Influence of root width and dentin wall thickness evaluated by endoscopy upon the outcome of periapical surgery. A cohort study

Background: An analysis was made of the correlation between root width, the thickness of the remaining dentinal wall as determined by endoscopy, and the outcome of periapical surgery. Material and Methods: A retrospective cohort study was carried out involving patients subjected to periapical surgery between 2017 and 2019 at the University of Valencia (Valencia, Spain). One year after surgery, cone-beam computed tomography (CBCT) was used to evaluate healing against the preoperative volumes. The maximum root width was measured on the postoperative CBCT scan at the apical section of the treated root. This measurement was transferred to the intraoperative endoscopic image, where the minimum root width, peripheral dentin thickness, and minimum dentin thickness were recorded. Root measurements, and the position (maxillary or mandibular) and type of tooth (roots of incisors, canines, premolars or molars) were further correlated to periapical surgery outcome. Results: A total of 51 patients, comprising 52 teeth and 62 roots, were included in the study. The mean measurements were: maximum root width (4.13 +/- 0.84 mm), minimum root width (2.46 +/- 0.72 mm), peripheral dentin thickness (0.77 +/- 0.2 mm) and minimum dentin thickness (0.4 +/- 0.2 mm). The success rate was 82.2%. Premolar roots showed a greater minimum dentin thickness (0.58 +/- 0.25 mm) ( p<0.003) than incisor roots. No significant association was found between the different measurements and the healing rate at one year, though the roots that failed to heal showed smaller minimum dentin thickness values than the roots that healed correctly. The position and type of tooth did not influence healing outcome. Conclusions: The root width and thickness of the remaining dentin wall did not significantly influence healing. However, the roots that failed to heal showed smaller minimum dentin thickness values than the roots that healed correctly

Impact of abutment geometry on early implant marginal bone loss. A double-blind, randomized, 6-month clinical trial

Objectives The objective of this study was to analyze the impact of the abutment width on early marginal bone loss (MBL). Material and Methods A balanced, randomized, double-blind clinical trial with two parallel experimental arms was conducted without a control group. The arms were “cylindrical” abutment and “concave” abutment. Eighty hexagonal internal connection implants, each with a diameter of 4 × 10 mm, were placed in healed mature bone. The main variable was the peri-implant tissue stability, which was measured as MBL at 8 weeks and 6 months. Results The final sample consisted of 77 implants that were placed in 25 patients. 38 (49.4%) were placed using the cylindrical abutment, and the other 39 (50.6%) were placed using the concave abutment. The early global MBL of −0.6 ± 0.7 mm in the cylindrical abutment group was significantly higher than it was in the concave abutment group, in which the early global MBL was −0.4 ± 0.6 mm (p = .030). The estimated effect size (ES) was negative for the cylindrical abutment (ES = −1.3730, CI −2.5919 to −0.1327; t-value = −2.4893; p = .0139), therefore implying a loss of mean bone level, and it was positive for the concave abutment (ES = 2.8231; CI: 1.4379 to 4.2083; t-value = 4.0957; p = .0002), therefore implying an increase in the average bone level. Conclusions The concave abutments presented significantly less early MBL at 6 months post-loading than classical cylindrical abutments did

Implants placed in the nasopalatine canal to rehabilitate severely atrophic maxillae: A retrospective study with long follow-up

To assess the survival rate of implants placed in the nasopalatine canal for the rehabilitation of patients with atrophic maxillae and the level of satisfaction of these patients. A retrospective study was performed between 2000 and 2009 of patients with severe atrophy of edentulous maxillae (Cawood and Howell’s class V) rehabilitated with implant-supported prostheses with 1 implant placed in the nasopalatine canal. A preoperative computed tomography scan was obtained of all patients and all surgeries were performed by the same surgeon. The following parameters were assessed: neurosensory status of the anterior palate (using the pointed/blunt discrimination method); implant success rate according to criteria described by Albrektsson et al; patient satisfaction with the prosthetic treatment (using visual analogue scales). Thirteen patients with a mean age of 54.8 years were treated, 5 men and 8 women. Seventy-eight implants were placed: 13 in the nasopalatine canal, 6 in the zygomatic bone, 12 in the pterygomaxillary region, 2 in the frontomaxillary buttress and 45 in other locations. Six patients reported a slight decrease in sensitivity in the anterior palate after surgery, which disappeared in all cases within a few weeks. Two early failures (before prosthetic loading) and no late failures (after prosthetic loading) of nasopalatine implants were recorded, yielding a success rate for these implants of 84.6% after a mean follow-up of 70 months (range 24 to 132 months. High patient satisfaction with the prosthetic restoration was generally achieved in terms of comfort, stability, function, esthetics, and ease of cleaning. Residual bone is associated with the nasopalatine canal, even in patients with severe maxillary atrophy. This canal may be considered a possible location for an anterior implant when rehabilitating atrophic patients using implant-supported prosthese

Metal Nanoparticles Released from Dental Implant Surfaces: Potential Contribution to Chronic Inflammation and Peri-Implant Bone Loss

Peri-implantitis is an inflammatory disease affecting tissues surrounding dental implants. Although it represents a common complication of dental implant treatments, the underlying mechanisms have not yet been fully described. The aim of this study is to identify the role of titanium nanoparticles released form the implants on the chronic inflammation and bone lysis in the surrounding tissue. We analyzed the in vitro effect of titanium (Ti) particle exposure on mesenchymal stem cells (MSCs) and fibroblasts (FU), evaluating cell proliferation by MTT test and the generation of reactive oxygen species (ROS). Subsequently, in vivo analysis of peri-implant Ti particle distribution, histological, and molecular analyses were performed. Ti particles led to a time-dependent decrease in cell viability and increase in ROS production in both MSCs and FU. Tissue analyses revealed presence of oxidative stress, high extracellular and intracellular Ti levels and imbalanced bone turnover. High expression of ZFP467 and the presence of adipose-like tissue suggested dysregulation of the MSC population; alterations in vessel morphology were identified. The results suggest that Ti particles may induce the production of high ROS levels, recruiting abnormal quantity of neutrophils able to produce high level of metalloproteinase. This induces the degradation of collagen fibers. These events may influence MSC commitment, with an imbalance of bone regeneration

Microbial Colonization of the Peri-Implant Sulcus and Implant Connection of Implants Restored With Cemented Versus Screw-Retained Superstructures: A Cross-Sectional Study

Background: The aim of this study is to investigate peri-implant and intraconnection microflora of healthy implants restored with cemented and screwed superstructures. Methods: Patients with two to three implants restored with cemented or screwed restorations and 5 years of follow-up were recruited. Samples were taken from peri-implant sulci, adjacent teeth, and the inner portion of connections. Prevalence of positive sites and bacterial loads for 10 microorganisms were obtained with quantitative real-time polymerase chain reaction. Implant connection permeability to the studied microorganisms was estimated using a standardized bacterial contamination index. Statistical analysis was performed using a generalized estimating equations model, Wald x2 test, and the least significant difference test. Results: The final sample consisted of 18 patients (55 implants) in the cemented group and 22 patients (46 implants) in the screw-retained group. Regarding prevalence of positive sites, significant differences between groups were only found for Tannerella forsythia, which was 8.7 times more frequent at peri-implant sulci of cemented than screw-retained prostheses. Bacterial loads of Porphyromonas gingivalis, T. forsythia, Parvimonas micra, and total bacterial load were significantly higher at peri-implant sulci for the cemented group; at the inner portion of connections, values were significantly higher for P. micra and Fusobacterium nucleatum for the screw-retained group. Contamination index values demonstrated higher permeability to most microbes in the cemented group. Conclusions: Internal implant surfaces were microbiologically contaminated for both cemented and screw-retained superstructures. Differences were found between the two methods of prosthetic retention: the cemented group presented significantly higher bacterial loads in the peri-implant sulcus but significantly lower bacterial loads at the inner portion of the implant connection

Culturomic and quantitative real- time- polymerase chain reaction analyses for early contamination of abutments with different surfaces: A randomized clinical trial

BackgroundRough and/or plasma- activated abutments seem to be able to increase soft tissue adhesion and stability; however, limited evidence is available about bacterial contamination differences.PurposeThe aim was to investigate the oral microbiota on four dental abutments with different surfaces by quantitative real- time polymerase chain reaction (qRT- PCR) and culturomic approach.MethodsForty patients needing a single implant rehabilitation were involved in the study. Forty healing abutments, especially designed for the study, were divided into four groups according to the surface topography (1. machined [MAC], 2. machined plasma of argon treated [plasmaMAC], 3. ultrathin threaded microsurface [UTM], 4. UTM plasma of argon treated [Plasma UTM]). Random assignment was performed according to predefined randomization tables. All patients underwent surgical intervention for implant and contextual healing abutment positioning. After 2 months of healing, a sterile cotton swab was used for microbiological sampling for culturomics, while sterile paper points inserted into the sulcus were used for qRT- PCR.ResultsAt the end of the study, 36 patients completed all procedures and a total of 36 abutments (9 per group) were analyzed. qRT- PCR retrieved data for 23 bacterial species whereas culturomics revealed the presence of 74 different bacteria, most of them not routinely included into oral cavity microbiological kits of analysis or never found before in the oral microenvironment. No statistically significant differences emerged analyzing the four different surfaces (p =- 0.053). On the contrary, higher total and specific bacterial counts were detected in the plasma- treated surfaces compared to the untreated ones (p =- 0.021).ConclusionsAbutments with different topographies and surface treatments resulted contaminated by similar oral bacterial flora. Abutments with moderately rough surface were not associated with a greater bacterial adhesion compared to machined ones. Conversely, more bacteria were found around plasma- treated abutments. Furthermore, data reported suggested to include new species not previously sought in the routine analyses of the oral bacterial microflora.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/169240/1/cid13028_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/169240/2/cid13028.pd

Culturomic and quantitative real‐time polymerase chain reaction analyses for early contamination of abutments with different surfaces: A randomized clinical trial

none9simixedCanullo, Luigi; Masucci, Luca; Quaranta, Gianluca; Patini, Romeo; Caponio, Vito Carlo Alberto; Pesce, Paolo; Ravidà, Andrea; Penarrocha‐Oltra, David; Penarrocha‐Diago, MiguelCanullo, Luigi; Masucci, Luca; Quaranta, Gianluca; Patini, Romeo; Caponio, Vito Carlo Alberto; Pesce, Paolo; Ravidà, Andrea; Penarrocha‐oltra, David; Penarrocha‐diago, Migue

The predictive value of microbiological findings on teeth, internal and external implant portions in clinical decision making

International audienceAim: The primary aim of this study was to evaluate 23 pathogens associated with peri-implantitis at inner part of implant connections, in peri-implant and periodontal pockets between patients suffering peri-implantitis and participants with healthy peri-implant tissues; the secondary aim was to estimate the predictive value of microbiological profile in patients wearing dental implants using data mining methods.Material and Methods: Fifty participants included in the present case─control study were scheduled for collection of plaque samples from the peri-implant pockets, internal connection, and periodontal pocket. Real-time polymerase chain reaction was performed to quantify 23 pathogens. Three predictive models were developed using C4.5 decision trees to estimate the predictive value of microbiological profile between three experimental sites.Results: The final sample included 47 patients (22 healthy controls and 25 diseased cases), 90 implants (43 with healthy peri-implant tissues and 47 affected by peri-implantitis). Total and mean pathogen counts at inner portions of the implant connection, in peri-implant and periodontal pockets were generally increased in peri-implantitis patients when compared to healthy controls. The inner portion of the implant connection, the periodontal pocket and peri-implant pocket, respectively, presented a predictive value of microbiologic profile of 82.78%, 94.31%, and 97.5% of accuracy.Conclusion: This study showed that microbiological profile at all three experimental sites is differently characterized between patients suffering peri-implantitis and healthy controls. Data mining analysis identified Parvimonas micra as a highly accurate predictor of peri-implantitis when present in peri-implant pocket while this method generally seems to be promising for diagnosis of such complex infections

Soft tissue response to titanium abutments with different surface treatment: preliminary histologic report of a randomized controlled trial

The aim of this preliminary prospective RCT was to histologically evaluate peri-implant soft tissues around titanium abutments treated using different cleaning methods. Sixteen patients were randomized into three groups: laboratory customized abutments underwent Plasma of Argon treatment (Plasma Group), laboratory customized abutments underwent cleaning by steam (Steam Group), and abutments were used as they came from industry (Control Group). Seven days after the second surgery, soft tissues around abutments were harvested. Samples were histologically analyzed. Soft tissues surrounding Plasma Group abutments predominantly showed diffuse chronic infiltrate, almost no acute infiltrate, with presence of few polymorphonuclear neutrophil granulocytes, and a diffuse presence of collagenization bands. Similarly, in Steam Group, the histological analysis showed a high variability of inflammatory expression factors. Tissues harvested from Control Group showed presence of few neutrophil granulocytes, moderate presence of lymphocytes, and diffuse collagenization bands in some sections, while they showed absence of acute infiltrate in 40% of sections. However, no statistical difference was found among the tested groups for each parameter (p > 0.05). Within the limit of the present study, results showed no statistically significant difference concerning inflammation and healing tendency between test and control groups