Dental Water irrigation devices

# Water irrigation devices (oral irrigators) have been shown to:
A. Eliminate plaque
B. Clean nonadherent bacteria and debris from the oral cavity more effectively than toothbrushes and mouth rinses.
C. Disinfect pockets for up to 12 hours
D. Prevent calculus formation

The correct answer is B. Clean nonadherent bacteria and debris from the oral cavity more effectively than toothbrushes and mouth rinses.

Oral irrigators for daily home use by patients work by directing a high-pressure, steady or pulsating stream of water through a nozzle to the tooth surfaces. Most often, a device with a built-in pump generates the pressure. Oral irrigators clean nonadherent bacteria and debris from the oral cavity more effectively than toothbrushes and mouth rinses.

When used as adjuncts to toothbrushing, these devices can have a beneficial effect on periodontal

health by reducing the accumulation of plaque and calculus and decreasing inflammation and pocket depth.

Oral irrigation has been shown to disrupt and detoxify subgingival plaque and can be useful in delivering antimicrobial agents into periodontal pockets. Note: Daily supragingival irrigation with a dilute antiseptic, chlorhexidine, for 6 months resulted in significant reductions in bleeding and gingivitis compared with water irrigation and ch1orhexidine rinse controls. Irrigation with water alone also reduced gingivitis significantly, but not as much as the dilute chlorhexidine.

Important: Oral irrigators may be contraindicated in patients requiring antibiotic premedication

prior to dental treatment since these devices have the potential for causing bacteremia. The patient's physician should be consulted.

Remember: The pathology associated with gingivitis is completely reversible with the

removal of plaque and the resolution of the inflammation.

In implantology, countersinking means:

# In implantology, "countersinking" refers to the process of:
A. Flaring or enlarging the coronal end of the osteotomy
B. Reversing the engine to remove the implant
C. Placing the implant in a counterclockwise rotation
D. Torquing the abutment to place

The correct answer is A. Flaring or enlarging the coronal end of the osteotomy.

As one of the final steps in the creation of the osteotomy to receive the implant body, a special bur is activated and inserted into the occlusal end of the osteotomy in order to increase the diameter of the opening slightly or to otherwise shape it. This step is referred to as "countersinking." Countersinking the implant osteotomy is called for by some manufacturers to compensate for very dense cortical bone or to prepare the bone for a particular implant shape (e.g., a flared implant shape at the coronal end).

Another of the final steps in the creation of the osteotomy is to place a threaded bur into the osteotomy so as to create a spiral groove on the wall of the osteotomy. This groove is placed so as to receive and guide the threads on the side of the implant during surgical placement and thus minimize the torque required and to minimize heat. This process of creating the groove on the inside of the osteotomy wall is referred to as "tapping" the osteotomy.

All of the burs used to create the osteotomy are used at relatively slow speeds (r.p.m.) to prevent injury to the bone, especially overheating of the bone. Also, water or saline irrigation is used to cool the burs and the bone during drilling.

Most common periodontal diagnosis in adults

# Which of the following periodontal
diagnoses is MOST COMMON in adults?
A. Localized aggressive periodontitis
B. Gingival hyperplasia
C. Generalized chronic periodontitis
D. Necrotizing ulcerative gingivitis
E. Plaque associated gingivitis

The correct answer is E. Plaque associated gingivitis.

Plaque associated gingivitis (marginal
gingivitis) is the MOST COMMON
periodontal diagnosis.

Prolonged exposure to plaque creates an
inflammatory response in the gingiva,
causing mild gingivitis.

Gingival overgrowth can be experienced
when taking:
- Calcium channel blockers
- Phenytoin
- Dilantin
- Cyclosporine

Localized aggressive periodontitis is MOST
COMMONLY seen younger patients and is
associated with Aggregatibacter
actinomycetemcomitans.

Management of a tooth with internal resorption

# Which of the following is the BEST method for managing a tooth with internal resorption?
A. Pulpectomy and root canal therapy
B. Extraction
C. Svek pulpotomy
D. Pulpotomy with calcium hydroxide

The correct answer is A. Pulpectomy and root canal therapy.

Internal resorption in a tooth requires complete pulp removal followed by a root canal procedure.

Pulpotomy does not completely remove the pulp,  so the internal resorption will persist and probably progress if the pulp is not completely removed.

Grossly decayed mandibular molar removal

# While attempting to remove a grossly decayed mandibular molar, the crown fractures. What is the recommended next step in order to facilitate the removal of this tooth?
A. Use a larger forceps and luxate remaining portion of tooth to the lingual
B.  Separate the roots
C.  Irrigate the area and proceed to remove the rest of the tooth
D. Place a sedative filling and reschedule patient

The correct answer is B. Separate the roots.

This can be done with a chisel, elevator, or most easily with a bur.

Teeth with two or more roots often need to be sectioned into single entities prior to successful removal.

A popular method of sectioning is to make a bur cut between the roots, followed by inserting

an elevator in the slot and turning it 90° to cause a break.

Roots can be removed by closed technique. The surgeon should begin a surgical removal if the

closed technique is not immediately successful.

Indications for surgical extractions:

• After initial attempts at forceps extraction have failed

• Patients with dense bone

• In older patients, due to less elastic bone

• Short clinical crowns with severe attrition (bruxers)

• Hypercementosis or widely divergent roots

• Extensive decay which has destroyed most of the crown

Root most often dislodged into maxillary sinus

# The root of which tooth is most often dislodged into the maxillary sinus during an extraction procedure?
A. Palatal root of the maxillary first premolar
B. Palatal root of the maxillary first molar
C. Palatal root of the maxillary second molar
D. Palatal root of the maxillary third molar

The correct answer is B. Palatal root of the maxillary first molar.

If an entire tooth or a large fragment of one is displaced into the sinus, it should be removed. If the tooth fragment is irretrievable through the socket, it should be

retrieved through a Caldwell-Luc approach ASAP. However, this should be performed only if the dental surgeon is well versed with the procedure, else, the patient should be referred to an oral and maxillofacial surgeon.

If a small communication is made with the maxillary sinus during extraction of a tooth, the best treatment is leave it alone and allow the blood clot to form.

Post-operative instructions to patient:

• Avoid nose blowing for 7 days

• Open mouth when sneezing

• Avoid vigorous rinsing

• Soft diet for 3 days

If a sinus communication should occur the following medications may be prescribed for one week:

1. local (nasal) decongestant

2. Antibiotics (Amoxicillin)

3. systemic decongestant

1. If the opening is of moderate size (2-6 mm), a figure of eight suture should be placed over the tooth socket.

2. If the opening is large (7 mm or larger), the opening should be closed with a flap procedure.

The integrity of the floor of the maxillary sinus is at greatest risk with surgery involving the removal of a single remaining maxillary molar. The fear here is possible ankylosis.

Ideal time to remove impacted third molars:

# The ideal time to remove impacted third molars is:
A. When the root is fully formed
B. When the root is approximately two-thirds formed
C. Makes no difference how much of the root is formed
D. When the root is approximately one-third formed

The correct answer is B. When the root is approximately two thirds formed.

• Patient would be around the age of 17-21.
• At this time, the bone is more flexible and the roots are not formed well enough to have developed curves and rarely fracture during extraction.
• When the root is fully formed, the possibility increases for abnormal root morphology and for fracture of the root tips during extraction.