Jonathan W. Leichter

A System of Calibrating Microtomography for Use in Caries Research

Desktop microcomputed tomography (micro-CT) offers a non-invasive 3-dimensional analysis of structures and their physical properties. To date, the use of micro-CT has mostly involved qualitative observations, with the extent of quantitative analysis relying on automated internal calibration by the micro-CT control software. However, the value of such calibration is limited by machine drift. For an accurate quantitative use of micro-CT, it is recognized that external means of calibration are needed. A novel system of calibration standards, also known as ‘phantoms’, is presented. A range of low mineral concentration phantoms involving triethylene glycol dimethacrylate/glycerolate dimethacrylate resin mixed with commercial pure hydroxyapatite (HAP), from 0.07 to 1.05 g/cm3, was fabricated. Sintered HAP was impregnated with the same resin, producing phantoms with medium-level mineral concentrations up to 1.90 g/cm3. These phantoms were easy to create, proved accurate and stable with repeated use, and were found to mimic the composite nature of dental enamel and dentine structures under investigation.

The impact of periodontitis on oral health-related quality of life: a review of the evidence from observational studies

Modern population based oral health management requires a complete understanding of the impact of disease in order to provide efficient and effective oral health care and guidance. Periodontitis is an important cause of tooth loss and has been shown to be associated with a number of systemic conditions. The impact of oral conditions and disorders on quality of life has been extensively studied. However, the impact of periodontitis on quality of life has received less attention. This review summarizes the literature on the impact of periodontitis on oral health-related quality of life (OHRQoL). Relevant publications were identified after searching the MEDLINE and EMBASE electronic databases. Screening of titles and abstracts and data extraction was conducted. Only observational studies were included in this review. Most of the reviewed studies reported a negative impact of periodontitis on OHRQoL. However, the reporting standards varied across studies. Moreover, most of the studies were conducted in developed countries.

Diabetes, periodontitis, and the subgingival microbiota

Abstract Both type 1 and type 2 diabetes have been associated with increased severity of periodontal disease for many years. More recently, the impact of periodontal disease on glycaemic control has been investigated. The role of the oral microbiota in this two-way relationship is at this stage unknown. Further studies, of a longitudinal nature and investigating a wider array of bacterial species, are required in order to conclusively determine if there is a difference in the oral microbiota of diabetics and non-diabetics and whether this difference accounts, on the one hand, for the increased severity of periodontal disease and on the other for the poorer glycaemic control seen in diabetics.

A comparison of Er:YAG laser and mechanical debridement for the non-surgical treatment of chronic periodontitis: A randomized, prospective clinical study

AIMS To compare a monotherapy of Er:YAG laser debridement (ERL), wavelength 2940 nm, with mechanical scaling and root planing (SRP) for the treatment of chronic periodontitis using clinical and patient-centred outcomes. METHODS Twenty-eight participants had two randomly assigned quadrants treated with ERL and two with SRP. Full-mouth plaque index, probing depth, bleeding on probing, clinical attachment level and gingival recession were recorded at baseline and 6- and 12-weeks post therapy. A questionnaire was used to assess pain, discomfort and satisfaction during and after treatment. RESULTS Twenty-two participants completed treatment and had 6- and 12-week clinical re-evaluations. SRP provided greater mean pocket depth reduction at 6- and 12-weeks (p = 0.01 and p = 0.003 respectively), and a greater reduction in pockets ≥ 4 mm at 6 weeks only (p = 0.03) compared with ERL. SRP also resulted in a significant reduction in bleeding on probing (BOP) sites at 12 weeks compared with ERL and a statistically significant greater reduction in mean clinical attachment level (CAL) at 6- (p = 0.02) and 12-weeks (p = 0.03). Patients expressed greater satisfaction with SRP on the day of treatment but were equally satisfied subsequently. CONCLUSION SRP resulted in a statistically significant greater short-term improvement in clinical parameters and patient satisfaction compared with ERL.

The use of laser therapy for dental implant surface decontamination: a narrative review of in vitro studies.

The aim of this narrative review was to critically evaluate in vitro studies assessing the efficacy of lasers in the bacterial decontamination of titanium implant surfaces. The MEDLINE, Web of Knowledge and Embase electronic databases were used to search for articles relating to the use of lasers in the bacterial decontamination of titanium specimen surfaces using predetermined search statements. Clinical studies, case reports, case series, review articles and animal models were excluded. Study selection was carried out independently and then cross-checked by two authors through abstract viewing. Eighteen articles were selected for full-text analysis. Erbium-doped yttrium–aluminium–garnet lasers had a wide range of powers capable of inducing bacterial decontamination. While carbon dioxide and gallium–aluminium–arsenide diode lasers demonstrated the ability to produce bacterial decontamination, the bacterial sensitivity to each varied depending on the species involved. There is no concensus on the laser type or settings that are optimal for bacterial decontamination of titanium implant surfaces as studies employ various test specimens, contamination methodologies, irradiation settings and protocols, and outcome measures resulting in limited study comparability. More investigations are required to provide guidelines for the use of laser therapy in the decontamination of implant surfaces.

Evaluating the efficiency of caries removal using an Er:YAG laser driven by fluorescence feedback control

INTRODUCTION Caries lesions in dental hard tissues autofluoresce when exposed to light of certain wavelengths, whereas sound tissues do not, and this can be used as an in vitro histological marker for dental caries. Detection of autofluorescence is the basis of KaVo DIAGNOdent™ technology, and provides objective feedback control of laser-stimulated ablation of dental caries for the KaVo Key Laser 3™. This Er:YAG laser operates at 2940nm wavelength, and is effective at removal of infected dental hard tissues. Micro-computed tomography (micro-CT) allows the non-invasive investigation of three-dimensional structures and analysis of mineral density profiles of dentine following laser ablation. OBJECTIVE To evaluate removal of infected, demineralised dentine by Er:YAG irradiation with a laser feedback mechanism, using micro-CT. DESIGN 27 carious teeth (1 control) and 1 sound tooth, treated with the KaVo Key Laser 3™ using a KaVo™ non-contact 2060 handpiece at specific feedback settings, were examined using a Skyscan 1172 Micro-CT, to observe the efficiency of demineralised dentine removal. Grey scale images obtained were colour rendered to assist detection of demineralised tissue if present. RESULTS Complete removal of demineralised tissue occurred with laser-stimulated ablation under feedback control at values of 7 and 8 when measured by micro-CT. At greater values, removal of demineralised dentine was incomplete. CONCLUSION Examination of dental tissues by micro-CT allowed determination of the efficiency of Er:YAG laser-stimulated ablation. Feedback control of the KaVo Key Laser 3™ appeared to operate like a cut-off switch when infected dentine was eliminated, at a threshold of between 6 and 7.

Periodontopathogen levels following the use of an Er:YAG laser in the treatment of chronic periodontitis

BACKGROUND Inflammatory periodontal diseases are initiated by microbial biofilms. The reduction of the biofilm is important in the management of the disease. This study compares periodontopathogen levels following the treatment of chronic periodontitis using Er:YAG laser (ERL) debridement and mechanical scaling and root planing (SRP). METHODS Using a split-mouth design, two quadrants were randomly allocated for treatment. Two hundred and fifty-two subgingival plaque samples were collected from 21 patients, before treatment (baseline) and at 6 and 12 weeks post-therapy. Multiplex qPCR was used to determine relative levels of Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythensis (Tf), and Aggregatibacter actinomycetemcomitans (Aa). RESULTS Tf and Pg were significantly reduced post-treatment for both ERL and SRP. ERL treatment resulted in a reduction of Td at 12 weeks. Following SRP treatment Aa was significantly reduced at 12 weeks. No statistically significant difference was seen when treatments were compared at 6 and 12 weeks. CONCLUSIONS A comparable reduction in the level of the four periodontal pathogens assayed was achieved with Er:YAG laser debridement and mechanical scaling and root planing.

Quantifying the Association Between Self-Reported Diabetes and Periodontitis in the New Zealand Population

BACKGROUND This study aims to investigate the association between diabetes and periodontitis in the New Zealand (NZ) adult population. METHODS Data from two NZ national surveys (N = 2,048) were analyzed to compare estimates of the strength of the association between diabetes and periodontitis using two multivariate epidemiologic approaches (cohort and matched case-control studies). This was possible because the first survey provided participants for the second survey. Periodontitis cases were identified using 14 case definitions, including six severe definitions. The cohort study identified those with diabetes in 2006/07 and those with periodontitis in 2009 to determine the patients with diabetes odds of having periodontitis, using logistic regression modeling (adjusting for smoking status, sociodemographic, and dental characteristics). The matched case-control study identified cases of severe periodontitis in 2009 and compared their 2006/07 diabetic status with that of controls (individually matched on age group, sex, and socioeconomic status). Conditional logistic regression modeling was used for the case-control study, adjusting for ethnicity, smoking status, and dental characteristics. RESULTS Overall, 3.6% of the periodontally examined adults reported having diabetes. There was no sex difference in diabetes prevalence, but it was greater in older age groups. Depending on the definition of periodontitis used, there were different estimates of risk for periodontitis, with odds ratios ranging from 1.91 (P = 0.01) to 3.51 (P = 0.22) using the cohort study approach. Diabetes was associated with a greater risk of having periodontitis using only two of the 14 periodontitis case definitions. No association was observed using the matched case-control study. CONCLUSIONS The diabetes-periodontitis association in the NZ population remains unclear. This study demonstrates that the determination of the strength of a putative association is method dependent.

Chronic periodontitis and implant dentistry

Dental implants are regularly placed in patients with a history of periodontitis, even though peri-implant tissues are susceptible to the same host-modulated plaque-induced factors that initiate and sustain periodontitis. This article endeavors to clarify the evidence regarding the history of periodontitis as a risk factor for implant success and survival, and the role of supportive periodontal therapy in maintaining implants for individuals with a history of periodontitis.

Periodontitis among adult populations in the Arab World

BACKGROUND The Arab World consists of 22 countries from North and North-east Africa and the Middle East. Periodontal disease is an important global oral health burden, and is highly prevalent in developing countries. OBJECTIVES The objective of this narrative review is to report on the recorded prevalence of periodontitis in the Arab World, and to examine the methods used in collecting the data. DATA AND SOURCES A search of the literature was performed using the PubMed database up to September 2011 to identify articles that reported on the prevalence of periodontal disease in the 22 Arab countries. Reports kept in the World Health Organization (WHO) Global Health Data bank were also used in this review. CONCLUSION There is a paucity of up-to-date data regarding the prevalence of periodontitis in the Arab adult population. Most relevant data are at least 10 years old. From the literature available, it is clear that there is a need for epidemiological data that are representative of the adult population from this region. Such data will enable proper development of guidelines, allocation of resources and the development of appropriate public health programmes.