A Manual Bristleless Toothbrush Demonstrates Slight Improvement in Gingival Recession Compared to a Conventional Soft Manual Brush.

PURPOSE: This randomized clinical trial tested whether a novel bristleless toothbrush design is more effective in preventing gingival recession in adults receiving periodontal maintenance than is a soft toothbrush with nylon bristles. MATERIALS AND METHODS: Twenty-three subjects with gingival recession were recruited who received regular periodontal maintenance care at Western University of Health Sciences Dental Center, and who did not exhibit signs of acute dental or systemic disease, occlusal discrepancies or parafunctional habits. These subjects were randomly assigned to to two groups, one using a soft nylon-bristled toothbrush, and the other using the experimental toothbrush that contains a brush head with short, soft, rubbery cones. Both groups received regular periodontal maintenance and periodontal exams by blinded examiners every 3-4 months, measuring probing depth, bleeding on probing, and plaque indices. Gingival recession was assessed clinically and through use of a stent on diagnostic casts obtained at each visit. RESULTS: Average probing depths, plaque levels, and the number of sites with bleeding on probing did not change over at least 9 months. After 9 months, there was a small but statistically significant improvement in gingival recession (0.4 mm, p < 0.01) at sites with gingival recession in the experimental toothbrush group compared to the control group. CONCLUSION: In periodontal maintenance patients, the bristleless toothbrush used in this study was as effective in plaque removal and prevention of gingival inflammation than a conventional toothbrush with soft nylon bristles, while increasing the possibility of gingival tissue rebound over denuded root surfaces.

Crown Lengthening Needs and Outcomes in Adults Attending a Predoctoral Clinic.

In this retrospective study of 5,536 patients admitted over four years at a predoctoral dental clinic for comprehensive care, general dentists identified crown lengthening needs in 584 patients and 760 teeth. Only 51 patients and 68 teeth actually received crown lengthening procedures. For the other cases, patients discontinued treatment or chose extraction or restoration without crown lengthening procedures. Teeth that received crown lengthening procedures were most likely restored and functioning for at least one year.

Transcriptome analysis of bacteriophage communities in periodontal health and disease.

BACKGROUND: The role of viruses as members of the human microbiome has gained broader attention with the discovery that human body surfaces are inhabited by sizeable viral communities. The majority of the viruses identified in these communities have been bacteriophages that predate upon cellular microbiota rather than the human host. Phages have the capacity to lyse their hosts or provide them with selective advantages through lysogenic conversion, which could help determine the structure of co-existing bacterial communities. Because conditions such as periodontitis are associated with altered bacterial biota, phage mediated perturbations of bacterial communities have been hypothesized to play a role in promoting periodontal disease. Oral phage communities also differ significantly between periodontal health and disease, but the gene expression of oral phage communities has not been previously examined. RESULTS: Here, we provide the first report of gene expression profiles from the oral bacteriophage community using RNA sequencing, and find that oral phages are more highly expressed in subjects with relative periodontal health. While lysins were highly expressed, the high proportion of integrases expressed suggests that prophages may account for a considerable proportion of oral phage gene expression. Many of the transcriptome reads matched phages found in the oral cavities of the subjects studied, indicating that phages may account for a substantial proportion of oral gene expression. Reads homologous to siphoviruses that infect Firmicutes were amongst the most prevalent transcriptome reads identified in both periodontal health and disease. Some genes from the phage lytic module were significantly more highly expressed in subjects with periodontal disease, suggesting that periodontitis may favor the expression of some lytic phages. CONCLUSIONS: As we explore the contributions of viruses to the human microbiome, the data presented here suggest varying expression of bacteriophage communities in oral health and disease.

Global transcription of CRISPR loci in the human oral cavity.

BACKGROUND: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) are active in acquired resistance against bacteriophage and plasmids in a number of environments. In the human mouth, CRISPR loci evolve to counteract oral phage, but the expression of these CRISPR loci has not previously been investigated. We sequenced cDNA from CRISPR loci found in numerous different oral bacteria and compared with oral phage communities to determine whether the transcription of CRISPR loci is specifically targeted towards highly abundant phage present in the oral environment. RESULTS: We found that of the 529,027 CRISPR spacer groups studied, 88 % could be identified in transcripts, indicating that the vast majority of CRISPR loci in the oral cavity were transcribed. There were no strong associations between CRISPR spacer repertoires and oral health status or nucleic acid type. We also compared CRISPR repertoires with oral bacteriophage communities, and found that there was no significant association between CRISPR transcripts and oral phage, regardless of the CRISPR type being evaluated. We characterized highly expressed CRISPR spacers and found that they were no more likely than other spacers to match oral phage. By reassembling the CRISPR-bearing reads into longer CRISPR loci, we found that the majority of the loci did not have spacers matching viruses found in the oral cavities of the subjects studied. For some CRISPR types, loci containing spacers matching oral phage were significantly more likely to have multiple spacers rather than a single spacer matching oral phage. CONCLUSIONS: These data suggest that the transcription of oral CRISPR loci is relatively ubiquitous and that highly expressed CRISPR spacers do not necessarily target the most abundant oral phage.

Characterization of bacteriophage communities and CRISPR profiles from dental plaque.

BACKGROUND: Dental plaque is home to a diverse and complex community of bacteria, but has generally been believed to be inhabited by relatively few viruses. We sampled the saliva and dental plaque from 4 healthy human subjects to determine whether plaque was populated by viral communities, and whether there were differences in viral communities specific to subject or sample type. RESULTS: We found that the plaque was inhabited by a community of bacteriophage whose membership was mostly subject-specific. There was a significant proportion of viral homologues shared between plaque and salivary viromes within each subject, suggesting that some oral viruses were present in both sites. We also characterized Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) in oral streptococci, as their profiles provide clues to the viruses that oral bacteria may be able to counteract. While there were some CRISPR spacers specific to each sample type, many more were shared across sites and were highly subject specific. Many CRISPR spacers matched viruses present in plaque, suggesting that the evolution of CRISPR loci may have been specific to plaque-derived viruses. CONCLUSIONS: Our findings of subject specificity to both plaque-derived viruses and CRISPR profiles suggest that human viral ecology may be highly personalized.

Conservation of streptococcal CRISPRs on human skin and saliva.

BACKGROUND: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) are utilized by bacteria to resist encounters with their viruses. Human body surfaces have numerous bacteria that harbor CRISPRs, and their content can provide clues as to the types and features of viruses they may have encountered. RESULTS: We investigated the conservation of CRISPR content from streptococci on skin and saliva of human subjects over 8-weeks to determine whether similarities existed in the CRISPR spacer profiles and whether CRISPR spacers were a stable component of each biogeographic site. Most of the CRISPR sequences identified were unique, but a small proportion of spacers from the skin and saliva of each subject matched spacers derived from previously sequenced loci of S. thermophilus and other streptococci. There were significant proportions of CRISPR spacers conserved over the entire 8-week study period for all subjects, and salivary CRISPR spacers sampled in the mornings showed significantly higher levels of conservation than any other time of day. We also found substantial similarities in the spacer repertoires of the skin and saliva of each subject. Many skin-derived spacers matched salivary viruses, supporting that bacteria of the skin may encounter viruses with similar sequences to those found in the mouth. Despite the similarities between skin and salivary spacer repertoires, the variation present was distinct based on each subject and body site. CONCLUSIONS: The conservation of CRISPR spacers in the saliva and the skin of human subjects over the time period studied suggests a relative conservation of the bacteria harboring them.

Diode laser activated indocyanine green selectively kills bacteria.

BACKGROUND AND OBJECTIVE: Commercially available photodynamic therapy for periodontal diseases utilizes methylene blue as a photosensitizer. Here we propose a novel photosensitizer dye, indocyanine green (ICG), because it can be readily activated by commercially available dental 810 nm diode lasers and has an established safety record as an intravascular agent in cardiac imaging and ophthalmologic photodynamic therapy. Therefore, we aim to characterize ICG uptake and killing of key periodontal pathogens to explore its potential as a periodontal photodynamic therapy agent. MATERIALS AND METHODS: We tested ICG uptake by spectroscopy in Porphyromonas gingivalis 381 and Aggregatibacter actinomycetemcomitans, in addition to Escherichia coli DH5alpha and a human gingival epithelial cell line, HepG, in relation to ICG dose and exposure time. We then measured killing of bacteria by determining viable bacteria counts before and after exposure to ICG and 810 nm diode laser light (0-0.5 W output settings, 0-5 seconds). ICG was also applied to extracted, restored teeth, and the teeth inspected visually for staining after rinsing with saline. RESULTS: We found rapid and significant uptake of indocyanine green into P. gingivalis 381 and A. actinomycetemcomitans 67, compared to E. coli DH5alpha and HepG gingival cell line. This correlated with significant killing of strains 381 and 67 compared to E.coli, with less than 10% survival. ICG does not appear to stain tooth surfaces and materials except calculus. CONCLUSION: ICG combined with an 810 nm diode laser may be useful as a photodynamic adjunct for reduction of bacterial load in periodontal pockets.

Fibrinogen binds IgG antibody and enhances IgG-mediated phagocytosis.

While Fibrinogen (Fg) and Immunoglobulin G (IgG) are traditionally thought to have separate functions in thrombosis and immune response, recent studies suggest overlapping functions. Here we present evidence that Fibrinogen binds to IgG specifically, and that Fibrinogen-IgG interactions enhance phagocytosis. We demonstrate specific, saturable binding of Fibrinogen to immobilized IgG and its fragments on nitrocellulose or poly-(L)-Lys styrene plates using Biotin/Streptavidin-Horse Radish Peroxidase detection systems. We also demonstrated that GFP-expressing E.coli coated with anti-E.coli antibody (IgG) and Fibrinogen elicit higher rates of phagocytosis than either Fibrinogen or IgG-treated E.coli alone (p < 0.001). We conclude that Fibrinogen enhances phagocytosis and possibly other leukocyte functions in concert with IgGs. This mechanism might focus leukocyte action triggered by fibrinogen towards specific antigens.

The epidemiology, consequences and management of periodontal disease in older adults.

BACKGROUND: This review summarizes the literature on periodontal disease (PD) in older adults. The authors focused on significant sequelae of PD and therapy in this population. TYPES OF STUDIES REVIEWED: The authors conducted a search on PubMed for human studies using the terms "periodontal disease OR periodontitis" and "older adults." They retrieved 649 articles and excluded studies that had poor experimental design. For each topic of the review, they selected one to three of the most recent studies or reviews for inclusion and cited classic articles where appropriate. RESULTS: PD is a common oral chronic inflammatory disease often found in older adults. In older patients, PD may lead to root caries, impaired eating and socialization. It also may increase patients' risk of developing systemic diseases such as diabetes mellitus, lung disease, heart disease and stroke. Treatment is not limited by chronological age but depends on the patient's medical and emotional status and the availability of financial resources. CLINICAL IMPLICATIONS: General dentists usually can treat the majority of older people with mild or moderate PD. For older adults who are medically compromised and dependent, the literature supports treatment that prevents PD progression.

Case report on managing incomplete bone formation after bilateral sinus augmentation using a palatal approach and a dilating balloon technique.

BACKGROUND: Patients with resorbed edentulous alveolar ridges in the posterior maxilla often require lateral window sinus augmentation procedures prior to implant placement. Lateral window sinus augmentation procedures can produce incomplete bone augmentation as consequence of surgical and healing complications producing unusual and complex sinus anatomy. Although incomplete bone formation after sinus augmentation has been described in a previous case reports, this is the first case report that describes grafting these compromised sites prior to implant placement. CASE PRESENTATION: A 65-year-old male patient with no known medical conditions presented with severe chronic localized periodontitis and a combined periodontal-endodontic lesion affecting three first molars. Initial ridge preservation and lateral window sinus augmentation resulted in incomplete bone formation and complex sinus floor anatomy on both right and left sides. A dilating balloon technique on one side and a palatal approach on the other side were utilized for additional sinus augmentation using particulate allograft and resorbable collagen membranes. Healing was uneventful, and implants could be placed and restored at all sites. Periodontal maintenance was conducted every 3 months, and the implants have been in function and periodontally healthy for 2 years. CONCLUSION: Despite initial failure of sinus augmentation to produce suitable implant sites, it is possible to rescue these sites with re-entry grafting procedures and allow successful implant placement and restoration.

Bacteriophage and their potential roles in the human oral cavity.

The human oral cavity provides the perfect portal of entry for viruses and bacteria in the environment to access new hosts. Hence, the oral cavity is one of the most densely populated habitats of the human body containing some 6 billion bacteria and potentially 35 times that many viruses. The role of these viral communities remains unclear; however, many are bacteriophage that may have active roles in shaping the ecology of oral bacterial communities. Other implications for the presence of such vast oral phage communities include accelerating the molecular diversity of their bacterial hosts as both host and phage mutate to gain evolutionary advantages. Additional roles include the acquisitions of new gene functions through lysogenic conversions that may provide selective advantages to host bacteria in response to antibiotics or other types of disturbances, and protection of the human host from invading pathogens by binding to and preventing pathogens from crossing oral mucosal barriers. Recent evidence suggests that phage may be more involved in periodontal diseases than were previously thought, as their compositions in the subgingival crevice in moderate to severe periodontitis are known to be significantly altered. However, it is unclear to what extent they contribute to dysbiosis or the transition of the microbial community into a state promoting oral disease. Bacteriophage communities are distinct in saliva compared to sub- and supragingival areas, suggesting that different oral biogeographic niches have unique phage ecology shaping their bacterial biota. In this review, we summarize what is known about phage communities in the oral cavity, the possible contributions of phage in shaping oral bacterial ecology, and the risks to public health oral phage may pose through their potential to spread antibiotic resistance gene functions to close contacts.

Human oral viruses are personal, persistent and gender-consistent.

Viruses are the most abundant members of the human oral microbiome, yet relatively little is known about their biodiversity in humans. To improve our understanding of the DNA viruses that inhabit the human oral cavity, we examined saliva from a cohort of eight unrelated subjects over a 60-day period. Each subject was examined at 11 time points to characterize longitudinal differences in human oral viruses. Our primary goals were to determine whether oral viruses were specific to individuals and whether viral genotypes persisted over time. We found a subset of homologous viral genotypes across all subjects and time points studied, suggesting that certain genotypes may be ubiquitous among healthy human subjects. We also found significant associations between viral genotypes and individual subjects, indicating that viruses are a highly personalized feature of the healthy human oral microbiome. Many of these oral viruses were not transient members of the oral ecosystem, as demonstrated by the persistence of certain viruses throughout the entire 60-day study period. As has previously been demonstrated for bacteria and fungi, membership in the oral viral community was significantly associated with the sex of each subject. Similar characteristics of personalized, sex-specific microflora could not be identified for oral bacterial communities based on 16S rRNA. Our findings that many viruses are stable and individual-specific members of the oral ecosystem suggest that viruses have an important role in the human oral ecosystem.

Altered oral viral ecology in association with periodontal disease.

UNLABELLED: The human oral cavity is home to a large and diverse community of viruses that have yet to be characterized in patients with periodontal disease. We recruited and sampled saliva and oral biofilm from a cohort of humans either periodontally healthy or with mild or significant periodontal disease to discern whether there are differences in viral communities that reflect their oral health status. We found communities of viruses inhabiting saliva and the subgingival and supragingival biofilms of each subject that were composed largely of bacteriophage. While there were homologous viruses common to different subjects and biogeographic sites, for most of the subjects, virome compositions were significantly associated with the oral sites from which they were derived. The largest distinctions between virome compositions were found when comparing the subgingival and supragingival biofilms to those of planktonic saliva. Differences in virome composition were significantly associated with oral health status for both subgingival and supragingival biofilm viruses but not for salivary viruses. Among the differences identified in virome compositions was a significant expansion of myoviruses in subgingival biofilm, suggesting that periodontal disease favors lytic phage. We also characterized the bacterial communities in each subject at each biogeographic site by using the V3 hypervariable segment of the 16S rRNA and did not identify distinctions between oral health and disease similar to those found in viral communities. The significantly altered ecology of viruses of oral biofilm in subjects with periodontal disease compared to that of relatively periodontally healthy ones suggests that viruses may serve as useful indicators of oral health status. IMPORTANCE: Little is known about the role or the constituents of viruses as members of the human microbiome. We investigated the composition of human oral viral communities in a group of relatively periodontally healthy subjects or significant periodontitis to determine whether health status may be associated with differences in viruses. We found that most of the viruses present were predators of bacteria. The viruses inhabiting dental plaque were significantly different on the basis of oral health status, while those present in saliva were not. Dental plaque viruses in periodontitis were predicted to be significantly more likely to kill their bacterial hosts than those found in healthy mouths. Because oral diseases such as periodontitis have been shown to have altered bacterial communities, we believe that viruses and their role as drivers of ecosystem diversity are important contributors to the human oral microbiome in health and disease states.