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Objective The aim of this in vitro study was to evaluate the ability of optical coherence tomography (OCT) to display calculus on root surfaces. Material and methods Ten teeth with calculus on the root surface were embedded in resin, omitting the root surface. A region of interest (ROI) was marked by small drill holes coronally and apically of the calculus and imaged by spectral-domain optical coherence tomography ([SD OCT], Telesto SP5, centre wavelength 1310 nm) and light microscopy (LM). To evaluate the impact of different fluids on calculus visualisation, using OCT, root surfaces were covered by a layer of NaCl and blood and displayed by OCT. Subsequently, teeth were completely covered with resin and sectioned for histological evaluation. Within the ROI, lengths of root surface and calculus were measured by LM and OCT, and the ratio [%] was calculated. In addition, at three sites of each ROI, agreement of presence and length of calculus was evaluated. Both methods were compared using Pearson’s correlation. Results Regarding the presence of calculus, agreement between LM and OCT was strong (κi = 0.783, p = 0.033), and measurements regarding the length of the calculus were strongly correlated (ri >0.906; pi Conclusion Calculus on the root surface can be displayed by SD-OCT, which therefore may be suited as imaging technology for subgingival calculus in periodontal pockets.

Orthodontic therapy is not contraindicated for patients with advanced periodontal destruction, provided that factors such as inflammation, plaque, subgingival calculus, and occlusal trauma are well controlled both before and during the orthodontic treatment. The application of extremely light continuous forces might have a better effect on the cell biology of tooth movements. By minimizing necrosis, and the subsequent hyalinization and indirect resorption, it might be possible to achieve continuous progress in tooth movement, avoiding the repeated interruptions occurring when the blood vessels are occluded, and reducing the great risk for further bone loss when treatment is rendered for individuals with decreased osseous support. A new generation of low friction, passive self-ligating brackets, in combination with newer wire and coil materials and longer activation spans, seems to be capable of exerting lower force levels providing more favorable periodontal reactions in patients with previous bone loss. A patient treated following these principles and using these newer technologies is presented. (Semin Orthod 2008;14:36-45.) © 2008 Elsevier Inc. All rights reserved.

This aim of this study was to evaluate the clinical effectiveness of Er:YAG laser at a high pulse rate (ER-D1: HOYA continuum, Japan) for scaling of subgingival calculus and root planning. Sixty-one patients with calculus deposition were treated with the Er:YAG laser (panel setting 30–108 mJ/pulse, 30 Hz) using contact tips and the results were then subjected to clinical analysis. Clinical assessments of calculus index, pain, redness, swelling, discomfort, roughness of root surface, efficiency of scaling, PlI, PD, BOP and mobility were made prior to and at 1, 4 weeks and 3 months after treatment. Fifteen of the sixty-one patients were treated during the flap operation. The Er:YAG laser high-pulse-rate irradiation was capable of ablating the calculus on the root surface precisely and effectively. The roughness of root surface after debridement was evaluated to be adequately plane for 41 cases and still rough for 20 cases. BOP and PD were significantly improved throughout the 3-month examination of this study. No negative side effects or influences were observed on the healing of periodontal tissue following Er:YAG laser irradiation during this clinical study. In conclusion, the Er:YAG laser high-pulse-rate irradiation would be a safe and effective, alternative method for root surface treatment in both nonsurgical and surgical periodontal therapy.

Whether the fluoride concentrations and profiles differ in human dental calculus obtained from different countries was investigated. A total of 203 dental calculus deposits on 203 permanent teeth from residents (mean age, 52.1 years) of Nagoya (Japan), Shanghai (China), Leeds (Great Britain) and the Wuhan mountainous area (China, fluoridated area) were analysed. An abrasive microsampling procedure was used to examine fluoride distribution. There were five types of fluoride profiles in dental calculus in each area/country (designated types L, J, U, T, W). In supragingival calculus, type L (highest in the outermost layers) and type J (highest in the innermost layers) both had significantly higher values than type U (high in the surface and innermost layers) but were relatively identical. In subgingival calculus, type W (high in the outermost, mid and innermost layers) was characteristic. Calculus from the Wuhan mountainous area (fluoridated) had the highest fluoride concentration, followed by Leeds (non-fluoridated), and Nagoya and Shanghai (non-fluoridated) calculus had the lowest. Fluoride concentrations in supragingival calculus were higher in teeth extracted because of periodontal diseases than dental caries. It is concluded that fluoride concentrations and distribution in dental calculus differ from country to country, probably due to different fluoride environments.

Objectives: The aims of this study were to assess the validity of the WHO 621 probe for the detection of subgingival calculus and to assess the effect of subgingival calculus on the measurement of probing pocket depths and clinical attachment levels. Methods: Teeth used in the study were designated for extraction under local analgesia. Prior to extraction the clinical detection of subgingival calculus was made with a WHO 621 probe. Probing pocket depths and clinical attachment levels were measured. The location and direction of the gingival margin and probing measurements were marked on the teeth with a fine, sterile pencil and following extraction, permanent reference grooves were cut with a fine, tapered diamond bur. The extracted teeth were stained with Gomori's stain and examined for the presence of calculus, and the pocket depths and attachment levels were measured using a stereomicroscope. Results: There was an 80% agreement between the clinical and laboratory detection of subgingival calculus. There was no systematic difference between clinical and histopathological measurements when calculus was present or absent (P > 0.05). Analysis of variance indicated a random error effect due to the presence of subgingival calculus. Conclusion: This study has demonstrated the validity of the WHO 621 probe in detecting subgingival calculus and has shown that subgingival calculus could be a source of error in the measurement of probing depths and clinical attachment levels.

A survey of the oral conditions of 1347 Navajo Indian children between the age of 3 and 20 years was conducted. The data recorded were, the gingival condition about each tooth, deposits, abrasion and dental caries. The prevalence, severity and incidence rate of gingivitis were found to be remarkably similar to that of a group of Alabama school children. The main differences were a high incidence of subgingival calculus at an early age, a high incidence of abrasion, a different intra-oral pattern of gingival disease and a low caries rate. The diet was studied of the Navajo Indians residing in the remote areas which were visited during a family to family survey. The mode of life, general health, climatic conditions are discussed with possible reference to the oral health findings.