Buccal bone dimensions and aesthetic outcome at maxillary incisors replaced by conventional dental implants. A case series with a 5-year follow-up.

In the aesthetic field, successful replacement of a tooth with a dental implant requires blend and harmony within the existing dentition. The influence of the dimension of buccal bone at implant sites on aesthetic outcomes and the relation between buccal bone horizontal and vertical dimensions are unclear. The aim of the present study is to investigate the correlation between buccal bone thickness, buccal bone level and aesthetic outcome in conventionally placed implants ­ placed five or more years previously ­ supporting single maxillary incisors. Eight subjects with 8 implants and with periapical and parallel profile X-rays were clinically examined to assess the "Pink Aesthetic Score" (PES). Buccal bone level and thickness, together with the interproximal bone level, were measured. Implant survival was 100%. The mean time of implants function was 89.3 months (standard deviation 43, range 61-145). The mean PES value was 9.4. The mean interproximal bone level was located 1.3 mm apically to the implant abutment junction, while the corresponding buccal value was 1.6 mm. Buccal bone was mostly absent at the implant abutment junction; 2 and 4 mm apically respect to the junction the thickness was on average 0.44 and 0.89 mm, respectively. The dimension of buccal bone level was correlated to the buccal bone thickness at 2mm-level, to the interproximal bone level and to the soft tissue contour score. Conventional implant placement in pristine bone might lead to satisfactory long-term aesthetic results. The level of the facial mucosa and appearance of the alveolar process might emerge as critical aspects.

Treatment of skin defects with growth factors and biodegradable collagen carrier: histological evaluation in animal model.

The aim of the present study is to evaluate the effects on skin regeneration of a new collagen matrix (CM-10826) when used in different combination with or without growth factors, using skin regeneration without membrane as control. An area of 10x15 cm on rabbit back was shaved and three circular wounds on test side were covered with a differently soaked membrane. The first wound was soaked with Epidermal Growth Factor (EGF, 26mg/130mL) (Test EGF), the second with Platelet-Derived Growth Factor (PDGF, 6mg/120mL) (Test PDGF) and the third with EGF (13mg/65mL) and PDGF (3mg/60mL) (Test EGF+PDGF). On the control side, there was a dry membrane. After 7 days, the experiment was concluded. Healing process was evaluated at day 2 and 6 postoperatively. Analysis was made clinically and with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Analyses with LM of Test EGF showed evidence of neoangiogenesis and good epithelium growth. Test PDGF resulted in moderate angiogenesis, less evident epithelial growth and more evident mesenchymal growth than Test EGF. Test EGF+PDGF showed rich angiogenesis, massive growth of epithelium and mesenchymal tissue. Control side showed weak angiogenesis, regenerating wound margin with normal epithelium and less dense mesenchymal layer. Analysis at TEM and SEM confirmed what was noticed at LM. In vivo studies on rabbits have shown that membrane CM10826 is well tolerated, it gives neither inflammation nor foreign body reactions and does not disturb healing process. CM10826 is safe, modulates angiogenesis and induces migration and proliferation of keratinocytes.

A novel CAD/CAM-based surgical template for mandibular osteoplasty and guided implant insertion.

Bone shaping is often a necessary procedure prior to implant insertion in mandibular full-arch rehabilitations. Adopting guided surgery procedures is necessary to use two distinct templates: one for bone shaping, a second for guided implant insertion. The present report describes the case of a 60-year-old patient requiring a full-arch, immediately loaded implant-supported mandibular rehabilitation. A CAD/CAM-bone supported surgical template for osteoplasty was used to develop a template for guided implant during an all-on-six immediate-loaded computer-aided implant surgery. The report describes the feasibility, accuracy and usefulness of this double, CAD/CAM developed, surgical template.

Bi-layered collagen nano-structured membrane prototype collagen matrix 10826® for soft tissue regeneration in rabbits: an in vivo ultra-structural study of the early healing phase.

Collagen Matrix (CM) 10826 is a nanostructured bi-layered collagen membrane obtained from type I and III porcine collagen, which in vitro has shown to have the potential to be a substitute and/or stimulant for soft oral tissue regeneration. The objective of this study was to evaluate the in vivo potential and safety of this membrane for soft tissue regeneration in the early stage of wound healing. Two soft tissue wounds (test and control) were created on the back skin of 5 rabbits (female New Zealand White Rabbits specific pathogen free). All wounds were protected by a special poly-tetra-fluoro-ethylene (PTFE) healing camera. On each rabbit on the test side CM-10826 was used, while on the control side conventional treatment (an autologous pedicle graft) was performed. The healing process was observed clinically after 2 and 6 days, and Magnetic Resonance Imaging (MRI) was performed after this period. After 7 days, animals were sacrificed and specimens were analyzed with light optic microscopy (LM), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). These in vivo trials on rabbits confirmed that CM-10826 is well tolerated, without signs of histological inflammatory reaction and proved to be able to accelerate the spontaneous repair of the skin defect taken as the control. The light-optic and ultra-microscopy of serial biopsies showed that the new matrix is biocompatible and is able to function as a scaffold inducing soft tissue regeneration. In conclusion this study demonstrates that CM-10826 promote early soft tissue regeneration and suggests it is a potential constituent for human autologous keratinocytes seeded derma bioequivalent. It protects the wound from injuries and bacterial contamination accelerating healing process. As a clinical relevance, we consider that the quality of life of patients will be improved avoiding the use of major autologous grafts, reducing the hospitalization time and morbidity.

Volume changes of autogenous bone grafts after alveolar ridge augmentation of atrophic maxillae and mandibles.

The aim of the present retrospective chart review was to determine the relationship between nonvascularized osseous graft remodeling and the three-dimensional (3D) features of grafts and recipient sites, the anatomical recipient regions and different graft sources. 32 iliac crest or chin grafts were onlay-positioned in the mandible or maxilla of 14 patients. CT scans, taken before implant positioning and after 1 year, revealed a mean volume resorption of 35-51%. For iliac crest grafts, the average resorption was 42% when the onlay was positioned in the anterior maxilla and 59% when it was positioned in the posterior mandible. Spearman correlation and 3D interpolation analysis revealed, for both iliac crest groups, a moderate or advanced remodeling pattern depending on 3D features, namely graft thickness and shape, basal bone volume of recipient site, and the basal bone/graft volume ratio of the recipient site. No statistically significant differences were found between the recipient and donor site groups. Retrospective analysis of the data indicates that iliac crest grafts, onlay-positioned on adequate basal bone volume, may register a reduced volume remodeling when shaped thick in the anterior maxilla or rounded and convex, on the external surface, in the posterior mandible.

Clinical survey of neurosensory side-effects of mandibular parasymphyseal bone harvesting.

The aim of the present survey was to assess neurosensory disturbances and/or tooth-pulp sensitivity losses after mandibular parasymphyseal bone-harvesting procedures. Twenty-eight harvesting areas in 16 patients were surveyed. Mucosal and skin sensitivity of the chin/lower lip, divided into four regions, were determined via Pointed-Blunt and Two-Point-Discrimination Tests. Pulp sensitivity of the mandibular teeth from the left second bicuspid to the right second bicuspid was tested by cold vitality preoperatively and 12 months postoperatively. Teeth were grouped according to sensitivity alterations and distance from the harvesting defects, as measured on CT scans, and statistically significant differences sought. At 12 months, 29% of preoperatively vital cuspids overlying the harvesting defects revealed pulp-sensitivity losses; no patient reported anaesthesia or analgesia; hypoaesthesia was present in 4% (8 sites; 2 patients), hypoalgesia was present in 3% (5 sites; 2 patients) and Two-Point-Discrimination Tests yielded pathologic responses in 5% of tested areas (10 sites; 4 patients). Teeth with and without pulp sensitivity changes were statistically indistinguishable regarding distances between root apices or mental foramen and the harvesting defect. The loss of pulp sensitivity in any tooth cannot be predicted simply on the basis of the distance between its apex and the harvesting osteotomy line.