Influence of Lactobacillus reuteri, Bifidobacterium animalis subsp. lactis, and prebiotic inulin on dysbiotic dental biofilm composition ex vivo.

BACKGROUND: Probiotic bacterial supplementation has shown promising results in the treatment of periodontitis and the maintenance of periodontal health. The purpose of this investigation was to evaluate the influence of Lactobacillus reuteri or Bifidobacterium animalis subsp. lactis supplementation with and without prebiotic inulin on biofilm composition using an ex vivo biofilm model. METHODS: Subgingival plaque specimens from three periodontitis-affected human donors were used to grow biofilms on hydroxyapatite disks in media supplemented with varying combinations of prebiotic inulin, Lactobacillus reuteri, and Bifidobacterium animalis subsp. lactis. Relative abundances of bacterial genera present in mature biofilms were evaluated using 16S rRNA next-generation sequencing. Diversity metrics of microbial communities were evaluated using a next-generation microbiome bioinformatics platform. RESULTS: Inulin supplementation produced statistically significant dose-dependent increases in relative abundances of Lactobacillus and Bifidobacterium species (p < 0.001) with concomitant decreases in relative abundances of Streptococcus, Veillonella, Fusobacterium, Parvimonas, and Prevotella species (p < 0.001). Inoculation with L. reuteri or B. animalis subsp. lactis increased the relative abundance of only the supplemented probiotic genera (p < 0.05). Supplemental inulin led to a statistically significant decrease in biofilm alpha diversity (p < 0.001). CONCLUSIONS: The described ex vivo model appears suitable for investigating the effects of probiotic bacteria, prebiotic oligosaccharides, and combinations thereof on biofilm composition and complexity. Within the limitations imposed by this model, results from the present study underscore the potential for prebiotic inulin to modify biofilm composition favorably. Additional research further elucidating biologic rationale and controlled clinical research defining therapeutic benefits is warranted.

Implant site development requirements in an advanced dental education program: A series of 290 implants.

PURPOSE: Our purpose was to assess the frequency and impact of various site development procedures provided before, during, and after implant placement in an advanced dental education program. METHODS: We evaluated all implant cases completed by two residents in each of three consecutive periodontics residency classes. Dependent variables included implant failure, complication occurrence, presence of radiographic bone loss, and need for tissue augmentation. We analyzed these outcomes against a panel of explanatory covariates. RESULTS: Our study sample involved 370 site development procedures at 290 implant sites in 160 patients. Three factors exhibited statistically significant associations with need for tissue augmentation: alveolar ridge preservation (ARP) (odds ratio [OR] 0.28; 95% confidence interval [CI] 0.13, 0.57), immediate implant placement (IIP) (OR 0.21; 95% CI 0.10, 0.47), and implant submergence (OR 8.3; 95% CI 4.5, 15.3). Four factors predicted treatment complications: ARP (OR 6.1; 95% CI 1.3, 29.1), IIP (OR 6.1; 95% CI 1.06, 35.3), implant submergence (OR 5.3; 95% CI 1.1, 24.9), and mandibular arch (OR 31.3; 95% CI 1.9, 500). Anterior sites (OR 2.7; 95% CI 1.3, 5.8) were more likely to receive IIP. CONCLUSIONS: In the evaluated sample, implant placement at a site exhibiting a favorable volume of native bone was rare. Seventy-eight percent of sites received hard tissue grafting during the treatment phase. The use of ARP or IIP at tooth extraction reduced subsequent tissue augmentation requirements. Education and training in ARP and other site development procedures may enhance the clinical practice and treatment outcomes of implant surgeons.

Assessment of Perceptions of Cone-beam Computed Tomography and Endodontic Treatment in a Military Population.

INTRODUCTION: Cone-beam computed tomographic (CBCT) imaging has had a significant impact in endodontic diagnosis and treatment planning. Previous studies have investigated provider attitudes and the use of CBCT technology, but little is known about patients' perceptions of the use of CBCT imaging in endodontics. This study assessed the perceptions of patients within a military population regarding the application of CBCT imaging for endodontic treatment. METHODS: One hundred three consecutive, volunteer patients who were treated in a military dental treatment facility and prescribed a CBCT study according to the American Association of Endodontists/American Academy of Oral and Maxillofacial Radiology guidelines were given a Likert-type survey that recorded an initial level of knowledge and attitudes regarding the use of CBCT in endodontics. After standardized patient education in the form of a 2-minute video presentation describing the applications and risks associated with CBCT technology, CBCT volumes were acquired. A second survey was administered to record the patients' perceptions of the benefits and risks associated with CBCT imaging. RESULTS: After the video, 75% of the participants had a more positive opinion of CBCT technology; 56% felt that CBCT imaging was essential, and 44% felt it was beneficial. Fifty percent of the participants reported CBCT imaging having less radiation than they previously thought, whereas 11% thought it was more radiation. A total of 85% would seek out a provider who uses CBCT imaging if treatment is needed in the future. CONCLUSIONS: When presented with basic information, most patients within a military population perceive CBCT imaging to have an important role in endodontic treatment.

Fracture necrosis: A risk indicator for tooth loss.

BACKGROUND AND OVERVIEW: The term "fracture necrosis" has been used to describe the condition found in a minimally restored tooth without a history of trauma when the suspected etiology for the loss of pulpal vitality is a crown-originating fracture. Teeth with fracture necrosis have a poor prognosis, and, when accompanied by characteristic radiographic findings, extraction may be considered the primary treatment option. CASE DESCRIPTIONS: Two adult men with crown-originating fractures and suspected fracture necrosis had localized periodontal bone and attachment loss associated with severe pain on mastication from mandibular second molars. In case 1, the patient desired to retain the tooth despite an unfavorable prognosis. Nonsurgical root canal therapy and a crown prolonged tooth survival for only 30 months. The patient in case 2 requested extraction after a thorough review of his dental condition and tooth prognosis. CONCLUSIONS: A tooth with fracture necrosis may continue to harbor virulent microorganisms after root canal therapy. When these microorganisms have access to the periodontal attachment, progressive loss of supporting tissues can be expected. PRACTICAL IMPLICATIONS: When weighing treatment options for teeth with fracture necrosis associated with characteristic radiographic findings, preference toward extraction and tooth replacement, rather than treatment aimed at tooth retention, may represent a sound clinical approach.

Heat Generation Changes with Electrically Heated Pluggers after Multiple Autoclave Cycles at Different Operating Temperatures.

INTRODUCTION: Electrically heated pluggers are the most commonly used instruments during warm obturation techniques. This study aimed to evaluate the effect of sterilization and operating temperature settings on the heat generation of pluggers of various taper sizes. METHODS: Fifty pluggers were sterilized at 132°C for 25 minutes for a total of 150 cycles. One group (Autoclave200) consisted of 25 pluggers tested at an operating temperature setting of 200°C, whereas another group (Autoclave400) consisted of 25 pluggers tested at 400°C. The heat generation at their tip surface was measured with T-type thermocouples at 0, 50, 100, and 150 autoclave cycles. An unpaired t test was used to compare the time it took the pluggers to reach 60°C and the mean maximum temperature change. RESULTS: After 50 autoclave cycles, all of the 0.04 taper pluggers in Autoclave200 failed to reach 60°C. After 100 autoclave cycles, one of the 0.10 taper pluggers in Autoclave200 did not reach 60°C, and after 150 autoclave cycles, one of the 0.04 taper pluggers failed to generate any heat. The mean increase in the time to reach 60°C ranged from 1071-4004 milliseconds and 510-2074 milliseconds for Autoclave200 and Autoclave400, respectively. The mean maximum temperature change decreased by 13-29°C and 24-116°C for Autoclave200 and Autoclave400, respectively. CONCLUSIONS: After multiple autoclave cycles and higher operating temperature use, the electrically heated pluggers transferred less heat to the tip surface, potentially making them less effective.