The Influence of History of Severe Periodontitis on Estimated Long-Term Marginal Bone Loss around Implants Restored with Fixed Segmented Full-Arch Rehabilitation.

The aim of this study was to analyze the long-term marginal bone level (MBL) of implants supporting fixed full-arch restoration in patients who had previously lost their dentition due to severe periodontitis. This retrospective study included 35 patients in whom 342 implants with internal tapered conical connections were placed. MBL was analyzed radiographically over time and a long-term estimation of MBL was calculated. A mixed linear model with abutment height, graft, diameter and location (maxilla/mandible) as factors and gender, age, implant length and prosthetic variables as covariates was used to evaluate the influence on MBL. MBL in these patients showed an estimator of predictions at 4108 days after loading of -0.307 mm, SE = 0.042. Only 0.15% of implants were radiographically affected with MBL of 3 mm or more. The mixed linear model results showed a main effect of the type of opposing dentition, gender, implant diameter, and abutment height. Particularly, an abutment height of 1 mm had associated larger MBL than the remaining heights. Thus, it can be concluded that dental implants restored with fixed segmented full-arch rehabilitation in patients with a history of severe periodontal disease do not suffer important marginal bone loss if some specific factors are considered, mainly the use of long transmucosal abutments (≥2 mm).

Ceramic Printing - Comparative Study of the Flexural Strength of 3D Printed and Milled Zirconia.

PURPOSE: To determine and compare the mechanical properties of 3D-printed yttriastabilized zirconia to milled isostatic pressed yttria-stabilized zirconia, with the following hypotheses: (1) The flexural strength of 3D-printed yttria-stabilized zirconia is comparable to milled yttria-stabilized isostatic pressed zirconia; and (2) thermocycling and chewing simulation do not affect the flexural strength of 3D-printed yttria-stabilized zirconia. MATERIALS AND METHODS: A total of 30 bars of an experimental 3D-printed 3 mol% yttriastabilized zirconia (LithaCon 3Y 230, Lithoz) and 10 bars of milled isostatic pressed zirconia (Prettau Zirconia, Zirkonzahn) were utilized. The printed zirconia bars were divided into three groups (n = 10 bars per group): (1) untreated (control); (2) thermocycled; and (3) tested after chewing simulation. A flexural strength test was performed on all samples using a three-point bend test in an Instron Universal testing machine. One-way analysis of variance on ranks was used to compare milled to printed zirconia. The effects of thermocycling and load cycling on 3D-printed zirconia were also determined. RESULTS: The flexural strength values for milled and printed zirconia were 936.3 ± 255.0 MPa and 855.4 ± 112.6 MPa, respectively. There was no statistically significant difference in flexural strength between the milled and printed zirconia (P = .178). No statistically significant differences were observed between the control 3D-printed zirconia group and the thermocycled (888.4 ± 59.3 MPa) or load-cycled printed zirconia (789.6 ± 133.8 MPa; P = .119). CONCLUSION: Printed 3 mol% yttria-stabilized zirconia has comparable flexural strength to milled yttria-stabilized isostatic pressed zirconia. The thermocycling and chewing simulation used in this study did not significantly alter the flexural strength of the printed 3 mol% yttria-stabilized zirconia. These results indicate a promising role for 3D printing in the fabrication of zirconia restorations. Additional studies are needed to explore the full potential of this technology.

On the Relationship Between White Matter Structure and Subjective Pain. Lessons From an Acute Surgical Pain Model.

Background: Pain has been associated with structural changes of the brain. However, evidence regarding white matter changes in response to acute pain protocols is still scarce. In the present study, we assess the existence of differences in brain white matter related to pain intensity reported by patients undergoing surgical removal of a mandibular impacted third molar using diffusion tensor imaging (DTI) analysis. Methods: 30 participants reported their subjective pain using a visual analog scale at three postsurgical stages: under anesthesia, in pain, and after the administration of an analgesic. The diffusion data were acquired prior to surgery. Results: DTI analysis yielded significant positive associations of fractional anisotropy in white matter areas related to pain processing (corticospinal tract, corona radiata, corpus callosum) with the differences in pain between the three postsurgery stages. Extent and location of these associations depended on the magnitude of the subjective pain differences. Tractography analysis indicated that some pain-tract associations are significant only when pain stage is involved in the contrast (posterior corona radiata), while others (middle cerebellar peduncle, pontine crossing) are only when anesthesia is involved in the contrast. Conclusions: The association of white matter fractional anisotropy and connectivity, measured before the pain stages, with subjective pain depends on the magnitude of the differences in pain scores.

CORRIGENDUM TO: "Preterm birth and/or low birth weight are associated with periodontal disease and the increased placental immunohistochemical expression of inflammatory markers".

This correct the article DOI: 10.14670/HH-11-671.

Does experienced pain affects local brain volumes? Insights from a clinical acute pain model.

Background/Objective:To study pain-brain morphometry associations as a function of post-surgery stages (anesthesia, pain and analgesia) in an acute pain model. Method:Impacted mandible third molar were extracted. Before surgery, an anatomical T1 scan was obtained. Regional brain volumen and subcortical nuclei shapes were obtained. Statistical analyses were done using multiple regression, being pain scores the predictors and voxel volumes, subcortical nuclei volumes and subcortical nuclei shapes, the outcomes. Results:Pain was significantly larger at pain than at anesthesia and analgesia stages, and was higher during anesthesia than during analgesia. Pain intensity was related to grey matter in several cortical (Insula, Mid Frontal and Temporal Gyruses, Precuneus, Anterior Cingulate), and subcortical nuclei (Hippocampus, Thalamus, Putamen, Amygdala), depending of the post-surgical stage. A larger number of brain areas showed significance at pain that at anesthesia and analgesia stages. Conclusions:The relationships of regional brain volumes and subcortical nuclei shapes with pain scores seemed to be unsteady, as they changed with the patient's actual pain stage.

Antecedentes/Objetivo:Se trata de determinar la asociación entre dolor percibido y morfometría cerebral en tres etapas postquirúrgicas (anestesia, dolor y analgesia), en un modelo de dolor agudo. Método:Se obtuvo una imagen cerebral estructural de alta resolución y posteriormente se extrajeron los terceros molares mandibulares impactados. Se realizó un análisis morfométrico para determinar volumen cerebral y forma de núcleos subcorticales. Se realizaron análisis de regresión múltiple, siendo la intensidad del dolor el predictor, y el volumen y la forma de los núcleos subcorticales, medidos pre-cirugía, las variables dependientes. Resultados:El dolor experimentado fue mayor en la etapa de dolor que en las de anestesia y analgesia, y mayor en anestesia que en analgesia. El dolor se asoció con el volumen de materia gris en áreas corticales (insula, giros frontal medial y temporal, precuneus y cingulado anterior) y subcorticales (hipocampo, tálamo, putamen y amígdala). El número de áreas asociadas al dolor experimentado fue mayor en la etapa de dolor que en las de anestesia y analgesia. Conclusiones:La relación entre volumen cerebral regional y forma de núcleos subcorticales con la intensidad del dolor no es fijo, sino que varía en función de la etapa post-quirúrgica (magnitud del dolor).

Does experienced pain affects local brain volumes? Insights from a clinical acute pain model / ¿Afecta el dolor al volumen local del cerebro? Aportaciones desde un modelo clínico de dolor agudo

Background/Objective: To study pain-brain morphometry associations as a function of post-surgery stages (anesthesia, pain and analgesia) in an acute pain model. Method: Impacted mandible third molar were extracted. Before surgery, an anatomical T1 scan was obtained. Regional brain volumen and subcortical nuclei shapes were obtained. Statistical analyses were done using multiple regression, being pain scores the predictors and voxel volumes, subcortical nuclei volumes and subcortical nuclei shapes, the outcomes. Results: Pain was significantly larger at pain than at anesthesia and analgesia stages, and was higher during anesthesia than during analgesia. Pain intensity was related to grey matter in several cortical (Insula, Mid Frontal and Temporal Gyruses, Precuneus, Anterior Cingulate), and subcortical nuclei (Hippocampus, Thalamus, Putamen, Amygdala), depending of the post-surgical stage. A larger number of brain areas showed significance at pain that at anesthesia and analgesia stages. Conclusions: The relationships of regional brain volumes and subcortical nuclei shapes with pain scores seemed to be unsteady, as they changed with the patient's actual pain stage

Antecedentes/Objetivo: Se trata de determinar la asociación entre dolor percibido y morfometría cerebral en tres etapas postquirúrgicas (anestesia, dolor y analgesia), en un modelo de dolor agudo. Método: Se obtuvo una imagen cerebral estructural de alta resolución y posteriormente se extrajeron los terceros molares mandibulares impactados. Se realizó un análisis morfométrico para determinar volumen cerebral y forma de núcleos subcorticales. Se realizaron análisis de regresión múltiple, siendo la intensidad del dolor el predictor, y el volumen y la forma de los núcleos subcorticales, medidos pre-cirugía, las variables dependientes. Resultados: El dolor experimentado fue mayor en la etapa de dolor que en las de anestesia y analgesia, y mayor en anestesia que en analgesia. El dolor se asoció con el volumen de materia gris en áreas corticales (insula, giros frontal medial y temporal, precuneus y cingulado anterior) y subcorticales (hipocampo, tálamo, putamen y amígdala). El número de áreas asociadas al dolor experimentado fue mayor en la etapa de dolor que en las de anestesia y analgesia. Conclusiones: La relación entre volumen cerebral regional y forma de núcleos subcorticales con la intensidad del dolor no es fijo, sino que varía en función de la etapa post-quirúrgica (magnitud del dolor)

Morphological and immunophenotypical differences between chronic periodontitis and peri-implantitis - a cross-sectional study.

PURPOSE: To examine differences in morphology and in immunophenotype subsets between chronic periodontitis (CP) and peri-implantitis (P-I) lesions and to test the diagnostic agreement (CP vs P-I) among three independent observers, based on histopathological features. MATERIALS AND METHODS: This observational cross-sectional study included 15 gingival biopsies of CP lesions and 15 biopsies of P-I lesions for double-blinded examination by three independent pathologists. Inflammatory infiltrate intensity was assessed semiquantitatively on a 4-point scale, determining the percentage of lymphocytes, plasma cells, monocytes/macrophages, and granulocytes and the presence/absence of bacterial colonies. Immunohistochemical analyses were performed to verify the inflammatory infiltrate subset data (CD45, CD38, CD68 and myeloperoxidase [MPO]-positive), and number of vessels. Kappa statistic was used to evaluate the degree of diagnostic concordance among examiners. RESULTS: Inflammatory infiltrate was significantly more severe in P-I cases (P = 0.01), which showed a significantly higher percentage of plasma cells (P = 0.004) than in CP cases. Immunohistochemically, the percentage of leukocyte subsets was generally lower in CP (CD38: 32.05%; CD68: 6.45% and MPO: 8.62%) than in P-I (CD38: 61.13%; CD68: 9.09% and MPO: 7.47%) (CD38 P = 0.001, P = 0.955 and P = 0.463, for remaining subsets, respectively; Mann-Whitney U-test). The inter-observer diagnostic agreement was poor or slight (kappa = -0.18 to 0.13). CONCLUSIONS: Despite the significantly more severe general inflammatory infiltrate and plasma cells in P-I cases, it proved difficult to detect reliable differential morphological features based on histopathological images of these CP and P-I soft-tissue samples, obtaining low inter-observer and intra-observer diagnostic agreement. Conflict of interest statement: This investigation was partially supported by Research Groups #CTS-138 and #CTS-583 (Junta de Andalucía, Spain). No conflict of interest.

Preterm birth and/or low birth weight are associated with periodontal disease and the increased placental immunohistochemical expression of inflammatory markers.

UNLABELLED: The objective of this study was to determine whether gynecological and periodontal clinical parameters and the immunohistochemical expression in placental chorionic villi of the markers cyclooxygenase-2 (COX-2), interleukin (IL)-1ß, vascular endothelial growth factor receptor 1 (VEGFR1), podoplanin, and Heat Shock Protein 70 (HSP70) are associated with preterm birth (PB) and/or low birth weight (LBW) neonates. MATERIAL AND METHODS: An observational case-control study was performed in 130 puerperal women: mothers of PB/LBW neonates (cases, n=65) and mothers of full-term normal-weight neonates (controls, n=65). Data were gathered from all participants on socio-demographic, gynecological, and periodontal variables and on placental immunohistochemical COX-2, IL-1ß, VEGFR1, podoplanin, and HSP70 expression. RESULTS: Among the 42 women with mild/moderate periodontitis or gingivitis, the studied periodontal variables were significantly worse and the placental COX-2 (p=0.043), HSP70 (p=0.001), IL-1ß (p=0.001), VEGFR1 (p=0.032), and podoplanin (p=0.058) expressions were significantly higher in the cases than in the controls. In comparison to the mothers without periodontitis, only COX-2 (p=0.026) and VEGFR1 (p=0.005) expressions were significantly increased in those with the disease. Increased COX-2 values were detected in the women with a history of genitourinary infection (p=0.036), premature rupture of membrane (p=0.012), or drug treatment (p=0.050). CONCLUSIONS: The etiology of preterm birth and/or low birth weight is multifactorial and involves consumption habits, social-health factors, and infectious episodes. These adverse pregnancy outcomes were associated with periodontitis and the increased placental expression of IL-1ß, COX-2, VEGFR1, and HSP70.

Significance of the Immunohistochemical Expression of Bone Morphogenetic Protein-4 in Bone Maturation after Maxillary Sinus Grafting in Humans.

BACKGROUND: Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-ß (TGFß) protein superfamily and are known to be involved in bone and cartilage formation. Within this family, BMP-4 is one of the most studied members. It has been shown to induce osteogenic differentiation of osteoblasts and osteoprogenitor cells in vitro, but the intimate processes in which this protein promotes and regulates osseous repair still remains unclear. PURPOSE: To assess whether the native cellular immunohistochemical expression of BMP-4 correlates with the maturation of bone samples obtained at 6 months after maxillary sinus augmentation. MATERIALS AND METHODS: Histopathological and histomorphometrical analyses were performed in all the samples, which were obtained from a total of 58 patients. Immunohistochemical expression of BMP-4 was analyzed in 30 core biopsies obtained from maxillary sinuses grafted with a combination of anorganic bovine bone and autogenous cortical bone [1:1] (AB-group), and 18 biopsies from maxillary sinuses grafted solely with a cortico-cancellous particulate allograft (M-group), all of them after a 6-month healing period. Also, 10 biopsies of native pristine bone were obtained and used as control group (C-group). RESULTS: Mild to moderate immunohistochemical expression of native granular BMP-4 was present in 56.8% (31.0% AB-group, 22.4% M-group, and 3.4% C-group) (p = 0.000, chi-square) of the specimens analyzed. BMP-4 expression was primarily located in the cytoplasm of osteoblasts, osteoclasts, and epithelial cells of the schneiderian membrane. Whereas significant differences were observed in the proportion of mineralized tissue and cellularity between sinuses grafted with anorganic bovine bone, allograft, or nongrafted sinuses, there were no statistically significant differences in the cellular expression of BMP-4 among groups. CONCLUSION: Our findings suggest that the native expression of BMP-4 appears to be associated with normal bone homeostasis and reparation in grafted and nongrafted maxillary sites.

Effect of barrier membranes on the outcomes of maxillary sinus floor augmentation: a meta-analysis of histomorphometric outcomes.

PURPOSE: Sinus floor elevation via the lateral window approach represents a reliable technique for augmenting bone volume in the atrophic posterior maxilla. However, controversy remains regarding the effect of placement of a barrier membrane over the lateral window. This histomorphometric meta-analysis sought to clarify the effect of barrier membranes in lateral window sinus augmentation. MATERIALS AND METHODS: An electronic search of three databases and a hand search in implant-related journals for studies published through January 2013 in the English language was conducted. Randomized controlled trials, prospective human clinical studies, retrospective investigations, and case series reporting histomorphometric results after sinus elevation using the lateral window approach with at least six patients and a minimum follow-up period of 6 months were included. RESULTS: The initial search yielded 1,040 articles, of which 94 were further evaluated for eligibility. Finally, 37 studies were chosen and separated into membrane (group 1) and no-membrane (group 2) groups. Similar vital bone formation was found in both groups: 32.36% for group 1 and 33.07% for group 2. CONCLUSION: Based does not influence the amount of vital bone formation after sinus augmentation. Additionally, the type of grafting material used and healing time did not influence the histomorphometric outcome.

Effect of cantilevers for implant-supported prostheses on marginal bone loss and prosthetic complications: systematic review and meta-analysis.

PURPOSE: The aim of this study was to conduct a systematic review and meta-analysis to evaluate the influence of cantilevers upon implant-supported fixed partial dentures on marginal bone loss (MBL) and prosthetic-related complications. MATERIALS AND METHODS: An electronic literature search was conducted in the PubMed database by two reviewers (LTM and AM) for articles written in English from June 2003 to January 2013 that were prospective human clinical trials with the clear purpose of appraising the effect of implant-supported fixed partial prostheses on peri-implant bone level and prosthetic complications. Data from the selected studies were extracted to carry out the statistical analysis. RESULTS: Following the method described earlier, from initial research of 643 studies, 4 human clinical studies met the inclusion criteria and provided enough data to include them in the present meta-analysis. For the overall data, the pooled weighted mean (WM) of the MBL was 0.72 mm (range, 0.49 to 1.10 mm), with a 95% confidence interval (CI) of 0.36 to 1.08 mm. For the chi-square test, P = .60, representing a low heterogeneity among studies. MBL around implant-supported restorations with and without cantilevers was not found to be significant between both groups. The weighted mean difference (WMD) was 0.10 mm (favoring the non-cantilever group), with a 95% CI = -0.18 to 0.39 mm (P = .47). For the chi-square test, P = .97, also indicating a low degree of heterogeneity between the studies. CONCLUSION: The dearth of scientific evidence in this matter does not permit clear conclusions to be drawn. However, within the limitations, marginal bone loss does not seem to be influenced by the presence of cantilever extensions. Moreover, minor technical complications were found when a cantilever was present when compared to the control groups.

The influence of implant diameter on its survival: a meta-analysis based on prospective clinical trials.

BACKGROUND: The use of narrow-diameter implants has been proposed to restore small edentulous spans, thus avoiding extensive bone augmentation procedures and reducing the surgical complexity of implant rehabilitations. Although success rates of narrow-diameter implants have already been analyzed in the literature, to the best of the authors' knowledge, no meta-analysis based on prospective and randomized controlled trials has been performed. The aim of this study is to analyze the survival rates of narrow-diameter implants compared with standard or wide-diameter implants. METHODS: An electronic search from three databases and a hand search in implant-related journals of studies published in English before September 1, 2012 were performed. Prospective human clinical studies with at least 10 implants and a follow-up period of 1 year were included in the meta-analysis. Implants were divided into two groups based on their diameters. RESULTS: The initial search yielded 484 articles, of which 49 were evaluated in full text for eligibility. Finally, 16 studies were chosen and separated into two groups: 1) implants of diameter <3.3 mm (group 1) and 2) implants of diameter ≥3.3 mm (group 2). A meta-analysis performed for groups 1 and 2 showed survival rates of 75% and 87%, respectively. CONCLUSIONS: This meta-analysis showed that narrower implants (<3.3 mm) had significantly lower survival rates compared with wider implants (≥3.3 mm). Other variables, such as type of prosthesis, implant surface, and timing of prosthetic loading, were found to have influenced the implant survival rates.

Effect of rhBMP-2 upon maxillary sinus augmentation: a comprehensive review.

PURPOSE: The purpose of this review was to summarize the recent in vitro and in vivo research findings in areas where rhBMP-2 was used as a grafting material for sinus augmentation. MATERIALS AND METHODS: An electronic literature search for relevant articles published in English was conducted in the PubMed database from February 1996 to August 2012. Randomized clinical trials or prospective human clinical and animal trials were included with the primary objective to compare and evaluate the effectiveness of rhBMP-2 for sinus augmentation. RESULTS: A total of 3 human studies and 4 animal trials qualified the selection criteria that were included in this review. In humans, the selected studies indicated that rhBMP-2 induces new bone formation with comparable bone quality or amount of newly formed bone to that induced by autogenous bone graft. Furthermore, no differences have been reported between new bone induced by rhBMP-2 and native bone. Animal model studies also demonstrated regular bone formation induced by rhBMP-2, followed by normal maturation of new bone. CONCLUSION: All these studies demonstrate the osteoinductive and osteogenic capacity of rhBMP-2 and support it as an alternative for autogenous bone in sinus floor augmentation.