Miswaak.

Siwaak [Miswaak] is a natural toothbrush, made from a piece of the fibrous root of the Araak tree, which grows around the Arabian Peninsula. You can buy a Miswaak stick in any good Islamic store. The outer bark will need to be stripped away from the tip of the stick, then the fibrous inner root can be gently chewed until it separates out into a brush. When the brush-end gets worn away, more bark can be removed and the process starts again.

It is narrated in two instances of correct prophetic traditions that God’s Messenger (sallallahu alayhi wasallam) said, “If I did not think that it would be difficult for my followers, I would have ordered them to brush their teeth with a Miswaak before each prayer.” 

Sahih Al Bukhari Volume 2, Book 13, Number 12

And also;

'Abdur-Rahman bin Abu 'Atiq (radhi Allahu anhu) narrated; "My father told me: 'I heard 'A'ishah (radhi Allahu anha) say, (narrating) from the Prophet (sallallahu alayhi wasallam): "Siwak is a means of purification for the mouth and is pleasing to the Lord."

Classed as Sahih in Sunan An Nasa'i Vol. 1, Book 1, Hadith 5

Ibn al Qayyim (rahimullah) said that the preferred type of Miswaak is from the Aloeswood tree because it tastes better and is more fragrant, and it’s better to let it soak a while in rose water before brushing.

God’s Messenger (sallallahu alayhi wasallam) also used to brush his teeth with it before retiring to bed and he (sallallahu alayhi wasallam) was also particularly ceremonial about cleaning his teeth with a Miswaak before taking his ablution for prayers, upon waking up for the supererogatory night prayers (Tahajjud or Qiyyaam ul Layl), before the Faj’r prayer and also upon entering home from being out.

Hudhaifa (radhi Allahu anhu) narrated that "Whenever the Prophet got up at night [for the Tahajjud Prayer], he used to clean his mouth with Siwaak."

Sahih Al Bukhari Volume 1, Book 4, Number 246 and also Volume 2, Book 21, Number 237

Such was the love of Siwaak to Rasool'Allah (sallallahu alayhi wasallam) that it was one of the very last acts he carried out in the throes of death just before he passed away;

Our Mother A'ishah (radhi Allahu anha) narrated; "It was one of the favors of Allah towards me that Allah's Apostle (sallallahu alayhi wasallam) expired in my house on the day of my turn while he was leaning against my chest and Allah made my saliva mix with his saliva at his death. 'Abdur-Rahman entered upon me with a siwak in his hand and I was supporting (the back of) Allah's Apostle (against my chest). I saw the Prophet looking at it (i.e. siwak) and I knew that he loved the siwak, so I said (to him), "Shall I take it for you?" He nodded in agreement. So I took it and it was too stiff for him to use, so I said, "Shall I soften it for you?" He nodded his approval. So I softened it and he cleaned his teeth with it. In front of him there was a jug or a tin, (The sub-narrator, 'Umar is in doubt as to which was right) containing water. He started dipping his hand in the water and rubbing his face with it, he said, "None has the right to be worshipped except Allah. Death has its agonies." He then lifted his hands (towards the sky) and started saying, "With the highest companion," till he (sallallahu alayhi wasallam) expired and his hand dropped down.

Sahih Al Bukhari Volume 5, Book 59, Number 730

Brushing one’s teeth excessively and roughly with a toothbrush or a Miswaak can dull their polish, harm the enamel and make bad breath symptoms worse because bacteria can harbour in the microscopic pores on the surface of the teeth which are uncovered once the enamel has worn away.

Regular and moderate brushing of the teeth with a Miswaak preserves their polish, strengthens their roots, renders the speech more eloquent, prevents plaque build-up, clears the brain, sharpens the memory, freshens the mouth and generates a good appetite. 

The use of a Miswaak is also highly recommended during fasting as long as no toothpastes or powders are also used. Dentists also advocate brushing the tongue whenever you brush your teeth as it can sometimes harbour the bacteria that cause bad breath.

Miswaak Toothpaste.

There are a number of manufacturers which now sell toothpaste with Miswaak extract. Some people may prefer to use these products but they do not contain any significant amount of extract, neither have there been any studies to look at how using them compares with using the Siwaak stick.

Some of these products contain high amounts of artificial flavourings and sweeteners, as well as potentially dangerous amounts of Fluoride. Some brands of Miswaak Toothpaste have higher amounts of Fluoride in them than regular toothpastes. Danger Of Bone Cancer From Fluoride In Toothpaste, Drinking Water

Bad breath is not something that is solely down to poor oral hygiene, it could be the result of a deeper, underlying problem which should be checked out by your doctor.

Drinking acidic drinks and drinks with a high sugar content frequently, like juices and colas, can have the effect of fermenting bad bacteria in the gut (this can also lead to a sluggish digestive system and bloating), which in turn causes bad breath and thickened saliva. It’s better to get into the habit of replacing such drinks with mineral water with increasing frequency until you only enjoy them now and then.

It’s also important to avoid eating raw onions and garlic because the mouth odour they cause is offensive to the Angels. Onions and garlic should always be cooked before eating unless the raw prescription was made by a qualified tabeeb to treat a medical condition.