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How to Use Antibiotic Impregnated Plaster of Paris for Alveolar Packing after Tooth Removal

  • Equine Medical Associates


Plaster of paris is an excellent material used to pack the alveolus after tooth removal. Advantages of plaster of paris include that it is cold curing, provides a form of local antimicrobial delivery, is biodegradable, and is economical. Authors' addresses: University of Wisconsin, School of Veteri-nary Medicine, Department of Surgical Sciences, 2015 Linden Dr. West, Madison, WI 53606 (Trostle and Santschi); Manor Equine Hospital, 2506 Monkton Rd, Monkton, MD 21111 (Juzwiak). © 2000 AAEP.
How to Use Antibiotic Impregnated Plaster of
Paris for Alveolar Packing after Tooth Removal
Steven S. Trostle, DVM, MS; James S. Juzwiak, DVM; and
Elizabeth M. Santschi, DVM
Plaster of paris is an excellent material used to pack the alveolus after tooth removal. Advantages
of plaster of paris include that it is cold curing, provides a form of local antimicrobial delivery, is
biodegradable, and is economical. Authors’ addresses: University of Wisconsin, School of Veteri-
nary Medicine, Department of Surgical Sciences, 2015 Linden Dr. West, Madison, WI 53606 (Trostle
and Santschi); Manor Equine Hospital, 2506 Monkton Rd, Monkton, MD 21111 (Juzwiak). © 2000
1. Introduction
The most common reason to remove a tooth is to elim-
inate a tooth that has incurred significant dental dis-
ease in which removal is the last resort. In a
comprehensive retrospective study, complications oc-
curred in 47% of horses with maxillary tooth involve-
ment and in 32% of those with mandibular tooth
The most common complications were
draining tracts, sinusitis, sequestrum, and loss of the
temporary seal provided by the dental packing.
In addition, if the dental packing is prematurely dis-
lodged, feed materials or debris from the oral cavity
can also be a source of infection.
The high inci-
dence of complications can often lead to a second
surgical procedure to resolve the complication.
Following tooth removal, packing or plugging
the alveolus to provide a temporary seal is thought
to be essential to protect the alveolus.
materials have included roll gauze, acrylic dental
base plate wax, dental acrylics, and polymethyl-
methacrylate (PMMA). Dental wax has the ad-
vantage in that it is cold curing unlike some
PMMA products, which undergo an exothermic
reaction in the curing process. However, PMMA
has an advantage in that it can elute antimicro-
bials if they are added to the PMMA, and den-
tal wax does not. Both dental plate wax and
PMMA are non-biodegradable and may need to
be removed. The purpose of this study was to
report the results of antibiotic-impregnated plas-
ter of paris for dental packing following tooth re-
moval. Plaster of paris has many advantages
over other dental packing materials because it is
cold curing, elutes antimicrobials, is biodegrad-
able, and is economical.
2. Materials and Methods
Medical records were reviewed from two surgical
referral hospitals that had horses with teeth re-
moval followed by packing with antibiotic-impreg-
nated plaster of paris. Eight horses were included
in the study. Various breeds and ages were repre-
sented in the study (Table 1) and all horses only had
a single tooth removed. Two horses had teeth
orally extracted and 6 horses had teeth removed by
repulsion either through a sinus trephination or si-
nusotomy. In all horses, after extraction of the
tooth, the alveolar socket was packed with a mixture
of plaster of paris. The plaster of paris dental pack-
ing was prepared by mixing approximately 40 g of
the hemihydrate (dried calcium sulphate hemihy-
drate [CaSO
]) and 12 ml of saline. Antibiotics
were added to mixture and varied in volume and
concentrations (Table 1). It takes approximately
10 to 15 minutes for hemihydrate plaster of paris to
reach a “dough ball” or working consistency. At
that time, the plaster of paris is molded to fill to 25
to 50% the depth of the socket and with a slight
flange was over the gingival line to seal the alveolus.
Care was taken to ensure that the plaster of paris
packing did not extend to the occlusal surface of the
tooth to prevent premature removal when the horse
masticates. Plaster of paris did not completely
harden or cure in most cases for approximately 30 to
35 min. All horses were examined the day after
surgery to ensure that the plaster of paris dental
packing was present. Outcome was assessed by
telephone conversation with owner or referring vet-
3. Results
Table 1 presents our results in tabular form.
180 2000 Vol. 46 AAEP PROCEEDINGS
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4. Discussion
Although advances are being made in endodontic
therapy, tooth removal is still a common procedure
in equine practice. There are many potential com-
plications associated with tooth removal, and pro-
tecting the alveolus with a temporary seal is critical
for preventing oral contamination and subsequent
infection. The temporary seal is most commonly
achieved with dental packing. Polymethylmethac-
rylate can be used, but should be “cold curing” and
avoid the exothermic reaction. The exothermic re-
action of some PMMAs can lead to surrounding soft
tissue damage, which may lead to premature loos-
ening. Many people also advocate the use of anti-
microbials in PMMA since the oral cavity is
impossible to aseptically prepare for the surgery and
infection of the tooth root and its surrounding tis-
sues is the most common reason for tooth removal.
With other non-biodegradable materials, the al-
veolus is only recommended to be filled to ap-
proximately 25% of the alveolus depth.
recommendation is made so that granulation tissue
can form without pushing the dental packing out
prematurely. Because plaster of paris is biode-
gradable, filling of the alveolus can occur to a greater
extent, but some portion of the alveolus should be
left void to allow for the formation of granulation
We feel that plaster of paris dental packing has
many advantages over other dental packing materi-
als. Plaster of paris is readily available and less
expensive than “cold curing” PMMA and dental wax.
Like PMMA, plaster of paris does elute antimicrobi-
als to provide local antimicrobial therapy over a
period of time. Unlike PMMA, plaster of paris is
biodegradable and therefore does not need to be
removed. Plaster of paris dental packing does take
a longer period of time to completely harden or set
and therefore may not be ideal to use in standing,
sedated horses that have teeth extracted orally.
1. Prichard MA, Hackett RP, Erb HN. Long-term outcome of
tooth repulsion in horses: a retrospective study of 61 cases.
Vet Surg 1992;21:145–149.
2. Easley JK. Equine tooth removal (Exodontia). In: Baker
GJ, Easley JK, eds. Equine Dentistry. Philadelphia: WB
Saunders, 1999;220 –249.
3. Pascoe JR. Oral cavity and salivary glands. In: Auer JA,
Stick JA, eds. Equine Surgery. Philadelphia: WB Saunders,
1999;189 –199.
4. Mousset B, Benoit MA, Delloye C, et al. Biodegradable im-
plants for potential use in bone infection: in vitro study of
antibiotic loaded calcium sulphate. Int Orthop 1995;19:
Table 1. Horses That Had Tooth Extraction Followed by Alveolus Packing with Antibiotic Impregnated Plaster of Paris
Tooth–Disease Extraction
Antibiotics Added to the
Plaster of Paris Outcome
16 yr, THB, F 108–Periodontal General
anesthesia sinusotomy
cefazolin, 1 g No complications
6 yr, QH, F 206–Periapical abscess Standing,
tranquilization orally
sodium ampicillin and
1.5 g
Lost plaster of paris packing
after removing mouth
speculum, had to be repacked
10 yr, WB, MC 209–Periapical abscess General
anesthesia sinusotomy
sodium ampicillin and
1.5 g
No complications
22 yr, QH, F 106–Periapical abscess General
anesthesia orally
sodium ampicillin and
1.5 g
No complications
5 yr, Paint, MC 208–Periodontal General
anesthesia sinusotomy
trimethoprim-sulfa, 2 g No complications
10 yr, THB, MC 107–Periapical abscess General
anesthesia sinusotomy
trimethoprim-sulfa, 2 g No complications
3 yr, WB, F 106–Periapical abscess General
anesthesia orally
trimethoprim-sulfa, 2 g No complications
6 yr, THB, MC 208–Periapical abscess General
anesthesia sinusotomy
metronidazole, 1 g No complications
Unasyn–1.0 gram of sodium ampicillin and 0.5 gram of sulbactam. THB–Thoroughbred, QH–Quarterhorse, WB–Warmblood.
AAEP PROCEEDINGS Vol. 46 2000 181
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... Antibiotic-impregnated POP has been used in horses to treat orthopedic infections and to prevent alveolar infection and osteomyelitis after dental extraction. 6,95 Plaster of Paris is biocompatible, biodegradable/absorbable, readily available, and inexpensive. Furthermore, the elution characteristics of gentamicin-POP beads suggest that they may be useful in the treatment and prevention of osteomyelitis caused by gentamicin-sensitive bacteria. ...
... 99 Clinically, the following antibiotic drugs and doses have been combined with POP for use as alveolar packing after cheek tooth removal in horses: cefazolin, 1 gram; sodium ampicillin-sulbactam, 1.5 grams (1 g ampicillin, 0.5 g sulbactam); trimethoprimsulfonamide, 2 grams; metronidazole, 1 gram. 95 In that study, approximately 40 grams of POP were combined with 12 ml of saline and the chosen antibiotic drug. After mixing and setting aside, the antibiotic-impregnated POP reached a good working consistency ("dough ball") in 10-15 minutes, at which time it was molded to fit the alveolus (filling only the gingival half of the socket depth). ...
... The POP packing hardened in situ in 30-35 minutes. 95 A similar process could be used in clinical practice for deep wounds involving bone. ...
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The first two articles in this 4-part series explored the question, Why do some infections persist and progress despite seemingly appropriate treatment?, as it pertains to wounds involving joints and other synovial structures. 1,2 Of the many possible reasons, most serious wound infections involve at least one, and usually a combination, of these factors: 3 1. extensive contamination, or bacterial burden that overwhelms the patient's resources 2. refugia which protect the bacteria from host defenses and antibiotic drugs 3. immunocompromise 4. poor perfusion 5. antibiotic insensitivity of the wound pathogen(s) These same factors, often in combination, also contribute to the persistence of wound infections that involve bone. In horses, wounds that involve bone range in severity, complexity, and long-term impact from those containing a thin sequestrum on the surface of the third metacarpus/tarsus that resolve with routine wound care after sequestrum removal, to septic osteomyelitis at the site of internal fixation that results in failure of the fracture repair and potentially in euthanasia. Yet in all cases, the principles of successful treatment are the same: • debride the devitalized or irreparably damaged bone and soft tissue • preserve and protect the vascular supply to bone and soft tissue • maintain or restore structural integrity at the site • control infection through appropriate local/regional and systemic antibiotic therapy • protect the wound from further contamination, desiccation, maceration, and trauma There are a number of review articles on the management of wounds involving bone in horses. 4-7 So, rather than plowing the same ground, this article examines some advances in wound care over the past 15 years as they relate to wound infections involving bone.
... What to pack dental sockets with after tooth removal remains an area of controversy and personal preference. Plaster of Paris, dental wax, cold-curing polymethylmethacrylate bone cement, silicone, and gauze sponges have been used [70,72,73,75,78]. Antimicrobial-impregnated plaster of Paris has the advantage of being biodegradable, and thus does not need to be removed. ...
... Antimicrobial-impregnated plaster of Paris has the advantage of being biodegradable, and thus does not need to be removed. In a series of eight horses managed with plaster of Paris, only one horse required repacking at the time of surgery and all eight horses healed without complication [78]. A longer curing time makes plaster of Paris less advantageous, particularly in standing sedated patients that have had an oral extraction. ...
Infectious conditions of the equine head are commonly encountered in clinical practice. Pathogenic bacterial, viral, and fungal organisms may localize in the extensive nasal passages, paranasal sinuses, and guttural pouches, creating a range of clinical signs and conditions that can be severe enough to lead to unexpected fatality. Renewed interest in equine dentistry has led to a greater recognition of dental disease that is associated with infection. This article focuses on bacterial and fungal infections of the main anatomic regions of the equine head, where advances in diagnosis and management have been made or consolidated in recent years. It also addresses recent advances made in the area of infectious equine corneal disease, including bacterial, viral, and fungal etiologies. Recent developments in equine recurrent uveitis as it relates to infectious diseases and ocular manifestations of systemic disease are also discussed.
... After tooth extraction, the alveolus and adjacent structures may be protected from ingesta and saliva with dental wax, impression compound, polymethyl methacrylate, bone cement, plaster of Paris, or a gauze swab impregnated with antimicrobials, until the granulation tissue pushes it away (10,12,13). The prosthesis is molded to fill 1/3 of the alveolar cavity, overlying the gingival margins. ...
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A 7-year-old mare presented with facial deformities associated with oral discomfort and weight loss was found to have bilateral, palatal, developmental displacements of the maxillary 08s, with secondary diastema. Following repulsion of both displaced teeth, the horse regained weight and resumed training. Bony deformities remained visible 9 mo after discharge.
Objective To report the outcomes and complications associated with antibiotic‐impregnated calcium sulfate beads for prevention and treatment of orthopedic‐related surgical site infection (SSI) in companion animals. Study design Retrospective case series. Animals Client‐owned cats (n = 2) and dogs (n = 14). Methods Medical records of 16 cases in which implantation of antibiotic‐impregnated calcium sulfate beads was performed for the prevention or treatment of SSI were reviewed. Information collected included signalment, prior surgery, reason for bead placement, antibiotics used, bacterial culture results, and clinical outcomes. Results Surgical site infection resolved in six of 10 animals treated therapeutically and did not occur in six of six animals treated prophylactically. Susceptibility of the causative bacteria to the antibiotic implanted was confirmed in five of six cases with resolved SSI treated therapeutically but in only one of four cases with unresolved SSI treated therapeutically. Complications directly related to bead placement were evident in only one case in which beads extruded from external skeletal fixator pin tracts 7 days after implantation. At final follow‐up, 11 of 12 animals without SSI had satisfactory limb use and no clinical, cytologic, or radiographic evidence of infection. Conclusion Implantation was well tolerated. Resolution of SSI was inconsistent; however, when bacteria were susceptible to the antibiotic implanted, SSI resolved in all but one case. Clinical significance Antibiotic‐impregnated calcium sulfate beads could be considered for prevention or treatment of orthopedic SSI in small animals. A prospective clinical study is required to obtain additional information, including the value of preoperative bacterial culture.
The local delivery of antimicrobials is a valuable therapeutic tool with a low morbidity, is practical to use, and is well tolerated by horses. Clinically, its use has allowed equine practitioners to achieve better results when treating musculoskeletal infections, and it represents an extremely useful tool in the practitioner's armamentarium against these types of infections. The technique is indicated to combat orthopedic infections involving bones, joints, physes, tendon sheaths, and foot tissues. Optimal treatment must include other approaches, such as systemic antimicrobial therapy and surgical debridement and lavage, and monitoring of the clinical progression of the patient can help to determine the ideal protocol for each patient.
To evaluate the effect of alveolar bone substitute on post-extraction drift of maxillary cheek teeth in ponies. In vivo longitudinal experimental study. Five ponies (5-7 years) with a healthy dentition. Both maxillary 4th premolar teeth (Triadan 08) were surgically removed. One alveolus was filled with a biocompatible non-resorbable bone substitute (Bioplant 24), whereas the other healed by second intention. A polyvinylsiloxane plug and spring wire isolated the bone substitute from the oral environment. Pathologic changes to dentition and adjacent soft tissue were recorded. Tooth drift was calculated after 1 and 2 years. At 1 month, bone substitute material was incorporated into healthy tissue. Tooth drift was observed but differed significantly between control and treated sides at 2 years (P<.01). For both techniques, tooth drift differed significantly between years 1 and 2 (P<.001). Total drift in control arcades for year 1 was 10.69+/-2.12 mm and for year 2 was 9.08+/-0.87 mm, whereas for bone substitute arcades it was 9.90+/-1.60 mm for year 1 and 5.60+/-1.78 mm for year 2. Partial tooth replacement therapy after maxillary P4 extraction provided good healing in the immediate post-surgical phase. Alveolar filling with bone substitute material significantly slowed post-extraction tooth drift but did not stop it completely. Clinical Relevance- Important changes occur in equine dentition after maxillary cheek teeth removal. Further longer term observations are needed to fully validate study findings.
The records of 61 horses undergoing tooth repulsion for treatment of alveolar periostitis were reviewed. Seventeen of 36 horses (47%) in which maxillary teeth were removed had serious postoperative complications, such as infection of a second tooth, bone sequestration, chronic sinusitis, draining tracts, retained dental packing, feed impaction of the alveolus or sinus, suture-line dehiscence, or skin-flap sloughs. Eight horses required at least one additional surgical procedure. Eight of 25 horses (32%) in which mandibular teeth were removed had serious postoperative complications, and four horses required an additional surgical procedure. Hospitalization lasted 2 to 61 days (median, 22 days) for maxillary teeth and 3 to 35 days (median, 8 days) for mandibular teeth. Long-term follow-up (at least 5 months) was possible in 47 horses. Twenty-four of 30 horses (80%) with maxillary tooth repulsion healed without further problems; six horses had persistent nasal discharge. Fourteen of 17 horses (82%) with mandibular tooth repulsion healed with no further problems or with only minor complications; three horses had a chronic draining tract.
Local antibiotic therapy by diffusion from plaster of Paris beads has proved promising in bone surgery. Sustained local delivery depends on thermostability, so we tested the antibacterial activity of 11 antibiotic solutions after storage at 37 degrees C using a microbiological method. Cephalosporins and penicillins were unstable, but aminoglycosides remained fully stable with 100% activity after 2 weeks. About 60% of the initial bactericidal activity of quinolone, glycopeptides and sodium fusidate were still detectable after 2 weeks. Release of these antibiotics from plaster of Paris beads was evaluated in vitro. Even those in the same family differed in their release rate. Plaster beads with sodium fusidate were the most effective association. A therapeutic level of glycopeptides, aminoglycosides and amoxicillin was leached for about 3 weeks. Cephalosporins and sodium amoxicillin were released in 2 to 3 days, and quinolone beads were too brittle to be used. Plaster of Paris, which is cheap, biocompatible and biodegradable, is an excellent carrier for sodium fusidate, aminoglycosides and glycopeptides.
Equine tooth removal (Exodontia)
  • J K Easley
Easley JK. Equine tooth removal (Exodontia). In: Baker GJ, Easley JK, eds. Equine Dentistry. Philadelphia: WB Saunders, 1999;220 -249.