Category Archives: Evidence

It’s all about the Image

Conventional x-rays were responsible for 5% of the total effective radiation dose in the US population during 2006. Dental x-rays contributed 2.5% of this figure.

In comparison, background radiation was responsible for 50% of the total effective radiation dose.

Source: NCRP Report No. 160, Ionizing Radiation Exposure of the Population of the United States



The estimated incidence of suffering from a true allergic reaction to local anesthetic in the dental surgery is 1 in 22 million*.

In comparative terms, you have a better chance of being canonized (1 in 20 million),^

or of dying in a Grand Canyon flash flood (1 in 14,270,000)…



*Severe adverse reactions to dental local anaesthetics: systemic reactions.

Sambrook PJ, Smith W, Elijah J, Goss AN.

Aust Dent J. 2011 Jun;56(2):148-53

^20 things more likely to happen than winning the Mega Millions lottery

By , Deseret News

Published: Wednesday, Nov. 28 2012 4:33 p.m. MST

#The Book of Odds: From Lightning Strikes to Love at First Sight, the Odds of Everyday Life Paperback


Oral Cancer

The Facts

  • Oral cancer is the 8th most common cancer worldwide.
  • Approximately 90% of oral cancer cases are caused by tobacco use and excessive alcohol intake.
  • Exposure of the lips to ultraviolet (UV) radiation for lengthy periods is an added risk factor for lip cancer.
  • Oral cancer survival rates for 3 and 5 years have improved with newer treatment approaches but are still considered unsatisfactory in late stage disease.


The treatment of oral cancer: an overview for dental professionals.

Deng H, Sambrook PJ, Logan RM.

Aust Dent J. 2011 Sep;56(3):244-52, 341. doi: 10.1111/j.1834-7819.2011.01349.x. Review.


Strengthening the prevention of oral cancer: the WHO perspective.

Petersen PE.

Community Dent Oral Epidemiol. 2005 Dec;33(6):397-9.

Vitamin Value

It is probable that Vitamin D supplementation reduces the risk of tooth decay in children….


Source: Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials

Authors: Evropi Theodoratou, Ioanna Tzoulaki, Lina Zgaga, John P A Ioannidis

BMJ 2014; 348 doi: (Published 1 April 2014)



Mercury Rising

Do mercury containing fillings cause Multiple Sclerosis?

Well, according to a systematic review of the available evidence, there is no significant link between the two.

Further research is required.

Source: Dental amalgam and multiple sclerosis: a systematic review and meta-analysis.

Aminzadeh KK, Etminan M.

J Public Health Dent. 2007 Winter;67(1):64-6. Review.

how the humble toothbrush saved a life

Sergeant Tisdale’s life was saved by his toothbrush. More about him later…

Much has been made in recent years of the relationship between gum health and cardiovascular disease, and in particular, whether the former is a cause of the latter.  Consequently, it is possible that some of us may have been warned by well-meaning health professionals to brush our teeth and gums, in order to prevent a heart attack, stroke and various other related events, or even death…

However, let’s examine the association objectively:

  • Both conditions share many risk factors such as smoking, obesity, diabetes, ageing, race/ethnicity, socioeconomic status, alcohol abuse, education and male gender. Therefore, it is possible that their true relationship can be clouded by such confounders. While observational studies have demonstrated an independent association between the two despite such variables, this evidence is insufficient to warrant causality. In addition, the strength of the relationship has been shown to be moderate at best.


  • Plausible mechanisms whereby gum disease or its causative bacteria can directly or indirectly produce/induce an adverse effect on the cardiovascular system e.g. via generalised inflammation, bacterial invasion of the bloodstream and consequent infection of blood vessel walls, or formation of plaque deposits on blood vessel walls, have been tested showing mixed results.



  • Treating gum disease using different methods can improve, at least in the short term, generalised inflammation, the function of cells lining blood vessel walls, and some, but not all, markers of cardiovascular disease.  It has not been shown to prevent or modify cardiovascular disease.

In view of the above, we remain uncertain as to whether gum disease is an independent risk factor for cardiovascular disease, and as they say, more quality research is needed.

Back to Sergeant Tisdale, of the South Lancashires, who took his toothbrush with him on going to war.  In a letter penned by the soldier from the front, he told of how a bullet to his heart was deflected by the toothbrush he was carrying, therefore saving his life.


*The Gundagai times and Tumut, Adelong and Murrumbidgee district advertiser, Friday 11 June 1915

# Lockhart PB, Bolger AF, Papapanou PN, Osinbowale O, Trevisan M, Levison ME,

Taubert KA, Newburger JW, Gornik HL, Gewitz MH, Wilson WR, Smith SC Jr, Baddour

LM; American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki

Disease Committee of the Council on Cardiovascular Disease in the Young, Council

on Epidemiology and Prevention, Council on Peripheral Vascular Disease, and

Council on Clinical Cardiology. Periodontal disease and atherosclerotic vascular

disease: does the evidence support an independent association?: a scientific

statement from the American Heart Association. Circulation. 2012 May

22;125(20):2520-44. doi: 10.1161/CIR.0b013e31825719f3. Epub 2012 Apr 18. PubMed

PMID: 22514251.