Perio Reports Vol. 25, No. 2 |
Perio Reports provides easy-to-read research summaries on topics of specific
interest to clinicians. Perio Reports research summaries will be included in each
issue to keep you on the cutting edge of dental hygiene science.
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Healing After Probing Implants - A Study in Dogs
Probing is an often-debated issue relating to implants.
Some clinicians say yes while others emphatically say no.
Researchers at the University of Berne in Berne, Switzerland,
evaluated the histology of the tissue/implant interface on
implants placed in foxhound dogs. A dog model has been
used for many years to learn about the tissue/tooth interface.
Evaluating the histology at the base of the sulcus over several
days requires sacrifice of the dogs and removal of the implant
and surrounding bone and soft tissue in a block section.
Mandibular premolar teeth were extracted from the
three test dogs. Three months later, ITO dental implants
were placed. The dogs received careful plaque control
regularly throughout the study period. After another three
months, the implants were osseointegrated and tissue
appeared healthy with little, if any, bleeding. Clinical
probing was performed on the mesial and distal sides of
each implant. Facial and lingual surfaces were evaluated as
unprobed controls. The probing was scheduled so that
when the dogs were sacrificed, the implants were one to
seven days after probing.
Probing caused separation between implant and epithelium,
but did not enter the connective tissue. By day one
after probing, a new epithelial attachment of 0.5mm was
evident. By day two, it measured 1.12mm, day three is was
1.52mm. By day five, the epithelial attachment was complete
at 1.92mm. Unprobed sites measured 1.69mm.
Clinical Implications: Based on this animal
study, probing implants appears to
be safe and any damage to the junction
of tissue-to-implant is completely healed
in five days
Etter, T., Hakanson, I, Lang, N., Trejo, P., Caffesse, R.: Healing after
Standardized Clinical Probing of the Pei-Implant Soft Tissue Seal: A
Histomorphometric Study in Dogs. Clin Oral Imp Res 13: 571-580, 2002.
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Excess Cement Significant Risk Factor for Peri-Implantitis
In the past it was common to attach a crown or bridge to
an implant with a screw, but problems with loosening,
occlusal adjustments and cost made cementation a preferred
choice. While the process is easier with cement, the risk of
leaving excess cement is significant. Cement residue provides
a retentive area for bacterial biofilm, leading to infection and
inflammation.
A periodontist in private practice in Dallas, Texas, evaluated
39 consecutive patients with peri-implantitis around 42
single implants. In these same patients, 20 similar singletooth
implants exhibited no clinical or radiographic signs of
infection. These implants constituted the control group.
A periodontal endoscope was used to evaluate both the
implant/crown margin and the adjacent tissue around diseased
and control implants. Light and magnification identified
cement with a characteristic white reflectance. Calculus
appears brown or yellow with the endoscope. Bacterial
biofilm appeared gray/blue in color and fluffy in nature.
After recording the areas of excess cement, either a periodontist
or dental hygienist used a hand instrument or power
scalers to remove the cement. In three cases, a surgical flap
was needed to accomplish complete removal.
Cement residue was found on 34 of the 42 infected
implants. None was found on the healthy controls. At one
month post-treatment, 33 of the 42 test implants were reevaluated
with the endoscope. Peri-implantitis was resolved
in 25 of the cases. No cause for continued infection in the
other eight implants was found.
Clinical implications: Care must be taken when implant restorations are cemented. At the first signs of peri-implantitis,
check for cement residue and remove it.
Wilson, T.: The Positive Relationship Between Excess Cement and Peri-Implant Disease: A prospective Clinical Endoscopic Study. J Perio 80:1388-1392, 2009.
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Hand Instruments Versus Power Scalers
on Implants
Overall, implants are successful, but in some cases, peri-implant infections do occur. Treatment focuses on reducing subgingival bacterial biofilm, with mechanical instrumentation, chlorhexidine on the curette tips and lasers. If non-surgical therapy doesn't work, a surgical flap procedure may be needed to gain sufficient access to remove biofilm and irritants.
Researchers at Kristianstad University in
Kristianstad, Sweden, compared two non-surgical
mechanical debridement methods in patients with
peri-implantitis. Each of the 31 subjects completing
the study had one, single-tooth implant with periimplantitis.
Any periodontitis on natural teeth in
the mouth was treated prior to treating the implant.
Clinical measurements for probing and bleeding
scores were measured using a plastic probe with a
standard pressure of 0.2 newtons. Plaque samples
were taken from subgingival areas for analysis.
Treatment instrumentation was with either
titanium curettes (17 subjects) or an ultrasonic
device (Vector System) with an implant tip (14
subjects). After the randomly assigned instrumentation,
all implants were polished with rubber cups
and polishing paste. Three in the curette group
and one in the ultrasonic group were smokers.
Average probing depths per implant varied from
2.8mm to 5.5mm.
Follow-up visits were at one week and one,
three and six months. No differences were evident
between treatment groups for bleeding, probing or
subgingival microflora. Bleeding scores reduced
insignificantly from 73 to 53 percent. Oral
hygiene improved slightly, but remained poor for
the entire study, despite repeated emphasis at each
visit. Perhaps new approaches to biofilm control
are needed.
Clinical Implications: Mechanical instrumentation
alone is not sufficient to manage periimplantitis.
Renvert, S., Samuelsson E., Lindahl, C., Persson, G.: Mechanical Non-Surgical
Treatment of Peri-Implantitis: A Double-Blind Randomized Longitudinal Clinical
Study. I: Clinical Results. J Clin Perio 36: 604-609, 2009.
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Classifying Peri-Implant Disease
The American Dental Association endorsed dental implants
in 1986. U.S. estimates suggest that more than 400,000
implants are now placed each year. Success rates for most dental
implant systems are reported to be more than 90 percent, but
with the increasing numbers of implants being placed today,
there may be an increase in peri-implant disease. Two periimplant
diseases have been identified: peri-implant mucositis,
affecting only mucosa, and peri-implantitis, affecting both
mucosa and supporting bone. Peri-implant mucositis occurs in
50 percent of implant sites and peri-implantitis occurs at 12-40
percent of sites, depending on the study. Diagnosis includes
probing to identify bleeding/suppuration and radiographs to
determine bone loss.
A proposed prognostic system might help clinicians predict
implant success after treatment, based on the extent of periimplant
disease (Fig. 1).
Clinical Implications: This simple prognostic system will
provide clinicians who treat peri-implant disease with a system
to anticipate outcomes of their treatment.
Nogueira-Filho, G., Iacopino, A., Tenenbaum, H.: Prognosis in Implant Dentistry: A System for Classifying the
Degree of Peri-Implant Mucosal Inflammation. J Can Dent Assoc 77:b8, 2010.
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Therapy for Peri-Implant Diseases, I
The term "peri-implantitis" was introduced in
1987 by Dr. Mombelli and his research team in
Switzerland. The primary etiology of peri-implantitis
is the same as periodontitis: bacterial biofilm. People
with periodontitis are more likely to experience periimplantitis
than those who are periodontally healthy
when implants are placed. As the number of implants
increases, so does the need for treatment of periimplantitis.
The research on peri-implantitis treatment
options is accumulating with no clear indication
as to which therapies are the most effective.
Researchers at the University of Athens in Athens,
Greece, systematically reviewed the published research
on treatment of peri-implantitis. Although many
studies are available, only five studies met the inclusion
criteria of being randomized, controlled trials
evaluating peri-implantitis treatments.
Four treatment approaches were evaluated: nonsurgical
debridement alone, non-surgical debridement
with local application of chlorhexidine, non-surgical
debridement with locally applied antibiotics, Er:YAG
laser alone or regenerative surgery. Mechanical instrumentation
alone was the least predictable for longterm
health. Another review in this issue demonstrates
that instrumentation using a periodontal endoscope is
an effective treatment of peri-implantitis in most cases.
Using the laser or combining instrumentation with
chlorhexidine or locally delivered minocycline provided
predictable results for 12 months. Regenerative
surgical procedures using bone substitute can be effective
treatments.
Preventing peri-implantitis is the best approach,
but when peri-implant infection is encountered, a
variety of treatments are available, depending on the
patient, the implant itself and the preferences of the
treating clinician.
Clinical Implications: There is no established
gold standard for treating peri-implantitis, but
several viable options can be considered.
Kotosovili, S., Karousis, I., Trianti, M., Fourmousis, I.: Therapy of Peri-Implantitis: A
Systemic Review. J Clin Perio 35:621-629, 2008.
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Therapy for Peri-Implant Diseases, II
Inflammation around implants is similar to infection and
inflammation found around natural teeth. As with natural
teeth, bacterial biofilm is responsible for peri-implant diseases.
Nearly 65 percent of all infectious diseases are caused
by bacterial biofilms. Staphylococcus aureus is associated
with peri-implantitis. This is interesting since foreign body
infections are also colonized by S. aureus. It seems S. aureus
favors titanium. Treatment of peri-implantitis follows traditional
treatments of periodontitis.
The screw shape and design of implants might enhance
biofilm formation and the crowns and bridges attached to
the implant might hinder effective biofilm disruption in the
area. Mechanical treatment is the primary approach, but
with the challenges implants pose for instrumentation,
antibiotics, antimicrobials and lasers have been suggested.
Researchers from Kristianstad University in Sweden, and
Trinity College in Dublin, Ireland, collaborated on a literature
review of treatments of peri-implant mucositis and periimplantitis.
From 437 studies, 24 were included in the review.
Mechanical non-surgical therapy was effective when
treating peri-implant mucositis (soft tissue involvement),
but not as effective used alone to treat peri-implantitis (soft
tissue and bone involvement). Adjunctive use of local and
systemic antibiotics improved outcomes. Lasers provided
minor benefits, but too few studies are published on lasers to
conclude they are the treatment of choice. Additionally,
antimicrobial mouthrinses were found to enhance the treatment
outcome of mechanical instrumentation. As with natural
teeth, it is easier to treat gingivitis than advancing
periodontitis with moderate bone loss.
Clinical Implications: Just as with periodontitis, a variety of treatment approaches are available for peri-implantitis,
and can be combined together for best results.
Renvert, S., Roos-Jansaker, A., Claffey, N.: Non-Surgical Treatment of Peri-Implant Mucositis and Peri-Implantitis: A Literature Review. J Clin Perio 35 (Suppl 8):305-315, 2008b. |