Clinical guide to periodontology: reconstructive periodontal treatment.

Regeneration of the lost tissues of the periodontium is an ideal therapeutic goal and has been the subject of much research and ingenious clinical techniques. Reconstructive or regenerative techniques are used either singly or in combination for three main purposes: (1) to regain lost periodontal ligament attachment, (2) to provide a wider zone of attached gingiva, and (3) to cover previously exposed root surfaces.

Clinical guide to periodontology: part 3. Multidisciplinary integrated treatment.

The establishment of periodontal health should be a primary aim in all treatment plans. The methods by which this can be achieved have been dealt with in previous chapters, but there are a number of situations where integration of these treatment methods with other dental disciplines needs to be clarified. To simplify matters this chapter will consider periodontal implications in three main areas: treatment of drifted anterior teeth, pre-restorative procedures and replacement of missing teeth.

A clinical guide to periodontology: pathology of periodontal disease.

An appreciation of dental plaque and the host response provides an essential basis from which to understand the disease process and treatment rationale. This information will help the reader to understand not only the way that plaque may have an impact on oral tissues but also why regular effective cleaning may improve periodontal health and why some individuals appear to have a greater susceptibility to periodontitis than others, either intrinsically or in relation to various systemic factors.

The effect of smoking on bone healing: A systematic review.

OBJECTIVES: To review the systemic impact of smoking on bone healing as evidenced within the orthopaedic literature. METHODS: A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies were included. The primary outcome measures were based on clinical and/or radiological indicators of bone healing. This review specifically focused on non-spinal orthopaedic studies. RESULTS: Nine tibia studies and eight other orthopaedic studies were considered for systematic review. Of these 17 studies, 13 concluded that smoking negatively influenced bone healing. CONCLUSIONS: Smoking has a negative effect on bone healing, in terms of delayed union, nonunion and more complications.

Risk management in clinical practice. Part 9. Dental implants.

Patients have high expectations of dental implants in terms of appearance, function and longevity. It is essential that these expectations are realistically managed and that treatment of the highest standard is provided. This involves very careful evaluation, including clinical and radiographic, and presentation of the pros and cons of treatment alternatives. Provision of a successful implant restoration requires many skills including a surgical procedure to place the implant in the best possible position and prosthodontic techniques to provide an aesthetic restoration in occlusal harmony with the rest of the dentition. Recognition of risk factors and long-term maintenance requirements are equally important. Clinicians involved in these treatments must obtain adequate training and develop skills through treatment of straightforward cases using well established protocols before embarking on more demanding cases.

Cultivation of a Synergistetes strain representing a previously uncultivated lineage.

Subgingival plaque samples obtained from human subjects with periodontitis, shown to include previously uncultivable members of the phylum Synergistetes, were used to inoculate Cooked Meat Medium (CMM). The presence of Cluster A (uncultivable) Synergistetes was monitored by fluorescent in situ hybridization (FISH) and quantitative PCR (Q-PCR). Cluster A Synergistetes were found to grow in CMM in co-culture with other plaque bacteria and growth was stimulated by the addition of mucin and serum. Plaque samples were also used to inoculate Blood Agar (BA) plates and growth of Cluster A Synergistetes was revealed after anaerobic incubation, by colony hybridization with specific probes. Surface growth on the plates in regions identified by colony hybridization was harvested and used to inoculate fresh plates, thus enriching for Cluster A Synergistetes. Cross-streaks of other plaque bacteria were also used to stimulate Synergistetes growth. In the early passages, no discrete Synergistetes colonies were seen, but after eight passages and the use of cross-streaks of other bacteria present in the enriched community, colonies arose, which consisted solely of Cluster A Synergistetes cells, as determined by 16S rRNA gene PCR and cloning. This is the first report of the successful culture of a member of the uncultivable branch of this phylum.

Diversity and morphology of members of the phylum "synergistetes" in periodontal health and disease.

Members of the phylum "Synergistetes" have frequently been detected in the human oral cavity at sites of dental disease, but they have rarely been detected in studies of oral health. Only two oral "Synergistetes" taxa are cultivable. The aims of this study were to investigate the diversity of "Synergistetes" in the oral cavity, to establish whether "Synergistetes" taxa are more strongly associated with periodontitis than with oral health, and to visualize unculturable "Synergistetes" in situ. Sixty samples (saliva, dental plaque, and mucosal swabs) were collected from five subjects with periodontitis and five periodontally healthy controls. Using phylum-specific 16S rRNA gene primers, "Synergistetes" were identified by PCR, cloning, and sequencing of 48 clones per PCR-positive sample. Subgingival plaque samples were labeled with probes targeting rRNA of unculturable oral "Synergistetes" using fluorescent in situ hybridization (FISH). Analysis of 1,664 clones revealed 12 "Synergistetes" operational taxonomic units (OTUs) at the 99% sequence identity level, 5 of which were novel. "Synergistetes" OTU 4.2 was found in significantly more subjects with periodontitis than controls (P = 0.048) and was more abundant in subgingival plaque at diseased sites than at healthy sites in subjects with periodontitis (P = 0.019) or controls (P = 0.019). FISH analysis revealed that unculturable oral "Synergistetes" cells were large curved bacilli. The human oral cavity harbors a diverse population of "Synergistetes." "Synergistetes" OTU 4.2 is associated with periodontitis and may have a pathogenic role.

Periodontal tissue engineering and regeneration: Consensus Report of the Sixth European Workshop on Periodontology.

AIM: To review the scientific preclinical background and clinical studies of current methods of periodontal regeneration in the treatment of infrabony defects and soft tissue deficiencies. METHOD: Five commissioned review papers including two systematic reviews were scrutinized by a group of experts in order to derive consensus conclusions, clinical relevance/implications and to propose future research requirements. RESULTS: The following five papers were assessed: 1. Biological mediators and periodontal regeneration: a review of enamel matrix proteins at the cellular and molecular levels. 2. Regeneration of periodontal tissues: combination of barrier membranes and grafting materials - Biological foundation and preclinical evidence. 3. Clinical outcomes with bioactive agents alone or in combination with grafting or GTR 4. Treatment of gingival recession with coronally advanced flap procedures. A systematic review. 5. Soft tissue management at implant sites.

Immediate and early replacement implants and restorations.

There have been rapid developments in dental implant treatment protocols to reduce the time between implant placement and restoration. Implants may be placed immediately following tooth extraction or following a period of healing to allow resolution of residual infection or sufficient bone and soft tissue healing. Early restoration and loading of implants has to be carefully controlled to avoid increased failure and complications. Advantages and disadvantages of the various techniques are described.

The management of developmentally absent maxillary lateral incisors--a survey of orthodontists in the UK.

OBJECTIVE: To investigate the orthodontic management of patients with developmentally absent maxillary lateral incisors. MATERIALS AND METHODS: A questionnaire was mailed to all orthodontists on the specialist list held by the British Orthodontic Society. RESULTS: The questionnaires (57.3% response) were analysed in two groups: Group 1 consisted of orthodontists who worked only in an orthodontic practice environment; Group 2 consisted of orthodontists who worked full-time or part-time in an environment where there were restorative dentists available for advice. Group 1 orthodontists were significantly more likely to recommend (p = 0.006) space closure in the management of developmentally absent maxillary lateral incisors. Group 2 orthodontists were significantly more likely to recommend (p = 0.004) minimal preparation bridges. Group 2 orthodontists also saw significantly more patients with hypodontia (p

Astra Tech single-tooth implants: an audit of patient satisfaction and soft tissue form.

AIM: To investigate patient centred outcomes, soft tissue morphology, and bone levels. MATERIAL AND METHODS: Sixty-six subjects, who had completed treatment for a single implant restoration at least l year previously. Appearance was recorded photographically and bone levels and interdental contact points measured from intra-oral radiographs using a x 7 scale loupe. Subjects completed a satisfaction questionnaire. RESULTS: Subjects were highly satisfied with all aspects of the restoration including the appearance of the soft tissue (median shape/colour score 6 on scale 1-6). Twenty-eight sites in 20 subjects had no contact point between implant crown and adjacent tooth. A normal height papilla was judged to be present in 19 of these sites. These were excluded from the subsequent analysis. In the remaining 46 subjects with contact points the presence (JEMT score 3) or deficiency (score 1/2) of the papilla was significantly related to the distance to the bone level on the adjacent tooth and implant head. Differences were observed between the mesial and distal aspects of the implant restoration. CONCLUSIONS: Examining clinicians were more critical of the restorations than the patients. The presence of a complete papilla was associated with a slightly greater distance from contact point to bone level than previously reported.

Management of smoking patients by specialist periodontists and hygienists in the United Kingdom.

OBJECTIVE: To assess the management of patients who are current smokers in dental practice. MATERIALS AND METHODS: A postal questionnaire to the 243 periodontists on the UK specialist register and 239 randomly selected hygienists on the General Dental Council register. RESULTS: Eighty per cent of both groups responded. There were significant demographic differences between the two groups of respondents: 88% of periodontists were in specialist practice and/or hospital or university departments, while 89% of hygienists were in general dental practice. Periodontists routinely asked their patients about smoking 99% of the time, hygienists 89%. More than 5 min. was spent advising a smoker patient by 35% of periodontists and 19% of hygienists. A proportion of both groups claimed to have had some recognized training in quit smoking (44% and 39%). When asked about the oral conditions of their smoking patients, 26% of periodontists stated that these patients did not have poorer oral hygiene, while 67% of hygienists thought that they did. While the majority of both groups discussed the oral effects of smoking, less than two-thirds discussed methods of giving up. CONCLUSION: Both periodontists and hygienists are generally aware of the problems of treating smokers, and accordingly ask and advise their patients. However, lack of time and poor patient response may inhibit active involvement in assisting patients to quit smoking.

Breakaway forces of flat and domed surfaced Magfit implant magnet attachments.

The aim of this in vitro study was to compare the resistance to separation (breakaway force) of flat (Magfit-IP-BF) and domed (Magfit-IP-BD) implant magnet attachments subjected to non-axial forces. The separating forces were applied by an Instron Universal Testing Instrument to single magnet attachments at angles of 0 degrees, 2 degrees, 5 degrees 10 degrees, and 20 degrees from the axial line of the components (angle of pull) and at crosshead speeds of 0.5 mn/min and 5 degrees mm/min. The breakaway forces were significantly (p < 0.0001) inversely related to the angle of pull for both flat magnets and for domed magnets. At the slow crosshead speed, the breakaway forces recorded for the domed magnets were significantly greater than those recorded for the flat magnets for angles of pull greater than 5 degrees. At the faster crosshead speed, the breakaway forces recorded for the domed magnets were significantly greater than those recorded for the flat magnets for angles of pull greater than 2 degrees. This apparent superiority of domed magnets under non-axially directed separating forces could influence the choice of magnet attachment for implant overdentures as intraoral displacing forces are multidirectional. Domed magnets may also be advantageous where implants are not parallel.

Atypical anxiolytic-like response to naloxone in benzodiazepine-resistant 129S2/SvHsd mice: role of opioid receptor subtypes.

RATIONALE: Mice of many 129 substrains respond to environmental novelty with behavioural suppression and high levels of anxiety-like behaviour. Although resistant to conventional anxiolytics, this behavioural phenotype may involve stress-induced release of endogenous opioids. OBJECTIVES: To assess the effects of opioid receptor blockade on behavioural reactions to novelty stress in a chlordiazepoxide-resistant 129 substrain. MATERIALS AND METHODS: Experiment 1 contrasted the effects of the broad-spectrum opioid receptor antagonist naloxone (1.0-10.0 mg/kg) in C57BL/6JOlaHsd and 129S2/SvHsd mice exposed to the elevated plus-maze. Experiments 2-4 examined the responses of 129S2/SvHsd mice to the mu-selective opioid receptor antagonist beta-funaltrexamine (2.5-10.0 mg/kg), the delta-selective antagonist naltrindole (2.5-10.0 mg/kg) and the kappa-selective antagonist nor-binaltorphimine (2.5-5.0 mg/kg). RESULTS: 129 mice displayed higher levels of anxiety-like behaviour and lower levels of general exploration relative to their C57 counterparts. Although naloxone failed to alter the behaviour of C57 mice, both doses of this antagonist produced behaviourally selective reductions in open-arm avoidance in 129 mice. Surprisingly, none of the more selective opioid receptor antagonists replicated this effect of naloxone: beta-funaltrexamine was devoid of behavioural activity, naltrindole suppressed rearing (all doses) and increased immobility (10 mg/kg), while nor-binaltorphimine (5 mg/kg) nonspecifically increased percent open arm entries. CONCLUSIONS: Recent evidence suggests differential involvement of opioid receptor subtypes in the anxiolytic efficacy of diverse compounds including conventional benzodiazepines. The insensitivity of 129 mice to the anxiolytic action of chlordiazepoxide, coupled with their atypical anxiolytic response to naloxone (but not more selective opioid receptor antagonists), suggests an abnormality in anxiety-related neurocircuitry involving opioid-GABA interactions.

Pilot study of the efficacy of renzapride on gastrointestinal motility and symptoms in patients with constipation-predominant irritable bowel syndrome.

AIM: To investigate the efficacy and safety of renzapride, a potent 5-hydroxytryptamine type-4 receptor full agonist and 5-hydroxytryptamine type-3 receptor antagonist in patients with constipation-predominant irritable bowel syndrome. METHODS: In this dose-escalating pilot study, 17 patients with constipation-predominant irritable bowel syndrome received placebo, renzapride 2 mg o.d. and renzapride 2 mg b.d. sequentially for 28 days. Response was determined by radio-opaque marker measurement of overall gastrointestinal and segmental colonic transit and patients' assessment of their irritable bowel syndrome symptoms. RESULTS: Renzapride reduced mean overall gastrointestinal transit time (placebo, 2.9 +/- 1.6 days; renzapride 2 mg o.d., 2.6 +/- 1.4 days; renzapride 2 mg b.d., 1.9 +/- 1.6 days) (P = 0.024) and accelerated segmental colonic transit, with statistically significant differences for renzapride 2 mg b.d. over placebo in caecum/ascending colon (P = 0.019) and descending colon (P = 0.022). Renzapride also reduced abdominal pain, increased the number of pain-free days and improved stool consistency. The frequency of reported adverse events was similar on renzapride and placebo. CONCLUSIONS: Renzapride is well-tolerated, stimulates gastrointestinal transit and improves symptoms in patients with constipation-predominant irritable bowel syndrome, particularly at the 2 mg b.d. dose, where improvements in gastrointestinal symptoms were evident over placebo. This study has established proof of concept and supports further investigation of renzapride in patients with constipation-predominant irritable bowel syndrome.

Novel subgingival bacterial phylotypes detected using multiple universal polymerase chain reaction primer sets.

INTRODUCTION: Molecular ecological analysis based on 16S rRNA gene sequence analysis is well established for the characterisation of complex bacterial communities. However, 'universal' PCR primers can introduce biases into the analysis of the species composition of clone libraries because of mismatches between the primer and target organism sequences. In this study, three universal primer sets were compared for the analysis of the microflora in subgingival plaque. METHODS: Three subgingival plaque samples were collected from two subjects with localised severe chronic periodontitis. Half of each sample was cultured while DNA was extracted from the remaining half and 16S rDNA amplified with universal primer pairs 27F, 1525R (A); 27F, 1492R (B) and 530F, 1525R (C). Amplified genes were cloned, sequenced and identified by comparison with 16S rRNA databases. RESULTS: 137 taxa were identified among 177 isolates and 417 clones sequenced. Of these, 86 were detected only by the molecular technique whereas 26 were found only by culture. Sequences from 81 taxa did not correspond to those of named species and of these, 38 were not represented in the nucleotide databases. 16S RNA genes for these 38 taxa were sequenced and deposited with GenBank. CONCLUSION: The use of three sets of universal primers allowed the identification of 38 novel bacterial phylotypes. There were marked differences in the composition of the libraries generated by the different primer sets. A combination of molecular and cultural techniques is recommended to maximise the coverage of detection of bacterial taxa in oral samples.

The influence of vitamin C on systemic markers of endothelial and inflammatory cell activation in smokers and non-smokers.

OBJECTIVE AND DESIGN: To determine the influence of vitamin C supplementation (500 mg, bd, 14 days) on the circulating concentrations of soluble ICAM-1 (a marker of endothelial activation), neopterin (a marker of monocyte activation), and neutrophil elastase (a marker of neutrophil activation) in smokers and non-smokers in a randomised, double-blind, placebo-controlled trial in a hospital setting. SUBJECTS: Twenty smokers (serum cotinine > or = 20 ng ml(-1)) and 20 age- and gender-matched non-smokers (serum cotinine < or = 13.7 ng ml(-1)). RESULTS: At baseline, there was a significant elevation in the concentration of sICAM-1 in smokers (median 247, IQR 199 to 357 ng ml(-1)) compared to non-smokers (median 207, IQR 189 to 227 ng ml(-1); p = 0.014). Vitamin C supplementation did not influence the circulating concentrations of ICAM-1 or neopterin, or leukocyte elastase activity, in smokers, non-smokers, or in the total population. CONCLUSIONS: Markers of monocyte and neutrophil activation were not influenced by smoking status in this study population. However, sICAM-1 concentrations were significantly elevated in tobacco smokers, reflecting tobacco-induced vascular activation that is unaffected by Vitamin C supplementation.

A prospective 3-year study of fixed bridges linking Astra Tech ST implants to natural teeth.

BACKGROUND: Connecting teeth and osseointegrated implants in fixed reconstructions is not generally recommended because of differences in their response to loading. AIM: The aim of the present study was to assess the clinical and radiographic performance of the teeth and implants used to support three unit fixed bridges subjected to normal functional loads. SUBJECTS AND METHODS: Nineteen subjects (10 males, nine females, age range 27-65 years) with an edentulous posterior free end saddle in either maxilla or mandible (Kennedy Class 2), and opposing natural teeth or a tooth-supported fixed bridge were treated and completed the 3-year trial. An Astra Tech ST implant (length: 9 mm (n=2), 11 mm (n=9) or 13 mm (n=8); diameter: 4.5 mm) was placed immediately distal to the last tooth or leaving a single premolar sized space. The distal tooth received a gold coping and the implant was restored with a customised Prepable abutment (Astra Tech Profile BiAbutment: diameter 5.5 or 7 mm). A fixed bridge was placed linking the gold coping and implant abutment either with the pontic as a distal cantilever (n=6, length 7-8 mm) or as a fixed-fixed design (n=13, length 6-12 mm). Standardised radiographs and clinical records were taken at delivery of the prosthesis (baseline BL) and annually. RESULTS: Plaque scores at implant sites increased between BL and subsequent years (P<0.02). Statistically significant increases in probing depth were observed at both abutment teeth and implants between baseline and subsequent years (P<0.001). Marginal bone levels (mm) at the implant and tooth were stable between BL, 1-, 2- and 3-year examinations (implant: BL 0.65+/-0.42, 1 year 0.63+/-0.47, 2 years 0.88+/-0.55, 3 years 0.78+/-0.64; tooth: BL 2.29+/-0.82, 1 year 2.41+/-0.8, 2 years 2.38+/-1.02, 3 years 2.68+/-0.86). No signs of the intrusion of the abutment teeth were detected. One case of abutment screw loosening occurred. Eight bridges required re-cementation with a permanent cement in place of the temporary cement. There were eight subjects presenting with fractures/chips to the composite component of the bridges. CONCLUSION: The 3-year results demonstrate fully functional successful restorations with no evidence of tooth intrusion and with stable bone levels at both teeth and implants.

A retrospective study of periodontal disease severity in smokers and non-smokers.

BACKGROUND: Smoking has been associated with increased risk of periodontitis. The aim of the present study was to compare the periodontal disease severity of adult heavy smokers and never-smokers referred for assessment and treatment of chronic periodontitis. METHODS: A random sample of patients with at least 20 teeth, stratified for smoking and age (5-year blocks, 35 to 55 years), was selected from an original referral population of 1,221 subjects with chronic adult periodontitis. Adequate records for 59 never-smokers and 44 subjects who smoked at least 20 cigarettes per day were retrieved. The percentage of alveolar bone support was measured from dental panoramic radiographs with a Schei ruler at x3 magnification with the examiner unaware of the smoking status. Probing depths at six sites per tooth were obtained from the initial consultation. RESULTS: There was no significant difference in age between groups. Smokers had fewer teeth (p<0.001), fewer shallow pockets (p<0.001) and more deep probing depths (p<0.001). The differences were greater in subjects 45 years of age and over. In this age group, smokers had approximately 13% more bone loss, 15% more pockets in the 4-6 mm category and 7% more pockets in the >/= 7 mm category than the never-smokers. CONCLUSIONS: This study confirmed that smokers had evidence of more severe periodontal disease than never-smokers. The differences increased with age confirming an exposure-related response.

Evaluation of a new periodontal probe tip design. A clinical and in vitro study.

AIMS: In the search for an accurate periodontal probe which does not frequently penetrate the pocket base, a new tip has been designed which is flattened, and of 1 mm width and 0.45 mm thickness. This study aimed to evaluate the physico-mechanical and clinical properties of this probe (test) in comparison to a conventional 0.5 mm circular probe (control). METHODS: Photoelastic stress analysis was undertaken for test and control probe tips at 3.15 and 5 N loads. To assess probing validity, the clinical probing depth with each probe (0.25 N force) at 125 sites on 27 teeth (27 subjects), was compared with the post-extraction connective tissue level measurement. Also evaluated were probing reproducibility (1200 sites in 25 subjects) and patient comfort (30 subjects). RESULTS: Using photoelastic stress analysis, the test probe demonstrated lower stresses and less local stress concentration than the control. Clinically, the test probe measured close to the post-extraction gold standard in greater frequency than the control - 26 versus 11 readings (21% versus 9%) exactly matched, and 90 versus 67 (72% versus 54%) were within +/-0.5 mm of the laboratory measurement. The test probe was, on average, 0.13 mm coronal to the connective tissue attachment level, whereas the control penetrated 0.27 mm past this level. The intraclass correlation between clinical and laboratory readings was greater for the test than the control (r=0.81 and 0.74, respectively). Although the control probe overestimated probing depth more markedly at bleeding (0.41 mm) than at non-bleeding (0.15 mm) sites, the relative position of the test probe hardly differed with inflammatory status (-0.11 and -0.14 mm, respectively). Each probe demonstrated good clinical reproducibility. However, the test probe examination was more comfortable for the patient. CONCLUSION: This new periodontal probe tip appears to have greater validity, good reproducibility and produces less patient discomfort.