Entire Dental Arch Mesial Movement after Extraction of Maxillary Right Central Incisor due to Root Fracture Treated with Temporary Anchorage Devices.

This case report describes a 19-year-old woman with skeletal Class I crowding and an unsalvageable maxillary right central incisor. She visited our clinic with the chief complaint of mobility of the maxillary right central incisor due to a traffic accident. After extraction of the maxillary right central incisor, the space was closed orthodontically. All the maxillary right teeth were moved mesially with an elastic chain attached to a palatal lever arm which was connected to palatal temporary anchorage devices (TADs). After orthodontic treatment had been completed, the maxillary right lateral incisor and peg-shaped left lateral incisor were restored with a porcelain laminate veneer. The maxillary right canine was morphologically reshaped and built up with composite resin. Consequently, esthetically ideal occlusion and functional lateral guidance with uncontacted molars were obtained. These results show that mesial movement of the entire dental arch with TADs is a useful orthodontic treatment option in patients in whom the maxillary central incisor has been extracted.

In vitro study of optimal removable partial denture clasp design made from novel high-performance polyetherketoneketone.

PURPOSE: This study aimed to investigate the retentive force and deformation of double Akers' polyetherketoneketone (PEKK) clasps on removable partial dentures (RPDs) with varying designs and undercut depths. METHODS: Thirty double Akers' PEKK clasps with two different widths and heights (Groups I and II) were fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM). Each design was further subdivided (n = 5) into three undercut depths (0.25, 0.50, and 0.75 mm). The retentive force of the clasps was measured after 10 years of clinical use (15,000 insertion/removal cycles), and the deformation of the clasp tips was analyzed before and after cycling. RESULTS: Clasps with 0.50-mm and 0.75-mm undercut depths exhibited greater initial retentive forces (3.15-3.51 N) compared to those in the 0.25-mm undercut group (2.40-2.80 N). Group I maintained consistent retentive forces over the cycles (P = 0.345), whereas Group II showed declining forces after the initial use (P < 0.003). In both groups, the 0.50-mm undercut exhibited a greater retentive force than the 0.25-mm (P < 0.001 and P < 0.004, respectively), with no significant differences between the 0.50-mm and 0.75-mm undercut depths. Despite a lower initial retentive force, the 0.25-mm undercut showed less deformation and clasp tip wear. CONCLUSIONS: The PEKK clasps did not exhibit significantly reduced retentive forces or permanent deformations after 15,000 fatigue cycles. These results suggest that the PEKK polymer displays superior mechanical properties as an esthetic clasp material, and clasps with 0.50-mm and 0.75-mm undercut depths are recommended for long-term clinical use.

Trisomy 12 compromises the mesendodermal differentiation propensity of human pluripotent stem cells.

Trisomy 12 is one of the most frequent chromosomal abnormalities in cultured human pluripotent stem cells (hPSCs). Although potential oncogenic properties and augmented cell cycle caused by trisomy 12 have been reported, the consequences of trisomy 12 in terms of cell differentiation, which is the basis for regenerative medicine, drug development, and developmental biology studies, have not yet been investigated. Here, we report that trisomy 12 compromises the mesendodermal differentiation of hPSCs. We identified sublines of hPSCs carrying trisomy 12 after their prolonged culture. Transcriptome analysis revealed that these hPSC sublines carried abnormal gene expression patterns in specific signaling pathways in addition to cancer-related cell cycle pathways. These hPSC sublines showed a lower propensity for mesendodermal differentiation in embryoid bodies cultured in a serum-free medium. BMP4-induced exit from the self-renewal state was impaired in the trisomy 12 hPSC sublines, with less upregulation of key transcription factor gene expression. As a consequence, the differentiation efficiency of hematopoietic and hepatic lineages was also impaired in the trisomy 12 hPSC sublines. We reveal that trisomy 12 disrupts the genome-wide expression patterns that are required for proper mesendodermal differentiation.

Comparative analysis of the retention force and deformation of PEEK and PEKK removable partial denture clasps with different thicknesses and undercut depths.

STATEMENT OF PROBLEM: The retentive force and deformation of milled polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) removable partial denture (RPD) frameworks are not well understood. PURPOSE: The purpose of this in vitro study was to assess the retentive force and deformation of PEEK and PEKK Akers clasps with different designs and undercut depths. MATERIAL AND METHODS: A master model containing the first and second molar abutments was used to design Akers clasps of different cross-sectional dimensions, undercut depths (0.5 and 0.75 mm), and materials. The components of the removable partial denture framework also included an occlusal rest and were manufactured using a milling machine (n=5). The fatigue resistance of the Akers clasps was measured before and after deformation regarding the retentive forces. RESULTS: The PEEK2-U50 clasp had the largest retentive force with no significant difference among all groups before and after the insertion and removal cycle. In addition, the increased cross-sectional dimensions of the design resulted in significant differences in retentive forces between the PEEK1 and PEEK2 groups and between the PEEK and PEKK materials. CONCLUSIONS: Increasing the clasp's cross-sectional dimensions significantly impacted retentive forces, especially between different PEEK groups and between PEEK and PEKK materials.

Effects of various functional monomers' reaction on the surface characteristics and bonding performance of polyetheretherketone.

PURPOSE: Polyetheretherketone (PEEK) is a new polymeric material that has received significant attention in dentistry because of its mechanical properties, biocompatibility, and aesthetics. However, the bonding performance of PEEK to other materials is not preferable. This study aimed to analyze the variations in the surface characteristics of PEEK under the chemical action of primers containing different functional monomers or polymers and to evaluate the bonding performance of PEEK and dental cement. METHODS: Disk-shaped PEEK samples were prepared by dental milling, blasting with alumina oxide, and covering with primers containing functional monomers or polymers. The surface characteristics of the samples were analyzed by microscopy and spectroscopy. The shear bond strength (SBS) between PEEK and dental cement, with and without thermocycling, was tested using a universal testing machine. Finally, the data were statistically analyzed and compared. RESULTS: Functional monomers or polymers were successfully bonded to the surface of PEEK. This treatment significantly improved its hydrophilicity and surface free energy (P < 0.05). The primer containing pentaerythritol triacrylate had the highest SBS without thermocycling (13.89 MPa). Meanwhile, the primers containing urethane dimethacrylate (UDMA) and methyl methacrylate (MMA) (abbreviated as the HC group) showed the highest SBS and lowest reduction (25.51%) after thermocycling. Notably, all the testing groups achieved the ISO10477 standard of 5 MPa. After thermocycling, adhesive failure accounted for the largest proportion of failures in all the groups except the HC group. CONCLUSIONS: The chemical priming treatment can significantly improve the SBS of PEEK and dental cement. Moreover, a primer containing both UDMA and MMA can provide improved bonding for PEEK materials.

Comparison of dental plaque flora between intellectually disabled patients and healthy individuals: a cross-sectional study.

Periodontal diseases, including gingivitis, are highly prevalent in individuals with intellectual disability (ID). In particular, gingivitis can be difficult to cure owing to the lack of patient cooperation. Here, we evaluated differences in the oral bacterial flora between individuals with ID (n = 16) and healthy controls (n = 14) to facilitate the development of strategies for the prevention of periodontal disease in people with ID. Our results showed no significant difference in the number of decayed, missing, and filled teeth between the two groups. However, there were significant differences in the median papillary-marginal-attached index, plaque index, and gingival index between groups (P < 0.0001). Additionally, the mean probing depth in the ID group was significantly higher than that in the control group (P < 0.0001). The diversity of oral flora in people with ID and concurrent gingivitis was significantly lower than that of healthy individuals without periodontal disease. The relative abundances of Tannerella spp. and Treponema spp. were significantly higher in the ID group than in the control group at the genus level (P = 0.0383 and 0.0432, respectively), whereas that of Porphyromonas spp. was significantly lower in the ID group (P < 0.0001). Overall, our findings provided important insights into differences in the oral microbiota between patients with ID and healthy controls.

Effect of Lacticaseibacillus rhamnosus L8020 on the abundance of periodontal pathogens in individuals with intellectual disability: a randomized clinical trial.

OBJECTIVES: Gingivitis refers to inflammation of the gingiva and its connective tissues. Research has revealed a higher prevalence of gingivitis in individuals with intellectual disability than in healthy individuals. Milk fermented with Lacticaseibacillus rhamnosus L8020 (L8020 yogurt) inhibits the accumulation of periodontal disease-related pathogens in vitro and alleviates the symptoms of periodontal disease. The aim of this study was to investigate the influence of L8020 yogurt on oral microbiota and the abundance of four periodontal pathogens (Tannerella forsythia, Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola) and on the microbiota in individuals with intellectual disability and gingivitis. METHOD AND MATERIALS: Forty-one outpatients with intellectual disability participated in this study. To examine the effects of daily consumption of L8020 yogurt, the patients were randomly divided into L8020 (test group, n = 21) and placebo (n = 20) yogurt groups. All patients consumed 80 g of yogurt for 12 weeks. Oral examination was performed before the first intake of yogurt and dental plaque was collected before and after the intake of yogurt. DNA was extracted from dental plaque and subjected to next-generation sequencing. RESULTS: The relative abundance of T forsythia was significantly lower in the test group than in the placebo group. Additionally, the relative abundance of the four pathogens reduced after 84 days of consuming L8020 yogurt compared with that after consuming placebo yogurt. CONCLUSION: Mixing L rhamnosus L8020 with probiotic products that are consumed daily would be effective in suppressing the increase in periodontal disease-causing bacteria and beneficial for individuals with intellectual disability.

Effect of CD146+ SHED on bone regeneration in a mouse calvaria defect model.

OBJECTIVE: Stem cells from human exfoliated deciduous teeth (SHED) have bone regeneration ability and potential therapeutic applications. CD146, a cell adhesion protein expressed by vascular endothelial cells, is involved in osteoblastic differentiation of stem cells. The effect of CD146 on SHED-mediated bone regeneration in vivo remains unknown. We aimed to establish efficient conditions for SHED transplantation. MATERIALS AND METHODS: SHED were isolated from the pulp of an extracted deciduous tooth and cultured; CD146-positive (CD146+ ) and CD146-negative (CD146- ) populations were sorted. Heterogeneous populations of SHED and CD146+ and CD146- cells were transplanted into bone defects generated in the skulls of immunodeficient mice. Micro-computed tomography was performed immediately and 4 and 8 weeks later. Histological and immunohistochemical assessments were performed 8 weeks later. RESULTS: Bone regeneration was observed upon transplantation with CD146+ and heterogeneous populations of SHED, with significantly higher bone regeneration observed with CD146+ cells. Bone regeneration was higher in the CD146- group than in the control group, but significantly lower than that in the other transplant groups at 4 and 8 weeks. Histological and immunohistochemical assessments revealed that CD146+ cells promoted bone regeneration and angiogenesis. CONCLUSION: Transplantation of CD146+ SHED into bone defects may be useful for bone regeneration.

Comparison of the accuracy of different handheld-type scanners in three-dimensional facial image recognition.

PURPOSE: Handheld-type scanners are widely used in clinical practice. This study examined the accuracy of handheld-type scanners using plaster statues to assess their performance in facial recognition. METHODS: Twelve 4-mm zirconia balls as measuring points were attached to the facial portions of three types of plaster statue. Six digital facial images of each plaster statue were obtained using one of the following five handheld-type scanners: Artec Eva, Artec Spider, Bellus 3D FaceApp, SNAP, and Vectra H1. Four-millimeter spherical objects were manually placed at the measurement points on the scanned data generated using computer-aided design software and coordinate positions were measured using a contact-type high-resolution three-dimensional measurement device. Consequently, the discrepancy between the distance measured using the contact-type device and that measured using the handheld-type scanner was calculated. The scanning time, processing time, and deviation of the distance between the measuring points were analyzed using two-way analysis of variance and t-test with Bonferroni correction. RESULTS: The scanning and processing times ranged from 15.2 to 42.2 s and 20.7 to 234.2 s, respectively. Overall, 97% of all measured distances by Spider were within ±1.00% deviation; 79%, Vectra; 73%, Eva; 70%, Bellus; and 42%, SNAP. CONCLUSIONS: The performance of handheld-type scanners using plaster statues varied among the different scanners. The scanning time of Eva and the processing time of Bellus were significantly shorter than those of other scanners. Furthermore, Spider exhibited the best accuracy, followed by Eva, Vectra, Bellus, and SNAP.

Combination of Carbonate Hydroxyapatite and Stem Cells from Human Deciduous Teeth Promotes Bone Regeneration by Enhancing BMP-2, VEGF and CD31 Expression in Immunodeficient Mice.

The objective of this study was to clarify the efficiency of a combination of stem cells from human deciduous teeth and carbonate apatite in bone regeneration of calvarial defects. Immunodeficient mice (n = 5 for each group/4 groups) with artificial calvarial bone defects (5 mm in diameter) were developed, and stem cells from human deciduous teeth (SHEDs) and carbonate hydroxyapatite (CAP) granules were transplanted with an atelocollagen sponge as a scaffold. A 3D analysis using microcomputed tomography, and 12 weeks after transplantation, histological and immunohistochemical evaluations of markers of bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF), and cluster of differentiation (CD) 31 were performed. In the 3D analysis, regenerated bone formation was observed in SHEDs and CAP, with the combination of SHEDs and CAP showing significantly greater bone regeneration than that in the other groups. Histological and immunohistochemical evaluations showed that combining SHEDs and CAP enhanced the expression of BMP-2, VEGF, and CD31, and promoted bone regeneration. This study demonstrates that the combination of SHEDs and CAP transplantation may be a promising tool for bone regeneration in alveolar defects.

Lansoprazole and zoledronate delays hard tissue healing of tooth extraction sockets in dexamethasone-treated mice.

Proton pump inhibitors (PPIs) are among the most commonly prescribed medicines for the management of acid-related gastrointestinal diseases. Osteonecrosis of the jaw (ONJ) is a serious adverse event that is associated with the use of antiresorptive and antiangiogenic agents. According to previous clinical reports, the use of PPIs contributes to the pathogenesis of severe ONJ that requires surgery. Here, we investigated the effects of lansoprazole (LP) or LP in combination with zoledronate (ZOL) on ONJ development in mice. C57BL/6J mice were administered ZOL (125 µg/kg intravenously, twice weekly) and/or LP (10 mg/kg intraperitoneally; 3 weeks of 3 consecutive days followed by 1 day off). One week after initiation of the study, the first molar was atraumatically extracted. Concurrently with ZOL administration, dexamethasone (Dex) was administered (5 mg/kg intraperitoneally, twice weekly). Micro-computed tomography and histological evaluation were performed to characterize femoral structures, tooth extraction sockets, and osteonecrosis areas. The results showed that ZOL/Dex significantly increased bone mass compared to saline/Dex, while the simultaneous administration of LP and ZOL/Dex diminished the ZOL-induced enhancement of bone mass. In the alveolar bone around the tooth extraction socket, necrotic bone was significantly increased in the LP/Dex group compared to the saline/Dex group. However, no signs of more severe ONJ-like lesions were observed following combined administration of LP and ZOL/Dex, other than an increase in the number of non-attached TRAP-positive cells. Our findings in a mouse model suggest that LP use can be a risk factor for the development of ONJ.

Occlusal Trauma and Bisphosphonate-Related Osteonecrosis of the Jaw in Mice.

Osteonecrosis of the jaw (ONJ) is a serious adverse event that is associated with antiresorptive agents, and it manifests as bone exposure in the maxillofacial region. Previous clinical reports suggest that mechanical trauma would trigger ONJ in a manner that is similar to tooth extractions. To the best of our knowledge, there have been few detailed pathophysiological investigations of the mechanisms by which occlusal/mechanical trauma influences ONJ. Here, we developed a novel mouse model that exhibits ONJ following experimental hyperocclusion and nitrogen-containing bisphosphonate (N-BP) treatment. This in vivo model exhibited ONJ in alveolar bone, particularly in the mandible. Moreover, the experimental hyperocclusion induced remarkable alveolar bone resorption in both mouse mandible and maxilla, whereas N-BP treatment completely prevented alveolar bone resorption. In this study, we also modeled trauma by exposing clumps of mesenchymal stem cells (MSCs)/extracellular matrix complex to hydrostatic pressure in combination with N-BP. Hydrostatic pressure loading induced lactate dehydrogenase (LDH) release by calcified cell clumps that were differentiated from MSCs; this LDH release was enhanced by N-BP priming. These in vivo and in vitro models may contribute further insights into the effect of excessive mechanical loading on ONJ onset in patients with occlusal trauma.

In Vivo Efficacy of Lacticaseibacillus rhamnosus L8020 in a Mouse Model of Oral Candidiasis.

Oral candidiasis presents with multiple clinical manifestations. Among known pathogenic Candida species, Candida albicans is the most virulent and acts as the main causative fungus of oral candidiasis. Novel treatment modalities are needed because of emergent drug resistance and frequent candidiasis recurrence. Here, we evaluated the ability of Lacticaseibacillus rhamnosus L8020, isolated from healthy and caries-free volunteers, to prevent against the onset of oral candidiasis in a mouse model. Mice were infected with C. albicans, in the presence or absence of L. rhamnosus L8020. The mice were treated with antibiotics and corticosteroid to disrupt the oral microbiota and induce immunosuppression. We demonstrated that oral consumption of L. rhamnosus L8020 by C. albicans-infected mice abolished the pseudomembranous region of the mouse tongue; it also suppressed changes in the expression levels of pattern recognition receptor and chemokine genes. Our results suggest that L. rhamnosus L8020 has protective or therapeutic potential against oral candidiasis, which supports the potential use of this probiotic strain for oral health management.

Alterations to Titanium Surface Depending on the Fluorides and Abrasives in Toothpaste.

Fluoride and abrasives in toothpastes may cause corrosion and deterioration of the titanium used for implants and other prostheses. The purpose of this study was to investigate how the presence or absence and types of fluoride and abrasives affected the titanium surface texture. Brushing with toothpastes was performed on pure-titanium discs using an abrasive testing machine. Unprocessed titanium discs without brushing were used as control samples. Surface roughness, color, and gloss of titanium were measured and the differences compared with the control were analyzed. Additionally, titanium surfaces and abrasives in toothpastes were observed using a scanning electron microscope to compare the surface texture of each sample. Some toothpastes (abrasive+) significantly increased the difference in surface roughness, color, and gloss, compared with ultrapure water. Toothpaste (fluoride+/abrasive+) that had many polygonal abrasive particles led to the largest color differences and exhibited notable scratches and a larger number of contaminant- or corrosion-like black spots. In contrast, brushing with toothpaste without fluoride or abrasives (fluoride-/abrasive-) caused little change to the titanium surface. These results suggest that both fluoride and abrasives in toothpaste used for brushing may be factors that affect surface texture and corrosion resistance of titanium.

Developing New Information Sheets for Evacuees and Evacuation Centers to be Used During All Natural Disaster Phases.

INTRODUCTION: Evacuees' quality of life can be improved by investigating both their health problems and the conditions of evacuation centers during natural disasters. STUDY OBJECTIVE: This study aims to develop new evacuee and evacuation center information sheets that focus on infection control, oral health and dentures, mental health, and rehabilitation during natural disasters. METHODS: The analysis was conducted with the Delphi method by questioning doctors from various fields (infectious disease, psychiatry, rehabilitation, and dentistry) about the information that may be needed for evacuees and in the evacuation center environment. RESULTS: Two information sheets were created in this study. One is an evacuation center environmental health assessment sheet that includes information about the overview of evacuees' health and the evacuation center environment. The other is an evacuee registration sheet that would be completed by the evacuees themselves. CONCLUSION: The information sheets developed in this study will be useful in times of disaster because they have the potential to improve evacuee health conditions, as well as evacuation center environments.

Cytotoxicity assay using a human pluripotent stem cell-derived cranial neural crest cell model.

Cleft lip and palate are the most common congenital abnormalities that occur early in pregnancy. The majority of cranial mesenchyme is derived from cranial neural crest cells that differentiate into odontoblasts, cartilage, craniofacial bone, and connective tissue. A subset of these cells differentiates into cranial ganglia. We have previously reported an induction protocol of cranial neural crest cell-like cells from human pluripotent stem cells. This study tested detection of the cytotoxic sensitivities of dental materials, including titanium ions, palladium ions, and hydroxyethyl methacrylate, on the cell viability of induced cranial neural crest cell-like cells (iNC-LCs) derived from Tic human induced pluripotent stem cell (hiPSC) line. Further, the sensitivity was compared with those of human fetal lung fibroblastic cell line MRC-5, which is origin of Tic hiPSC, and osteoblastic cell line MC3T3-E1 which was derived from mouse calvaria. The results suggested that this cell-based assay system using iNC-LCs is a potential method for in vitro screening as an alternative to animal testing to predict toxic effects of dental materials on early craniofacial development.

Comprehensive analysis of transcriptional profiles in oral epithelial-like cells stimulated with oral probiotic Lactobacillus spp.

OBJECTIVE: The mechanisms of action of probiotics can vary among species and among strains of a single species; thus, they can affect host cells in a complex manner. In the present study, Lactobacillus spp. were evaluated for their ability to adhere to gingival epithelial-like cells. Comprehensive analyses of transcriptional profiles of mouse gingival epithelial GE1 cells treated with L. rhamnosus L8020 were performed to assess the putative in vivo probiotic potential of this strain. METHODS: Five Lactobacillus spp., isolated from the oral cavity, traditional Bulgarian yoghurt, and the feces of a healthy human, were each co-cultured with GE1 cells. Adhesion assays with serial dilution plating and DNA microarray analysis were performed to identify differentially expressed genes (DEGs) in GE1 cells grown in co-culture with L. rhamnosus L8020. RESULTS: The oral isolates L. rhamnosus L8020, L. casei YU3, and L. paracasei YU4 demonstrated significantly greater adhesion compared with the non-oral isolates. In total, 536 genes in GE1 cells exhibited more than twofold upregulation or downregulation, compared with the 0 h timepoint, during co-culture with L. rhamnosus L8020. Gene ontology enrichment analysis revealed that DEGs were differentially enriched in a time-dependent manner. Early responses involved widespread changes in gene expression. CONCLUSIONS: This study reveals changes in expression of genes involved in the epithelial physical barrier and immune response in gingival epithelial-like cells co-cultured with L. rhamnosus L8020. Further investigations regarding the molecular mechanisms by which L. rhamnosus L8020 serves as a probiotic may provide evidence to support clinical use.

Simulation and navigation of living donor hepatectomy using a unique three-dimensional printed liver model with soft and transparent parenchyma.

Three-dimensional printed liver models have been used for preoperative simulation. Unlike the standard three-dimensional system on a monitor, the three-dimensional printed model can be observed from any angle manually; therefore, surgeons can obtain a clear image directly from the model. We herein report the use of a unique three-dimensional liver model with a soft and transparent liver parenchyma. Through the parenchyma, the surgeons can observe the intrahepatic vessels and perform incisions in the model as a preoperative simulation. In this study, we applied this model to donor hepatectomy, which under most circumstances requires meticulous attention to detail. The actual processes and uses of a three-dimensional liver model in clinical surgery for liver transplantation are presented.

Occlusal support is associated with nutritional improvement and recovery of physical function in patients recovering from hip fracture.

OBJECTIVE: This study aimed to elucidate the association between occlusal support and nutritional improvement and recovery of activities of daily living (ADLs) among elderly patients recovering from hip fracture. BACKGROUND: Many patients with hip fracture are malnourished, and malnutrition is associated with poor functional outcomes. Poor oral status is one reason for malnutrition because loss of occlusal support leads to masticatory disorders and can cause nutrient deficiencies. METHODS: We evaluated 202 elderly patients aged 65 years and older (mean age, 84.9 ± 7.9 years). We assessed nutritional status using the Mini Nutritional Assessment-Short Form and ADLs using functional independence measure (FIM) scores. Occlusal support was recorded in accordance with the Eichner Index. We categorised participants into two groups according to the presence or absence of occlusal support, and statistical analyses were performed to investigate the differences between the groups. RESULTS: One group contained 152 participants (mean age, 85.5 ± 7.4 years) with occlusal support, and the other group contained 50 participants (mean age, 83.0 ± 8.9 years) without occlusal support. The group with occlusal support had greater gain of FIM and higher FIM efficiency than did the other group. Multivariate analyses showed that occlusal support was independently associated with nutritional improvement [odds ratio (OR) = 4.00, 95% confidence intervals (CI) = 1.90-8.43] and motor FIM efficiency (R2  = .338, P < .001). CONCLUSIONS: Our findings suggest that occlusal support is associated with nutritional improvement and the recovery of ADLs in patients recovering from hip fracture.

Effect of bovine milk fermented with Lactobacillus rhamnosus L8020 on periodontal disease in individuals with intellectual disability: a randomized clinical trial.

OBJECTIVE: Studies on the oral health of individuals with intellectual disability (ID) have identified problems that include a high prevalence of periodontal disease. The use of probiotics to treat periodontal disease has been the focus of considerable research, and bovine milk fermented with Lactobacillus rhamnosus L8020 (L8020 yogurt) has been shown to reduce the oral prevalence of four periodontal pathogens. The aim of this randomized, double-blind, placebo-controlled trial was to compare the effects of L8020 yogurt (test group) with those of placebo yogurt (placebo group) on the papillary-marginal-attached (PMA) index, gingival index (GI), and probing depth (PD) in 23 individuals with ID. METHODOLOGY: All patients were required to consume the allocated yogurt after breakfast for 90 days. PMA index and GI scores as well as PDs were assessed before the start of yogurt consumption (baseline), after 45 and 90 days of consumption, and 30 days after the cessation of consumption. Student's t-test, Mann-Whitney U test or Fisher's exact test was used for inter-group comparisons, and the mixed effect model of repeated measurements was used for data analysis. RESULTS: The decrease in PMA index score was significantly greater in the test group than in the placebo group (p<0.001). The GI score also decreased during the study, with a tendency for greater decrease in the test group. Furthermore, decreases in PD between baseline, 45 and 90 days tended to be greater in the test group than in the placebo group. CONCLUSION: These results suggest that regular consumption of bovine milk fermented with L. rhamnosus L8020 can lower the risk of periodontal disease in individuals with ID.