Endodontic Retreatment of Teeth With Uncertain Endodontic Prognosis Versus Dental Implants: 5-year Results From a Randomised Controlled Trial

PURPOSE. To ascertain whether it is better to endodontically retreat a previously endo-dontically treated tooth with periapical pathology and/or symptoms and an uncertain prognosis, or to replace the tooth with a single implant-supported crown. MATERIALS AND METHODS. Twenty patients requiring treatment of a previously endodon-tically treated tooth with periapical pathology and/or symptoms of endodontic origin and an uncertain prognosis, as judged by the recruiting investigator, were randomly allocated to endodontic retreatment (endo group; 10 patients) or tooth extraction and replacement with an implant-supported crown (implant group; 10 patients) according to a paral-lel-group design at a single centre. Patients were followed up to 5 years after treatment completion. Outcome measures were: procedure failure; complications; marginal bone level changes at both teeth and implants; radiographic endodontic success (teeth only); number of patient visits and days to complete treatment; chairside time; costs; and ae-sthetics, as assessed using the pink aesthetic score (PES) for the soft tissues and the white aesthetic score (WES) for the tooth/crown by independent assessors. RESULTS. One patient from the endo group dropped out. One endodontically retreated tooth fractured. There were no statistically significant differences in treatment failure between groups (difference in proportions = 0.1; 95% CI-0.18 to 0.35; P = 1.00). Three endo group patients had one complication each versus one complication in the implant group, the difference not being statistically significant (difference in proportions = 0.2; 95% CI-0.17 to 0.51; P = 0.582). The mean marginal bone levels at endo retreatment/implant insertion were 2.10 ± 0.66 mm for the endo and 0.05 ± 0.15 mm for the implant group. Five years after treatment completion, teeth lost on average 0.60 ± 0.96 mm and implants 0.56 ± 0.77 mm, the difference not being statistically significant (mean difference =-0.05 mm; 95% CI:-0.95 to 0.86; P = 0.914). Of the four teeth that originally showed periapical radiolucency, one was lost, two displayed complete healing, and one showed radiographic improvement. There were no statistically significant differences in the number of patient visits (endo = 6.7 ± 0.7; implant = 6.1 ± 0.7; mean difference = 0.6; 95% CI:-0.1 to 1.3 P = 0.106). However, it took significantly more days (endo = 61 ± 13.0; implant = 191.4 ± 75.0; mean difference =-130.4; 95% CI:-184.5 to-76.4; P < 0.001) but less chairside time (endo = 628 ± 41.4 min; implant = 328.5 ± 196.4 min; mean difference =-299.5; 95% CI:-441.3 to 1.0; P = < 0.001) to complete the rehabilitation. Implant treatment was significantly more expensive (endo = 1440 ± 549.7; implant = 2099 ± 170.3; mean difference = 659; 95% CI: 257.2 to 1060.8; P = 0.004). Five years after treatment completion, mean PES were 12.3 ± (1.3) and 8.9 ± 2.2 and mean WES were 8.1 ± 1.4 and 7.1 ± 1.7 in the endo group and implant group, respectively. Soft tissues aesthetics (PES) was significantly better at endodontically retreated teeth (mean difference-3.4; 95% CI-5.1 to-1.6; P (t-test) = 0.001), whereas no significant differences were observed between treatments in tooth aesthetics (WES) (mean difference =-1.0; 95% CI-2.6 to 0.5; P (t-test) = 0.178)

Bone Remodelling in BioShape

AbstractMany biological phenomena are inherently multiscale, i.e. they are characterised by interactions involving different scales at the same time. This is the case of bone remodelling, where macroscopic behaviour (at organ and tissue scale) and microstructure (at cell scale) strongly influence each other. Consequently, several approaches have been defined to model such a process at different spatial and temporal levels and, in particular, in terms of continuum properties, abstracting in this way from a realistic – and more complex – cellular scenario. While a large amount of information is available to validate such models separately, more work is needed to integrate all levels fully in a faithful multiscale model.In this scenario, we propose the use of BioShape, a 3D particle-based, scale-independent, geometry and space oriented simulator. It is used to define and integrate a cell and tissue scale model for bone remodelling in terms of shapes equipped with perception, interaction and movement capabilities. Their in-silico simulation allows for tuning continuum-based tissutal and cellular models, as well as for better understanding – both in qualitative and in quantitative terms – the blurry synergy between mechanical and metabolic factors triggering bone remodelling

Soft Tissue Substitutes at Immediate Postextractive Implants to Reduce Tissue Shrinkage – 3-year Results From a Randomized Controlled Trial

PURPOSE. The aim of this parallel randomized controlled trial (RCT) was to evaluate whether placement of a soft tissue graft substitute (STGS) could decrease peri-implant tissue shrinkage at immediate post-extractive implants. MATERIALS AND METHODS. Twenty patients with one missing tooth between two adja-cent healthy teeth in aesthetic areas and at least 4 mm of bone apically to the tooth apex were randomly allocated after tooth extraction to receive or not a subepithelial buccal STGS. Implants were inserted with a torque of at least 30 Ncm and sites were grafted with a cancellous particulate allograft. Ten patients received a buccal STGS and 10 patients did not (control group). All patients were restored with non-occluding immediate provisional screw-retained crowns, replaced after 6 months by definitive metal-ceramic crowns, and were followed to 3-year after grafting/loading. RESULTS. Three-year after loading, no drop-out, crown or implant failure or complication occurred. No statistically significant difference or trends in aesthetics (difference = 0.2, 95% CI:-0.81 to 1.21; P = 0.97), peri-implant marginal bone loss (difference = 0.14 mm; 95% CI:-0.27 to 0.57; P = 0.58) and keratinized mucosa heights (difference = 0.8 mm; 95% CI:-1.79 to 3.39; P = 0.57) between the two groups were observed. CONCLUSIONS. Acknowledging that the sample size was small, no clinical benefits could be observed using a soft tissue graft substitute at immediate post-extractive implants up to 3-year after grafting. CONFLICT OF INTEREST STATEMENT. The manufacturer (BEGO Implant Systems, Bremen, Germany) of the implants used in this investigation, partially supported this trial, however data belonged to the authors and by no means the sponsor interfered with the conduct of the trial or the publication of its results

Immediate, Early (6 Weeks) and Delayed Loading (3 Months) of Single, Partial and Full Fixed Implant- Supported Prostheses: Three-year Post- Loading Data From a Multicentre Randomised Controlled Trial

PURPOSE. To compare the clinical outcomes of single, partial and complete fixed im-plant-supported prostheses immediately loaded (within 48 hours), early loaded at 6 we-eks, and conventionally loaded at 3 months (delayed loading). MATERIALS AND METHODS. Fifty-four patients (18 requiring single implants, 18 partial fixed prostheses, and 18 total fixed cross-arch prostheses) were randomised in equal numbers in two private practices to immediate loading (18 patients), early loading (18 patients), and conventional loading (18 patients) according to a parallel group design with three arms. To be immediately or early loaded, implants had to be inserted with a torque superior to 40 Ncm. Implants were initially loaded with provisional prostheses, replaced after 4 months by definitive ones. Outcome measures were prosthesis and implant failu-res, complications and peri-implant marginal bone levels. RESULTS. Two conventionally loaded patients rehabilitated with cross-arch fixed total prostheses dropped-out before 3-year post-loading follow-up. No implant failed. One early-loaded partial prosthesis had to be remade (P = 1.0). Three complications occurred in the immediately loaded group, two in the early-loaded and one in the conventionally loaded group with no statistically significant differences across groups (P = 0.861). Pe-ri-implant marginal bone loss was-0.04 ± 0.85 mm at immediately loaded implants,-0.01 ± 0.55 mm at early-loaded implants and 0.33 ± 0.36 mm at conventional loaded implants with no statistically significant differences between the three loading strategies (P=0.191). CONCLUSIONS. All loading strategies were highly successful, and no differences were observed in terms of implant survival and complications when implants were loaded immediately, early or conventionally

Conventional Drills Versus Piezoelectric Surgery Preparation for Placement of Four Immediately Loaded Zygomatic Oncology Implants in Edentulous Maxillae: 3 Year Results of a Within Person Randomised Controlled Trial

PURPOSE. A within-person randomised controlled trial to compare the outcome of site preparation for two zygomatic oncology implants per zygoma using conventional preparation with rotary drills or piezoelectric surgery with dedicated inserts. MATERIALS AND METHODS. Twenty edentulous patients with severely atrophic maxillae and insufficient bone volumes for placing dental implants with less than 4 mm of bone height subantrally had their hemi-maxillae randomised according to a within-patient study design into implant site preparation with either conventional rotational drills or piezoelectric surgery. Two zygomatic oncology implants (unthreaded coronal portion) were placed in each hemi-maxilla. Implants that achieved an insertion torque of greater than 40 Ncm were immediately loaded with provisional screw-retained metal-reinforced acrylic prostheses. Outcome measures were: prosthesis and implant failures, any com-plications, time to place the implants, presence of post-operative haematoma, and patient preference, as assessed by blinded assessors when possible. All patients were followed up for 3 years after loading. RESULTS. In two patients, drills had to be used in the piezoelectric surgery arm in order to prepare implant sites properly. One implant from the conventional drill group did not achieve an insertion torque of greater than 40 Ncm since the zygoma fractured. Three patients dropped out. Two distal oncology implants failed in the same patient (one per group), who was not prosthetically rehabilitated. Six patients experienced at least one complication at drilled sites and five at piezoelectric surgery sites (three patients had bilateral complications), the difference not being statistically significant (odds ratio = 1.5; P [McNemar’s test] = 1.0; 95% CI of odds ratio: 0.25 to 8.98). Implant placement with con-vention drills took on average 14.35±1.76 minutes vs. 23.50±2.26 minutes with piezoelectric surgery, the implant placement time being significantly shorter with conventional drilling (difference = 9.15±1.69 minutes; 95%CI: 8.36 to 9.94 minutes; P = 0.000). Post-operative haematomas were larger at drilled sites in 11 patients and similar at both sides in nine patients (chi-square = 20.4; df = 3; P = 0.0001), and 16 patients found both techniques equally acceptable while four preferred piezoelectric surgery (chi-square = 34.4; df = 3; P<0.0001). CONCLUSIONS. Although these results may be system-dependent, and therefore cannot be generalised to other zygomatic systems with confidence, both drilling techniques achieved similar clinical outcomes. However, conventional drilling required 9 minutes less and could be used in all instances, though it was more aggressive

Clinical efficacy of minimally invasive surgical (MIS) and non-surgical (MINST) treatments of periodontal intra-bony defect. A systematic review and network meta-analysis of RCT's

Objective: The aim of this systematic review was to explore the efficacy of different minimal invasive surgical (MIS) and non-surgical (MINST) approaches for the treatment of intra-bony defect in terms of clinical attachment level (CAL) gain and periodontal pocket depth (PPD) reduction. / Methods: A detailed review protocol was designed according to PRISMA guideline. Online search was conducted on PubMed, Cochrane library and Embase. Only randomized clinical trials (RCTs) testing MIS or MINST procedure, with or without the application of a regenerative tool for the treatment of intra-bony defect, were included. Cochrane checklist for risk of bias assessment was used. Network meta-Analysis (NMAs) was used to rank the treatment efficacy. / Results: Nine RCTs accounting for 244 patients and a total of 244 defects were included. Only two studies were at low risk of bias. CAL gain for included treatment ranged from 2.58 ± 1.13 mm to 4.7 ± 2.5 mm while PPD reduction ranged from 3.19 ± 0.71 mm to 5.3 ± 1.5 mm. On the basis of the ranking curve, MINST showed the lowest probability to be the best treatment option for CAL gain. Pairwise comparisons and treatment rankings suggest superiority for regenerative approaches (CAL difference 0.78 mm, (0.14–1.41); P < 0.05) and surgical treatment elevating only the buccal or palatal flap (CAL difference: 0.95 mm, (0.33–1.57); P < 0.05). / Conclusions: Minimally invasive surgical (MIS) and non-surgical (MINST) periodontal therapy show promising results in the treatment of residual pocket with intra-bony defect. / Clinical relevance: MIS procedures represent a reliable treatment for isolated intra-bony defect

A meta-analysis of comparative transcriptomic data reveals a set of key genes involved in the tolerance to abiotic stresses in rice

Several environmental factors, such as drought, salinity, and extreme temperatures, negatively affect plant growth and development, which leads to yield losses. The tolerance or sensitivity to abiotic stressors are the expression of a complex machinery involving molecular, biochemical, and physiological mechanisms. Here, a meta-analysis on previously published RNA-Seq data was performed to identify the genes conferring tolerance to chilling, osmotic, and salt stresses, by comparing the transcriptomic changes between tolerant and susceptible rice genotypes. Several genes encoding transcription factors (TFs) were identified, suggesting that abiotic stress tolerance involves upstream regulatory pathways. A gene co-expression network defined the metabolic and signalling pathways with a prominent role in the differentiation between tolerance and susceptibility: (i) the regulation of endogenous abscisic acid (ABA) levels, through the modulation of genes that are related to its biosynthesis/catabolism, (ii) the signalling pathways mediated by ABA and jasmonic acid, (iii) the activity of the \u201cDrought and Salt Tolerance\u201d TF, involved in the negative regulation of stomatal closure, and (iv) the regulation of flavonoid biosynthesis by specific MYB TFs. The identified genes represent putative key players for conferring tolerance to a broad range of abiotic stresses in rice; a fine-tuning of their expression seems to be crucial for rice plants to cope with environmental cues

3D enamel thickness in Neandertal and modern human permanent canines

Enamel thickness figures prominently in studies of human evolution, particularly for taxonomy, phylogeny, and paleodietary reconstruction. Attention has focused on molar teeth, through the use of advanced imaging technologies and novel protocols. Despite the important results achieved thus far, further work is needed to investigate all tooth classes. We apply a recent approach developed for anterior teeth to investigate the 3D enamel thickness of Neandertal and modern human (MH) canines. In terms of crown size, the values obtained for both upper and lower unworn/slightly worn canines are significantly greater in Neandertals than in Upper Paleolithic and recent MH. The 3D relative enamel thickness (RET) is significantly lower in Neandertals than in MH. Moreover, differences in 3D RET values between the two groups appear to decrease in worn canines beginning from wear stage 3, suggesting that both the pattern and the stage of wear may have important effects on the 3D RET value. Nevertheless, the 3D average enamel thickness (AET) does not differ between the two groups. In both groups, 3D AET and 3D RET indices are greater in upper canines than in lower canines, and overall the enamel is thicker on the occlusal half of the labial aspect of the crown, particularly in MH. By contrast, the few early modern humans investigated show the highest volumes of enamel while for all other components of 3D enamel, thickness this group holds an intermediate position between Neandertals and recent MH. Overall, our study supports the general findings that Neandertals have relatively thinner enamel than MH (as also observed in molars), indicating that unworn/slightly worn canines can be successfully used to discriminate between the two groups. Further studies, however, are needed to understand whether these differences are functionally related or are the result of pleiotropic or genetic drift effects