Radiographic evaluation of marginal bone levels around implants supporting splinted fixed bridges: A retrospective study on 412 implants.

OBJECTIVES: The effect of the implant position within the prosthesis on bone remodeling is scarcely documented so far. Thus, the aim of the present study was to investigate whether central implants may suffer higher peri-implant marginal bone levels (MBL) compared to laterals in case of fixed splinted bridges supported by ≥ three implants. MATERIALS AND METHODS: Partially edentulous subjects rehabilitated with at least one fixed bridge supported by ≥ three dental implants were enrolled. MBL was assessed radiographically by means of intraoral radiographs acquired with phosphor plates and imported in a dedicated software. MBL was calculated as the distance between the implant platform level and the most coronal visible bone-to-implant contact. A three-level linear mixed effects model was used for investigating the fixed effect of patient-, prosthesis-, and implant-level variables on the MBL. RESULTS: Overall, 90 patients rehabilitated with 130 splinted fixed bridges supported by 412 implants were included. The median follow-up was 136 months. The mean peri-implant MBL resulted statistically significantly higher at central implants if compared to lateral implants (p < .01). The estimated MBL averages for central and external implants were 1.68 and 1.18 mm, respectively. The prosthesis-level variables suggested that a cement-retained bridge was prone to a significant 0.82 mm higher MBL than a screw-retained one. Implant surface showed an association with MBL changes, although less pronounced than implant retention. CONCLUSIONS: In case of ≥3 adjacent implants supporting splinted bridges, central implants were more predisposed to MBL compared to laterals. At the prosthesis level, implants supporting cement-retained bridges were statistically more susceptible to MBL compared to screw-retained ones. Surface characteristics can also influence MBL stability at the implant level.

Oral health-related quality of life in implant-supported rehabilitations: a prospective single-center observational cohort study.

BACKGROUND: Oral Health-Related Quality of Life (OHRQoL) is a comprehensive concept covering daily comfort, self-esteem, and satisfaction with oral health, including functional, psychological, and social aspects, as well as pain experiences. Despite abundant research on OHRQoL related to oral diseases and hygiene, there is limited data on how patients perceive changes after implant-prosthetic rehabilitation. This study aimed to evaluate OHRQoL and aesthetic perception using OHIP-14 and VAS scales respectively, before (baseline-TB), during (provisional prostheses-TP), and after (definitive prostheses-TD) implant-prosthetic rehabilitation. It also explored the impact of biological sex, substitution numbers, and aesthetic interventions on OHRQoL and VAS scores, along with changes in OHIP-14 domains. METHODS: A longitudinal prospective single-center observational cohort study was conducted with patients requiring implant-prosthetic rehabilitation. Quality of life relating to dental implants was assessed through the Italian version of Oral Health Impact Profile-14 (IOHIP-14), which has a summary score from 14 to 70. Patients' perceived aesthetic was analyzed through a VAS scale from 0 to 100. Generalized Linear Mixed Effect Models, Linear Mixed Effect Models, and Friedman test analyzed patient responses. RESULTS: 99 patients (35 males, 64 females) aged 61-74, receiving various prosthetic interventions, were enrolled. Both provisional and definitive prosthetic interventions significantly decreased the odds of a worse quality of life compared to baseline, with odds ratios of 0.04 and 0.01 respectively. VAS scores increased significantly after both interventions, with estimated increases of 30.44 and 51.97 points respectively. Patient-level variability was notable, with an Intraclass Correlation Coefficient (ICC) of 0.43. While biological sex, substitution numbers, and aesthetic interventions didn't significantly affect VAS scores, OHRQoL domains showed significant changes post-intervention. CONCLUSIONS: These findings support the effectiveness of implant-prosthetic interventions in improving the quality of life and perceived aesthetics of patients undergoing oral rehabilitation. They have important implications for clinical practice, highlighting the importance of individualized treatment approaches to optimize patient outcomes and satisfaction in oral health care.

Metamaterial architecture from a self-shaping carnivorous plant.

As meticulously observed and recorded by Darwin, the leaves of the carnivorous plant Drosera capensis L. slowly fold around insects trapped on their sticky surface in order to ensure their digestion. While the biochemical signaling driving leaf closure has been associated with plant growth hormones, how mechanical forces actuate the process is still unknown. Here, we combine experimental tests of leaf mechanics with quantitative measurements of the leaf microstructure and biochemistry to demonstrate that the closure mechanism is programmed into the cellular architecture of D. capensis leaves, which converts a homogeneous biochemical signal into an asymmetric response. Inspired by the leaf closure mechanism, we devise and test a mechanical metamaterial, which curls under homogeneous mechanical stimuli. This kind of metamaterial could find possible applications as a component in soft robotics and provides an example of bio-inspired design.

Autogenous Chin Block Grafts for Implant-Supported Rehabilitation: A 20-Year Follow-Up Case Series.

The aim of the present study was to analyze the survival and success rates of dental implants placed in atrophic alveolar ridges reconstructed with mandibular symphysis autogenous onlay bone grafts, with a 20-year follow-up. A sample of five patients referred to the authors' department between 2000 and 2001 seeking for an implant-supported fixed rehabilitation. Patients were treated by means of autogenous bone blocks grafted from the mandibular symphysis and covered with bone substitutes (DBB) and a resorbable membrane. Then delayed implants were placed and finally prosthetic restoration was performed. In total, 10 implants placed in 5 patients were evaluated with a follow-up of 20 years. Both implant survival and success rate were 100%. The mean marginal bone loss was 0.32  [[EQUATION]]  0.39 mm (range 0-1.3 mm). Considering the conditions of peri-implant hard and soft tissues, the diagnosis of peri-implant health was made for all the implants included. According to this study, implants placed in alveolar ridges augmented by means of autogenous chin bone grafts showed long-term survival and high success rates. A correct management of peri-implant soft tissues and an accurate prosthetic rehabilitation are also fundamental to obtain the durable success of the treatment.

Cast-free digital workflow for implant-supported rehabilitation in a completely edentulous patient: A clinical report.

Digitalization of edentulous areas restored with dental implants is still considered a demanding procedure, mainly because of the lack of fixed reference landmarks, together with an increased interimplant distance. To overcome such limitations, an auxiliary device is introduced with the 3-fold purpose of stretching the soft tissues with a fixed object connected to the scan bodies, creating areas with nonhomogeneous architectures between the implants, and shortening the interimplant distance with the interposition of solid geometric figures. The rationale was to increase the accuracy of digital scans in a cast-free digital implant workflow.

Influence of Timing on the Horizontal Stability of Connective Tissue Grafts for Buccal Soft Tissue Augmentation at Single Implants: A Prospective Controlled Pilot Study.

PURPOSE: The timing for soft tissue augmentation during implant therapy is still debated. Therefore, the present study clinically evaluated whether immediate versus delayed soft tissue augmentation procedures had an impact on the stability of peri-implant mucosal thickness (PMT). MATERIALS AND METHODS: Patients requiring a single implant posterior to the canines in association with soft tissue augmentation procedures at the buccal aspect of single implants using a connective tissue graft (CTG) were enrolled. Patients were randomly allocated to 2 different timing protocols: simultaneous implant and CTG placement (test group) or implant placement and then CTG placement after 3 months (control group). PMT was measured clinically at the mid-buccal aspect of the implant site by bone sounding with an endodontic K-file using customized acrylic stents. PMT measurements were recorded before and after implant placement and at 1, 2, 3, 4, 6, 9, and 12 months after implant insertion. Parametric statistical tests were used to compare PMT between the test and control groups at each study period and to evaluate changes in PMT over time. The level of significance was set at a P value less than .05. RESULTS: Fourteen implants placed in 14 patients were available for statistical comparison. At 12 months, the difference in PMT between the test and control groups was 0.12 ± 0.51 mm. This difference was not statistically significant (P = .54). A significant increase in PMT was observed from baseline to 12 months after implantation in the test (P = .004) and control (P < .001) groups. CONCLUSIONS: The present study indicated that changes in PMT after CTG placement were not influenced by the timing of soft tissue augmentation and remained stable up to 1 year after implant insertion.

Left ventricular functional parameters by gated SPECT myocardial perfusion imaging in a Latin American country.

BACKGROUND: There is paucity of data on left ventricular (LV) functional parameters using gated SPECT myocardial perfusion imaging (MPI) from the Latin American region. This study provides detailed information in low-risk patients both at rest and during exercise. METHODS AND RESULTS: We studied 90 patients (50 men) with a very low likelihood of coronary artery disease. Gated-SPECT MPI was performed with Tc-99m MIBI using a 2-day protocol, with 16 frames/R-R cycle. The LV ejection fraction and volumes were not different between the rest and post-stress images. LVEF was 68 ± 7% post-stress and 70 ± 7% at rest in women, and 62 ± 7% and 63 ± 7%, respectively, in men (P = .19, .26). LV volumes were larger in men than women (P < .01). There were no differences in most variables obtained at rest or post-stress. Transient ischemic dilatation was similar, with upper limits of 1.20 and 1.19 in women and men, respectively (P = NS). CONCLUSIONS: These data could prove helpful for the interpretation of gated SPECT MPI data in Latin America using identical protocol as used in this study.

Virtually guided alveolar ridge reduction combined with computer-aided implant placement for a bimaxillary implant-supported rehabilitation: A clinical report.

Insufficient crown height space, particularly in the interforaminal region of edentulous ridges with knife-edge morphology, may prevent successful prosthetic rehabilitation. Such conditions require osteoplasty, which might complicate computer-guided implant placement. This clinical report illustrates the treatment of a patient with complete edentulism rehabilitated with a mandibular implant-supported fixed dental prosthesis by using a virtually guided approach. Both alveolar ridge reduction and prosthetically driven implant insertions were computer-guided by surgical stents to increase accuracy and predictability. This approach enabled the immediate loading of the implants with an interim prosthesis before the delivery of a definitive screw-retained fixed prosthesis. At the 1-year follow-up visit, clinical and radiographic examination revealed a stable outcome.

Oral Rehabilitation of a Patient With Ectodermal Dysplasia Treated With Fresh-Frozen Bone Allografts and Computer-Guided Implant Placement: A Clinical Case Report.

Ectodermal dysplasia (ED) is an inherited disorder characterized by abnormality of ectodermally derived structures. A recurrent oral finding is oligodontia, which in turn leads to a severely hypotrophic alveolar process with typical knife-edge morphology and adverse ridge contours. This unfavorable anatomy can seriously hamper proper implant placement. Fresh-frozen bone (FFB) allografts recently have been proposed to augment the residual bone volume for implant placement purposes; however, scientific evidence concerning the use of FFB to treat ED patients is absent. Similarly, data reporting computer-aided template-guided implant placement in medically compromised patients are limited. Thus the purpose of this report is to illustrate the oral rehabilitation of a female patient affected by ED and treated with appositional FFB block grafts and consecutive computer-guided flapless implant placement in a 2-stage procedure. Fixed implant-supported dental prostheses were finally delivered to the patient, which improved her self-esteem and quality of life. During the follow-up recall 1 year after the prosthetic loading, the clinical examination showed healthy peri-implant soft tissues with no signs of bleeding on probing or pathologic probing depths. The panoramic radiograph confirmed the clinical stability of the result. Peri-implant marginal bone levels were radiographically stable with neither pathologic bone loss at the mesial and distal aspects of each implant nor peri-implant radiolucency. Within the limitations of this report, the use of FFB allografts in association with computer-aided flapless implant surgery might be considered a useful technique in patients affected by ED.

Confined Polymerization in Highly Ordered Mesoporous Organosilicas.

Hybrid mesoporous organosilica exhibiting crystal-like order in the walls provided an ideal channel reaction vessel for the confined polymerization of acrylonitrile (PAN). The resulting high-molecular-mass PAN fills the channels at high yield and forms an ordered nanostructure of polymer nanobundles enclosed into the hybrid matrix. The in situ thermal transformation of PAN into rigid polyconjugated and, eventually, into condensed polyaromatic carbon nanofibers, retains the periodic architecture. Simultaneously, the matrix evolves showing the fusion of the p-phenylene rings and the cleavage of carbonsilicon bonds: this gives rise to graphitic-carbon/silica nanocomposites containing hyper-oxydrylated silica nanophases. Interestingly, the 3D hexagonal mesostructure survives in the carbonaceous material. The exploitation of porous materials of high capacity and a hybrid nature, for polymerization in the confined state, followed by high temperature treatments, allowed us to achieve unique and precisely fabricated nanostructures, thus paving the way for the construction of fine-tuned electronic and light-harvesting materials.

Dipolar rotors orderly aligned in mesoporous fluorinated organosilica architectures.

New mesoporous covalent frameworks, based on hybrid fluorinated organosilicas, were prepared to realize a periodic architecture of fast molecular rotors containing dynamic dipoles in their structure. The mobile elements, designed on the basis of fluorinated p-divinylbenzene moieties, were integrated into the robust covalent structure through siloxane bonds, and showed not only the rapid dynamics of the aromatic rings (ca. 10(8) Hz at 325 K), as detected by solid-state NMR spectroscopy, but also a dielectric response typical of a fast dipole reorientation under the stimuli of an applied electric field. Furthermore, the mesochannels are open and accessible to diffusing in gas molecules, and rotor mobility could be individually regulated by I2 vapors. The iodine enters the channels of the periodic structure and reacts with the pivotal double bonds of the divinyl-fluoro-phenylene rotors, affecting their motion and the dielectric properties.

Engineering switchable rotors in molecular crystals with open porosity.

The first example of a porous molecular crystal containing rotors is presented. The permanently porous crystal architecture is sustained by rotor-bearing molecular rods which are connected through charge-assisted hydrogen bonds. The rotors, as fast as 10(8) Hz at 240 K, are exposed to the crystalline channels, which absorb CO2 and I2 vapors at low pressure. The rotor dynamics could be switched off and on by I2 absorption/desorption, showing remarkable change of material dynamics by the interaction with gaseous species and suggesting the use of molecular crystals in sensing and pollutant management.

Alveolar ridge reconstruction with titanium meshes: a systematic review of the literature.

Alveolar 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.

Xenograft Combined with a Mixture of Polynucleotides and Hyaluronic Acid (PNs-HA) for Horizontal Alveolar Bone Regeneration: Clinical and Histologic Assessments in a Case Series.

The present case series aims to investigate the use of polynucleotides mixed with hyaluronic acid (PNs-HA) in the form of gel to promote bone regeneration in horizontal alveolar defects. Overall, 6 adult patients underwent localized horizontal guided bone regeneration by means of xenogeneic bone substitute and a resorbable barrier with a staged approach. The graft consisted in a mixture of deproteinized bovine bone mineral (DBBM) particles and PNs-HA gel in a 3:1 ratio, respectively. The material was covered by a resorbable collagen membrane fixed with pins to the underlying bone. Implant placement was performed after 5 months. Healing proceeded uneventfully, and, upon re-entry, the graft appeared well vascularized and firmly attached to the recipient bone. Histologically, the regenerated bone appeared highly mineralized, well-organized in lamellae and totally embedding the residual granules of the biomaterial. Histomorphometric evaluations revealed that newly formed bone occupied on average 41.2% ± 12.4% of the analysed samples. Linear measurements performed on CBCT scans yielded an overall linear horizontal bone gain of 4.91 ± 0.88 mm. These data suggest that a mixture of DBBM and PNs-HA can be safely used to promote bone regeneration in case of horizontal alveolar defects.

Correlation between Accuracy in Computer-Guided Implantology and Peri-Implant Tissue Stability: A Prospective Clinical and Radiological Pilot Study.

The present pilot study was designed by hypothesizing a possible correlation between lack of accuracy in implant placement and peri-implant hard and soft tissue health. A total of five patients underwent computer-guided implant surgery and full-arch immediate loading between 2013 and 2014. They subsequently underwent postoperative cone-beam computed tomography (CBCT). After a follow-up of 5 years, all patients were recalled for a clinical-radiographic evaluation of peri-implant health status. The mean linear deviation was 0.5 ± 0.2 mm at the implant's head and 0.6 ± 0.2 mm at the implant's apex, while the mean angular deviation of the long axis was 2.8° ± 1.2°. A mean marginal bone loss (MBL) of 1.16 ± 0.94 mm and 2.01 ± 1.76 mm was observed after 1 and 5 years of follow-up, respectively. At 5 years, the mean peri-implant probing depth (PPD) was 4.09 ± 1.44 mm, 66.6% of the evaluated implants showed peri-implant bleeding on probing (BOP), keratinized mucosa (KM) was <2 mm in 48.4% of cases, and mucosal recession (REC) ≥ 1 mm was assessed in 45.4% of the included implants. A negative correlation was observed between bucco-palatal/lingual linear inaccuracy and MBL, PPD, BOP, and KM.

The efficacy of a porcine collagen matrix in keratinized mucosa width augmentation: a 10-year follow-up clinical prospective study.

PURPOSE: The aim of the present study was to evaluate the long-term effectiveness of a xenogeneic collagen matrix (CM) in pre-prosthetic augmentation of the keratinized mucosa width (KMW) at implant sites. METHODS: All of the patients with localized implant-supported rehabilitation previously treated with vestibuloplasty and KMW augmentation with a non-cross-linked porcine CM were recalled. KMW was measured clinically in an apico-coronal direction from the mucogingival junction to the mucosal margin at the prosthetic zenith of each crown. Measurements were performed clinically by means of a PCP-UNC15 periodontal probe and rounded to the nearest mm. KMW values recorded at 1 year, 5 and 10 years from the soft tissue augmentation procedure were compared using a one-way repeated-measures ANOVA with Bonferroni multiple comparison post-hoc analysis. The level of significance was set at 0.05. RESULTS: Measurements were conducted on 13 patients. All implants were in function with no signs of biological complications. All except one implant site showed KMW ≥ 2 mm. KMW decreased significantly from 1 year (3.33 ± 1.11 mm) to 5 years (2.77 ± 0.92 mm) (p = 0.001), and finally remained stable from 5 to 10 years (3.2 ± 0.99 mm) (p = 0.607). From a visual aspect, peri-implant soft tissues were characterized by a good texture and color blending compared to the adjacent teeth, highlighting good integration of the remodeled tissues and stability of the esthetic result. CONCLUSIONS: The use of a CM in pre-prosthetic soft tissue augmentation at implant sites has proven to be effective in obtaining and maintaining at least 2 mm of KMW around dental implants over a follow-up of 10 years.

Computer Aided Full Arch Restoration by Means of One-Piece Implants and Stackable Guide: A Technical Note.

This technical note aims to present a recently developed computer-guided protocol characterized by titanium-reinforced stackable surgical guides during post-extractive implant placement and subsequent immediate loading. A full maxillary edentulism was rehabilitated with one-piece implants, starting from a pre-existing removable denture. 3D digital scans of the removable denture and upper and lower arches were performed. On this basis, a prototype with ideal esthetic and functional outcomes was realized and replicated into a custom-made radiological stent with markers. The superimposition of STL and DICOM files allowed virtual planning of one-piece implants in the ideal prosthetically driven position. The stackable guides, composed of a fixed base template and additional removable components, were then realized. The fixed template, initially secured with anchor pins to the bone, was no longer removed. The removable components, which were screwed to the base template, were used to perform implant surgery and immediate prosthetic loading. No surgical complications occurred, the implants achieved a minimum insertion torque of 35 Ncm, and immediate prosthetic loading was performed. The base template allowed for the maintenance of a fixed reference during the entire workflow, improving the transition between the digital project, the surgical procedure, and the prosthetic rehabilitation.