Effect of Long-Term Brushing on Deflection, Maximum Load, and Wear of Stainless Steel Wires and Conventional and Spot Bonded Fiber-Reinforced Composites

Fiber-reinforced composite (FRC) retainers are an aesthetic alternative to conventional Stainless Steel splints. They are generally used with a full bonded technique, but some studies demonstrated that they could be managed with a spot bonding technique to significantly decrease their rigidity. In order to propose this FRC spot bonding technique for clinical use, the aim of this study was to evaluate mechanical properties and surface wear of fibers left uncovered. Tests were made by simulating tooth brushing, comparing FRC spot bonding technique splints with stainless steel and FRC traditional technique splints. Specimens were tested both at 0.1 mm of deflection and at maximum load, showing higher values of rigidity for the FRC full bonded technique. After tooth brushing, no significant reduction in values at 0.1 mm deflection was reported, while we found a similar reduction in these values for the Stainless Steel and FRC spot bonding technique at maximum load, and no significant variation for the FRC full bonded technique. SEM images after tooth brushing showed wear for FRC fibers left uncovered, while no relevant wear signs in metal and conventional FRC fibers were noticed. Results showed that FRC spot bonding technique has advantages in mechanical properties when compared to the FRC traditional full bonding technique, also after tooth brushing. However, the surface wear after tooth brushing in the FRC spot bonding technique is considerable and other tests must be performed before promoting this technique for routine clinical use.

Effect of different enamel pretreating agents on bonding efficacy and survival rates of orthodontic brackets: In vitro study and split-mouth randomized clinical trial

INTRODUCTION

This double in vitro study and randomized clinical trial aimed to investigate the bonding failure rates of orthodontic brackets after enamel pretreatment with agents showing different particle sizes.

METHODS

For the in vitro study, 80 bovine teeth were randomly divided into 4 groups according to the pretreating method used and their particle sizes: erythritol (14 μm), glycine (18-22 μm), sodium bicarbonate (70 μm), and no pretreatment. Scanning electron microscopy microphotographs were performed after pretreatment. Then, brackets were bonded, and shear bond strength was calculated. For the clinical study, agents with low (erythritol) and high (sodium bicarbonate) particle sizes were chosen. Twenty consecutive patients willing to start fixed orthodontic treatment with vestibular stainless steel brackets were enrolled. Patients were randomly divided into 2 groups following a split-mouth design. Group A underwent a 5-second enamel pretreatment procedure with erythritol for teeth belonging to maxillary left and mandibular right quadrants, whereas the remaining quadrants were pretreated for 5 seconds with sodium bicarbonate powder. In group B, quadrants were inverted. Then, brackets were bonded on the vestibular surfaces of teeth, and patients were visited monthly for 12 months to assess bond failures. Periodontal evaluation of probing pocket depth, bleeding on probing, plaque index, and papilla bleeding index was conducted before bonding and after 1, 3, 6, and 12 months.

RESULTS

The in vitro study showed that erythritol and control presented significantly higher shear bond strength values for other agents. Bicarbonate showed the lowest values. In the clinical study, 20 patients (aged 16.4 ± 3.9 years) were enrolled, and all completed the study. Erythritol showed a significantly lower failure rate (3%) than sodium bicarbonate (7.5%). Kaplan-Meier survival plots showed statistically significant differences in risk of failure between the 2 groups during the 12-month follow-up.

CONCLUSIONS

Enamel pretreatment with erythritol can be a viable technique to reduce failure rates of orthodontic brackets.

REGISTRATION

The trial was not registered.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

No funding or grant was received for this research.

Effect of blood contamination on shear bond strength of orthodontic brackets and disinclusion buttons

Our aim was to assess the effect of blood contamination on the shear bonding strength and sites of failure of orthodontic brackets and bondable buttons. We randomly divided 160 bovine permanent mandibular incisors into 8 groups of 20 specimens each. Both orthodontic brackets (Step brackets, Leone, Sesto Fiorentino, Italy) and bondable buttons (Flat orthodontic buttons, Leone, Sesto Fiorentino, Italy) were tested on four different enamel surfaces: dry; contamination with blood before priming; after priming; and before and after priming. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bonding strength and the rate of adhesive failures were recorded. Data were analysed using the analysis of variance (ANOVA), Scheffè tests, and the chi-square test. Uncontaminated enamel surfaces showed the highest bonding strengths for both brackets and buttons. When they were contaminated with blood, orthodontic brackets had significantly lower shear strengths than bondable buttons (P=0.0001). There were significant differences in sites of failure among the groups for the various enamel surfaces (P=0.001). Contamination of enamel by blood during bonding lowers the strength of the bond, more so with orthodontic brackets than with bondable buttons.

Photodynamic Therapy in Non-Surgical Treatment of Periodontitis: A Systematic Review and Meta-Analysis

Aim: to evaluate the adjunctive effects of photodynamic therapy (aPDT) on nonsurgical mechanical treatment in patients with periodontitis. Materials and methods: The search strategy was conducted according to the PRISMA guidelines to answer research questions regarding the effectiveness of aPDT in association with non-surgical periodontal therapy. The mean values and standard deviations were collected by data extraction. A descriptive comparison between aPDT in association with periodontal treatment and periodontal treatment alone was performed, and meta-analyses of PPD were also performed. Both randomized controlled clinical trials (RCTs) and controlled clinical trials (CCTs) were included. Results: Out of 2059 records, 14 articles on adjunctive photodynamic therapy were included because they met the eligibility criteria. A comparison between the aPDT data and the control group showed improved PPD for photodynamic therapy (SMD −0.76, p = 0.003; I2 = 88%). Statistical analysis was then applied to the three PPD subgroups. The first group included studies that used indocyanine green in association with a wavelength of 810 nm (SMD −1.79, p < 0.00001, I2 = 88%). The second group included studies that used phenothiazine chloride at a wavelength of 660 nm (SMD −0.03, p = 0.84, I2 = 0%). The last group included studies that used methylene blue photosensitizers treated with a wavelength 628–670 nm were included (SMD −0.13, p = 0.38; I2 = 0%). Conclusions: despite the limited number of RCTs and the great heterogeneity between them, it can be concluded that aPDT in association with nonsurgical periodontal treatment improved the clinical parameters at 3 months.

Historical and bibliometric notes on the use of fluoride in caries prevention

AIM

The aim of the present report was to highlight historical and bibliometric aspects of fluoride in dentistry.

METHODS

Study design: In the first part of the manuscript, history of fluoride has been reported. In the second part, some bibliometric considerations have been explained. The historical research evaluated the first documents about fluoride in dentistry. The bibliometric research considered Scopus-indexed documents from 1945 to 2019.

RESULTS

Historical search showed the consistent presence of documents since 1803, even if modern research started in the 1930s.

STATISTICS

Descriptive statistics of documents about fluoride showed a constantly increasing interest on the topic, starting from 1965 to nowadays.

CONCLUSIONS

The topic of fluoride has a long history in dental practice, and future interesting research is needed in order to combine this well-known inorganic, monatomic anion with new emerging technologies.

Reliability of Orthodontic Miniscrews: Bending and Maximum Load of Different Ti-6Al-4V Titanium and Stainless Steel Temporary Anchorage Devices (TADs)

Temporary anchorage devices (TADs) have been introduced into orthodontic clinical practice in order to allow tooth movements while avoiding strain on adjacent teeth. Miniscrews are available in the market with different diameters and materials. Accordingly, the purpose of the present report was to measure and compare the forces to bend and fracture different mini implants. Ti-6Al-4V titanium and stainless steel TADs of different manufacturers (Spider ScrewHDC; Mini Implants⁻Leone; Benefit⁻Orteam; Storm⁻Kristal) were evaluated. Two different diameters (1.5 mm and 2.0 mm) were tested. The sample included 10 unused specimens for each group, blocked in an Instron Universal Testing Machine, and a shear load was applied at the neck of the miniscrew. The force to bend the miniscrew was measured at 0.1 mm and 0.2 mm deflections. Also, the maximum force before screw fracture was recorded. Data were submitted for statistical analysis. Results showed significantly higher forces for 2.0 mm than 1.5 mm screws, both at 0.1 mm and 0.2 mm deflections and at maximum load. Moreover, no significant differences were reported between titanium and stainless steel miniscrews of equal diameters.

Influence of different luting protocols on shear bond strength of computer aided design/computer aided manufacturing resin nanoceramic material to dentin

BACKGROUND

The purpose of this study was to evaluate the influence of three different luting protocols on shear bond strength of computer aided design/computer aided manufacturing (CAD/CAM) resin nanoceramic (RNC) material to dentin.

MATERIALS AND METHODS

In this in vitro study, 30 disks were milled from RNC blocks (Lava Ultimate/3M ESPE) with CAD/CAM technology. The disks were subsequently cemented to the exposed dentin of 30 recently extracted bovine permanent mandibular incisors. The specimens were randomly assigned into 3 groups of 10 teeth each. In Group 1, disks were cemented using a total-etch protocol (Scotchbond™ Universal Etchant phosphoric acid + Scotchbond Universal Adhesive + RelyX™ Ultimate conventional resin cement); in Group 2, disks were cemented using a self-etch protocol (Scotchbond Universal Adhesive + RelyX™ Ultimate conventional resin cement); in Group 3, disks were cemented using a self-adhesive protocol (RelyX™ Unicem 2 Automix self-adhesive resin cement). All cemented specimens were placed in a universal testing machine (Instron Universal Testing Machine 3343) and submitted to a shear bond strength test to check the strength of adhesion between the two substrates, dentin, and RNC disks. Specimens were stressed at a crosshead speed of 1 mm/min. Data were analyzed with analysis of variance and post-hoc Tukey's test at a level of significance of 0.05.

RESULTS

Post-hoc Tukey testing showed that the highest shear strength values (P < 0.001) were reported in Group 2. The lowest data (P < 0.001) were recorded in Group 3.

CONCLUSION

Within the limitations of this in vitro study, conventional resin cements (coupled with etch and rinse or self-etch adhesives) showed better shear strength values compared to self-adhesive resin cements. Furthermore, conventional resin cements used together with a self-etch adhesive reported the highest values of adhesion.

Effect of blood contamination on shear bond strength of brackets bonded with a self-etching primer combined with a resin-modified glass ionomer

This study assessed the effect of blood contamination on the shear bond strength and bond failure site of a resin-modified glass ionomer (Fuji Ortho LC, GC Europe, Leuven, Belgium) used with 3 enamel conditioners (10% polyacrylic acid, 37% phosphoric acid, and self-etching primer). One hundred twenty bovine permanent mandibular incisors were randomly divided into 8 groups; each group consisted of 15 specimens. Two enamel surface conditions were studied: dry and contaminated with blood. One hundred twenty stainless steel brackets were bonded with the resin-modified glass ionomer. After bonding, all samples were stored in distilled water for 24 hours and then tested in shear mode on a testing machine. The groups conditioned with self-etching primer and 37% phosphoric acid had the highest bond strengths for both dry and blood-contaminated enamel. The groups conditioned with 10% polyacrylic acid showed significantly lower shear bond strength value, and the unconditioned groups had the lowest bond strengths. For each enamel conditioner, no significant difference was reported between dry and blood-contaminated groups. Significant differences in debond locations were found among the groups bonded with the different conditioners. Blood contamination of enamel during the bonding procedure of Fuji Ortho LC did not affect its bond strength values, no matter which enamel conditioner was used.

Microbiological Changes during Orthodontic Aligner Therapy: A Prospective Clinical Trial

The purpose of this study is to assess the variations induced by Clear Aligner Treatment (CAT) on the periodontal status and microbiological composition of oral microbiota. A total of 20 orthodontic patients were submitted to professional oral hygiene and, subsequently, underwent CAT (Group one, trials). A total of 20 non orthodontic patients (Group two, controls) remained untreated after oral hygiene. At T0 (baseline) and T1 (after 2 months), the participants were clinically examined for Probing Pocket Depth (PPD), Bleeding on Probing (BOP) and Plaque Index (PI), and microbiological tests were performed to detect bacteria of the red and orange complexes as well as the presence of Aggregatibacter actinomycetemcomitans. No significant inter- or intra-group differences were shown neither for PPD, PI and BOP (p > 0.05), nor for bacteria expressed in copies/microlitre or in percentages (p > 0.05). The only significant difference was assessed from T0 (baseline) to T1 (2 months) in both groups and is related to the total bacteria count increase. However, this parameter encompasses all the bacteria of the common oral microbiota, thus, not representing a significant result from a clinical point of view. Despite the limitations of this study, CAT does not significantly affect periodontal and microbiological parameters with respect to untreated patients for the first two months of therapy.

Color Stability of New Esthetic Restorative Materials: A Spectrophotometric Analysis

The aim of this in vitro study was to evaluate and compare the color stability of different esthetic restorative materials (one microfilled composite, one nanofilled composite, one nanoceramic composite, one microfilled hybrid composite, one microfilled hybrid composite, one nanohybrid Ormocer based composite and one supra-nano spherical hybrid composite) after exposure to different staining solutions (physiological saline, red wine, coffee). All materials were prepared and polymerized into silicon rings (2 mm × 6 mm × 8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. Specimens were immersed in staining solutions (physiological saline, coffee and red wine) over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro-Wilk test and ANOVA were applied to assess significant differences among restorative materials. A paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. All restorative materials showed significant color differences after immersion in coffee. Coffee caused a significant color change in all types of tested composite resins. Only Filtek Supreme XTE demonstrated a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials' different compositions.

Effect of light-tip distance on the shear bond strengths of resin-modified glass ionomer cured with high-intensity halogen, light-emitting diode, and plasma arc lights

INTRODUCTION

The purpose of this study was to assess the effect of light-tip distance on the shear bond strength and the failure site of brackets cured with 3 light-curing units (high-intensity halogen, light-emitting diode, and plasma arc).

METHODS

One hundred thirty-five bovine mandibular permanent incisors were randomly allocated to 9 groups of 15 specimens each. Stainless steel brackets (Victory Series, Unitek/3M, Monrovia, Calif) were bonded with a resin-modified glass-ionomer (Fuji Ortho LC, GC Europe, Leuven, Belgium) to the teeth, and each curing light was tested at 3 distances from the bracket: 0, 3, and 6 mm. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength.

RESULTS

When the 3 light-curing units were compared at a light-tip distance of 0mm, they showed no significantly different shear bond strengths. At a light-tip distance of 3 mm, no significant differences were found between the halogen and plasma arc lights, but both lights showed significantly higher shear bond strengths than the light-emitting diode light. At a light-tip distance of 6 mm, no significant differences were found between the halogen and light-emitting diode lights, but both showed significantly lower bond strengths than the plasma arc light. When the effect of the light-tip distance on each light-curing unit was evaluated, the halogen and light-emitting diode lights showed no significant differences among the 3 distances. However, the plasma arc light produced significantly higher shear bond strengths at a greater light-tip distance. No significant differences were found among the adhesive remnant index scores of the various groups, except with the LED light at a distance of 3 mm.

CONCLUSIONS

In hard-to-reach areas, the plasma arc curing light is suggested for optimal curing efficiency.

Spot-Bonding and Full-Bonding Techniques for Fiber Reinforced Composite (FRC) and Metallic Retainers

Fiber reinforced Composite (FRC) retainers have been introduced as an aesthetic alternative to conventional metallic splints, but present high rigidity. The purpose of the present investigation was to evaluate bending and fracture loads of FRC splints bonded with conventional full-coverage of the FRC with a composite compared with an experimental bonding technique with a partial (spot-) resin composite cover. Stainless steel rectangular flat, stainless steel round, and FRC retainers were tested at 0.2 and 0.3 mm deflections and at a maximum load. Both at 0.2 and 0.3 mm deflections, the lowest load required to bend the retainer was recorded for spot-bonded stainless steel flat and round wires and for spot-bonded FRCs, and no significant differences were identified among them. Higher force levels were reported for full-bonded metallic flat and round splints and the highest loads were recorded for full-bonded FRCs. At the maximum load, no significant differences were reported among spot- and full-bonded metallic splints and spot-bonded FRCs. The highest loads were reported for full bonded FRCs. The significant decrease in the rigidity of spot-bonded FRC splints if compared with full-bonded retainers suggests further tests in order to propose this technique for clinical use, as they allow physiologic tooth movement, thus presumably reducing the risk of ankylosis.

Home Oral Care Domiciliary Protocol for the Management of Dental Erosion in Rugby Players: A Randomized Clinical Trial

People performing regular physical activity are at high risk of dental erosion especially in cases of high sport drinks intake. Biomimetic hydroxyapatite-based oral hygiene products, like toothpastes and mouthwashes, have been investigated in recent years for their remineralizing activity on the teeth. The aim of the present study was to evaluate the efficacy of two different oral hygiene protocols, respectively consisting of the combination of a hydroxyapatite-based toothpaste plus mouthwash (Trial group) or toothpaste alone (Control Group). At baseline (T0), as well as at 15 days (T1), 30 days (T2) and 90 days (T3), the following clinical indexes were assessed: Basic Erosive Wear Examination (BEWE), Schiff Air Index (SAI), Visual Analogue Scale (VAS), Plaque Index (PI) and Bleeding Index (BI). In general, for all the indexes assessed, a progressive intragroup reduction was noticed from the baseline to the subsequent timepoints, with no intergroup differences. Accordingly, the use of the hydroxyapatite-based toothpaste, alone or in combination with the mouthwash containing hydroxyapatite as well, is an effective method for the domiciliary management of dental erosion in physically active individuals like rugby players.

Orthodontic debonding and tooth sensitivity of anterior and posterior teeth

OBJECTIVES

To assess whether orthodontic debonding and onset of tooth sensitivity were related and if anterior and posterior teeth showed different sensitivity.

MATERIALS AND METHODS

40 patients were divided into a trial group (group 1, at the end of the multibracket treatment) and a control group (group 2, not under treatment). After the application of compressed air and cold water to mandibular incisors and first molars, participants were asked to report the pain felt for each tooth using a 100-mm visual analogue scale. In group 1, assessment was performed just before debonding (T0), immediately after completion of debonding (T1) and 7 days after (T2). In group 2, values were assessed at the beginning of a follow-up visit (T0), at the end of the same visit (T1) and 7 days after (T2).

RESULTS

Considering overall teeth, statistical analyses showed significantly higher values in the trial group at T1 after both stimuli, especially after cold water, besides a significant difference between T0 and T2 values in the same group. Anterior teeth showed significantly higher VAS scores than posterior after the two thermal stimuli, except after air stimulation in group 1 at T2 and in group 2.

CONCLUSIONS

Orthodontic debonding leads to sensitivity to thermal stimuli especially in the anterior teeth, however pain level is restored within 7 days.

Evaluation of the Efficacy of Probiotics Domiciliary Protocols for the Management of Periodontal Disease, in Adjunction of Non-Surgical Periodontal Therapy (NSPT): A Systematic Literature Review

Introduction: Periodontitis is a multifactorial chronic inflammatory disease induced by a dysbiosis between the host and oral microbiota, which can compromise the host’s immune defenses and lead to the destruction of periodontal tissues. Despite the efficacy of non-surgical periodontal therapy (NSPT) as the gold standard of periodontal treatment, its application can produce lower results due to anatomical and microbiological limitations. This systematic literature review was performed to assess the long-term efficacy of the effects of probiotics as an adjunct to NSPT compared to the control groups with follow-up of clinical, microbiological and immunological outcomes. Materials and methods: A literature review was conducted, considering manuscripts published from November 2016 to February 2022. The research question was formulated following the population, intervention, comparison and outcome strategies. Randomized controlled trials (RCT), systematic review and meta-analysis investigating the periodontal efficacy of domiciliary probiotic therapy in an adjunct to the mechanical therapy were included. Results: Regarding clinical outcomes, there is a reduction in periodontal probing depth (PPD), clinical attachments level (CAL), bleeding on probing (BoP) and plaque index (PI) for the test groups compared to the control groups in a short-term period. No differences were generally observed in the following indices over a period of more than 3 months for most studies considered. Conclusions: Weak evidence suggests that the use of probiotics as an adjunct to non-surgical periodontal therapy treatment may be able to show improvements in periodontal clinical parameters for up to 3 months. However, a significant and large heterogeneity of studies, along with the absence of long-term microbiological and immunological data, preclude any definitive conclusions.

Decalcifying effect of different ethylenediaminetetraacetic acid irrigating solutions and tetraclean on root canal dentin

INTRODUCTION

The objective of this study was to evaluate and compare in vitro the decalcifying capability on root canal dentin of 4 different irrigating solutions.

METHODS

Twenty-five freshly extracted maxillary central incisors were selected. The canals were prepared to obtain a total of 4 samples from each root. The samples were randomly divided into 5 equal experimental groups (n = 20) according to the irrigating solutions tested (Tetraclean, Largal Ultra, 17% ethylenediaminetetraacetic acid, Tubuliclean). For each irrigating solution, the specimens were immersed for 5, 10, and 15 minutes. After exposures, the concentration of Ca(2+) extracted was measured by inductively coupled plasma-atomic emission spectrometry. Data were analyzed by means of nonparametric tests, and statistical analysis was performed.

RESULTS

The higher release of Ca(2+) was observed in samples treated with Tetraclean; this citric acid-based agent showed significantly higher decalcifying capability. For all irrigating solutions tested, 10 minutes of application are sufficient to obtain the maximum Ca(2+) release.

CONCLUSIONS

The results indicated that Tetraclean could be applied to obtain more efficient removal of the smear layer and to facilitate the biomechanical instrumentation procedures.

In vitro antibacterial activity of different self-etch adhesives

PURPOSE

The aim of this study was to evaluate and compare the antimicrobial activity of different self-etch adhesives by means of the agar disc diffusion test.

METHODS

Streptococcus salivarius, Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrobial activity of various self-etch adhesives (Futurabond NR, G-aenial Bond, Adper™ Easy Bond Self-Etch Adhesive, Clearfil Protect Bond, One Coat 7.0, Clearfil S3 Bond, Clearfil SE Bond) using the agar disc diffusion test; 0.2% Chlorexidine digluconate was used as control. Paper disks were saturated with 10 µL of each adhesive system and placed onto culture agar plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each adhesive were recorded and compared for each bacterial strain.

RESULTS

The test results of the various self-etch adhesives were significantly different.

CONCLUSIONS

The results of the present investigation showed that the addition of MDPB monomer to an adhesive system enhances its antibacterial effect against S. salivarius, S. sanguis and S. mutans.

Dental Hygiene and Orthodontics: Effect of Ultrasonic Instrumentation on Bonding Efficacy of Different Lingual Orthodontic Brackets

Dental hygienists are often faced with patients wearing lingual orthodontic therapy, as ultrasonic instrumentation (UI) is crucial for oral health. As the application of external forces can lead to premature bonding failure, the aim of this study was to evaluate the effect of UI on shear bond strength (SBS) and on adhesive remnant index (ARI) of different lingual orthodontic brackets. 200 bovine incisors were divided into 10 groups. Four different lingual (STB, Ormco; TTR, Rocky Mountain Orthodontics; Idea, Leone; 2D, Forestadent) and vestibular control (Victory, 3M) brackets were bonded. UI was performed in half of specimens, whereas the other half did not receive any treatment. All groups were tested with a universal testing machine. SBS and ARI values were recorded. Statistical analysis was performed (significance: P = 0.05). TTR, Idea, and 2D lingual brackets significantly lowered SBS after UI, whereas for other braces no effect was recorded. Appliances with lower mesh area significantly reduced their adhesion capacity after UI. Moreover groups subjected to UI showed higher ARI scores than controls. UI lowered SBS of lingual appliances of small dimensions so particular care should be posed avoiding prolonged instrumentation around bracket base during plaque removal. Moreover, UI influenced also ARI scores.

Shear bond strength of deciduous and permanent bovine enamel

PURPOSE

The use of bovine teeth as a substitute for human enamel has been proposed for dental studies. The aim of this study was to determine the shear bond strength and Adhesive Remnant Index (ARI) of deciduous and permanent bovine teeth.

MATERIALS AND METHODS

Twenty deciduous and 20 permanent extracted bovine teeth were embedded in resin blocks. Stainless steel conventional orthodontic brackets were bonded to the teeth using an orthodontic adhesive. All samples were tested in shear mode on a testing machine. ARI scores were then recorded. Statistical analysis was performed to determine significant differences in bond strength and ARI scores.

RESULTS

The bond strength of permanent bovine teeth was significantly higher (p = 0.0010) than that of the deciduous teeth. ARI scores showed no significant differences (p = 0.74).

CONCLUSION

Deciduous teeth show lower shear bond strength than permanent teeth.

Root Injury During Interradicular Insertion is the most Common Complication Associated with Orthodontic Miniscrews

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Complications reported with the use of orthodontic miniscrews: A systematic review. Giudice AL, Rustico L, Longo M, Oteri G, Papadopoulos MA, Nucera R. Korean J Orthod 2021 May 25;51(3):199-216. doi: 10.4041/kjod.2021.51.3.199. PMID: 33984227.

SOURCE OF FUNDING

There is no information about funding.

TYPE OF STUDY/DESIGN

Systematic review.

In vitro antibacterial activity of different endodontic irrigants

AIM

The objective of this study was to compare in vitro the antibacterial activity of Tetraclean (mixture of doxycycline, citric acid and polypropylene glycol), Niclor 5 (5.25% sodium hypochlorite solution), Cloreximid (0.2% chlorhexidine and 0.2% cetrimide solution) and hydrogen peroxide 12 volumes on three endodontic pathogens associated with primary endodontic infections. Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus strains were selected to evaluate the antibacterial activity of endodontic irrigants by the agar disc-diffusion test.

MATERIAL AND METHODS

Paper discs were saturated with each one of the test solutions (at room temperature and preheating at 50°C) and placed onto culture agar-plates preadsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each irrigant were recorded and compared for each bacterial strain. Kruskal-Wallis and Mann-Whitney tests were applied to compare the various groups.

RESULTS

At room temperature, Tetraclean showed significantly higher inhibition of bacteria growth than all other irrigants tested. Preheating at 50°C significantly increased growth inhibition for all the groups tested. At 50°C, hydrogen peroxide 12 volumes and Tetraclean showed significantly higher efficacy than all other irrigants tested.

CONCLUSIONS

50°C-preheated hydrogen peroxide 12 volumes and Tetraclean showed highest inhibition of the bacterial growth.

In vitro evaluation of antimicrobial efficacy of endodontic irrigants

PURPOSE

The objective of this study was to compare in vitro, by MTT assay, the antimicrobial efficacy of Niclor 5 (5% NaOCl solution), Cloreximid (0.2% chlorhexidine and 0.2% cetrimide solution), 3% hydrogen peroxide and 17% EDTA against two microorganisms associated with primary endodontic infections.

METHODS

Enterococcus faecalis and Streptococcus mutans strains were selected for this test. Freshly extracted single-rooted human teeth were endodontically treated, inoculated with bacterial strains and then divided into different groups, each of them rinsed with Niclor 5 (5% NaOCl solution), Cloreximid (0.2% chlorhexidine and 0.2% cetrimide solution), 3% hydrogen peroxide,17% EDTA and with 5% NaOCl solution (positive control).

RESULTS

Even though all the tested irrigating solutions demonstrated antibacterial effects against E. faecalis and S. mutans, the results were significantly different between the various groups. The greatest antimicrobial effects were observed in groups treated with 5% NaOCl and 17% EDTA. Interestingly, the effectiveness of EDTA could be ascribed to its capability of detaching biofilm from canal walls.

Biomimetic Action of Zinc Hydroxyapatite on Remineralization of Enamel and Dentin: A Review

Biomimetic zinc-carbonate hydroxyapatite technology was developed to realize materials that mimic the natural hydroxyapatite of enamel and dentin and possess good activity in terms of affinity to adhere to these biological tissues. The chemical and physical characteristics of this active ingredient allows the hydroxyapatite itself to be particularly similar to dental hydroxyapatite, enhancing the bond between biomimetic hydroxyapatite and dental hydroxyapatite. The aim of this review is to assess the efficacy of this technology in terms of benefits for enamel and dentin and reduction of dental hypersensitivity.

MATERIALS AND METHODS

A literature search (Pubmed/MEDLINE and Scopus) of articles from 2003 to 2023 was conducted to analyze studies focused on the use of zinc-hydroxyapatite products. Duplicates were eliminated from the 5065 articles found, leaving 2076 articles. Of these, 30 articles were analyzed based on the use of products with zinc-carbonate hydroxyapatite in these studies.

RESULTS

30 articles were included. Most of the studies showed benefits in terms of remineralization and prevention of enamel demineralization in terms of occlusion of the dentinal tubules and reduction of dentinal hypersensitivity.

CONCLUSION

Oral care products such as toothpaste and mouthwash with biomimetic zinc-carbonate hydroxyapatite were shown to provide benefits according to the aims of this review.

Oral Hygiene Practice among Hospitalized Patients: An Assessment by Dental Hygiene Students

AIM

An epidemiological study was carried out, in hospital wards, with the aim of assessing the oral health status of patients subjected to multiple medical treatments.

MATERIAL AND METHODS

The study was conducted at Fondazione IRCCS Policlinico San Matteo (Pavia, Italy). A questionnaire was submitted to patients for the evaluation of oral hygiene devices used; then, a clinical examination was conducted to collect Decayed Missing Filled Teeth (DMFT) index, Plaque Index (PI), and Marginal Gingival Index (MGI) values.

RESULTS

Manual toothbrushes were used by a wide range of the sample study (65-100% among hospital wards), together with mouthwash (20-80%); interproximal aids were used by few patients (the lowest recorded value was 33.3%).

CONCLUSION

dental hygienists could be integrated into hospital wards as oral hygiene procedure instructors, for the improvement of the oral health conditions of hospitalized patients.

Effects of NiTi rotary and reciprocating instruments on debris and smear layer scores: an SEM evaluation

PURPOSE

The purpose of the present study was to investigate the cleaning efficacy of 2 different nickel-titanium (NiTi) rotary systems: a new single system Reciproc compared with the rotary full sequence Mtwo. The amount of debris and the morphology of smear layer were the parameters for the evaluation of the cleanliness of root canals. The null hypothesis of the study was that there would be no significant difference in debris scores and smear layer scores between the 2 systems. 


METHODS

Forty single-rooted freshly extracted teeth were selected and divided into 2 groups. For each group, all root canals were shaped with 2 different NiTi instruments (Mtwo and Reciproc) and irrigated with 5.25% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA) solutions by 3 trained operators. Specimens were fractured longitudinally and prepared for scanning electron microscopy (SEM) analysis at a standard magnification of ×5,000. The presence/absence of smear layer and the presence/absence of debris at the coronal, middle and apical third of each canal were evaluated using two 5-step scales for scores. Numeric data were analyzed using the Kruskal-Wallis and Mann-Whitney U statistical tests, and significance was set at a P value <0.05. 


RESULTS

This study revealed significant differences among the various groups. The Mtwo group presented significantly lower smear layer scores than the Reciproc group (P<0.01) in the middle and apical third of the canal. 


CONCLUSIONS

Conventional continuous rotary NiTi instruments associated with 5.25% NaOCl and 17% EDTA solutions seem to be better for obtaining clean dentinal canal walls. Reciprocating instruments leave a higher quantity of smear layer which covers dentinal walls and dentinal tubules.