Adjunctive procedure with solvent mixtures in non-surgical endodontic retreatment: does it affect root dentin hardness?

The aim of this study was to compare the effects of new irrigation solvent mixtures with Methyl ethyl ketone (MEK)/Tetrachloroethylene (TCE) and MEK/Orange oil (OOil), and different agitation techniques on dentin hardness. One hundred forty-four mandibular teeth were prepared and standardized, with each root’s middle part transversely sectioned. Initial hardness was measured using a Vickers microhardness tester. Specimens were divided into four groups of agitation techniques (n?=?36): no agitation; EndoActivator; IrriSafe; and XP-endo Finisher R. Each group was subdivided into six subgroups of irrigation protocols (n?=?6): saline solution; NaOCl?+?EDTA; NaOCl?+?EDTA?+?MEK/TCE; MEK/TCE; NaOCl?+?EDTA?+?MEK/OOil; MEK/OOil. Final hardness was measured. The irrigation protocols NaOCl?+?EDTA, NaOCl?+?EDTA?+?MEK/TCE, and NaOCl?+?EDTA?+?MEK/OOil significantly decreased dentin hardness, while MEK/OOil increased it (p?<?0.05). Comparing to NaOCl?+?EDTA sequence, dentin hardness increased significantly with the additional exposure to MEK/TCE (3%NaOCl?+?17%EDTA?+?MEK/TCE) or MEK/OOil (3%NaOCl?+?17%EDTA?+?MEK/OOil) (p?<?0.05). There were no significant differences regarding agitation effects on dentin hardness decrease. The irrigation protocols affected dentin hardness significantly. However, the additional solvent proposals do not seem to address further concerns on dentin’s mechanical properties. Agitation did not show any influence on dentin’s hardness reduction.

     

The effect of commercial conjugated linoleic acid products on experimental periodontitis and diabetes mellitus in Wistar rats

Objective: The aim of present study was to determine the effects of conjugated linoleic acid enriched milk on alveolar bone loss, hyperglycaemia, oxidative stress and apoptosis in ligature-induced periodontal disease in diabetic rat model.

Methods: Wistar rats were divided into six experimental groups: 1; non-ligated (NL, n?=?6) group, 2; ligature only (LO, n?=?6) group, 3; streptozotocin only (STZ, n?=?8) group, 4; STZ and ligature (STZ?+?L, n?=?8) group, 5; ligature and conjugated linoleic acid (CLA) (L?+?CLA, n?=?8) group, 6; STZ, ligature and CLA group (STZ?+?L?+?CLA, n?=?8) group. Diabetes mellitus was induced by 60?mg/kg streptozotocin. Rats were fed with CLA enriched milk for four weeks. Silk ligatures were placed at the gingival margin of lower first molars of mandibular quadrant. The study duration was four weeks after diabetes induction and the animals were sacrificed at the end of this period. Changes in alveolar bone levels were clinically measured and tissues were histopathologically examined. Inducible nitric oxide synthase (iNOS) and Bax protein expressions, serum interleukin-1β (IL-1β), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride levels and tartrate resistant acid phosphatase (TRAP)+?osteoclast numbers were also evaluated.

Results: At the end of four weeks, alveolar bone loss was significantly higher in the STZ?+?LO group compared to the other groups (p?p?p?p?>?.05).

Conclusion: Within the limits of this study, commercial CLA product administration in addition to diet significantly reduced alveolar bone loss, increased osteoblastic activity and decreased osteoclastic activity in the diabetic Wistar rats.     

The effect of diabetes mellitus on the shear bond strength of composite resin to dentin and enamel

Diabetes mellitus might be linked to the deterioration of certain physical properties of dentin and enamel. This study aimed to determine the effect of two types of diabetes on the shear bond strength of enamel and dentin, by using the single bond universal bonding system. Sixty specimens [from 15 teeth; 5 from each group—non-diabetic (ND), Diabetic type I (D1), and Diabetic type II (D2)], were prepared with equal amounts of dentin (n?=?5) and enamel (n?=?5). Enamel specimens (E20) were etched with 37% phosphoric acid, for 20 s, and dentin specimens (D15) were etched for 15 s. A standard shear bond strength test was performed on all specimens. Their failure modes were also studied under a scanning electron microscope, and the data were analyzed by using ANOVA and Post Hoc Tukey’s test (a?=?0.050). For the enamel groups, significant differences were only noticed between the ND and D1 (P?<?0.050) groups, and between the ND and D2 (P?<?0.050) groups. In the dentin groups, there was a significant difference only between the ND and D1 (P?<?0.050) groups. The micrographs showed that the ND group had the highest number of specimens with cohesive failure and D1 had the highest number of specimens with adhesive failure. It can be concluded that both types of diabetes reduce the shear bond strength of composite resin on dentin and enamel. However, it seems that the negative effect of diabetes on shear bond strength of dental composite resin is more drastic in individuals with type I diabetes as compared with type II.

     

The quality of root canal treatment and periapical status of permanent teeth in Turkish children and teens: a retrospective CBCT study

Objective

This study aimed to assess the quality of root canal fillings and the prevalence of periapical radiolucencies in the permanent teeth of 6–18 year-old Turkish children.

Methods

CBCT images of 150 patients’ 235 teeth with a mean age of 16.0?±?2.06 years were included. Root development stage, quality of root canal filling, the presence and severity of periapical radiolucencies, and their relationship with anatomical structures were recorded. Correlations between the quality of root canal filling, periapical lesion, and lesion size were assessed using regression analyses.

Results

A total of 235 teeth (528 root canals) were evaluated. 65.5% of root canals had periapical lesions. Immature roots and mandibular teeth had the highest prevalence and the largest size of periapical radiolucencies (p?<?0.05). Overfilling (n?=?52), underfilling (n?=?93), unfilled (n?=?46), inhomogeneously filled (n?=?113) root canals and poor coronal restoration (n?=?85 teeth) were observed in terms of technical failures of endodontic treatment. The quality of endodontic treatment was associated with the presence of periapical lesion and lesion size (p?<?0.05). Teeth with under-filled, overfilled or inhomogeneously filled root canals and poor coronal restoration had a periapical lesion larger than 5 mm (p?<?0.05). Immature teeth were most associated with the presence of lesion (OR?=?4.07) and the lesion size?>?5 mm (OR?=?3.71).

Conclusion

The prevalence of periapical radiolucencies in young permanent teeth showed an increase when the tooth was an incisor, had incomplete root development, or the root filling had technical errors.

     

The effect of lockdown during SARS-CoV-2 pandemic on maxillofacial injuries in a level I trauma centre: a comparative study

Introduction

The SARS-CoV-2 pandemic forced many governments to impose nation-wide lockdowns. Government legislation forced limited travel on the population with restrictions on the normal way of life to limit spread of the SARS-CoV-2 virus. The aim of this study is to explore the effects of lockdown on the presentation of maxillofacial trauma in a level I trauma centre.

Methods

Comparative analysis was carried out using prospective and retrospective review of all consecutive patients admitted with any maxillofacial fracture in the lockdown period between 15th March and 15th June 2020 with the same period in 2019 to a Regional Trauma Maxillofacial Surgery Unit. Data included basic demographics and mechanism of injury including alcohol/drug influence, polytrauma, site of injury and treatment modality including escalation of care.

Results

Across both periods, there were a total of one hundred and five (n?=?105) recorded episodes of traumatic fractures with fifty-three (n?=?53) in the pre-lockdown cohort and fifty-two (n?=?52) in the lockdown. Included patients were significantly (p?=?0.024) older during lockdown (mean age 41.44 years SD 20.70, range 5–96) with no differences in gender distribution between cohorts (p?=?0.270). Patients in lockdown were more likely to be involved in polytrauma (p?<?0.05) and have sustained their injury by cycling/running or any outdoor related activity (p?=?0.013). Lockdown saw a significant reduction in alcohol and drug related violence (p?<?0.05). Significantly more patients required operative management (p?=?0.038).

Conclusion

Local lockdowns form part of the governments public health strategy for managing future outbreaks of SARS-CoV-2. Our study showed no significant reduction in volume of trauma during lockdown. It is vital that hospitals maintain trauma capacity to ensure that patients are treated in a timely manner.

     

Effects of oral administration of Bifidobacterium animalis subsp. lactis HN019 on the treatment of plaque-induced generalized gingivitis

Objectives

This double-blind, randomized, placebo-controlled clinical trial evaluated the adjuvant effects of Bifidobacterium lactis HN019 on the treatment of plaque-induced generalized gingivitis.

Materials and methods

Sixty patients were submitted to professional supragingival scaling and prophylaxis. They were randomly assigned to test (probiotic lozenges containing B. lactis HN019, n?=?30) or control (placebo lozenges, n?=?30) groups. Lozenges were consumed twice a day for 8 weeks. Bleeding on probing (BoP), Gingival Index (GI), Plaque Index (PI), probing depth (PD), and clinical attachment level (CAL) were evaluated at baseline and after 2 and 8 weeks. Gingival crevicular fluid (GCF) was collected at baseline and at 8 weeks for analysis of the inflammatory mediators IL-1β, IL-1α, IL-8, MCP-1, and MIP-1β. Data were statistically analyzed (p?<?0.05).

Results

After 8 weeks, both groups showed reduction in the percentage of PI, with no significant difference between groups (p?=?0.7423). The test group presented a lower percentage of BoP and a higher percentage of sites with GI?≤?1 when compared with the control group at the end of the study (p?<?0.0001). At 8 weeks, the test group had a greater number of patients without generalized gingivitis than the control group (20 and 11 patients, respectively; p?<?0.05). The test group presented significantly lower levels of IL-1α, IL-1β, and MCP-1 in GCF than the control group at the end of the study (p?<?0.05).

Conclusion

The adjunct use of B. lactis HN019 promotes additional clinical and immunological benefits in the treatment of generalized gingivitis.

Clinical relevance

B. lactis HN019 can be an efficient and side-effect-free adjunct strategy in the treatment of generalized gingivitis.

     

Impact of combined CO2 laser irradiation and fluoride on enamel and dentin biofilm-induced mineral loss

Objectives

The caries-protective effects of CO₂ laser irradiation on dental enamel have been demonstrated using chemical demineralization models. We compared the effect of CO₂ laser irradiation, sodium fluoride, or both on biofilm-induced mineral loss (∆Z) and Streptococcus mutans adhesion to enamel and dentin in vitro.

Materials and methods

Ground, polished bovine enamel, and dentin samples were allocated to four groups (n = 12/group): no treatment (C); single 22,600-ppm fluoride (F) varnish (5 % NaF) application; single CO₂ laser treatment (L) with short pulses (5 μs/λ = 10.6 μm); and laser and subsequent fluoride treatment (LF). Samples were sterilized and submitted to an automated mono-species S. mutans biofilm model. Brain heart infusion plus 5 % sucrose medium was provided eight times daily, followed by rinses with artificial saliva. After 10 days, bacterial numbers in biofilms were enumerated as colony-forming units/ml (CFU/ml) (n = 7/group). ∆Z was assessed using transversal microradiography (n = 12/group). Univariate ANOVA with post hoc Tukey honestly-significant-difference test was used for statistical analysis.

Results

Bacterial numbers were significantly higher on dentin than enamel (p < 0.01/ANOVA). On dentin, LF yielded significantly lower CFUs than other groups (p = 0.03/Tukey), while no differences between groups were found for enamel. The lowest ∆Z in enamel was observed for L (mean/SD 2036/1353 vol%×μm), which was not only significantly lower than C (9642/2452 vol%×μm) and F (7713/1489 vol%×μm) (p < 0.05) but also not significantly different from LF (3135/2628 vol%×μm) (p > 0.05). In dentin, only LF (163/227) significantly reduced ∆Z (p < 0.05).

Conclusion/clinical relevance

CO₂ laser irradiation did not increase adhesion of S. mutans in vitro. Laser treatment alone protected enamel against biofilm-induced demineralization, while a combined laser-fluoride application was required to protect dentin.

     

Semi-automated three-dimensional volumetric evaluation of mandibular condyles

Objectives

The aim of this study is to research the mandibular condyle volumes of the Turkish subpopulation by sex, age, laterality, and posterior occlusal support, to provide volumetric data for young and old patient groups.

Methods

The CBCT images of 690 condyles from 345 patients (165 females and 180 males) were assessed. Patients aged 18–25 years were chosen for the younger group, and 45–70 years for the older group. The dental statuses of the older patient group were divided into three categories, based on the Eichner index. All the CBCT images were transferred to the three-dimensional volumetric analysis software, ITK-Snap (Penn Image Computing and Science Laboratory (PICSL) at the University of Pennsylvania and Scientific Computing and Imaging Institute (SCI) at the University of Utah) and analyzed with sagittal, coronal, and axial sections. Mandibular condyles were defined using semi-automatic segmentation, then manual segmentation was performed to ensure accuracy. Analyses were performed using MedCalc statistical software. The p value <?0.05 was considered statistically significant.

Results

The mean right condyle volume for the whole sample (n?=?345) was 1678.8 mm³ and the left condyle volume was 1661.3 mm³. Males had a larger condyle volume than females in both the younger and older patient groups (p?=?0.035, p?<?0.01, respectively). The Eichner index did not correlate significantly with condylar volume in the older patient group (p?=?0.134, p?=?0.122).

Conclusion

There were significant differences between the volumes of mandibular condyles for different sex, while there were no significant differences in relation to age, laterality, and posterior occlusal support.

     

In vitro evaluation of the antibacterial effect of four root canal sealers on dental biofilms

Objectives

To dynamically evaluate the effect of four root canal sealers on the killing of biofilms within dentinal tubules.

Materials and methods

Dentin blocks were prepared for infection of the dentinal tubules. Enterococcus faecalis VP3-181 and multi-species bacteria from two donors were cultured. After 3 days of incubation, the infected dentin specimens were rinsed with sterile water for 1 min and subjected to treatment. Additionally, multi-species bacteria from donor 1 were incubated for 3 weeks to allow biofilm maturation and then the specimens were subjected to treatment. Gutta-percha-treated dentin specimens comprised the control group. A root canal sealer (bioceramic sealers: EndoSequence BC Sealer, ProRoot Endo Sealer, or GuttaFlow Bioseal; and a traditional silicone-based sealer: Guttaflow 2) was spread onto the canal walls of the dentin. The specimens were examined with confocal laser scanning microscopy at 7, 30, or 60 days.

Results

In the 3-day-old biofilm group, the proportion of killed bacteria decreased significantly from the first 7 days of treatment to 60 days of treatment for all sealers (p?<?0.05). In the 3-week-old biofilm group, 60 days of exposure to bioceramic sealers resulted in more significant dead bacteria than 7-day exposures of the biofilms (p?<?0.05). Bioceramic sealers were more effective in killing bacteria than the GuttaFlow 2 sealer (p?<?0.05).

Conclusions

Calcium silicate–based sealers showed good antimicrobial effects against biofilms within dentinal tubules, especially in the first week in young biofilms. There is no substantive antibacterial activity observed for the examined root canal sealers against young dentinal tubule biofilms.

Clinical relevance

The bioceramic root canal sealers examined demonstrate minimal additional antibacterial effects after long-term exposure to young biofilms.

     

Effect of non‐thermal atmospheric plasma on the dentin‐surface topography and composition and on the bond strength of a universal adhesive

This study investigated the effect of application of non‐thermal atmospheric plasma (NTAP) on the topography and composition of the dentin surface, as well as the microtensile bond strength (μTBS) of a universal adhesive to NTAP‐treated dentin. Exposed flat dentin surfaces from human third molars were either treated with NTAP for 10 and 30 s or untreated (control). The dentin‐surface topography and chemical composition were characterized by atomic force microscopy (n = 3) and Raman confocal spectroscopy (n = 5), respectively. The μTBS (n = 8) of Scotchbond Universal to dentin was determined after storage for 24 h and 1 yr, either by direct water exposure or under simulated pulpal pressure. In‐situ zymography was used to evaluate the influence of NTAP on the dentin‐enzymatic activity. Non‐thermal atmospheric plasma produced no remarkable topographical or chemical alterations at the dentin surface; only the amount of phosphate decreased following 10 s of treatment with NTAP. After 1 yr of direct water exposure, the μTBS of NTAP‐treated specimens did not differ statistically significantly from that of untreated controls, whereas simulated pulpal pressure‐aging resulted in a significantly higher μTBS for NTAP‐treated dentin. The dentin‐enzymatic activity appeared to be treatment‐dependent, but the untreated controls showed more intense fluorescence within the hybrid layer. Scotchbond Universal maintained its μTBS strength after 1 yr of direct water exposure and simulated pulpal pressure, although remarkable statistical differences between treatments were observed depending on the aging condition.     

Radiation therapy alters microhardness and microstructure of enamel and dentin of permanent human teeth

Objectives

To evaluate, in vitro, the effects of ionizing radiation on the mechanical and micro-morphological properties of enamel and dentin of permanent teeth.

Methods

Enamel and dentin microhardness (n = 12 hemi-sections) was evaluated at three depths (superficial, middle and deep) prior to (control) and after every 10 Gy radiation dose up to a cumulative dose of 60 Gy by means of longitudinal microhardness. Data were analyzed using two-way analysis of variance and Tukey's test at a significance level of 5%. Enamel and dentin morphology was assessed by scanning electron microscopy (SEM) for semi-quantitative analysis (n = 8 hemi-sections). Data were analyzed using Kruskal–Wallis and Dunn's or Fisher exact tests at a significance level of 5%.

Results

The application of ionizing radiation did not change the overall enamel microhardness, although an increase in superficial enamel microhardness was observed. The micro-morphological analysis of enamel revealed that irradiation did not influence rod structure but interprismatic structure became more evident. Dentin microhardness decreased after 10, 20, 30, 50 and 60 Gy cumulative doses (p < 0.05) compared with non-irradiated dentin, mainly in the middle portion of the tissue. The micro-morphological analysis revealed fissures in the dentin structure, obliterated dentinal tubules and fragmentation of collagen fibers after 30 and 60 Gy cumulative doses.

Conclusions

Although ionizing radiation did not affect the enamel microhardness of permanent teeth as a whole, an increase in superficial enamel microhardness was observed. Dentin microhardness decreased after almost all radiation doses compared with the control, with the greatest reduction of microhardness in the middle depth region. The morphological alterations on enamel and dentin structures increased with the increase of the radiation dose, with a more evident interprismatic portion, presence of fissures and obliterated dentinal tubules, and progressive fragmentation of the collagen fibers.

Clinical significance

This study shows that irradiation affects microhardness and micro-morphology of enamel and dentin of permanent teeth. The effects of gamma irradiation on dental substrate might contribute to increased risk of radiation tooth decay associated with salivary changes, microbiota shift and high soft and carbohydrate-rich food intake.     

Shaping ability of non-adaptive and adaptive core nickel–titanium single-file systems with supplementary file in ribbon-shaped canals analysed by micro-computed tomography

This study compared shaping ability between two single-file systems and before/after using supplementary file in untouched area, volume of removed dentin, maximum cut depth (the highest cut depth by main file) and remaining thinnest dentin (the thinnest root dentin after preparation). Ribbon-shaped distal canals of mandibular molars were prepared with non-adaptive core (WaveOne Gold) or adaptive core (XP-endo Shaper) files (n = 15/group) and additionally prepared with a supplementary file (XP-endo Finisher), and the shaping ability was investigated using micro-computed tomography. XP-endo Shaper group demonstrated significantly less overall untouched area than WaveOne Gold group (38.21 ± 6.98% vs. 47.68 ± 9.16%) (p < 0.05). No significant difference was detected between XP-endo Shaper and WaveOne Gold groups in volume of removed dentin (1.85 ± 0.53 vs. 1.66 ± 0.33 mm³), maximum cut depth (0.10–0.28 vs. 0.10–0.29 mm) and remaining thinnest dentin (0.66–0.80 vs. 0.78–0.88 mm). Supplementary XP-endo Finisher treatment significantly decreased untouched area (11%–23% reduction) (p < 0.05) with minimally cut root dentin (0.01–0.02 mm).     

Effect of three different photosensitizers in photodynamic therapy on bond strength of a calcium silicate-based sealer to radicular dentin

To evaluate the effect of the photodynamic therapy (PDT) using with different photosensitizers on the bond strength of BioRoot RCS (BR) to radicular dentin by comparing with AH Plus (AH). The shaped root canals of 80 human mandibular premolars were divided into four groups based on the final disinfection protocol: NaOCl/EDTA, PDT with methylene Blue (MB), PDT with curcumin (CUR) and PDT with toluidine blue O (TBO) (n = 20). Each group was randomly divided into two subgroups (n = 10), according to the endodontic sealer used for obturation (n = 10). The test of push-out bond strength (PBS) was performed using an universal test machine. The data were analysed using ANOVA, Tukey post-hoc, and independent sample t-test (α = 0.05). MB-BR group showed the highest PBS at the cervical level (p < 0.05). The selection of the photosensitizer in PDT influenced adhesion of root canal sealers to radicular dentin.     

Effects of traditional and novel proteolytic agents on tissue dissolution and dentine microhardness

The study aimed to evaluate the tissue-dissolving ability of papain and bromelain with respect to that of sodium hypochlorite (NaOCl) at the temperatures of 25°C and 60°C. The study also assessed the effects of these proteolytic agents on radicular dentine microhardness. Warming NaOCl, papain and bromelain solutions resulted in significant tissue dissolution at all time intervals (p < 0.001). At 60°C, bromelain showed significantly higher tissue weight loss at every time interval when compared to NaOCl (p < 0.001). All of the three organic tissue dissolvents reduced the microhardness at 1 hr when compared to their respective baseline values. The reduction in microhardness from the baseline reading was statistically significant only in the papain group at 30 min (p = 0.018) and at 60 min (p = 0.03) when compared to the control group. Hence it was concluded that bromelain exerted superior tissue dissolution action, especially when warmed, with minimal effect on dentine microhardness.     

Evaluation of final irrigation regimens with maleic acid for smear layer removal and wettability of root canal sealer

Objective: To evaluate the smear layer removal and wettability of AH Plus sealer on root canal dentin treated with MA (maleic acid), MA?+?CTR (cetrimide) and MA?+?CTR?+?CHX (chlorhexidine) as final irrigating regimens.

Material and methods: For smear layer removal, 40 teeth were instrumented to size F4 and divided into four groups: (1) 7% MA, (2) 7% MA?+?0.2% CTR, (3) 7% MA?+?0.2% CTR?+?2% CHX, (4) distilled water (control). After irrigation, teeth were subjected to SEM analysis. For contact angle analysis, 20 teeth were split longitudinally and divided into four groups similar to smear layer analysis. AH plus sealer was placed on each specimen and contact angle was analysed.

Results: In both smear layer (p?=?.393) and contact angle analysis (p?=?.961), there was no significant difference between the groups MA and MA?+?CTR. However, MA?+?CTR?+?CHX removed smear layer less effectively (p?=?.023) and increased the contact angle of the sealer (p?=?.005). In smear layer analysis, specimens in negative control group were heavily smeared. In case of contact angle analysis, samples in the control group had least contact angle.

Conclusion: MA alone or in combination with CTR removed smear layer effectively and increased the wettability of AH plus sealer to root canal dentin.     

Effect of temporary cements and their removal methods on the bond strength of indirect restoration: a systematic review and meta-analysis

Objectives

For a conventional indirect restoration, temporary cementation inevitably contaminated collapsed dentin collagen. The purpose of this review was to evaluate the optimal strategy for minimizing its negative effects.

Material and methods

Databases such as PubMed, Web of Science, EMBASE, and the Cochrane Library were searched for in vitro studies, involving the influence of immediate dentin sealing (IDS), different temporary cements, and their removal strategies on dentin bond strength. The meta-analysis used the inverse variance method with effect method of the standardized mean difference and statistical significance at p?≤?0.05. The I² value and the Q-test were used to assess the heterogeneity.

Results

A total of 14 in vitro trials were subjected to the meta-analysis. Within the study’s limitations, we assumed that IDS eliminated the negative effects of temporary bonding, achieving the comparable immediate bond strength with the control (p?=?0.46). In contrast, under delayed dentin sealing (DDS), temporary cementation statistically decreased bond strength (p?=?0.002). Compared with resin-based and non-eugenol zinc oxide cements, polycarboxylate and calcium hydroxide cements performed better on bond strength with no statistical difference from the control group (p?>?0.05). Among the removal methods of temporary cements, the Al₂O₃ abrasion restored the decreased bond strength (p?=?0.07) and performed better than hand instruments alone (p?=?0.04), while pumice removal slightly reduced the bond strength in contrast with the control group (p?=?0.05, 95% CI?=????1.62 to 0).

Conclusions

The choices of IDS, polycarboxylate and calcium hydroxide temporary cements, Al₂O₃ abrasion removal method were feasible and efficient to enhance the bond strength.

Clinical relevance

It is worthwhile applying IDS technique, polycarboxylate and calcium hydroxide temporary cements during indirect restoration. The Al₂O₃ abrasion of cleaning dentin can minimize the negative effects of temporary cement.

     

Local delivery of a CXCR3 antagonist decreases the progression of bone resorption induced by LPS injection in a murine model

Objectives

This experimental study was carried out to investigate the effects of locally delivered nanoparticles (AMG-487 NP) containing a CXCR3 antagonist in inhibiting the progression of LPS-induced inflammation, osteoclastic activity, and bone resorption on a murine model.

Materials and methods

Thirty, 7-week-old C57BL/6 J male mice were used. Inflammatory bone loss was induced by Porphyromonas gingivalis–lipopolysaccharide (P.g.-LPS) injections between the first and second maxillary molars, bilaterally, twice a week for 6 weeks (n?=?20). AMG-487 NP were incorporated into a liposome carrier and locally delivered on sites where P.g.-LPS was injected. Control mice (n?=?10) were injected with vehicle only. Experimental groups included (1) control, (2) LPS, and (3) LPS?+?NP. At the end of 1 and 6 weeks, mice were euthanized, maxillae harvested, fixed, and stored for further analysis.

Results

Volumetric bone loss analysis revealed, at 1 week, an increase in bone loss in the LPS group (47.9%) compared to control (27.4%) and LPS?+?NP (27.8%) groups. H&E staining demonstrated reduced inflammatory infiltrate in the LPS?+?NP group compared to LPS group. At 6 weeks, volumetric bone loss increased in all groups; however, treatment with the CXCR3 antagonist (LPS?+?NP) significantly reduced bone loss compared to the LPS group. CXCR3 antagonist treatment significantly reduced osteoclast numbers when compared to LPS group at 1 and 6 weeks.

Conclusions

This study showed that local delivery of a CXCR antagonist, via nanoparticles, in a bone resorption model, induced by LPS injection, was effective in reducing inflammation, osteoclast numbers, and bone loss.

Clinical relevance

CXCR3 blockade can be regarded as a novel target for therapeutic intervention of bone loss. It can be a safe and convenient method for periodontitis treatment or prevention applicable in clinical practice.

     

Sleep quality in patients with xerostomia: a prospective and randomized case-control study

Objectives To investigate sleep quality, anxiety/depression and quality-of-life in patients with xerostomia. Materials and methods This prospective, observational, cross-sectional study was conducted among a group of xerostomia patients (n?=?30) compared with 30 matched control subjects. The following evaluation scales were used to assess the psychological profile of each patient: the Hospital Anxiety and Depression Scale, the Oral Health Impact Profile-14 (OHIP-14), the Xerostomia Inventory, the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS). Results The PSQI obtained 5.3 3?±?1.78 for patients with xerostomia compared with 4.26?±?1.01 for control subjects (p?=?0.006); ESS obtained 5.7?±?2.1 for test patients vs 4.4 0?±?1 for control subjects (p?=?0.010). Statistical regression analysis showed that xerostomia was significantly associated with depression (p?=?0.027). Conclusions Patients with xerostomia exhibited significant decreases in sleep quality compared with control subjects.     

Bond strength between temporary 3D printable resin and conventional resin composite: influence of cleaning methods and air-abrasion parameters

Objectives

The influence of different cleaning methods, air-abrasion parameters, and aging on shear bond strength (SBS) and tensile bond strength (TBS) of 3D resin luted to composite resin.

Materials and methods

Nine hundred resin substrates were 3D printed (D20II, Rapid Shape) and cleaned with either isopropanol (ISO), butyldiglycol-based solution (BUT), or centrifugation (CEN). After 24-h storage in 37 °C water, specimens were air-abraded (mean particle size 50 µm; n?=?60) with either alumina at 0.1 MPa (AL0.1) or 0.4 MPa (AL0.4) and glass pearls at 0.1 MPa (GP0.1) and 0.4 MPa (GP0.4) or conditioned with visio.link (control) and luted with PanaviaV5. Initially (24 h, 37 °C water storage) or after aging (10,000 thermal cycles), SBS and TBS were measured, and fracture types were examined. Surface free energy (SFE) and roughness (Ra) were determined after air-abrasion. Kolmogorov–Smirnov, Kruskal–Wallis H, Mann–Whitney U, chi-square, and partial eta-squared were computed.

Results

SBS measurements presented higher values than TBS (p?<?0.001–0.033). Within the pretreatment groups, CEN showed the highest SBS and TBS values compared to cleaning with ISO or BUT (p?<?0.001–0.040). Pretreatment with GP0.1 displayed the lowest bond strength values (p?<?0.001–0.049), and mostly adhesive fractures occurred. The highest Ra values (p?<?0.001) were observed for AL0.4 pretreatment.

Conclusions

Pretreatment with AL0.4 and the control group mainly presented the highest bond strength values. Thermocycling had a positive effect on the bond strength.

Clinical relevance

According to this study, 3D-printed restorations should be pretreated with AL0.4 or with visio.link before adhesive luting, regardless of their cleaning.

     

Factors associated with geographic tongue and fissured tongue

Objectives: The primary objective of this study was to investigate the association of systemic diseases, use of medications, allergies and tobacco habits with geographic tongue (GT) and fissured tongue (FT) lesions. The secondary objectives were to evaluate the clinical characteristics of tongue lesions and to compare the overall results for referred and non-referred patients.

Methodology: Non-referred patients with GT (GTgp; n?=?130) and FT (FTgp; n?=?62) were examined by general practitioners (gp) and compared to a control group without oral mucosal lesions (C; n?=?1029). Referred patients with GT (GTs; n?=?166) and FT (FTs; n?=?15) were examined by oral medicine specialists (s) and compared to GTgp and FTgp. Statistical analyses were performed using unpaired t-test or Fisher’s exact test. A multiple logistic regression model was developed to control for age and gender as confounders.

Results: Compared to the C group, GTgp patients used more anti-hypertensive medications and Swedish snus (p?p?p?Conclusion: This study identified an association between GT and anti-hypertensive medications, as well as the use of Swedish snus. It also found differences in the activities and symptoms of the lesions between referred patients and their counterparts who were seen in general dental practice; these parameters influenced the results when these conditions were taken into account.