Randomized Controlled Study to Evaluate Microbial Ecological Effects of CPP-ACP and Cranberry on Dental Plaque.

INTRODUCTION: Ecological approaches to dental caries prevention play a key role in attaining long-term control over the disease and maintaining a symbiotic oral microbiome. OBJECTIVES: This study aimed to investigate the microbial ecological effects of 2 interventional dentifrices: a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) dentifrice and the same dentifrice supplemented with a polyphenol-rich cranberry extract. METHODS: The interventional toothpastes were compared with each other and with an active control fluoride dentifrice in a double-blinded randomized controlled trial. Real-time quantitative polymerase chain reaction (qPCR) analysis was used to determine changes in the bacterial loads of 14 key bacterial species (8 caries associated and 6 health associated) in the dental plaque of trial participants after they used the dentifrices for 5 to 6 wk. RESULTS: From the baseline to the recall visit, significant differences were observed between the treatment groups in the bacterial loads of 2 caries-associated bacterial species (Streptococcus mutans [P < 0.001] and Veillonella parvula [P < 0.001]) and 3 health-associated bacterial species (Corynebacterium durum [P = 0.008], Neisseria flavescens [P = 0.005], and Streptococcus sanguinis [P < 0.001]). Compared to the fluoride control dentifrice, the CPP-ACP dentifrice demonstrated significant differences for S. mutans (P = 0.032), C. durum (P = 0.007), and S. sanguinis (P < 0.001), while combination CPP-ACP-cranberry dentifrice showed significant differences for S. mutans (P < 0.001), V. parvula (P < 0.001), N. flavescens (P = 0.003), and S. sanguinis (P < 0.001). However, no significant differences were observed in the bacterial load comparisons between the CPP-ACP and combination dentifrices for any of the targeted bacterial species (P > 0.05). CONCLUSIONS: Overall, the results indicate that dentifrices containing CPP-ACP and polyphenol-rich cranberry extracts can influence a species-level shift in the ecology of the oral microbiome, resulting in a microbial community less associated with dental caries (Australian New Zealand Clinical Trial Registry ANZCTR 12618000095268). KNOWLEDGE TRANSFER STATEMENT: The results of this randomized controlled trial indicate that dentifrices containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and polyphenol-rich cranberry extracts were able to beneficially modulate the microbial ecology of dental plaque in a group of high caries-risk patients. This could contribute toward lowering the risk of developing new caries lesions, an important goal sought by patients, clinicians, and policy makers.

A longitudinal case-control study of caries development from birth to 36 months.

BACKGROUND/AIMS: The aim of this longitudinal case-control study was to investigate variables associated with caries development from birth to 36 months. METHODS: Children (n = 1,017) who were followed up every 6 months from birth to 36 months were grouped into those that developed caries by age 30 and 36 months, respectively, and compared with children without caries. RESULTS: By 30 months (n = 608) there were 24 children (4%) who had caries and an additional 23 developed first caries at 36 months (n = 552), giving a total prevalence of 47 children with caries (9%) at 36 months. Children who showed caries by 30 months were more likely to be mutans streptococci (MS) colonised by 18 months (p = 0.001) compared to those who developed caries at 36 months, and showed the following variables: MS counts of >10(5) CFU/ml at 12 months (p = 0.005), missing enamel (p = 0.001), sugar in pacifier at 18 months (p = 0.02), child sleeping next to mother at 6, 18 and 24 months (p = 0.001 to p = 0.02), and exposure to household cigarette smoke at 24 months (p = 0.02). Caries at 36 months was associated with pregnancy problems (p = 0.024), mother having dental cavitations (p = 0.001) and MS presence at 36 months (adjusted odds ratio, AOR = 0.1, p = 0.01 for counts <10(5) CFU/ml). Caries at both 30 and 36 months was associated with MS presence at 18 months (AOR = 6.3, p = 0.005 and AOR = 4.9, p = 0.01). CONCLUSIONS: Children who developed caries by 30 months are colonised by MS at younger ages and with higher MS counts compared with children who develop caries at 36 months.

A longitudinal study comparing mutans streptococci and lactobacilli colonisation in dentate children aged 6 to 24 months.

This longitudinal study aimed to investigate variables associated with colonisation of mutans streptococci (MS) compared with lactobacilli (LB) colonisation in a cohort of children (n = 214) from the time of first tooth eruption at approximately 6 months until 24 months of age. Repeated plaque and salivary samples were collected from the same infants at 6, 12, 18 and 24 months and assayed for MS and LB using a microbiological culture kit. Children having both MS and LB increased from 4% at 6 months to 13% at 12 and 18 months to 20% at 24 months (p = 0.004). LB presence at 6 months was correlated with MS presence at 12, 18 and 24 months (r = 0.21 to r = 0.46, p = 0.02), while MS presence at 6 months correlated with LB presence at all other times (r = 0.19 to r = 0.31, p = 0.03). At 6 and 12 months, the key variables for MS colonisation included unrestored dental cavities in the mother (p = 0.03), mother not persisting with toothbrushing (p = 0.001) and bottle taken to bed at night (p = 0.033), while the only significant variable for LB colonisation was natural birth (p = 0.01). At 24 months, the significant variables for MS colonisation were condiments added to pacifier (p = 0.022) and child being uncooperative for toothbrushing (p = 0.025), while the significant variables for LB colonisation were pregnancy problems (p = 0.028) and child being uncooperative for toothbrushing (p = 0.013). The ages 6-12 months thus represent a time period when key variables may be controlled to reduce MS and LB colonisation.

Clinical assessment and management of the oral environment in the oncology patient.

The dental care of oncology patients is an important component of general dental practice. Oncology patients have additional requirements for their outpatient care in the dental office. Intense involvement of the general dental practitioner in the patient's overall plan of care is essential so that appropriate preventive and therapeutic strategies are followed prior to chemotherapy, radiation and other medical treatments. This paper provides an overview of the role of the dental practitioner in the pre-treatment workup and post-treatment maintenance of oncology patients, and discusses the complications which occur during the intensive and in-hospital phases of care, in the context of approaches that show promise for reducing or preventing these. The role of the general dental practitioner in the maintenance of oral health for the remainder of the patient's life is stressed, with evidence-based recommendations given for optimal use of home care products which support oral health and improve quality-of-life.

Microleakage of composite resin restorations in cervical cavities prepared by Er,Cr:YSGG laser radiation.

BACKGROUND: Evaluation of microleakage is important for assessing the success of new methods for surface preparation and new adhesive restorative materials. The aim of this laboratory study was to assess microleakage at the margins of composite restorations in Er,Cr:YSGG laser prepared cavities on the cervical aspects of teeth by means of dye penetration, and compare this with conventionally prepared and conditioned cavities. METHODS: Class V cavities were produced on sound extracted human teeth, which had been assigned randomly to one of three groups (N = 10 each), as follows: Group 1 - prepared using a diamond cylindrical bur and then treated with 37% phosphoric acid; Group 2 - irradiated with an Er,Cr:YSGG laser (Biolase Waterlase) and then treated with 37% phosphoric acid; Group 3 - irradiated only with the laser. After application of bonding agent (Excite, Ivoclar Vivadent), all cavities were restored with composite resin (Heliomolar). After polishing the restorations, the teeth were thermocycled from 5-50 degrees C for 500 cycles. Dye leakage was assessed after immersion in methylene blue, by examining longitudinal sections in a stereomicroscope at x 30 magnification. RESULTS: The extent of dye penetration was lowest in the laser only group (Group 3). Penetration of dye to dentine and axial walls occurred in 80 per cent of conventionally prepared (bur + acid) specimens, but in the laser group, dye penetration to the axial wall occurred in only 30 per cent of cases. There was a strong statistical association between treatment group and the distribution of microleakage scores (Chi-square, P = 0.0023). CONCLUSIONS: For Class V cavities, with the adhesive materials employed, higher microleakage occurs with phosphoric acid etching of bur- or laser-cut surfaces, than with the surface created by use of the laser alone without additional conditioning.

Laser-activated fluoride treatment of enamel as prevention against erosion.

BACKGROUND: Erosion is the loss of dental hard tissues from an acidic challenge, often resulting in exposure of dentinal tubules and hypersensitivity to environmental stimuli. Laser-activated fluoride (LAF) therapy with 488nm laser energy has been shown previously to increase the resistance of human enamel and dentine to acid dissolution. The aims of this study were to investigate the action spectrum of LAF in protecting tooth enamel from softening in response to an erosive challenge, and to examine for any temperature change with the treatment. MATERIALS AND METHODS: Buccal and lingual surfaces of extracted sound molar and premolar teeth were used to prepare matched pairs of enamel slabs (N = 10 per group). After application of 1.23% neutral sodium fluoride gel (12 300ppm F ion), slab surfaces were lased with 488, 514.5, 532, 633, 670, 830 or 1064nm wavelength (energy density 15J/cm(-2); spot size 5mm), then exposed to an erosive challenge (1.0M HCI for five minutes). The Vicker's hardness number (VHN) was recorded before fluoride gel application and again following the acid challenge. Negative controls did not receive laser exposure. RESULTS: All wavelengths of laser light examined provided a protective LAF effect against softening, compared with the negative control surfaces. CONCLUSION: From these findings, we conclude that the action spectrum of the LAF effect extends across the visible spectrum, providing protection to dental enamel from an erosive challenge.

Combined CPP-ACP and photoactivated disinfection (PAD) therapy in arresting root surface caries: a case report.

A 19-year-old male was referred to the School of Dentistry, University of Queensland for management and treatment of uncontrolled root caries. A total of 12 teeth had non-cavitated root carious lesions requiring treatment. The lesions were treated with a daily application of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP; GC Tooth Mousse) and in-surgery photo-activated disinfection (PAD). Laser fluorescence (KaVo Diagnodent) was used to monitor the changes in the carious lesions. The combination of CPP-ACP and PAD proved to be very effective and holds great potential as a recommended treatment for stabilising root surface caries in the clinical practice.

Laser-activated fluoride treatment of enamel against an artificial caries challenge: comparison of five wavelengths.

BACKGROUND: Laser-activated fluoride (LAF) therapy with 488 nm laser energy has been shown previously to increase the resistance of human enamel and dentine to acid dissolution in laboratory models of dental caries. The aims of this study were to examine whether LAF therapy, conducted using a range of wavelengths in the visible and near infrared regions, can protect human dental enamel from an artificial cariogenic challenge. MATERIALS AND METHODS: Buccal and lingual surfaces of extracted sound, molar and premolar teeth were used to prepare matched pairs of enamel slabs (N=10 per group). After application of neutral sodium fluoride gel (12300 ppm F ion), slab surfaces were lased (energy density 15 J/cm2; spot size 5mm, wavelength 532, 633, 670, 830 or 1064nm), then exposed to an artificial cariogenic challenge for a period of seven days. The Vicker's hardness number (VHN) was recorded before and after laser treatment and again following the cariogenic challenge. Negative controls did not receive laser exposure. RESULTS: All wavelengths of laser light examined provided an effective LAF effect, compared with the unlased negative control surfaces. CONCLUSION: Using this in vitro model, we conclude that the action spectrum of the LAF effect extends across the visible and near-infrared regions of the spectrum.

The current status of laser applications in dentistry.

A range of lasers is now available for use in dentistry. This paper summarizes key current and emerging applications for lasers in clinical practice. A major diagnostic application of low power lasers is the detection of caries, using fluorescence elicited from hydroxyapatite or from bacterial by-products. Laser fluorescence is an effective method for detecting and quantifying incipient occlusal and cervical carious lesions, and with further refinement could be used in the same manner for proximal lesions. Photoactivated dye techniques have been developed which use low power lasers to elicit a photochemical reaction. Photoactivated dye techniques can be used to disinfect root canals, periodontal pockets, cavity preparations and sites of peri-implantitis. Using similar principles, more powerful lasers can be used for photodynamic therapy in the treatment of malignancies of the oral mucosa. Laser-driven photochemical reactions can also be used for tooth whitening. In combination with fluoride, laser irradiation can improve the resistance of tooth structure to demineralization, and this application is of particular benefit for susceptible sites in high caries risk patients. Laser technology for caries removal, cavity preparation and soft tissue surgery is at a high state of refinement, having had several decades of development up to the present time. Used in conjunction with or as a replacement for traditional methods, it is expected that specific laser technologies will become an essential component of contemporary dental practice over the next decade.

The effects of chlorhexidine gel on Streptococcus mutans infection in 10-month-old infants: a longitudinal, placebo-controlled, double-blind trial.

PURPOSE: This study investigated the long-term effects of 0.2% chlorhexidine gel, used as a weekly brush-on gel, on Streptoccocus mutans infection in 10-month-old infants. METHODS: The investigation followed the criteria of a placebo-controlled, double-blind, longitudinal clinical trial. Infants were recruited at birth and oral microbiological swabs were taken at 3 monthly intervals, together with medical, dental, dietary and brushing histories. Children who were found to be colonized with S. mutans were randomly assigned to either the chlorhexidine-gel group (N = 50) or placebo gel group (N = 46), and parents were instructed to brush the gel on the teeth once per week for 12 weeks. In another control group (N = 210), infants did not use either chlorhexidine or placebo gels. Saliva samples were cultured using S. mutans-selective tryptone-yeast extract-cysteine-sucrose-bacitracin (TYCSB) agar. The mean age of the children was 10.2 +/- 2.6 months at the start of the trial and subjects were followed until the ages of 18 months. RESULTS: In the children with initial low S. mutans counts of < 300 CFU/mL, there was a significant percentage reduction in S. mutans counts in the chlorhexidine-gel group compared to the placebo gel and no-gel control groups after 3 months of weekly gel brushing. However, no significant differences with the placebo group were observed after 15 months of follow-up. There were 39 children (41%) who achieved reduction of their S. mutans to 0 CFU/mL. Compared to those who remained infected with S. mutans, these children had higher toothbrushing frequencies (P < .001) and toothpaste use (P < .001), as well as lower frequencies of daily feeds (P < .01), and lesser weekly frequencies of sweet solids and liquids (P < .001). CONCLUSIONS: Children with relatively low initial S. mutans counts (< 300 CFU/mL) showed a reduction in S. mutans counts in the first 3 months when 0.2% chlorhexidine gel was brushed on the teeth weekly. No differences were observed when compared with the placebo and no-treatment groups at later follow-up periods.

The pathogenesis of oral lichen planus.

Both antigen-specific and non-specific mechanisms may be involved in the pathogenesis of oral lichen planus (OLP). Antigen-specific mechanisms in OLP include antigen presentation by basal keratinocytes and antigen-specific keratinocyte killing by CD8(+) cytotoxic T-cells. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase (MMP) activation in OLP lesions. These mechanisms may combine to cause T-cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T-cell migration, and keratinocyte apoptosis in OLP. OLP chronicity may be due, in part, to deficient antigen-specific TGF-beta1-mediated immunosuppression. The normal oral mucosa may be an immune privileged site (similar to the eye, testis, and placenta), and breakdown of immune privilege could result in OLP and possibly other autoimmune oral mucosal diseases. Recent findings in mucocutaneous graft-versus-host disease, a clinical and histological correlate of lichen planus, suggest the involvement of TNF-alpha, CD40, Fas, MMPs, and mast cell degranulation in disease pathogenesis. Potential roles for oral Langerhans cells and the regional lymphatics in OLP lesion formation and chronicity are discussed. Carcinogenesis in OLP may be regulated by the integrated signal from various tumor inhibitors (TGF-beta 1, TNF-alpha, IFN-gamma, IL-12) and promoters (MIF, MMP-9). We present our recent data implicating antigen-specific and non-specific mechanisms in the pathogenesis of OLP and propose a unifying hypothesis suggesting that both may be involved in lesion development. The initial event in OLP lesion formation and the factors that determine OLP susceptibility are unknown.

Mast cell/T cell interactions in oral lichen planus.

Lichen planus is a disorder characterized by lesions of the skin and oral mucous membranes. Although many patients have involvement of both skin and oral mucosa at some stage during the progress of the disease, a larger group has oral involvement alone. It has been reported that oral lichen planus (OLP) affects one to two percent of the general population and has the potential for malignant transformation in some cases (1, 2). Like many chronic inflammatory skin diseases, it often persists for many years. Numerous disorders may be associated with OLP such as graft-vs.-host disease and Hepatitis C virus infection (3), however, it is unclear how such diverse influences elicit the disease and indeed whether they are identical to idiopathic OLP. Available evidence supports the view that OLP is a cell-mediated immunological response to an induced antigenic change in the mucosa (4-6). Studies of the immunopathogenesis of OLP aim to provide specific novel treatments as well as contributing to our understanding of other cell-mediated inflammatory diseases. In this paper, the interactions between mast cells and T cells are explored from the standpoint of immune regulation. From these data, a unifying hypothesis for the immunopathogenesis of OLP is then developed and presented.

Comparison of five selective media for the growth and enumeration of Streptococcus mutans.

BACKGROUND: Although a few growth media are available for selective isolation of the cariogenic bacteria, Streptococcus mutans (S. mutans), it is still unclear as to which is the most efficacious. This study compared the selectivity and sensitivity of five different media for growing a laboratory strain of S. mutans (NCTC 10449), and for enumerating S. mutans from teeth of a group of young children, aged 2-10 years. METHODS: The media tested in this study were mitis salivarius with bacitracin (MSB), mitis salivariuskanamycin-bacitracin (MSKB), glucose-sucrose-tellurite-bacitracin (GSTB), trypticase soy-sucrose-bacitracin (TYS20B) and tryptone-yeast-cysteine-sucrose-bacitracin (TYCSB) agars. These were prepared according to the respective manufacturer's instructions. RESULTS: The results showed that at concentrations of bacteria 1 x 10(3) to 1 x 10(10)/mL, the recovery of the laboratory S. mutans strain was highest in TYCSB agar, followed by in descending order by TYS20B, MSB, GSTB, and MSKB (p<0.01). Similar results were obtained using dental plaque samples collected from swabs of the teeth of a group of children. In the clinical samples, TYCSB again showed the highest recovery rates of S. mutans compared to the other four media. Results were reproduced at dilutions of the samples at 1:20 x 10(6) to 1:2 x 10(6), and S. mutans concentrations of 1.6 to 7.7 Log 10 CFU/mL. In addition, there were highest ratios of mutans to non-mutans bacteria in TYCSB compared to the other media, suggesting high selectivity of this media for mutans species. CONCLUSION: The results of our study suggest that TYCSB is the most sensitive and selective media for culture of S. mutans for laboratory and clinical studies.

Expression of RANTES and CCR1 in oral lichen planus and association with mast cell migration.

BACKGROUND: T lymphocytes and mast cells infiltrate the lamina propria in oral lichen planus (OLP). Chemokines and their receptors are involved in T cell and mast cell migration and accumulation during the inflammatory process. METHODS: In the present study, we investigated the role of RANTES and its receptors in OLP using immunohistochemistry, RT-PCR and an in vitro chemotaxis assay. RESULTS: RANTES and CCR1 were expressed on T cells and mast cells in OLP, while OLP lesional T cell supernatants stimulated CCR1 mRNA expression in a human leukemia mast cell line (HMC-1). TNF-alpha stimulated CCR1, CCR4 and CCR5 mRNA expression in the same cell line. OLP lesional T cell supernatants stimulated HMC-1 migration, which was partly inhibited by anti-RANTES antibody. CONCLUSIONS: The present study shows, for the first time, the distribution of RANTES and CCR1 in OLP. It is hypothesized that RANTES and CCR1 may play important roles in mast cell trafficking and related events in OLP.

Association of Streptococcus mutans infection and oral developmental nodules in pre-dentate infants.

Since dental caries may present soon after tooth eruption, we hypothesized that colonization of Streptococcus mutans can occur in the predentate stages. In this study, we examined S. mutans colonization and its association with oral developmental nodules (Bohn's nodules) in 60 pre-term and 128 full-term, three-month-old infants. Overall, S. mutans was cultured from 30% (56/188) of the infants, and oral developmental nodules were noted in 55% (103/188). Compared with the pre-term, full-term infants showed a higher prevalence of S. mutans (34% vs. 20%, p < 0.02) as well as developmental nodules (61% vs. 42%, p < 0.05). In both groups, S. mutans was positively associated with numbers of developmental nodules in a dose-response relationship (p < 0.001), and with maternal salivary levels of the bacteria (p = 0.03). The permanence of S. mutans infection was confirmed by repeat saliva sampling at 6 months of age. Our results thus showed that many infants have already acquired S. mutans at 3 months of age, prior to tooth eruption.

Mast cell degranulation and the role of T cell RANTES in oral lichen planus.

OBJECTIVES: The present study investigated mast cell degranulation in oral lichen planus (OLP) and the effect of OLP lesional T cell supernatants on mast cell degranulation. MATERIALS AND METHODS: Immunohistochemistry was used to identify mast cell degranulation in both OLP (n = 22) and normal control (n = 14) tissues. OLP lesional T cell lines (n = 5) and HMC-1 (a human leukemia mast cell line) were used to examine the effects of OLP T cell supernatants on mast cell degranulation in vitro. RESULTS: Approximately 60% of mast cells were degranulated in OLP. OLP lesional T cells expressed mRNA for RANTES, and TNF-alpha stimulation upregulated OLP lesional T cell RANTES secretion. OLP lesional T cell supernatants induced degranulation of HMC-1 with release of TNF-alpha and histamine. Human recombinant RANTES similarly induced mast cell degranulation. Anti-RANTES antibody blocked OLP lesional T cell supernatant-induced mast cell degranulation. CONCLUSIONS: This study is the first to show that OLP lesional T cells produce and secrete RANTES which triggers human mast cell degranulation. Degranulating mast cells release TNF-alpha which upregulates OLP lesional T cell RANTES secretion. Such a cyclical mechanism may underlie disease chronicity and future therapies may include blocking RANTES or TNF-alpha activity in OLP.

Matrix metalloproteinases and their inhibitors in oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is characterized by a sub-epithelial lymphocytic infiltrate, basement membrane (BM) disruption, intra-epithelial T-cell migration and apoptosis of basal keratinocytes. BM damage and T-cell migration in OLP may be mediated by matrix metalloproteinases (MMPs). METHODS: We examined the distribution, activation and cellular sources of MMPs and their inhibitors (TIMPs) in OLP using immunohistochemistry, ELISA, RT-PCR and zymography. RESULTS: MMP-2 and -3 were present in the epithelium while MMP-9 was associated with the inflammatory infiltrate. MMP-9 and TIMP-1 secretion by OLP lesional T cells was greater than OLP patient (p < 0.01) and healthy control subject (p < 0.001) peripheral blood T cells. MMP-9 and TIMP-1 mRNA levels were greater in OLP lesional T cells compared with healthy control subject peripheral blood T cells p < 0.01). Tumor necrosis factor (TNF)-alpha upregulated OLP lesional T-cell MMP-9 (not TIMP-1) mRNA and secretion (p < 0.05). The in vitro activation rate of MMP-9 from OLP lesional T cells was greater than that from OLP peripheral blood T cells (p < 0.05). CONCLUSION: T-cell-derived MMP-9 may be involved in the pathogenesis of OLP. Relative over-expression of MMP-9 (compared with TIMP-1) may cause BM disruption and facilitate intra-epithelial T-cell migration in OLP.

Changes in the periodontal status of patients undergoing bone marrow transplantation.

BACKGROUND: Patients receiving an HLA-matched bone marrow transplant (BMT) from a relative or unrelated donor undergo a permanent alteration of their immune system, followed by a prolonged period of immunodeficiency. This study aimed to examine alterations in the periodontal status of patients over 6 months post-bone marrow transplantation. METHODS: Thirty-seven patients scheduled for bone marrow transplantation participated in this study. One calibrated examiner carried out periodontal examinations (clinical and radiographic) immediately prior to and at 3 and 6 months after transplantation. All patients followed an intense oral care program. Subgingival plaque samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia. Data were subjected to statistical analyses to determine the relationships between the frequency distribution of the radiographic and clinical variables over time. RESULTS: Gains in clinical attachment level (CAL) of > or =2 mm at 4 or more sites from baseline to 6 months post-BMT were noted in 9/16 patients (56%), while 6/16 (38%) patients experienced a loss of CAL > or =2 mm at 4 or more sites in the same period. At a site level, 4.8% of sites exhibited a gain in CAL > or =2 mm between baseline and 3 months post-BMT while 2.3% of sites showed a loss of CAL > or =2 mm in the same period. From baseline to 6 months, a gain in CAL of > or =2 mm was recorded at 3.1% of sites, and 2.4% of sites experienced a loss of > or =2 mm. A significant improvement in the gingival index occurred between all sequential time periods when assessed at a site level. At a patient level, 11/18 (61%) patients showed a significant change in gingival index between baseline and 3 months and 10/16 (63%) between baseline and 6 months. There was no significant relationship between clinical changes and the prevalence of the periodontal pathogens at the various time periods. CONCLUSIONS: An improvement in periodontal health was recorded between baseline and 6 months post-transplantation. Most of the improvement in periodontal status was noted in the first 3 months after BMT, with a slight decline in periodontal health between 3 and 6 months post-transplant. No significant alteration was noted in the prevalence of periodontal pathogens during the study period.

Periodontal implications of immunodeficient states: manifestations and management.

The importance of the immune system in modulating the host response to plaque is well recognised, and in this context the immune system is clearly a risk/modifying factor for human periodontal disease. This review examines the periodontal manifestations of subjects with immunodeficiencies and considers potential preventive protocols for the periodontal management of these patients.

An assessment of techniques for dehydrating root canals using infrared laser radiation.

Infrared lasers have been used for debridement and sterilisation of both soft and hard tissues, but there have been few studies of such laser applications in endodontics. The present laboratory study was undertaken to examine the feasibility of using pulsed infrared laser radiation to remove moisture from root canals (with an adjunctive sterilising effect). Canals were prepared in extracted teeth and a standardised technique used to fill the apical half of the root canal with saline. Pulses of CO2 or Nd:YAG laser energy were delivered into the root canal system via miniature applicators and residual fluid determined, as well as temperature changes on the root surface. With the CO2 laser, long pulse durations were effective at dehydrating the canals, but elicited deleterious thermal changes both locally within the canal as well as on the root surface. With Nd:YAG laser treatment, large temperature increases on the root surface occurred even with low powers and low pulse frequencies, and extended times were necessary for dehydration. With higher powers and pulse frequencies, complete dehydration could be achieved in less than 60 seconds, however root surface temperatures increased approximately 25 degrees, and the radicular dentine was damaged by the production of plasma. Dehydration of root canals could not be achieved safely with these two infrared lasers, and damage to both radicular dentine and the periodontal ligament would occur if these techniques were to be applied clinically. Alternative methods which do not exert significant thermal effects should be investigated.