Herpes Zoster (Shingles)

This patient had an apicoectomy on #4. Six days later while traveling out of town, he began to have severe pain and lesions form on his face. He came to our office for evaluation of the surgical area. As you can see, he experienced the classic outbreak of herpes zoster (shingles).

For a brief review, after initial infection with the VZV (chickenpox), the virus goes into a dormant state in the dorsal spinal ganglia. The re-activation of this virus causes herpes zoster. The reactivated virus will become apparent in the distribution of the affected sensory nerve. Zoster occurs in 10-20% of individuals, and increases with age.
As opposed to the herpes simplex virus (HSV), single recurrences are generally the rule.
Predisposing factors for reactivation of the virus include, immunosuppresion, treatement with cytotoxic drugs, radiation, malignancy, age, alcohol abuse & dental manipulation.


Clinical features begin with pain in the epithelium of the affected sensory nerve (dermatome). Typically one dermatome is affected. Prodromal pain often accompanied by fever, malaise and headache is usually present for 1 to 4 days before the outbreak of the cutaneous or oral lesions.
Involved skin will exhibit a cluster of vesicles on an erythematous base. After 3 to 4 days, the vesicles become pustular & ulcerate. Crusting develops after 7 to 10 days. The exanthem usually resolves within 2 to 3 weeks. Scarring can occur.
Pain lasting longer than 1 month following a shingles outbreak is known as postherpetic neuralgia. Most of these will resolve within a year.

Treatment for herpes zoster is mostly supportive and symptomatic. Fever should be treated with antipyretics without aspirin. Lesions should be kept dry and clean to prevent secondary infection. Topical or systemic antipruritics can be given to decrease itching. Corticosteriods have been used to minimize associated neuralgia. High dose acyclovir can decrease duration of the exanthem and severity of pain.


In this case, special consideration was given to the involvement of the eye. Proper referral to medical and dental specialists is important to prevent permanant damage to affected areas such as the eye.

Photographs used with patient's written permission.
(Source: Neville, Damm, Allen & Bouquot. Oral & Maxillofacial Pathology, 188-191, 1995)

Research Update: Direct Pulp Capping with MTA

A recent study published in the Journal of the American Dental Association discusses the use of MTA (Mineral Trioxide Aggregate) as a direct pulp capping agent.

Up to now, MTA has been used mainly by specialists, mostly endodontists, as a restorative material for root end fillings (apico retrofills) and root perforation repair. However, new applications for MTA may put it in the hands of a wider variety of practicioners.



MTA is a bioactive silicate cement. It is essentially a medical grade portland cement. There are several properties of MTA that make it such an ideal material. It has small particle size, alkaline pH when set and slow release of calcium ions. It is known for its sealing ability. It has also been reported to induce cell proliferation, cytokine release, hard tissue formation and an interface with dentin resembling hydroxyapatite. It is non-absorbable and requires moisture to set. In short, its sealing ability, biocompatibility & hydrophilic nature make it an excellent repair material.

Endodontists have been using MTA for pulp capping, apexification/apexogenesis for all of the properties described above. The recent article by Bogen, Kim & Bakland provide evidence that supports the use of MTA as a direct pulp capping agent.

The authors selected 53 teeth that had deep caries with vital pulpal tissue and no prior restorations. Caries were removed under magnification and NaOCl was used to obtain hemostasis within a short period of time (1 to 10 min.). 1.5-3.0mm thick layer of MTA was placed over the exposure. The teeth were restored provisionally with unbonded resin restoration. At a subsequent visit, the teeth were restored with a bonded restoration.

Over a 9 year period of observation, the authors found that 49 of 53 had a favorable outcome on the basis of radiographic appearance, subjective symptoms & cold testing. All teeth (15 of 15) in younger patients with open apices showed completed root formation (apexogenesis).

Many are reluctant to perform direct pulp capping procedures due to unpredictable outcomes with traditional materials. MTA may be a more predictable and successful material for direct pulp capping teeth with a pulpal condition no more severe than reversible pulpitis.

(Source: Bogen, George, Kim, Jay, Bakland, Leif. "Direct Pulp Capping with Mineral Trioxide Aggregate", JADA 2008, 139:3, p 305-315.)

Fantastic Endodontic Healing

This tooth #30 was diagnosed with a necrotic pulp with chronic apical abscess. Large periapical lesion noted, 4mm pocketing, class II mobility with large subgingival/subcoronal repair. Proper diagnosis indicated that this lesion is a true endodontic lesion. Therefore, endodontic therapy should yield good results.

Endodontic treatment completed.

3 year recall illustrates complete endodontic healing.  The tooth is completely asymptomatic and functional. A new coronal restoration to include the previous repair done on the distal is recommended to prevent coronal leakage.

Golden Rules for NiTi Rotary Preparation

The introduction of nickel-titanium rotary instruments has changed the way most people practice endodontics. The use of rotary instrumentation allows an experienced practicioner to do consistent, reproducible shaping procedures on his/her patients.

As part of the AAE Colleagues for Excellence program, which produces a biannual clinical newsletter for all practicing general dentists, "Rotary Instrumentation: An Endodontic Perspective" reviews the basics of NiTi instrumentation design, prevention of fracture & clinical tips for use of rotary instrumentation.

There are over 30 different NiTi instrument systems on the market. The two main factors to consider when selecting a NiTi system are cross sectional design and tip configuration.

The biggest challenge with using rotary instrumentation is fracture of the NiTi instrument. Understanding the metallurigical properties of NiTi rotary files and some clinical "Golden Rules" are critical for success with rotary instrumentation.

The "Golden Rules" for NiTi rotary preparation are as follow:

1. Assess Case Difficulty
2. Provide Adequate Access
3. Prepare with hand files up to size #20 prior to rotary use
4. Use light touch and low RPM
5. Proceed with crown-down sequence
6. Replace rotary instruments frequently

Separated instruments can be a source of stress that can be reduced or eliminated from your practice. If you have not received the latest "Collegues for Excellence" publication from the AAE, contact your local endodontist or the AAE to get a copy.

Endodontic Retreatment or Implant?

This patient is wondering if she would be better off having tooth #10 extracted and an implant placed.

This is her situation. She had this silver point root canal done back in the 70's. A new crown was placed about a month ago and then the crown broke off. She came to my office for an evaluation. I recommended that we retreat the root canal, and place a new post for retention of the build-up/crown.

Since the crown broke off the remaining tooth structure supporting it, the ideal situation would be to make a new crown and improve the ferrrule effect.

I explained to her that as long as the tooth is not fractured, the retention of the natural tooth will actually help maintain the bone in the esthetic zone and give her the most natural appearance.

The silver point root canal is almost 40 years old. There is no sign of failure of the endodontics. This is actually a restorative failure. Any disturbance of the silver point can jeopardize it's seal. In retrospect, it would have been best to have retreated the RCT and placed a new post and core prior to the new crown.

Research Update: Use of Articaine for Buccal Infiltration of Mandibular Molars

The inferior alveolar nerve block (IANB) is the most commonly used technique for pulpal anesthesia in the mandible, especially the mandibular molars. Due to the dense cortical bone of the mandible, buccal infiltration techniques have been known to be less successful.

However, the IANB has challenges of its own. Passing through layers of soft tissue and muscle and depositing the anesthetic in adjacent to the mandibular foramen can be very difficult. Anatomical variation among patients, including the course of the nerve, location of the mandibular foramen, accessory nerves also innervating the area can all make consistancy with this technique challenging.

If the block is unsuccessful, then the practitioner has typically repeats the block or trys another technique. The most common alternative techniques are: closed mouth block (Vazirani/Akinosi), Gow-Gates Block, intraligamentary injection, intrapulpal injection, or intraosseous injection.

Manibular buccal infiltration has traditionally not been considered as an option due to the inability for the anesthetic to diffuse through the thick cortical plate. Kanaa et al. reported that a mandibular buccal infiltration is more effective with 4% articaine with 1:100,000 epinephrine than with the traditional 2% lidocaine.

A recent study by Il-Young Jung et. al. compared the efficacy of IANB with that of buccal infiltrations in mandibular first molars.

Using 4% articaine subjects were given IANB and BI on separate appointments. Pulpal anesthesia was determined using an electric pulp tester. 54% of BI were successful and 43% of IANB were successful. (the difference was not significant p=0.34) The onset of pulpal anesthesia was significantly faster with BI (p=0.03). This study concluded that BI with 4% articaine for mandibular first molars can be a useful alternative to IANB due to it's faster onset and similar success rate.

Having difficulty with anesthetizing mandibular molars? Try using some 4% articaine in a buccal infiltration.

Sources:

Kanaa MD, Whitworth, JM, Corbett, IP, Meechan JG. Articaine and lidocaine mandibular buccal infiltration anesthesia: a prospective randomized double blind cross-over study. JOE 2006:32:919-23.

Jung, Il-Young, Kim, Jun-Hyung, Kim, Eui-Seong, Lee, Han-Young, Lee, Seung Jong. An evaluation of buccal infiltrations and inferior alveolar nerve blocks in pulpal anesthesia for mandibular first molars. JOE 2008:34:11-13.

Rotary & Warm Vertical Obturation

This video clip shows my non-surgical RCT technique on an extracted bicuspid.

Specific instruments I like to use:
1. Endo Z bur (long shank, non-end cutting bur to create direct line access)
2. Hand files #10 & #15 to open canals and create a path
3. Gates Glidden drills #2, #3, #4 to open the coronal third of the canal system (inexpensive, easy to remove if separation occurs)
4. #15 hand file for length determination (using Root ZX or radiographs)
5. .06 tapered, ISO sized NiTi Rotary files
6. .06 tapered gutta percha, gauged to ISO size at tip using a gutta gauge
7. System B heat carrier
8. Obtura for gutta percha backfill

Rhodium Coated Mirrors

Mirrors used for intraoral photography are not all the same. There are several kinds of mirrors. Standard metal mirrors reflect 55-60% of light. Chromium coated mirrors reflect 65-70% of light and rhodium coated mirrors reflect 75% of light. The manufacturer of the mirror that I use claims that this mirror reflects 99.5% visible light. This increased light reflection is also due to the flatness of the mirror. I usually use a standard mirror, but when want a good photograph, I'll pull out a rhodium coated mirror.

Here is a standard mirror.

This is the exact same photograph using a rhodium plated mirror.

When taking intraoral photographs, the quality of the mirror can make a big difference in the quality of your images.

Pulpal & Periapical Diagnosis

As previously described, endodontic diagnosis is composed of two parts.

A pulpal diagnosis, which indicates the status of the pulpal (nerve & connective tissue inside the tooth), and a periapical diagnosis, which indicates the status of the periapex (tissue around the end of the root).

Pulpal Diagnosis can be accomplished using cold, heat or electric stimulus. Cold testing is the most reliable. Endo Ice is the most convenient, and easy to use product for thermal testing.

The following flowchart will help you with your pulpal diagnosis.



As previously discussed, the new diagnostic terminology defined by the American Board of Endodontics simplifies the periapical diagnosis based upon pain and swelling. The following flowchart can be useful in helping to understand the diagnostic terminology.

New Endodontic Diagnosis Terminology

Endodontic diagnosis can be very confusing. Much of this confusion comes from differences in diagnostic terminology. The diagnostic terminology used from school to school is different. Even endodontic textbooks fail to create a systematic approach to endodontic terminology. The American Board of (ABE), the organization which oversees the board certification of endodontists, even allows for board candidates to describe the terminology they will be using during their board certification process.

Endodontic diagnostic terminology is based on clinical signs & symptoms, radiographic appearance & presence or lack of swelling or drainage. It is easily understood how confusing this can be with so many variables.

In an effort to simplify and unify the endodontic diagnostic terminology, the ABE has recently published a list of pulpal and periapical diagnostic terminology. In our practice we have adopted this terminology and will be using it in our daily practice of endodontics. We will also begin using this terminology in our cases presented in the blog. The following is the new terminology recommended by the ABE.

A complete endodontic diagnosis is made up of two parts:
1. Pulpal diagnosis
2. Periapical diagnosis


PULPAL DIAGNOSIS
Normal pulp – A clinical diagnostic category in which the pulp is symptom free and normally responsive to vitality testing.

Reversible pulpitis – A clinical diagnosis based upon subjective and objective findings indicating that the inflammation should resolve and the pulp return to normal.

Irreversible pulpitis – A clinical diagnosis based on subjective and objective findings indicating that the vital inflamed pulp is incapable of healing.

Additional descriptions:
Symptomatic – Lingering thermal pain, spontaneous pain, referred pain
Asymptomatic – No clinical symptoms but inflammation produced by caries,
caries excavation, trauma, etc.

Pulp necrosis – A clinical diagnostic category indicating death of the dental pulp. The pulp is non-responsive to vitality testing.

Previously Treated – A clinical diagnostic category indicating that the tooth has been endodontically treated and the canals are obturated with various filling materials, other that intracanal medicaments.

Previously Initiated Therapy – A clinical diagnostic category indicating that the tooth has been previously treated by partial endodontic therapy (e.g. pulpotomy, pulpectomy).




PERIAPICAL DIAGNOSIS

Normal apical tissues – Teeth with normal periradicular tissues that will not be abnormally sensitive to percussion or palpation testing. The lamina dura surrounding the root is intact and the periodontal ligament space is uniform.

Symptomatic apical periodontitis – Inflammation, usually of the apical periodontium, producing clinical symptoms including painful response to biting and percussion. It may or may not be associated with an apical radiolucent area. (This category includes what many of us call Acute Apical Periodontitis & Phoenix Abscess)

Asymptomatic apical periodontitis – Inflammation and destruction of apical periodontium that is of pulpal origin, appears as an apical radiolucent area and does not produce clinical symptoms. (This is what many of us have previously called a Chronic Apical Periodontitis)

Acute apical abscess – An inflammatory reaction to pulpal infection and necrosis characterized by rapid onset, spontaneous pain, tenderness of the tooth to pressure, pus formation and swelling of associated tissues.

Chronic apical abscess – An inflammatory reaction to pulpal infection and necrosis characterized by gradual onset, little or no discomfort and the intermittent discharge of pus through an associated sinus tract.


You can see that the pulpal diagnostic terminology has not changed. The periapical terminology is where are the confusion was and that is what they have tried to simplify. If you look closely at the definitions, you will see that the radiographic signs are not part of the periapical definition anymore. That is the reason that a Acute Apical Periodontitis & Phoenix Abscess are now both called a Symptomatic Apcial Periodontitis. Is your head spinning yet? Go back to the top and read it again. We'll have more on diagnosis to help you apply these definitions in your practice.

(Source: www.aae.org/certboard)