Category: Statistics

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s227-s234. doi: 10.11607/prd.6163.

ABSTRACT

PURPOSE: To investigate the effects of experience level on the clinical and esthetic results of coronally advanced flap (CAF) surgery.

MATERIAL AND METHODS: A postgraduate student’s first 40 CAF operations in the periodontology residency program were followed. The Miller Class I gingival recessions were divided into four chronologic groups (n: 10 in each). Clinical and esthetic evaluations were performed at baseline and after 6 months. The results of chronologic intervals were statistically compared.

RESULTS: While the overall mean root coverage (RC) percentage was 73.6% and the complete RC was 60%, the mean RC percentages of the groups, respectively, were 45%, 55%, 86%, and 95%, showing that the mean and complete RC percentage increased as the experience level increased (P < .05). Similarly, as the experience level increased, closure of the gingival recession depth and width and esthetic scores increased, while the surgical time decreased significantly (P < .05). Complications were observed in three patients during the first interval and in two patients during the second interval, while no complications were observed in the other groups.

CONCLUSIONS: This study showed that experience level can significantly affect the clinical and esthetic outcomes, operative time, and complication rates of CAF surgery. All education programs should determine how many of each surgical procedure residents must perform before they are considered experienced or expert surgeons who can work independently and predictably achieve safe, acceptable outcomes.

PMID:37879060 | DOI:10.11607/prd.6163

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s217-s226. doi: 10.11607/prd.6212.

ABSTRACT

OBJECTIVES: To quantify the buccal bone thickness, area, and perimeter following guided bone regeneration (GBR) using stabilizing periosteal sutures. The loss in hard tissue volume may impair proper implant placement. GBR has been used to regenerate the lost alveolar ridge prior to or at the same time as dental implant placement. The most important factor for GBR success is graft stability. The periosteal mattress suture (PMS) stabilizing technique is an alternative to pins and screws to stabilize bone grafting material and has the advantage of not requiring the removal of the fixing devices.

MATERIALS AND METHODS: A CBCT was acquired before and 6 months after surgery from six patients who underwent GBR with the PMS stabilizing technique. Images were analyzed for buccal bone thickness, area, and perimeter.

RESULTS: The mean change in buccal bone thickness was 3.42 mm (± 1.31 SD) and proved statistically significant (P = .005). The mean change in bone crest area also proved statistically significant (P = .001). No significant difference was found in bone perimeter (P = .12).

CONCLUSIONS: The PMS technique delivered optimal results without clinical complications. This study shows the potential of this technique as an alternative to pins or screws for graft stabilization in the esthetic zone.

PMID:37879059 | DOI:10.11607/prd.6212

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s156-s167. doi: 10.11607/prd.6294.

ABSTRACT

PURPOSE: To investigate the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser conditioning on dentin bond strength and nanoleakage of different universal and self-etch adhesives.

MATERIALS AND METHODS: A total of 84 intact human third molar teeth were cut at the dentin level, and half of them were laser conditioned. The specimens were divided into three groups; two different universal resins and one self-etch adhesive resin were applied and composite resin restorations were created. For the microtensile bond strength (µTBS) test, 20 microspecimens were prepared from the laser and control group of each adhesive (n = 20) and tested with a universal device. For nanoleakage observation, 10 specimens were prepared from each group (n = 10) and stored in silver nitrate solution, and then the amount of nanoleakage was analyzed by field emission scanning electron microscopy (FESEM). Data were analyzed with two-way ANOVA, Tukey’s honestly significant difference, and chi-square tests.

RESULTS: The mean dentin bond strength of all adhesives in the laser groups was found to be statistically significantly lower than those of the control groups (P < .05). No difference was found between the mean bond strength of the adhesives in the laser and control groups (P > .05). Higher nanoleakage was observed in all adhesives in the laser groups compared to the control groups (P < .05).

CONCLUSIONS: Irradiation of the dentin surface with Er,Cr:YSGG could adversely affect the µTBS and nanoleakage, likely by affecting the structure of the hybrid layer.

PMID:37879055 | DOI:10.11607/prd.6294

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s129-s145. doi: 10.11607/prd.4866.

ABSTRACT

PURPOSE: To evaluate the marginal leakage of three different types of bonding agents used with two posterior composites and a giomer, available commercially.

MATERIAL AND METHODS: Class II box-only cavities were prepared on 90 mandibular first molars with margins extending 1 mm beyond the cementoenamel junction. The samples were divided into nine groups based on three different bonding agents, two different composites, and a giomer. Cavities were restored per the manufacturer’s description. Teeth were subjected to a thermocycling procedure (500×, 5°C to 55°C) and dye penetration by immersing in a 2% methylene blue solution (Merck Specialties) for 24 hours. The marginal adaptation was evaluated as a continuous margin at the gingival level under a stereomicroscope. The results were analyzed using the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS: The results of the groups with the total-etch technique showed no statistical difference between the nanohybrid Filtek Z250 XT (3M ESPE) and fine hybrid SwissTEC composite (ColtèneWhaledent AG). The groups with the self-etch technique showed no statistical difference when used with either of the two composites. The acid-etch technique showed better marginal adaptation than the self-etch technique. When the giomer (Beautifil II, Shofu) was used with the total-etch technique, it showed better adaptation than when used with the self-etch technique but overall showed more marginal leakage than the composites.

CONCLUSION: The total-etch technique provided better marginal adaptation for the composites and giomer compared to the self-etch technique.

CLINICAL SIGNIFICANCE: The demand for esthetic restorations continues to increase, and composite restorations are now considered the material of choice for Class II cavities. There are various concerns with composite restorations, one of them being good marginal adaptation to increase the life of the restoration. This study evaluated marginal leakage with the nanohybrid composite Filtek Z250 XT, fine hybrid composite SwissTEC, and a giomer when used with the total-etch technique and self-etch technique and reported satisfactory adaptation with the total-etch technique.

PMID:37879054 | DOI:10.11607/prd.4866

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s65-s77. doi: 10.11607/prd.6318.

ABSTRACT

PURPOSE: To investigate the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia.

MATERIALS AND METHODS: A total of 15 unsintered zirconia ceramic green bodies (10 × 10 × 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-μm aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks’ surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by the Kruskal-Wallis test (P < .05).

RESULTS: Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 μm, 1.26 ± 0.10 μm, and 1.69 ± 0.15 μm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching.

CONCLUSIONS: Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths.

PMID:37879051 | DOI:10.11607/prd.6318

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s18-s25. doi: 10.11607/prd.6528.

ABSTRACT

PURPOSE: To evaluate the effects of desensitizing MI Varnish (GC America) applied before or after bleaching on the mineral component of enamel and surface topography.

MATERIALS AND METHODS: The coronal portions of 10 freshly extracted bovine teeth were segmented for a total of 40 specimens. Enamel specimens obtained from each tooth were randomly divided into four groups (n = 10): Group A = no bleaching; Group B = bleaching with 40% hydrogen peroxide (HP); Group C = MI Varnish applied before bleaching; and Group D = MI Varnish applied after bleaching. The calcium (Ca) and phosphorus (P) levels of the specimens in each group were determined by energy dispersive spectroscopy (EDS). Morphologic changes were observed using scanning electron microscopy (SEM). One-way ANOVA and Tukey HSD tests were used for statistical analyses (α = .05).

RESULTS: The mean Ca content of Group B was significantly lower than those of Groups A, C, and D (P < .05). The mean Ca content of Group C was significantly lower than that of Group A (P < .05). There was no significant difference in Ca content between the other groups (P > .05). The mean P content of Group A was significantly higher than those of Groups B to D (P < .05). There was no significant difference in P content between Groups B to D (P > .05).

CONCLUSIONS: Application of MI Varnish before or after in-office bleaching was effective in reducing mineral loss. However, applying MI Varnish after bleaching was more effective.

PMID:37879050 | DOI:10.11607/prd.6528

Int J Periodontics Restorative Dent. 2023 Oct 24;(7):s9-s17. doi: 10.11607/prd.6404.

ABSTRACT

The aim of this study was to compare radiographic and clinical status and peri-implant sulcular fluid (PISF) prostaglandin E2 (PGE2) levels among patients with and without peri-implant disease. Patients with peri-implant mucositis (PiM) (Group 1) and peri-implantitis (Group 2) and individuals without peri-implant disease (Group 3) were included. Demographic information was collected, and peri-implant modified plaque and bleeding indices (mPI and mBI), probing depth (PD), and crestal bone loss (CBL) were recorded. PISF samples were collected and PGE2 levels measured. Statistical significance was set at P < .01. A total of 22 patients with PiM, 22 with peri-implantitis, and 23 without peri-implant disease (controls) were included. Scores of mPI (P < .01), mBI (P < .01), and PD (P < .01) were higher in patients with PiM and peri-implantitis than the controls. The volumes of collected PISF were significantly higher in patients with peri-implantitis (P < .01) compared to patients with PiM and the controls. The PISF volume was significantly higher in PiM patients (P < .01) than in the controls. There was a significant correlation between peri-implant PD and PISF PGE2 levels in patients with peri-implantitis (P < .001). Raised PISF PGE2 levels indicate poor peri-implant health; therefore, PGE2 is a potential biomarker for the assessment of peri-implant health status.

PMID:37879049 | DOI:10.11607/prd.6404

ACS Nano. 2023 Oct 25. doi: 10.1021/acsnano.3c06897. Online ahead of print.

ABSTRACT

In many disordered systems, the diffusion of classical particles is described by a displacement distribution P(x, t) that displays exponential tails instead of Gaussian statistics expected for Brownian motion. However, the experimental demonstration of control of this behavior by increasing the disorder strength has remained challenging. In this work, we explore the Gaussian-to-exponential transition by using diffusion of poly(ethylene glycol) (PEG) in attractive nanoparticle-polymer mixtures and controlling the volume fraction of the nanoparticles. In this work, we find “knobs”, namely nanoparticle concentration and interaction, which enable the change in the shape of P(x,t) in a well-defined way. The Gaussian-to-exponential transition is consistent with a modified large deviation approach for a continuous time random walk and also with Monte Carlo simulations involving a microscopic model of polymer trapping via reversible adsorption to the nanoparticle surface. Our work bears significance in unraveling the fundamental physics behind the exponential decay of the displacement distribution at the tails, which is commonly observed in soft materials and nanomaterials.

PMID:37879044 | DOI:10.1021/acsnano.3c06897

ACS Appl Mater Interfaces. 2023 Oct 25. doi: 10.1021/acsami.3c08579. Online ahead of print.

ABSTRACT

Ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-co-TrFE)] thin films have been deposited by spin-coating onto the Bi_0.5Na_0.5TiO₃(BNT)/LNO/SiO₂/Si heterostructure. The copolymer microstructure investigated by using grazing-incidence wide-angle X-ray diffraction (GIWAXD) and deduced from the (200)/(110) reflections demonstrates that the b-axis in the P(VDF-co-TrFE) orthorhombic unit cell is either in the plane or out of the plane, depending on the face-on or on the two types of edge-on (called I and II) lamellar structures locally identified by atomic force microscopy (AFM). For edge-on I lamellae regions, the electroactivity (d_zz^eff ∼ -50.3 pm/V) is found to be twice as high as that measured for both edge-on II or face-on crystalline domains, as probed by piezoresponse force microscopy (PFM). This result is directly correlated to the direction of the ferroelectric polarization vector in the P(VDF-co-TrFE) orthorhombic cell: larger nanoscale piezoactivity is related to the b-axis which lies along the normal to the substrate plane in the case of the edge-on I domains. Here, the ability to thoroughly gain access to the as-grown polar axis direction within the edge-on crystal lamellae of the ferroelectric organic layers is evidenced by combining the nanometric resolution of the PFM technique with a statistical approach based on its spectroscopic tool. By the gathering of information at the nanoscale, two orientations for the polar b-axis are identified in edge-on lamellar structures. These findings contribute to a better understanding of the structure-property relationships in P(VDF-co-TrFE) films, which is a key issue for the design of future advanced organic electronic devices.

PMID:37878996 | DOI:10.1021/acsami.3c08579

Lupus. 2023 Oct 25:9612033231211065. doi: 10.1177/09612033231211065. Online ahead of print.

ABSTRACT

OBJECTIVE: To report the differences in phenotypic characteristics, disease course, and outcome in monogenic and sporadic childhood lupus (SC-lupus) from a single tertiary childhood lupus clinic.

METHODS: A descriptive, observational, cross-sectional study was conducted. Data were retrospectively collected at the last follow-up visit on patients with monogenic lupus proven by genetic variants and SC-lupus seen between June 1997 and July 2022. SC-lupus patients were selected by systematic sampling from lupus patients presenting to our lupus clinic; the first patient was chosen randomly, and the subsequent patients were chosen at intervals of three. Data comprised the clinical and laboratory findings, disease activity using the SLEDAI, and damage measured by the pSDI.

RESULTS: A total of 54 patients with a median disease duration of 6.8 (IQR 3.5-10.5) years were included. There were 27 patients with monogenic lupus and 27 patients with SC-lupus, with a median age at disease onset of 3.5 (IQR 1.0-6.0), and 9.5 (IQR 7.0-11.8), respectively. (p < 0.05). The rate of consanguinity and family history of lupus were higher in monogenic lupus patients. The two groups were comparable. However, monogenic lupus patients showed more gastrointestinal tract symptoms, and failure to thrive (p < 0.05). They also had more infections. The frequency of the autoantibody profile was higher in monogenic lupus patients. Belimumab was more frequently used in monogenic lupus while rituximab in SC-lupus patients. Monogenic lupus patients had a higher mean SLEDAI, but statistically, it was insignificant. Patients with monogenic lupus had greater disease damage, with a higher mean pSDI and a higher mortality rate (p < 0.05).

CONCLUSION: Patients with monogenic lupus are likely to have an early disease onset and a strong family history of lupus, as well as a guarded prognosis, which is likely due to the disease’s severity and frequent infections. These differences may be related to the high consanguinity rate and underlying genetic variants.

PMID:37878993 | DOI:10.1177/09612033231211065