Dental Research Journal
Volume:17 Issue: 1, Jan-Feb 2020

Elderly with dementia or cognitive impairment are at increased risk of poor oral health. Oral health education programs targeting carers may be an effective strategy to improve oral hygiene. The aim of this review was to assess the effectiveness of oral health education programs for carers on the oral hygiene of elderly with dementia. A literature search was performed to identify studies published in five electronic databases (PubMed, MEDLINE, EMBASE, CINAHL, and PsycINFO), without time and language restrictions. Two independent coders extracted data and assessed the risk of bias for each included study. Of the 243 studies, only four studies met the inclusion criteria. All four studies reported a significant improvement for some oral health measures in dementia elderly following a carer oral health education program. The included studies did not report any other relevant outcomes of interest for this review. This review identifies limited evidence for a carer oral health education as an efficient means to improve oral health in dementia elderly. The review also clearly highlights the need for well‑designed, high‑quality studies with more relevant outcome measures to better address this knowledge gap.

Regeneration of bone defects remains a challenge for maxillofacial surgeons. The objective of this study was to assess the osteogenic potential of octacalcium phosphate (OCP) and bone matrix gelatin (BMG) alone and in combination with together in artificially created mandibular bone defects.

In this experimental study Forty‑eight male Sprague–Dawley rats (6–8 weeks old) were randomly divided into four groups. Defects were created in the mandible of rats and filled with 10 mg of OCP, BMG, or a combination of both (1/4 ratio). Defects were left unfilled in the control group. To assess bone regeneration and determine the amount of the newly formed bone, specimens were harvested at 7, 14, 21, and 56 days postimplantation. The specimens were processed routinely and studied histologically and histomorphometrically using the light microscope and eyepiece graticule. The amount of newly formed bone was quantitatively measured using histomorphometric methods. Histomorphometric data were analyzed using SPSS software. Mean, standard deviation, mode, and medians were calculated. Tukey HSD test was used to compare the means in all groups. P < 0.05 was considered as statistically significant (i.e., 5% significant level).

In the experimental groups, the new bone formation was initiated from the margin of defects during the 7–14 days after implantation. By the end of study, the amount of newly formed bone increased and relatively matured, and almost all of the implanted materials were absorbed. In the control group, slight amount of new bone had been formed at the defect margins (next to the host bone) on day 56. The histomorphometric analysis revealed statistically significant differences in the amount of newly formed bone between the experimental and the control groups (P < 0.001).

Combination of OCP/BMG may serve as an optimal biomaterial for the treatment of mandibular bone defects.

Considering the increase in demand for orthodontic treatment in adults, bracket bond to restored teeth is a clinical challenge. This study sought to compare the shear bond strength (SBS) of orthodontic brackets to feldspathic porcelain using universal adhesive and conventional adhesive with and without silane application.

In this in vitro study Fifty‑six feldspathic porcelain discs were roughened by bur, and 9.6% hydrofluoric acid was used for surface preparation. Samples were divided into the following four groups (n = 14): Group 1: universal adhesive, Group 2: universal adhesive/silane, Group 3: conventional adhesive, and Group 4: conventional adhesive/silane. Mandibular central incisor brackets were bonded, and SBS was measured by Instron® machine. To assess the mode of failure, adhesive remnant index (ARI) score was determined. The data were analyzed using SPSS software and two‑way ANOVA, Bonferroni test, and Kruskal–Wallis test (P < 0.05 considered significant).

The highest SBS was noted in the universal adhesive/silane group (12.7 MP) followed by conventional adhesive/silane (11.9 MP), conventional adhesive without silane (7.6 MP), and universal adhesive without silane (4.4 MP). In the absence of silane, the conventional adhesive yielded significantly higher SBS than universal adhesive (P = 0.03). In the presence of silane, the two adhesives showed SBS values significantly higher than the values obtained when silane was not applied, while the two adhesives were not significantly different in terms of SBS in the presence of silane (P = 0.53). Based on ARI score, there were statistically significant differences between Groups 1 and 4 (P = 0.00) and Groups 2 and 4 (P = 0.023).

Based on the current results, SBS of bracket to porcelain mainly depends on the use of silane rather than the type of adhesive. Both universal and conventional adhesives yield significantly higher SBS in the presence of silane compared to that in the absence of silane.

Optimal stress distribution around implants plays an important role in the success of mandibular overdentures. This study sought to assess the pattern of stress distribution around short (6 mm) and long (10 mm) implants in mandibular two implant‑supported overdentures using finite element analysis (FEA).

In this descriptive and experimental study two implant‑supported overdenture models with bar and clip attachment system on an edentulous mandible were used. Two vertical implants were connected by a bar. The implant length was 6 mm (short implant) in the first and 10 mm (long implant) in the second model. Vertical loads (35, 65, and 100 N) were applied bilaterally to the second molar area. In another analysis, vertical loads of 43.3 N and 21.6 N were applied to working and nonworking sides, respectively, at the second molar area. Furthermore, the lateral force (17.5 N) was applied to the canine area of overdenture. The stress distribution pattern around implants was analyzed using FEA.

The maximum von Mises stress was 57, 106, and 164 MPa around short implants and 64, 118, and 172 MPa around long implants following the application of 35, 65, and 100 N bilateral forces, respectively. Application of bilateral loads created 87 and 65 MPa stress around working and nonworking short implants, respectively; while these values were reported to be 92 and 76 MPa for long implants at the working and nonworking sides, respectively. Increasing the vertical loads increased the level of stress distributed around the implants; however, no considerable differences were noted between long and short implants for similar forces. Following unequal load application, the stress in the working side bone was more than that in the nonworking side, but no major differences were noted in similar areas around long and short implants. Following lateral load application, the stress distributed in the peri‑implant bone at the force side was more than that in the opposite side. In similar areas, no notable differences were observed between long and short implants regarding the maximum stress values.

Using implants with different lengths in mandibular overdenture caused no major changes in stress distribution in peri‑implant bone; short implants were somehow comparable to long implants

The type of housing retaining material may affect the bond strength of the housing to denture base resin. The aim of this in vitro study was to evaluate the bond strength of locator housing attached to polymethyl methacrylate (PMMA) denture base resin secured with different retaining materials.

In this in vitro study Forty‑four PMMA blocks (10 mm × 15 mm × 15 mm) were prepared with a central cylindrical canal inside to allow the insertion of locator housings. The prepared specimens were then randomly divided into four groups (n = 11). Each group received one of the following retaining materials for housing insertion: Auto‑polymerized acrylic resin (APAR), auto‑polymerized composite resin (Quick up), application of alloy primer on titanium housing plus Quick up (AL‑Quick), and heat‑polymerized acrylic resin (HPAR). The specimens were thermocycled 5000 times between 5°C and 55°C, followed by 1000 cycles of vertical insertion separation on the locator abutment. A push‑out force was applied on the flat back surface of the housing after which the failure and shear bond strength values were calculated. The data were analyzed using one way‑ANOVA and Games‑Howell test (α = 0.05).

HPAR group had significantly higher shear bond strength values compared to the other groups (P < 0.05). No significant differences were found among the other remaining material groups (P > 0.05).

Inserting of locator housing using HPAR resulted in higher bond strength between housing and denture base resin. The application of alloy primer did not improve the bond strength of locator housing which was retained with “Quick up”

Since secondary caries is one of the main problems of dental composites. The creation of an antibacterial property in these composites is essential. The objective of this study was to synthesize 3‑(2, 5‑dimethylfuran‑3‑yl)‑1H‑pyrazole‑5(4H)‑one and check its biocompatibility and antibacterial properties in flowable dental composites.

In this animal study, the antibacterial activity of flowable resin composites containing 0–5 wt% 3‑(2,5‑dimethylfuran‑3‑yl)‑1H‑pyrazole‑5 (4H)‑one was investigated by using agar diffusion and direct contact tests on the cured resins. Statistical analysis was performed using one‑way ANOVA test (P < 0.001). Thirty male albino Wistar rats were used, weighing 200–250 g. Animals were randomly divided into three groups of ten; each animal received three implants, 3‑(2, 5‑dimethylfuran‑3‑yl)‑1H‑pyrazole‑5 (4H) ‑one, penicillin V, and an empty polyethylene tube. A pathologist, without knowing the type of material tested and the timing of the test, examined the samples. Statistical analysis was performed using Kruskal–Wallis test (P < 0.001).

According to our findings, although the agar diffusion test reveals no significant difference between the groups, the direct contact test demonstrates that, by increasing the 3‑(2,5‑dimethylfuran‑3‑yl)‑1H‑pyrazole‑5(4H)‑one content, the bacterial growth was significantly diminished and the 3‑(2,5‑dimethylfuran‑3‑yl)‑1H‑pyrazole‑5 (4H)‑one has a good biocompatibility (P < 0.05).

Incorporation of 3‑(2,5‑dimethylfuran‑3‑yl)‑IH‑pyrazole‑5(4H)‑one into flowable resin composites can be useful to prevent Streptococcus mutans activity. The formula is not displayea correctly.

The use of stem cells, growth factors, and scaffolds to repair damaged tissues is a new idea in tissue engineering. The aim of the present study is the investigation of Avocado/soybean (A/S) effects on chondrogenic differentiation of human adipose‑derived stem cells (hADSCs) in micromass culture to access cartilage tissue with high quality.

In this an experimental study After hADSCs characterization, chondrogenic differentiation was induced using transforming growth factor beta 1 (TGF‑β1) (10 ng/ml) and different concentrations (5, 10, and 20 μg/ml) of A/S in micromass culture. The efficiency of A/S on specific gene expression (types I, II, and X collagens, SOX9, and aggrecan) was evaluated using quantitative polymerase chain reaction. In addition, histological study was done using hematoxylin and eosin and toluidine blue staining all data were analyzed using one‑way analysis of variance (ANOVA) and P ≤ 0.05 was considered to be statistically significant.

The results of this study indicated that A/S can promote chondrogenic differentiation in a dose‑dependent manner. In particular, 5 ng/ml A/S showed the highest expression of type II collagen, SOX9, and aggrecan which are effective and important markers in chondrogenic differentiation. In addition, the expression of types I and X collagens which are hypertrophic and fibrous factors in chondrogenesis is lower in present of 5 ng/ml A/S compared with TGF‑β1 group (P ≤ 0.05). Moreover, the sulfated glycosaminoglycans in the extracellular matrix and the presence of chondrocytes within lacuna were more prominent in 5 ng/ml A/S group than other groups.

It can be concluded that A/S similar to TGF‑β1 is able to facilitate the chondrogenic differentiation of hADSCs and do not have adverse effects of TGF‑β1. Thus, TGF‑β1 can be replaced by A/S in the field of tissue engineering.

The relationship between the dimensions of the cranial base and skeletal anterioposterior problem has been controversial for years. The aim of this study was to determine the relationship between the anterioposterior cephalometric indicators and the cranial base cephalometric indicators in an Iranian population.

In this historical cohort cephalograms of 100 skeletal Class I patients, 101 skeletal Class II patients, and 98 skeletal Class III patients were selected. The cephalograms were traced manually and the indicators were measured. Finally, data were analyzed by SPSS software using the Mann–Whitney test and Pearson’s correlation test. The significance level was set at 0.05. In cases that the correlation coefficient (r) was 0.6 or higher, linear regression was used.

The dimensions of the cranial base are significantly larger in men than that in women. Anterior cranial base length (SN) showed statistically significant difference between Class I and Class II groups (P < 0.05). BaSN, ArSN, and SN‑FH showed statistically significant differences between Class II and Class III groups (P < 0.05).

Smaller cranial base angle in the skeletal Class III malocclusion compared to skeletal Class II malocclusion has been demonstrated in this study. A significant correlation between the cranial base angle, the cranial base dimension, and the effective length of the maxilla was observed, and the smaller cranial base angle in Class III malocclusion was also confirmed. These findings indicate that the cranial base can affect the development of maxilla and mid‑face.

One‑visit apexification is a treatment of choice in necrotic immature open apex teeth. Calcium silicate base materials are suitable for this method. The purpose of this study was to investigate and compare the sealing efficiency of Biodentine, mineral trioxide aggregate (MTA) ProRoot, and calcium‑enriched mixture (CEM) cement orthograde apical plug using bacterial leakage method.

In this in vitro study a total of 70 extracted maxillary incisors were cleaned and shaped. A 1.1‑mm standardized artificially open apex was created in all samples. The teeth were randomly divided into three experimental groups of 20, and two negative and positive control groups of 5. In experimental groups, 4‑mm thick apical plugs of ProRoot MTA, CEM cement, or Biodentine were placed in an orthograde manner. Negative control samples were completely filled with MTA while positive control samples were left unfilled. Sealing efficiency was measured by bacterial leakage method, and results were analyzed by Kaplan–Meier and Chi‑square tests. The level of significance was set at 0.05.

The highest number of turbidity was recorded for ProRoot MTA samples, while the lowest for Biodentine. There was a significant difference in the number of turbidity between ProRoot MTA and Biodentine groups (P < 0.001), but there was no significant difference between CEM cement and Biodentine (P = 0.133) and ProRoot MTA (P = 0.055).

Within the limitation of this in vitro study, Biodentine showed promising results as a substance with good‑sealing efficiency.

The aim of this study was to determine the effect of low‑level light therapy (LLLT) on orthodontic tooth movement (OTM) rate, heat shock protein 70 (HSP‑70) expression, and matrix metalloproteinase 8 (MMP‑8) expression.

In this experimental study twenty‑four male guinea pigs were randomly divided into three groups (n = 8): control group (K) without orthodontic force and LLLT; treatment group 1 (T1) with orthodontic force, and treatment group 2 (T2) with orthodontic force and LLLT. The labial surfaces of both maxillary central incisors in treatments groups were installed with single‑wing bracket before being inserted with close coil spring to give 10 g/cm2 orthodontic force. For the T2 group, 4 J/cm2 of LLLT was administered in the mesial‑distal and labial‑palatal regions for 3 min every day. On day 14, the gap between teeth was measured and immunohistochemistry staining was done to determine HSP‑70 and MMP‑8 expression. Data were analyzed using (IBM, New York, (ANOVA), followed by Turkey’s HSD test to determine the differences between groups. Nonnormal distributed data would be analyzed using Kruskal–Wallis test, followed by Mann–Whitney test with P < 0.05 being performed.

The gap between teeth in the T2 group was greater compared to T1 group (P = 0.00). However, there was a significant decrease of HSP‑70 and MMP‑8 expression in T2 group compared to T1 group in the tensile and compressive sides.

LLLT intervention during orthodontic treatment could accelerate OTM rate and decreased HSP‑70 and MMP‑8 expression both in tension and in compressive side. Thus, LLLT interventions can be used as adjuvant therapy to shorten orthodontic treatment duration.

Rehabilitation of patients with a severe mandibular defect is challenging to prosthodontists. The esthetic and functional rehabilitation of patients with lateral mandibular resection is difficult due to the lack of supporting tissues for the prosthesis. The mandibular deviation furthermore results in facial asymmetry and unstable occlusion. This case report describes an innovative technique to rehabilitate a patient with lateral mandibular resection using customized access post attachment system to retain guide flange prosthesis for reducing mandibular deviation.