Short implants in native bone versus long implants in reconstructed bone: a randomised controlled clinical trial at 5 years

Obbiettivo: valutare se impianti dentali corti 5 mm, con una superficie innovativa in calcio nanostrutturato e titanio, possano essere una valida alternativa ad impianti lunghi almeno 10 mm posizionati in osso ricostruito, nelle atrofie dei mascellari posteriori. Materiali e Metodi: quaranta pazienti con mandibole posteriori atrofiche e quaranta pazienti con mascellari superiori posteriori atrofici sono stati randomizzati secondo un disegno di studio a gruppi paralleli, nel ricevere impianti corti 5 mm (gruppo test), oppure impianti lunghi almeno 10 mm dopo chirurgie di innesto osseo (gruppo controllo). I pazienti sono stati seguiti per 5 anni dopo il carico protesico e i parametri valutati sono stati i fallimenti implantari e protesici, le complicanze e i livelli ossei marginali peri-implantari. Risultati: cinque anni dopo il carico le differenze riscontrate nei fallimenti protesici ed implantari non sono risultate essere statisticamente significative. Una differenza in termini di complicanze statisticamente significativa è stata invece registrata per quanto concerne i pazienti trattati in mandibola: 17 pazienti del gruppo controllo hanno avuto complicanze a fronte di 9 complicanze relative a pazienti trattati con impianti corti. Prendendo in considerazione i livelli ossei marginali peri-implantari, gli impianti corti hanno mostrato a 5 anni dal carico protesico una perdita ossea minore rispetto agli impianti lunghi posizionati in osso ricostruito sia nel mascellare che in mandibola. Conclusioni: cinque anni dopo il carico protesico gli impianti corti 5 mm hanno raggiunto risultati simili rispetto agli impianti lunghi posizionati in osso ricostruito. Gli impianti corti quindi potrebbero rappresentare una scelta terapeutica da preferirsi rispetto alle chirurgie di aumento osseo, specialmente nella mandibola posteriore, dato che il trattamento risulta essere più veloce, economico ed associato ad una minore morbidità. Tuttavia saranno necessari dati ad almeno 10 anni dal carico protesico, prima di essere in grado di formulare raccomandazioni cliniche più affidabili.Purpose: to evaluate whether 5x5 mm dental implants with a novel nanostructured calcium-incorporated titanium surface could be an alternative to implants at least 10 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. Materials and Methods: forty patients with atrophic posterior mandibles and 40 patients with atrophic posterior maxillae, were randomised according to a parallel group design to receive 5 mm implants or implants at least 10 mm long in augmented bone. Mandibles were vertically augmented with interpositional bovine bone blocks and implants were placed after 4 months. Maxillary sinuses were augmented with particulated porcine bone via a lateral window approach and implants were placed simultaneously. All implants were loaded after 4 months with provisional prostheses. Four months later, definitive prostheses were delivered. Patients were followed up to 5 years post-loading and the outcome measures were: prosthesis and implant failures, any complication and peri-implant marginal bone level changes. Results: sixteen patients dropped-out before the 5-year evaluation. There were no statistically significant differences in prosthesis and implant failures up to 5 years after loading between maxilla and mandible. Significantly more complications occurred at mandibular grafted sites: 17 augmented patients were affected by complications versus 9 patients treated with short implants in mandibles. Moreover, longer implants showed a greater bone loss up to 5 years after loading than short implants both in maxillae and in mandibles. Conclusions: five years after loading 5x5 mm implants achieved similar results than longer implants placed in augmented bone. As a consequence short implants might be a preferable choice to bone augmentation especially in posterior mandibles since the treatment is faster, cheaper and associated with less morbidity, however 10-year post-loading data are necessary before making reliable recommendations

Enucleation of a multilocular odontogenic keratocyst using sagittal osteotomy: A case report

Odontogenic keratocysts are significant cysts of the jaw that are characterized by aggressive behavior and a high tendency to recur. The treatments of choice may be radical or conservative, and in the literature a debate is still open about the gold standard in the treatment of OKCs.This report describes a wide multilocular OKC extended in the right mandibular ramus and illustrates atypical behavior of a cystic lobe after marsupialization, not found to our knowledge in the previous literature. Moreover, an orthognathic procedure, consisting of sagittal osteotomy was chosen for the excision of the cyst to preserve as much bone as possible and the integrity of the inferior alveolar nerve

Clinical Relevance of Bone Density Values from CT Related to Dental Implant Stability: A Retrospective Study

PURPOSE: The majority of the techniques used to assess the primary implant stability are subjective and empirical and can be used during or after the surgery. The aim of this study is to evaluate the bone density prior to surgery, in order to give recommendations to the clinician about the best surgical technique and the type of implant which is needed. MATERIALS AND METHODS: A surgeon operated on 75 patients for 269 implants over the period 2010-2014. He required a CT to plan the surgery and he documented the type, the diameters, and the lengths of the implants, the insertion torque, and the ISQ values. At a later stage another clinician measured bone density and cortical thickness. We endeavoured to get the most accurate superimposition between the implants placed by the surgeon and those placed by the clinician. RESULTS: In maxilla ISQ showed a significant positive correlation with HU values detected for coronal-buccal (r = 0.302; p = 0.020) and middle-lingual (r = 0.295; p = 0.023). Torque showed a positive correlation with cortical bone thickness at the middle of the ridge (\u3c1 = 0.196; p = 0.032). CONCLUSION: It is important to take into consideration the Hounsfield Units and the cortical thickness as predictive parameters during the preoperative assessment, with regard to the choice of the implant type as well as the surgical technique

Osteoblasts and Fibroblasts Interaction with a Porcine Acellular Dermal Matrix Membrane

The use of collagen membranes has remained the gold standard in GTR/GBR. In this study, the features and the biological activities of an acellular porcine dermis collagen matrix membrane applicable during dental surgery were investigated, and also by applying hydration with NaCl. Thus, two tested membranes were distinguished, the H-Membrane and Membrane, compared to the control cell culture plastic. The characterization was performed by SEM and histological analyses. In contrast, the biocompatibility was investigated on HGF and HOB cells at 3, 7, and 14 days by MTT for proliferation study; by SEM and histology for cell interaction study; and by RT-PCR for function-related genes study. In HOBs seeded on membranes, mineralization functions by ALP assay and Alizarin Red staining were also investigated. Results indicated that the tested membranes, especially when hydrated, can promote the proliferation and attachment of cells at each time. Furthermore, membranes significantly increased ALP and mineralization activities in HOBs as well as the osteoblastic-related genes ALP and OCN. Similarly, membranes significantly increased ECM-related and MMP8 gene expression in HGFs. In conclusion, the tested acellular porcine dermis collagen matrix membrane, mainly when it is hydrated, behaved as a suitable microenvironment for oral cells

From sea monsters to charismatic megafauna: changes in perception and use of large marine animals

Marine megafauna has always elicited contrasting feelings. In the past, large marine animals were often depicted as fantastic mythological creatures and dangerous monsters, while also arousing human curiosity. Marine megafauna has been a valuable resource to exploit, leading to the collapse of populations and local extinctions. In addition, some species have been perceived as competitors of fishers for marine resources and were often actively culled. Since the 1970s, there has been a change in the perception and use of megafauna. The growth of marine tourism, increasingly oriented towards the observation of wildlife, has driven a shift from extractive to non-extractive use, supporting the conservation of at least some species of marine megafauna. In this paper, we review and compare the changes in the perception and use of three megafaunal groups, cetaceans, elasmobranchs and groupers, with a special focus on European cultures. We highlight the main drivers and the timing of these changes, compare different taxonomic groups and species, and highlight the implications for management and conservation. One of the main drivers of the shift in perception, shared by all the three groups of megafauna, has been a general increase in curiosity towards wildlife, stimulated inter alia by documentaries (from the early 1970s onwards), and also promoted by easy access to scuba diving. At the same time, environmental campaigns have been developed to raise public awareness regarding marine wildlife, especially cetaceans, a process greatly facilitated by the rise of Internet and the World Wide Web. Currently, all the three groups (cetaceans, elasmobranchs and groupers) may represent valuable resources for ecotourism. Strikingly, the economic value of live specimens may exceed their value for human consumption. A further change in perception involving all the three groups is related to a growing understanding and appreciation of their key ecological role. The shift from extractive to non-extractive use has the potential for promoting species conservation and local economic growth. However, the change in use may not benefit the original stakeholders (e.g. fishers or whalers) and there may therefore be a case for providing compensation for disadvantaged stakeholders. Moreover, it is increasingly clear that even non-extractive use may have a negative impact on marine megafauna, therefore regulations are needed.SFRH/BPD/102494/2014, UID/MAR/04292/2019, IS1403info:eu-repo/semantics/publishedVersio

Displacement of a dental implant in the mandible body: an unusual case report

Purpose: to present a case of a woman referred for the management of displacement of one implant in her right posterior mandible occurred three days earlier. Materials and methods: After implant placement, the dentist was not able to detect the implant anymore and inserted a second implant in the same site without taking a control x-ray. At the end of the surgery, when finally an x-ray was taken, the first implant appeared displaced into the mandible body. The patient suffered total paraesthesia on the right lower lip and chin area. A flap was raised and bone osteotomies were performed on the lateral side of the mandible to create a rectangular cortical bone window that was removed. The implant was stuck by the second implant placed coronally, and only after unscrewing this second implant it was possible to remove the first one. Results: Eighteen months later, the patient recovered full sensitivity. Conclusions: In case of implant displacement, it is always recommended to perform appropriate radiographs to visualize where the implants could have been displaced in order to avoid more serious consequences

Threaded Implants in the Atrophic Posterior Mandible

Partial edentulism in the posterior mandible is a common clinical issue, particularly with the early loss of molars and premolars. Rehabilitation of patients with this deficiency can be achieved using a removable prosthesis, but this solution does not guarantee optimal function and is often declined by patients for comfort or psychologic reasons. In addition, denture-associated plaque accumulation can result in further caries in the remaining teeth and damage to the periodontal tissue, and poor denture design can lead to tooth mobility and even tooth loss. For these reasons and the reported successful long-term outcomes with dental implant-supported fixed restorations, this option has become the treatment of choice for the posterior mandible among clinicians and patients alike. As originally prescribed for machine-turned (ie, Br\ue5nemark-type, Nobel Biocare) threaded implants, many clinicians still believe that predictably successful treatment requires longer (ie, at least 10 mm) implants in the posterior mandible. However, if the teeth intended for replacement have been missing for many years or if their removal was traumatic (causing excessive bone loss), there may be inadequate bone volume to allow placement of standard-length implants. Deficits in bone can be vertical, horizontal, or both. This chapter focuses on the use of short and ultra-short moderately rough threaded implants (MRTIs) from several manufacturers for sites with advanced vertical bone atrophy in the posterior mandible in combination with adequate buccolingual alveolar ridge width (Seibert Class II). Guidelines, clinical indications, advantages, and disadvantages are given with a special focus on short and ultra-short implants as an alternative to vertical bone augmentation

Reabilita\ue7\ue3o de mand\uedbula posterior atr\uf3fica com implantes curtos (4 mm): um relato de caso

Este relato de caso descreve uma reabilita\ue7\ue3o prot\ue9tica sobre implante bem-sucedida de mand\uedbula posterior atr\uf3fica com implantes de 4 mm de comprimento. O paciente recusou ser submetido a qualquer cirurgia reconstrutiva e, como o osso dispon\uedvel at\ue9 o nervo alveolar inferior tinha somente 5 mm ou menos, o paciente recebeu quatro implantes de 4 mm de comprimento. Quatro meses depois da instala\ue7\ue3o dos implantes, uma pr\uf3tese provis\uf3ria foi instalada; ap\uf3s quatro meses, ela foi ent\ue3o substitu\uedda pela pr\uf3tese definitiva. O uso desse tipo de implantes curtos permite uma solu\ue7\ue3o prot\ue9tica fixa sem a necessidade de aumentar verticalmente o osso mandibular. Esse processo reduz consideravelmente o desconforto do paciente intra e p\uf3s-operat\uf3rio comparado com a cirurgia reconstrutiva para a instala\ue7\ue3o de implantes mais longos. O tempo de acompanhamento foi de 1 ano ap\uf3s a carga dos implantes

Short implants: an alternative to bone augmentation in atrophic patients [Impianti corti: un’alternativa alla rigenerazione ossea in pazienti con atrofia dei mascellari]

OBJECTIVES: To evaluate the current state of the art in the surgical management of the fixed rehabilitations in the vertical atrophies of the jaws. Guidelines and clinical indications will be given, with a special attention to short implants. MATERIALS AND METHODS: Taken into consideration the current scientific literature and evidence, and clinical authors evaluations, the different surgical approaches to patients with vertical bone atrophies of the jaws have been analysed. Particularly, short implants effectiveness and their advantages and disadvantages have been examined. RESULTS: Short implants represent a treatment option faster, cheaper and associated with fewer complications, compared to vertical bone augmentation procedures. CONCLUSIONS: Short dental implants nowadays could represent a reliable and preferable choice to long implants placed in augmented bone