1,720,964 research outputs found
HEALING AND REMODELING OF CONNECTIVE TISSUE GRAFT AROUND IMPLANTS WITH POOR KERATINIZED MUCOSA.INFLUENCE OF PROVISIONALIZATION TIMING (DELAYED VS IMMEDIATE) USING BOPT ABUTMENTS.A CLINICAL OBSERVATIONAL CONTROLLED PILOT STUDY.
Full text linkAim of the study : the aim of the present study was to investigate the most effective timing of the surgical-prosthetic procedure in order to obtain a stable soft tissue augmentation around dental implants using BOPT abutments.
Materials and Methods : Overall, 13 patients have been enrolled. A total amount of 21 implants have been placed and they have been alternatively assigned to the case (immediate provisionalization) or control group (delayed provisionalization) on the basis of the waiting list. The clinical criteria adopted for the enrollment in the study were the partial edentulism in which the teeth were lost at least 2 months before the date of implant placement with KM lower than 2 mm or inadequate soft tissues volume for a proper ridge contour. The two parameters evaluated for test and control groups were the apico-coronal migration and the soft tissue gain after grafting procedure.
Results : gingival recession: for the control group 10 implants were analyzed between first and second evaluation. The mean difference was - 0.011 ± 0.8 mm (95% CI: - 0.3 to 0.27mm). For the test group 9 implants were analyzed between first and second evaluation. The mean difference was 0.0 ± 0.8mm (95% CI: - 0.35 to 0.37mm).
Soft tissue gain: for the control group 8 implants were analyzed at the first evaluation. The mean augmentation was 1.17± 0.55 mm (95% CI: 1.12 to 1.45 mm). For the test group 4 implants were analyzed at the first evaluation. The mean augmentation was 0.82 ± 0.52 mm (95% CI: 0.85 to 0.65 mm).
Conclusions : Both the prosthetic-surgical approaches are valid in order to treat limited horizontal defects with the application of connective tissue graft without recurring to costly, invasive and long lasting guided bone regeneration procedures. Considering the lack of available information from the preliminary results it is impossible to assess which is the best therapeutic option. A total amount of 34 implants will be necessary to be able to reject the null hypothesis that the population means of the experimental and control groups are equal with probability (power) 0.8
Long-term retrospective evaluation of dental implants placed in resorbed jaws reconstructed with appositional fresh-frozen bone allografts
No full textIntroduction: The aim of this study was to evaluate the outcome of fresh-frozen bone allografts in preprosthetic surgery for implant placement purposes. Materials and Methods: The cohort comprised 45 patients treated with fresh-frozen bone block grafts and dental implants. Clinical and radiological evaluations were performed to evaluate the survival rate. The data were statistically analyzed with the Kaplan-Meier estimator to assess the influence of possible predictors of implant failure on survival. Results: Overall, 262 implants were retrospectively analyzed. The survival rate was 90.84% over a mean follow-up of 50 months. Comparing the donor site and the position of the implants, no statistically significant differences could be detected (P = 0.7194 and P = 0.2901, respectively), whereas sex resulted in a marginally statistically significant difference (P = 0.0581). When considering age categorized on the median value (≤55/>55 years), age resulted in a statistically significant difference (P = 0.0340), with higher failures found in older people. Conclusion: Implant loss was strictly related to the lack of primary osseointegration. Female sex and old age were found to be risk factors, which could negatively influence implant survival
A retrospective evaluation of 192 implants placed in augmented bone : long-term follow-up study
No full textThe purpose of the present study was to assess the cumulative survival rate (CSR) of 192 implants placed in association with guided bone regeneration (GBR) procedures to evaluate the long-term predictability of this technique. Moreover, the Kaplan Meier survival analysis was applied to the data in order to evaluate predictors of implant failures, including the source of the graft, the type of membrane, and the timing of implant placement. The CSR of the sample was 95.6% over a mean follow-up period of 78 months (range, 1-175 months). Considering the source of graft, a 95.0%, 93.3%, and 97.7% CSR was obtained for demineralized bovine bone mineral (DBBM), autologous, and 1:1 ratio mixture of autologous and DBBM grafts, respectively. The CSR referred to bioabsorbable membranes was 96.5%, whereas 94.6% was the CSR reported for nonresorbable membranes. The CSR of simultaneous surgeries was 96.8%, whereas staged surgeries showed a CSR of 94.5%. According to the data, implants placed in conjunction with GBR procedures presented a satisfying survival rate even in the long term. All the procedures performed with different bone grafts and type of membranes guaranteed optimal results both in one-and two-stage approaches. No statistically significant differences could be detected among the groups; indeed, the use of DBBM associated with resorbable membranes may be suggested to reduce patients' morbidity and treatment time. Therefore, the dental implants placed in association with bone regenerative procedures presented safe and predictable long-term clinical results
The use of a collagenated porcine cortical lamina in the reconstruction of alveolar ridge defects. A clinical and histological study
No full textOBIETTIVO: La ricostruzione alveolare per mezzo di membrane riassorbibili e non-riassorbibili è stata proposta al fine di incrementare il volume dei tessuti duri nei siti deficitari. L’obiettivo del presente studio è stato quello di testare clinicamente e istologicamente l’impiego di una lamina corticale in collagene suino in caso di procedure di incremento osseo orizzontale e verticale, associato a innesto osseo suino particolato.
METODI: Complessivamente, sono stati reclutati 8 pazienti parzialmente edentuli (6 femmine e 2 maschi) con una età media di 45 anni, che necessitavano procedure di rigenerazione ossea al fine di eseguire un posizionamento implantare protesicamente guidato. Tutti i difetti alveolo-crestali sono stati rigenerati per mezzo di una barriera eterologa di osso corticale in combinazione con osso eterologo particolato. Le biopsie ossee sono state prelevate durante il rientro chirurgico.
RISULTATI: Un totale di 15 impianti sono stati posizionati sia simultaneamente che con procedura differita nei siti aumentati. Non sono occorse complicanze durante le successive fasi riabilitative. Da un punto di vista istologico, la lamina ossea è risultata essere ampiamente vascolarizzata ed integrata con i tessuti molli circostanti e l’osso nativo. La presenza di lacune osteoclastiche ha suggerito un rimodellamento attivo dell’innesto particolato e una graduale sostituzione con osso di neoformazione.
CONCLUSIONI: La ricostruzione alveolare per mezzo di lamina corticale collagenata ha dato risultati clinici e istologici incoraggianti. La rigidità e il lento pattern di riassorbimento hanno permesso la protezione del coagulo ematico anche in caso di difetti ossei verticali, evitando allo stesso tempo il rientro chirurgico per la sua rimozione.BACKGROUND: Alveolar ridge reconstruction by means of resorbable and non-resorbable membranes has been proposed to increase the hard tissue volume in deficient sites. The purpose of this study was therefore to clinically and histologically evaluate the use of collagenated porcine bone lamina in case of horizontal and vertical bone augmentation procedures in conjunction with particulate porcine xenograft. METHODS: Overall, 8 partially edentulous patients (6 females and 2 males) with a mean age of 45 years requiring bone regeneration procedures to achieve a prosthetically driven implant placement were enrolled. All ridge defects were augmented using a xenogeneic cortical bone barrier in combination with particulate heterologous bone. Bone biopsies were collected during the re-entry procedure. RESULTS: A total of 15 implants were placed both simultaneously or in a staged approach in the augmented sites. No complications occurred during the rehabilitation. Histologically, the bone lamina was widely vascularized and integrated with the surrounding soft tissues and the native bone. The presence of osteoclastic lacunae suggested an active remodeling of the particulate graft and a gradual substitution with the newly formed bone. CONCLUSIONS: Alveolar reconstruction by means of the collagenated cortical lamina gave promising clinical and histological results. The rigidity and the slow resorption pattern allowed for the blood clot protection even in case of vertical defects, avoiding at the same time the re-entry surgery for its removal
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Surgical Treatment of Peri-Implantitis: A 17-Year Follow-Up Clinical Case Report
Full text linkThe purpose of the present case report was to describe the surgical treatment of a peri-implantitis lesion associated with a regenerative approach. A 48-year-old patient came to authors’ attention 36 months after the placement of a dental implant (ITI-Bonefit Straumann, Waldenburg, Switzerland) in position 46. A swelling of the peri-implant soft tissues was observed, associated with bleeding on probing and probing depth > 10 mm. A significant peri-implant bone loss was clearly visible on the periapical radiograph. A nonsurgical periodontal supportive therapy was firstly conducted to reduce the inflammation, followed by the surgical treatment of the defect. After mechanical and chemical decontamination with tetracycline solution, a regenerative approach consisting in the application of deproteinized bovine bone mineral (Bio-Oss, Geistlich Pharma AG, Wolhusen, Switzerland) and a collagen membrane (Bio-Gide, Geistlich Pharma AG, Wolhusen, Switzerland) was performed. An antibiotic therapy was associated with the treatment. The 17-year follow-up showed a physiological probing depth with no clinical signs of peri-implant inflammation and bleeding on probing. No further radiographic bone loss was observed. The treatment described in the present case report seemed to show improved clinical results up to a relevant follow-up period
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Alveolar ridge reconstruction with titanium meshes: a systematic review of the literature
No full textAlveolar bone regeneration by means of titanium meshes is a widespread procedure, however to date, only few
relevant studies were reported in literature concerning this technique. Consequently, the aim of the present systematic review was to analyze the reliability of the titanium mesh as a barrier, in conjunction with horizontal and
vertical ridge reconstruction for implant placement purposes. A total of 17 articles complying with the inclusion
and exclusion criteria were reviewed. Three outcome variables were defined: a) horizontal and vertical bone regeneration obtained, b) complication rate, defined as the percentage of membrane exposures and c) evaluation of
implant survival, success and failure rate.In regards to the vertical regeneration the mean was 4.91 mm (range:
2.56 - 8.6), while a mean of 4.36 mm (range: 3.75 - 5.65) was calculated for horizontal reconstruction. Considering
the exposure rate, a mean of 16.1% was found, nevertheless, implant placement were placed in almost all of the
sites. A mean success rate of 89,9%, a mean survival rate of 100% and a failure rate of 0% emerged from the data
evaluation. A meta-analysis could not be performed due to the heterogeneity of the data, however the final results
were comparable with those reported in case of bone regeneration obtained through other types of non-resorbable
membranes. An advantage in favour of the titanium mesh was found in terms of bone loss after exposure, as
implant placement was not jeopardized in almost all of the cases. It could be deduced that titanium meshes represented a reliable solution for alveolar ridge reconstruction. The clinical studies currently available in literature
have shown the predictability of this technique in both lateral and vertical bone regeneration
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