Bactericidal properties of experimental dental composites based on dimethacrylate resins reinforced by nanoparticles

The aim of this study was to examine the possibility of replacing a part of the filler in experimental dental composites by nanoparticles with antibacterial potential. Experimental dental composites containing silver nanoparticles deposited on titanium and silica dioxide of different size were analyzed in terms of antibacterial properties. The depth of cure and mechanical properties of composite surface layer were examined. Bactericidal properties were tested according to the LIVE/DEAD cell viability assay. The mechanical properties were determined with a NanoTest 600 instrument. Composites containing silver nanoparticles deposited on titanium dioxide and nanosilica carrier exhibit the strongest antibacterial properties. High content of TiO2 causes strong absorption of light irradiation, which makes their curing process more difficult. Hardness of surface layer increases but the deeper layers of the samples remain uncured. Composites containing nanosilver on titanium dioxide and nanosilica carrier exhibit the highest antibacterial activity. High content of TiO2 causes strong absorption of light irradiation impairing their curing process. The presence of nanosilver changes composite color causing limited light penetration and lower surface hardness

Residual Adhesive Removal Methods for Rebonding of Debonded Orthodontic Metal Brackets: Systematic Review and Meta-Analysis

Debonding of orthodontic brackets is a common occurrence during orthodontic treatment. Therefore, the best option for treating debonded brackets should be indicated. This study aimed to evaluate the bond strength of rebonded brackets after different residual adhesive removal methods. This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, The Cochrane Library, SciELO, Scopus, LILACS, IBECS, and BVS databases were screened up to December 2020. Bond strength comparisons were made considering the method used for removing the residual adhesive on the bracket base. A total of 12 studies were included for the meta-analysis. Four different adhesive removal methods were identified: sandblasting, laser, mechanical grinding, and direct flame. When compared with new orthodontic metallic brackets, bond strength of debonded brackets after air abrasion (p = 0.006), mechanical grinding (p = 0.007), and direct flame (p < 0.001) was significantly lower. The use of an erbium-doped yttrium aluminum garnet (Er:YAG) laser showed similar shear bond strength (SBS) values when compared with those of new orthodontic brackets (p = 0.71). The Er:YAG laser could be considered an optimal method for promoting the bond of debonded orthodontic brackets. Direct flame, mechanical grinding, or sandblasting are also suitable, obtaining clinically acceptable bond strength values

Effect of Collagen Crosslinkers on Dentin Bond Strength of Adhesive Systems: A Systematic Review and Meta-Analysis

This study aimed to identify the role of crosslinking agents in the resin-dentin bond strength (BS) when used as modifiers in adhesives or pretreatments to the dentin surface through a systematic review and meta-analysis. This paper was conducted according to the directions of the PRISMA 2020 statement. The research question of this review was: "Would the use of crosslinkers agents improve the BS of resin-based materials to dentin?" The literature search was conducted in the following databases: Embase, PubMed, Scielo, Scopus, and Web of Science. Manuscripts that reported the effect on the BS after the use of crosslinking agents were included. The meta-analyses were performed using Review Manager v5.4.1. The comparisons were performed by comparing the standardized mean difference between the BS values obtained using the crosslinker agent or the control group. The subgroup comparisons were performed based on the adhesive strategy used (total-etch or self-etch). The immediate and long-term data were analyzed separately. A total of 50 articles were included in the qualitative analysis, while 45 articles were considered for the quantitative analysis. The meta-analysis suggested that pretreatment with epigallocatechin-3-gallate (EGCG), carbodiimide, ethylenediaminetetraacetic acid (EDTA), glutaraldehyde, and riboflavin crosslinking agents improved the long-term BS of resin composites to dentin (p ≤ 0.02). On the other hand, the use of proanthocyanidins as a pretreatment improved both the immediate and long-term BS values (p ≤ 0.02). When incorporated within the adhesive formulation, only glutaraldehyde, riboflavin, and EGCG improved the long-term BS to dentin. It could be concluded that the application of different crosslinking agents such as carbodiimide, EDTA, glutaraldehyde, riboflavin, and EGCG improved the long-term BS of adhesive systems to dentin. This effect was observed when these crosslinkers were used as a separate step and when incorporated within the formulation of the adhesive system

Temporomandibular Myofascial Pain Syndrome—Aetiology and Biopsychosocial Modulation. A Narrative Review

This review elaborates on the aetiology, diagnosis, and treatment of temporomandibular (TMD) myofascial pain syndrome (MPS) regulated by psychosocial factors. MPS impairs functioning in society due to the accompanying pain. Directed and self-directed biopsychosocial profile modulation may be beneficial in the treatment of MPS. Moreover, nutrition is also a considerable part of musculoskeletal system health. A fruit and vegetable diet contributes to a reduction in chronic pain intensity because of its anti-inflammatory influence. Cannabidiol (CBD) oils may also be used in the treatment as they reduce stress and anxiety. A promising alternative treatment may be craniosacral therapy which uses gentle fascia palpation techniques to decrease sympathetic arousal by regulating body rhythms and release fascial restrictions between the cranium and sacrum. MPS is affected by the combined action of the limbic, autonomic, endocrine, somatic, nociceptive, and immune systems. Therefore, the treatment of MPS should be deliberated holistically as it is a complex disorder

Dentine Surface Morphology after Chlorhexidine Application—SEM Study

Chlorhexidine (CHX) is a widely known and a very popular antibacterial agent that decreases the level of cariogenic bacteria. CHX applied on the cavity surface of dentine may influence adhesive bond strength. The aim of the study was to evaluate the dentine surface after different chlorhexidine digluconate (CHG) application protocols. Different CHG application protocols were introduced. A concentration of 0.2% or 2.0% CHG was applied on the etched or unetched dentine surface for 15 or 30 s, then water rinsed or drained. Scanning electron microscopy (SEM) observations and energy disperse spectrometer (EDS) analysis of the dentine surfaces were performed. The application of 0.2% CHG for 15 s, followed by draining, on either etched or unetched dentine surface effectively removed the smear layer, leaving the surface enriched with CHG deposits. Conclusions: The concentration of CHG and its application time influenced the amount of CHG deposits and the degree of smear layer removal from the dentine surface

Complicated Crown Fracture of Permanent Incisors: A Conservative Treatment Case Report and a Narrative Review

Dental trauma may have a severe impact on the social and psychological wellbeing of a patient. Most cases of dental injuries involve anterior teeth, especially the maxillary upper incisors. Crown fractures, with or without pulp exposure, are the most common trauma in permanent dentition. There are many methods of management, in which the initial state of the pulp, the time since the injury, and the presence of an accompanying injury play a key role. This case report aimed at showing a possible conservative treatment after complicated tooth fracture that consisted of partial pulpotomy followed by adhesive reattachment of the tooth fragment using a technique based on heated resin composite. Such a specific procedure represents a conservative approach to traumatic coronal lesions, providing a suitable opportunity to maintain the tooth vitality, aesthetics, and function. Indeed, reattachment of tooth fragment using a composite/adhesive is a simple technique to achieve excellent results in terms of aesthetic and function

The Bruxoff Device as a Screening Method for Sleep Bruxism in Dental Practice

Sleep bruxism (SB) is a masticatory muscle activity during sleep and a common phenomenon. Severe SB can have a serious impact on the success of dental treatment. Reliable methods of screening and diagnosing patients with SB are crucial. Therefore, in this study, a Bruxoff device as a potential screening and diagnostic method for sleep bruxism was evaluated. A total of 60 adults participated in this study: 35 patients with symptoms of bruxism (study group) and 25 asymptomatic patients (control group). Data were recorded using Bruxoff. All symptomatic patients participating in the study turned out to be bruxers, while not all asymptomatic patients turned out to be non-bruxers according to the Bruxoff device. Bruxoff is a simple screening device that can be safely used to evaluate masseter muscle activity during sleep. Since the device does not have a built-in microphone and/or video camera and, therefore, cannot record grinding sounds, the objective capabilities of Bruxoff as a single diagnostic device for sleep bruxism are limited

Relationship between Sleep Bruxism, Perceived Stress, and Coping Strategies

Sleep bruxism (SB) is a common phenomenon defined as a masticatory muscle activity during sleep. Untreated severe SB can have significant dental and orofacial consequences. SB has often been linked with stress and maladaptive coping strategies. Therefore, in this study, a potential correlation between SB, perceived stress and coping strategies was evaluated. A total of 60 adults were enrolled into this study. Participants underwent a detailed intra- and extraoral exam focused on detecting bruxism symptoms. Additionally, the overnight Bruxism Index was recorded using the Bruxoff device. A total of 35 participants with symptoms of bruxism were assigned to the study group, whereas 25 asymptomatic participants were assigned to the control group. The Perceived Stress Scale (PSS-10) was used for stress assessment and Brief-COPE for coping strategies. Results showed that the higher the PSS-10 score, the higher the Bruxism Index was in the study group. Positive coping strategies were chosen most frequently in the control group, while maladaptive ones were chosen in the study group. It can be concluded that there is a relationship between perceived stress and sleep bruxism. Moreover, the type of coping strategies used by participants may have an impact on sleep bruxism, but the relationship should be further investigated

The Influence of Water Sorption of Dental Light-Cured Composites on Shrinkage Stress

The contraction stress generated during the photopolymerization of resin dental composites is the major disadvantage. The water sorption in the oral environment should counteract the contraction stress. The purpose was to evaluate the influence of the water sorption of composite materials on polymerization shrinkage stress generated at the restoration-tooth interface. The following materials were tested: Filtek Ultimate, Gradia Direct LoFlo, Heliomolar Flow, Tetric EvoCeram, Tetric EvoCeram Bulk Fill, Tetric EvoFlow, Tetric EvoFlow Bulk Fill, X-tra Base, Venus BulkFil, and Ceram.X One. The shrinkage stress was measured immediately after curing and after: 0.5 h, 24 h, 72 h, 96 h, 168 h, 240 h, 336 h, 504 h, 672 h, and 1344 h by means of photoelastic study. Moreover, water sorption and solubility were evaluated. Material samples were weighted on scale in time intervals to measure the water absorbency and the dynamic of this process. The tested materials during polymerization generated shrinkage stresses ranging from 6.3 MPa to 12.5 MPa. Upon water conditioning (56 days), the decrease in shrinkage strain (not less than 48%) was observed. The decrease in value stress in time is material-dependent

Flow Cytometry Analysis of Antibacterial Effects of Universal Dentin Bonding Agents on <i>Streptococcus mutans</i>

There is no consensus on the antibacterial activity of dentin bonding systems (DBS). Many study models have been used to evaluate the antimicrobial activity of dental materials. In this study, a novel detection method, flow cytometry, was introduced. It allows for evaluation of the antibacterial activity of DBS, based on assessment of the disruption of the bacterial physical membrane induced by DBS. The aim of the study was to evaluate the antibacterial properties of selected dentin bonding systems against Streptococcus mutans. The highest antibacterial activity against S. mutans was observed for Adhese Universal (99.68% dead cells) and was comparable to that of Prime&amp;Bond Universal, OptiBond Universal, or Clearfil Universal Bond Quick (p &gt; 0.05). The lowest activity of all tested systems was displayed by the multi-mode adhesive, Universal Bond (12.68% dead bacteria cells), followed by the self-etch adhesive, OptiBond FL (15.58% dead bacteria cells). The present study showed that in the case of two-component DBS, the primer exhibited higher antimicrobial activity than the adhesive (or bond) itself