confocal Microscopy (CFM) and Scanning Electron Microscope (SEM). The primary outcome variable was surface roughness (Ra). RESULTS: CFM showed that the TDC, mean changes in surface roughness (Ra) were reduced by 0.11 ± 0.14 (p-value = 0.000), and the TDB, Ra: were reduced by 0.27 ± 0.86 (p-value = 0.037). Non-statistically significant differences were observed in Ra (p-value = 0.581) between the two polishing instruments. SEM showed that the Group 2 showed a generally rougher surface with more parallel grooves than Group 1. CONCLUSION: There are no statistically significant differences between these two polishing systems, although TDB seems to reduce the surface roughness more than the TDC after being treated with Gracey Curettes.

Anterior maxillary and mandibular biotype: relationship between gingival thickness and width with respect to underlying bone thickness.

PURPOSE: : Periodontal biotype is considered to be a significant factor related to successful dental treatments. The purpose of this study was to determine the relationship between gingival thickness (GT) and width with respect to the underlying bone thickness in the maxillary and mandibular anterior sextant. MATERIALS AND METHODS: : Overall, 180 anterior teeth within healthy patients were assessed. GT and buccal bone thickness (BT) were measured at 3 locations: crestal/gingival margin, tooth apex, and a midpoint between the 2. In addition, the apicoincisal gingival width (GW) was recorded. Clinical and cone beam CT measurements were compared and correlated. RESULTS: : No statistically significant relations were observed between GT and BT measures at any of the 3 positions. The mean GT at crestal mid and apical position for the maxillary teeth was 1.01 (±0.58) mm, 1.06 (±0.48) mm, and 0.83 (±0.47) mm, respectively, and the corresponding mean BT was 1.24 (±0.90) mm, 0.81 (±0.33) mm, and 2.78 (±1.62) mm, respectively. The GW is directly related (R = 0.007; P < 0.05) to the crestal BT. CONCLUSION: : In this study, the GT is not linked to the BT. However, the GW seems to be associated with the crestal BT.

Isolation and characterization of probiotic strains for improving oral health.

UNLABELLED: Probiotics have been proven effective for preventing caries. In contrast, the effect of probiotics on improving oral diseases such as gingivitis, periodontitis and halitosis has been less explored. OBJECTIVE: To perform a screening of lactic acid bacteria, according to international guidelines for the evaluation of probiotics, in order to select candidate probiotic strains for preventing oral disorders. STUDY DESIGN: The strains were isolated from healthy children and were subjected to a variety of in vitro tests in order to show their functionality. The safety of the strains was assessed by determining antibiotic susceptibility and production of lactic acid. RESULTS: Forty-six of the 100 new isolates were assigned to lactic acid bacteria genera after a biochemical characterization. Most of the new isolated strains seem to be resistant to oral conditions, have great ability to form aggregates and have high antagonistic activity against oral pathogens. None of the strains produced unpleasant volatile compounds. The strains showed high ability to adhere to oral tissues and they do not present any antibiotic resistance. Moreover, an increased risk of developing caries due to their ability to produce lactic acid was discarded in seven pre-selected probiotic candidates. CONCLUSIONS: These lactic acid bacteria show promising properties to be used as potential probiotics for improving oral health.

Preservación de alvéolo postextracción: a propósito de un caso / No disponible

El proceso de cicatrización posterior a la extracción dental conlleva una serie de cambios en la morfología ósea que no sigue un patrón constante, produciéndose con frecuencia una pérdida ósea excesiva tanto en anchura como en altura. La preservación de alvéolo es una técnica predecible para preveniro minimizar la pérdida de la cresta ósea, lo que mejora la predictibilidad del éxito de los implantes y su estabilidad a largo plazo y favorece una rehabilitación protésica estética y funcional. El presente artículo ilustra un caso clínico de técnica de preservación de alvéolo tras la extracción dentaria de 2.4, mediante la colocación de xenoinjerto de origen bovino desproteinizado (Bio-Oss® Collagen,Geistlich Biomaterials) y membrana reabsorbible de colágeno (Bio-Gide®, Geistlich Biomaterials) (AU)

The healing process after a tooth extraction results in changes of bone morphology without a constant pattern and frequently an excessive bone loss of original height and width. Socket preservation is a predictable technique to prevent and minimize alveolar ridge loss, improving implant success and long-term stability and achieving esthetic and functional prosthetic reconstruction. The present article illustrates a case report of socket preservation after extraction of 2.4 with deproteinized xenograft of bovine origin(Bio-Oss® Collagen, Geistlich Biomaterials) and resorbable collagen membrane (Bio-Gide®, Geistlich Biomaterials) (AU)

Qualitative and quantitative characterization of the in vitro dehydration process of hydrogel contact lenses.

PURPOSE: To investigate the in vitro dehydration process of conventional hydrogel and silicone-hydrogel contact lens materials. METHODS: Eight conventional hydrogel and five silicone-hydrogel contact lenses were dehydrated under controlled environmental conditions on an analytical balance. Data were taken at 1-min intervals and dehydration curves of cumulative dehydration (CD), valid dehydration (VD), and dehydration rate (DR) were obtained. Several quantitative descriptors of the dehydration process were obtained by further processing of the information. RESULTS: Duration of phase I (r(2) = 0.921), CD at end of phase I (r(2) = 0.971), time to achieve a DR of -1%/min (r(2) = 0.946) were strongly correlated with equilibrium water content (EWC) of the materials. For each individual sample, the VD at different time intervals can be accurately determined using a 2nd order regression equation (r(2) > 0.99 for all samples). The first 5 min of the dehydration process show a relatively uniform average CD of about -1.5%/min. After that, there was a trend towards higher average CD for the following 15 min as the EWC of the material increases (r(2) = 0.701). As a consequence, average VD for the first 5 min displayed a negative correlation with EWC (r(2) = 0.835), and a trend towards uniformization among CL materials for the following periods (r(2) = 0.014). Overall, silicone-hydrogel materials display a lower dehydration, but this seems to be primarily due to their lower EWC. CONCLUSIONS: DR curves under the conditions of the present study can be described as a three-phase process. Phase I consists of a relatively uniform DR with a duration that ranges from 10 to almost 60 min and is strongly correlated with the EWC of the polymer as it is the CD during this phase. Overall, HEMA-based hydrogels dehydrate to a greater extent and faster than silicone-hydrogel materials. There are differences in water retention between lenses of similar water content and thickness that should be further investigated.

Equivalences between refractive index and equilibrium water content of conventional and silicone hydrogel soft contact lenses from automated and manual refractometry.

PURPOSE: The purpose of the present study was to develop mathematical relationships that allow obtaining equilibrium water content and refractive index of conventional and silicone hydrogel soft contact lenses from refractive index measures obtained with automated refractometry or equilibrium water content measures derived from manual refractometry, respectively. METHODS: Twelve HEMA-based hydrogels of different hydration and four siloxane-based polymers were assayed. A manual refractometer and a digital refractometer were used. Polynomial models obtained from the sucrose curves of equilibrium water content against refractive index and vice-versa were used either considering the whole range of sucrose concentrations (16-100% equilibrium water content) or a range confined to the equilibrium water content of current soft contact lenses (approximately 20-80% equilibrium water content). RESULTS: Values of equilibrium water content measured with the Atago N-2E and those derived from the refractive index measurement with CLR 12-70 by the applications of sucrose-based models displayed a strong linear correlation (r2 = 0.978). The same correlations were obtained when the models are applied to obtain refractive index values from the Atago N-2E and compared with those (values) given by the CLR 12-70 (r2 = 0.978). No significantly different results are obtained between models derived from the whole range of the sucrose solution or the model limited to the normal range of soft contact lens hydration. CONCLUSIONS: Present results will have implications for future experimental and clinical research regarding normal hydration and dehydration experiments with hydrogel polymers, and particularly in the field of contact lenses.

Técnica de túnel con matriz dérmica acelular para cubrimiento radicular. A propósito de un caso / No disponible

Para tratar una recesión gingival existen varias técnicas de cirugíamucogingival para el cubrimiento radicular. El artículo es una revisiónbibliográfica sobre la técnica de túnel, haciendo una breve descripciónde las diferentes técnicas publicadas en la literatura. Contienedesde la técnica convencional de cubrimiento radicular de tejidoconectivo subepitelial de Langer y Langer en el 1985, hasta llegara la técnica de túnel propiamente dicha descrita por Allen en 1994y posteriores modificaciones de ésta realizadas por Zabalegui en el1999, Blanes y Allen en el mismo año, Santarelli en el 2001 y Mahnen el 2001 quien incorporó la matriz dérmica acelular para cubrimientoradicular aplicando la técnica de túnel, y Tözum en el 2003.Finalmente se presenta un caso clínico de cubrimiento radicularcon matriz dérmica acelular, aplicando la técnica de túnel en elárea de premolares superiores obteniendo un exitoso resultado decubrimiento radicular de la zona tratada

For treating gingival recession there are many mucogingival proceguresto obtain a root coverage. This article is a tunnel technique’sreview, initiating with a brief description of different techniquespublished in the literature, from the conventional connective tissuegraft technique for root coverage described by Langer and Langerin 1985 to the tunnel technique described by Allen in 1994 andsubsequent modifications described by Zabalegui in 1999, Blanesand Allen in the same year, Santarelli in 2001 and Mahn in 2001who incorporated acellular dermal matrix in the tunnel techniquefor root coverage and Tözom in 2003. Finally is presented a caseof gingival recessions in maxillary premolar area treated by tunneltechnique with acellular dermal matrix, obtaining a satisfactory result with this procedure

Correlations between central and peripheral changes in anterior corneal topography after myopic LASIK and their implications in postsurgical contact lens fitting.

PURPOSE: To investigate the changes in central and peripheral anterior corneal curvatures after myopic laser in situ keratomileusis (LASIK) and to correlate them with the manifest refractive change to discuss how such results could affect post-LASIK corneal topography profiles and midterm stability and their implications in postsurgical contact lens fitting. METHODS: Topographic and refractive data from 18 eyes of 11 patients that had undergone myopic LASIK were collected for 6 months after surgery. Short-term and midterm topographic responses were investigated and correlated with spherical equivalent manifest refractive changes. RESULTS: There was a strong correlation between eccentricity changes and manifest refractive change 15 days after surgery (r = 0.753, P < 0.001), with no significant changes thereafter for the following 6 months (r = 0.148, P = 0.114). A strong linear relationship was found between baseline manifest refraction and changes in corneal curvature at the center (r = 0.810, P < 0.001), 4-mm chord (r = 0.895, P < 0.001), and 6-mm chord (r = 0.696, P < 0.001). Statistically significant changes were also found after the first 15 days (P < 0.005) and showed a regression effect that affects the three zones. In this case, a weaker relationship was found between curvature regression and the final refractive change for the central location (r = 0.412, P = 0.004), 4-mm chord area (r = 0.430, P = 0.003), and 6-mm chord area (r = 0.283, P = 0.023). CONCLUSIONS.: After myopic LASIK, the anterior corneal dioptric power is expected to change, on average, approximately 77% of the attempted spherical equivalent correction at the center; 60% at the 4-mm chord region, where the stronger correlation between topographic and refractive change is found; and 30% at the 6-mm chord area. The paracentral area 4 mm from the center seems to be more likely to predict baseline corneal curvature from manifest refractive change. Some degree of regression in the midterm period is expected to occur after myopic LASIK, which shows a significant correlation with the manifest refractive change. Again, this effect is more evident and more accurately predicted at the 4-mm chord area. The results of the current study are of interest for those fitting contact lenses after myopic LASIK.