Optimizing the Esthetic Potential of Implant Restorations Through the Use of Immediate Implants With Immediate Provisionals

Providing patients with optimal esthetics remains challenging when teeth require replacement with implant-supported crowns. However, it can be a source of great satisfaction for the patient and the practitioner when the outcome is excellent. Maintenance of soft tissue contours is requisite in gaining ideal esthetic outcomes in cases where the gingival margin is displayed when the patient speaks or smiles. In turn, maintenance of soft tissue contours is dependent on a traumatic extraction techniques followed by providing support for the overlying soft tissues during the post extraction healing period. Optimal support of the soft tissues during healing following loss of a tooth in the esthetic zone might best be provided through immediate implant placement and insertion of an immediate, minimally functional fixed provisional. This article describes a novel approach to immediate provisionalization in the esthetic zone.

The techniques illustrated in this case report were undertaken on patients treated by the author in a solo periodontal practice in Tucson, Arizona. This practice (and practitioner) had participated in an observational investigation in 2004 that included >500 patients treated in >150 practices.1,2 The protocol of this study included multiple implants in partially edentulous patients, with a single-stage surgical approach, either to include use of healing cuffs or immediate fixed provisionals. Based on the author’s favorable experiences in this study, including excellent healing for all seven study patients treated by him, the decision was made in late 2004 to begin offering immediate fixed provisionals for patients receiving implants, in most case immediate implants, in the esthetic zone. It is the author’s clinical opinion that a well-designed provisional allows esthetic temporary replacement of an anterior tooth or teeth while posing minimal risk of adversely affecting the initial stages of integration. In some respects, an esthetic fixed provisional that is adjusted to avoid occlusal contacts in centric occlusion and in excursive movements seems analogous to a tall thin healing cuff or abutment, and singlestage implant surgeries have an excellent track record of safety and efficacy. During an 18-month period (November 2004 to May 2006), 36 maxillary anterior teeth were treated in the fashion described in this article.


MATERIALS AND METHODS
Each patient was diagnosed with a hopeless maxillary anterior tooth (or teeth), and an agreement was reached that replacing the tooth with an implant-supported crown was the treatment of choice. Informed consent was obtained for intravenous sedation, tooth removal, implant placement, and insertion of an immediate fixed provisional. The two patients profiled in the present report provided signed, informed consent for inclusion in this publication. All 36 patients treated in the manner described in this report were managed in a fashion consistent with the Helsinki Declaration, as revised in 2000.



All patients were given prescriptions for systemic antibiotics, with the first dose taken 1 hour before surgery. Antibiotic coverage was continued for the first postoperative week. Intravenous access was gained using a 19-gauge butterfly, 20 ml whole blood was drawn, and the blood was centrifuged and managed in a fashion as recommended by the manufacturer† to obtain ;2 ml of platelet-rich plasma (PRP). Titration of intravenous conscious sedation was then undertaken, almost exclusively with midazolam as a single-agent sedative. After the patient was sedated the surgical site was anesthetized, most commonly using 0.5% bupivacaine.



Following anesthesia, the tooth was removed using periotomes, allowing removal of the root without elevation of a flap. The extraction site was debrided, as needed, and the implant osteotomy was then preparedwith harvesting of the autogenous bone through use of a disposable bone trap.‡ On completion of the osteotomy, an endosseous implant was placed with the fixture platform positioned at or just apical to the osseous crest on the mid-labial aspect of the socket. Insertion of the implant was completed using a manual torque wrench set to 25 Ncm. The implants used for the cases described in this article include a textured, fluoride-treated surface with microthreads extending to the bevel that defines the platform.§ Additionally, the design of these implants includes a double hex-indexed internal machined conical abutment–implant interface. The socket was filled with PRP immediately before implant placement, and any gaps wider than 1mmbetween the socket and the implant were grafted using a combination of autogenous bone particles with PRP. Perforations of the buccal cortical plate, such as are frequently encounteredwith teeth having histories of prior apical surgery (e.g., case 1 in this report), were grafted through the socket, also with autogenous bone and without elevation of a flap. On rare occasions, the autogenous bone was supplemented with freeze-dried allogenic bone.i Neither of the cases presented in this report required supplemental bone.



The existing clinical crown, whether a porcelain fused to metal (PFM) crown (case 1) or a toothwith- veneer (case 2), or a natural toothwith or without intracoronal restorations (not illustrated) was then relieved to fit over and around a screw-retained temporary abutment inserted into the implant, and the crown was luted to the abutment intraorally using flowable light-cured composite. The crown and abutment were then removed as a single piece so that the provisional could be finished extra orally. When completed, the provisional was inserted back into the implant to allow careful adjusting of the occlusion, avoiding contact between the provisional and the opposing tooth or teeth in centric occlusion and in protrusive and lateral movements.



When all adjustments were complete, the provisional was tightened using firm finger pressure with a manual hex drive, and the screw access opening was closed using cotton and a plaster-based filling material. Postoperative instructions included cautioning the patient to avoid functioning (chewing food or other objects) against the provisional. The patient was then seen for postoperative visits as needed, including at least one early (7 to 10 days) postoperative visit, with a follow-up radiograph at ;3 months.



All cases healed with favorable labial gingival contours and apparently favorable crestal bone height (no posthealing bone sounding or exploratory flaps were undertaken). Two patients, including case 1 illustrated in this article, had their antibiotic coverage extended for a second week because of pronounced tenderness over the apical aspect of the implant site. Of the 36 immediate implants, immediate provisional cases replacing maxillary anterior teeth during this 18-month period, 35 were completed with no flap and no sutures, whereas just one (a trauma case that included loss of most of the labial cortical plate) necessitated elevation of a flap.


CASE 1

The patient, a 62-year-old woman, suffered nonrestorable structural failure of the maxillary left lateral incisor (tooth #10; vertical root fracture [Fig. 1A]). The preoperative radiograph, taken before the crown and post had come out (Fig. 1B), documents favorable alveolar ridge height. Following removal of the tooth, the implant osteotomy was prepared, the implant was inserted, a temporary abutment was screwed into place, and the patient’s porcelain-fused-to-metal crown was relieved to fit around the temporary abutment (Fig. 1C). The crown was then luted in place using flowable light-cured composite (Fig. 1D), and was unscrewed from the implant and removed from the mouth (Fig. 1E). Additional flowable composite was added and cured extraorally, and the provisional was then finished and polished (Fig. 1F).

Once finished and polished, the provisional crown was screwed into the implant, and the occlusion was checked and adjusted to eliminate centric and lateralprotrusive contacts. The immediate postoperative photograph (Fig. 1G) and radiograph (Fig. 1H) reveal favorable implant placement and appropriate contours of the provisional restoration.





Three months following implant and provisional placement, a clinical assessment and photograph (Fig. 1I) revealed excellent tissue health, and a radiograph (Fig. 1J) revealed maintenance of interproximal crestal bone height. The patient was then referred back to her restorative dentist for fabrication of the zirconiumabutment and crown. Soft tissue health and contours were noted to be ideal (Fig. 1K) on the day that the crown was cemented. The patient was seen 15 months postoperative for a follow-up photograph (Fig. 1L) and a radiograph (Fig. 1M), documenting excellent maintenance of tissue health, bone height, and esthetic outcome.


CASE 2

The patient, a 52-year-old woman, suffered non-restorable structural failure of tooth #8, in this case a complete mesial-distal chisel fracture extending into (and being held in place at the moment of fracture by only) the labial attachment (Fig. 2A). Aradiograph (Fig. 2B) documented favorable alveolar bone height. This tooth had a history of trauma nearly 30 years before the recent fracture, followed by discoloration of the tooth over a period of years. Because the tooth reportedly remained vital (responsive) at the time of discoloration, and because external bleaching was ineffective, the patient elected to have a veneer. Subsequently, the tooth did become non-vital and abscessed, necessitating endodontic therapy ;15 years before its fracture. The original veneer remained in place.



Following removal of the extracoronal splint, the tooth was removed in two pieces (Fig. 2C). With careful, judicious use of periotomes, the author managed to remove the root without elevation of a flap. In amanner essentially identical to the treatment sequence described in case 1, the tooth and its veneer were attached to a temporary abutment, with subsequent finishing as a screw-retained provisional (Figs. 2D through 2G). As with case 1, the immediate postoperative radiograph (Fig. 2H) reveals favorable implant placement and provisional contours.



In case 2, the patient elected to have the implant crown fabricated and placed while she was away from Tucson for the summer. The permanent restoration is shown (Figs. 2I and 2J) 12 months following implant placement. The 12-month radiograph (Fig. 2K) reveals maintenance of crestal bone height on the proximals of the adjacent teeth and bone contact with the implant very near the bevel corresponding to the junction between the textured surface and the machined titanium.


DISCUSSION
The two cases presented here are representative of the outcomes obtained by the author in managing 36 immediate implant, immediate provisional cases over an 18-month period. The provisionalization stage of the surgical appointment has been time consuming, averaging 30 to 40 minutes of chair time following placement of each implant. Given the fact that patients leave with ‘‘their own’’ tooth in place, feedback following these procedures has been extremely favorable. Whether because of the use of PRP, the lack of elevation of a flap, or atraumatic extractions through use of periotomes, reports from the patients concerning their postoperative comfort also have been positive. Although not quantified on a visual pain scale, anecdotally the pain levels have tended to range from ‘‘none’’ to ‘‘very little.’’ It has been the exception when patients return for their postoperative visits and report that they needed any opiate analgesics.



Relieving existing porcelain and porcelain-fusedto- metal crowns for use as provisional crowns, as described and shown in this article, can be challenging. A diamond burr in a high-speed handpiece is effective for removal and recontouring of the porcelain, whereas a carbide burr designed for cutting through metal can be used to penetrate the metal coping. On occasion, the porcelain has fractured in the process of fabricating the provisional, and the author always requests a back-up composite crown or denture tooth from the restorative dentist for cases involving preexisting porcelain or porcelain-fused-to-metal crowns.



Natural teeth or teeth with veneers, as shown in case 2, have posed no problems with fracture for the author. Additionally, as shown in Figure 2D, the ability to bond to the dentin and enamel of the internally relieved tooth, rather than carefully hollowing out the crown to fit around the abutment (as in Fig. 1C), facilitates the process of fabricating the provisional. Once fabricated and inserted, the provisionals have generally proved to require little in the way of professional intervention during the period between the surgery and the impression appointment for the final restoration.



Although early positive feedback from patients is always rewarding, it is the exceptional tissue health, along with maintenance of soft tissue contours and alveolar bone height, which provides the real impetus for pushing the envelope with this new approach to maximizing the esthetic potential of implants in the esthetic zone. The author considers it extremely important to avoid the use of cemented provisionals when using the approach described in this article because the lack of flap access in these cases seems to rule out definitive, absolute avoidance of excess cement contaminating the peri-implant surgical environment. This commitment to avoidance of immediate cemented provisionalsmandates that the straight-line access to the internal aspect of the implant be just palatal to the incisal edge of the tooth or provisional to avoid cutting through the incisal edge of the crown while modifying it for use as a provisional. Compromising the incisal edge of a porcelain crown is unacceptable both structurally and esthetically, whereas compromising the incisal edge of a natural tooth (or denture tooth or composite crown) is undesirable froma perspective of the amount of chair time necessary to gain a good esthetic result while reestablishing incisal continuity. In either event, cutting through the incisal edge for screw access also commits the restorative dentist to additional chair time during the final impression appointment and any try-in appointments before insertion of the permanent crown.



Recently, Zeren3 described an approach to managing removal and replacement of teeth with implant- supported crowns in the esthetic zone. He also emphasized the importance and benefits of atraumatic extraction techniques. Instead of PRP, with the addition of autogenous bone only in site gaps between the socket and implant >1 mm, as described in this report, he used enamel matrix protein and freeze-dried bone allograft for all cases and seemed to achieve very good results.Another difference between Zeren’s3 report and the present article is the fact that provisionalswere not fixed to Zeren’s implants immediately on placement.



Steigmann and Wang4 report on use of a submarginal ‘‘esthetic buccal flap’’ to allow access to graft labial- buccal fenestration defects in otherwise flapless immediate implant surgeries, with apparently excellent results. Their approach allows definitive management of osseous defects. In the present report, fenestration defects were managed by placing the autogenous bone and PRP through the socket-osteotomy. The healing results obtained through internal graft placement without flap access have been very good, as evidenced by the outcome with case 1. The one patient treated by the author who did have flap access had lost much of the labial plate because of trauma, with formation of a dehiscence defect rather than a fenestration.



At the very least, attaching ‘‘tall thin healing cuffs’’ (minimally functional fixed provisionals, as described herein) increases the length of the lever arm, imparting increased stress into the implant through lip and tongue pressure and through inadvertent pressure from the occasional food boluses, even if the opposing teeth do not quite touch the provisional. Is this presumptive increased risk of imparting perioperative instability counterbalanced by any benefit? In addition to offering the opportunity for ideal support of the soft tissues, it is the author’s opinion that establishing positive contours permucosally improves the cleansibility of the wound margin. Because plaque and debris accumulations can cause inflammation, thereby resulting in bone resorption, any improvement in postoperative cleanliness and tissue health has the potential to result in improved bone height on final healing. The improved patient satisfaction of having a fixed provisional, thereby avoiding a flipper, the opportunity for ideal tissue support, and the possibility of improved tissue health do seem to offer sufficient benefit to warrant the presumptive increased risk.



The question then arises, how significant is this presumed increased risk? Del Fabbro et al.5 have published a review of survival rates for immediately loaded implants, including single implants. They cite 23 studies that included immediately loaded single maxillary implants, although only eight of these 23 studies included immediately loaded implants placed into extraction sites. The authors of this literature review5 computed a survival rate of 96.1% for the 336 immediately loaded implants placed into extraction sties compared to a 98.5% survival rate for immediately loaded implants placed into edentulous sites. The authors conclude that ‘‘(f)urther research is required to specifically address this comparison.’’ It is difficult to disagree with their conclusion, although their review, along with the experiences of the author of this present report certainly seem to suggest that immediate loading of immediately placed implants must be considered a viable treatment option.



In the maxillary anterior segment, highly scalloped gingival margins tend to be the rule rather than the exception. As a consequence, placing the fixture platform at or just apical to the labial osseous crest has translated into the fixture being several millimeters subgingival and subcrestal interproximally. It is the author’s opinion and experience that amachined conical abutment-implant interface allows for deep margins to be essentially free of inflammation, as noted in Figure 1K (the lining of the implant provisional socket is a darker red than the surface of the surrounding gingiva because of the presumption of it being lined with non-keratinized sulcular epithelium) and as evidenced by the lack of inflammation of the interdental papillae in all clinical photos.



Case 2 is one of a very few immediate provisionals that the author is aware of that loosened before the impression appointment for the permanent crown. As an aside, the esthetic outcome of the final restoration might have been improved in case 2 throughmodifying the height and shape of the gingival margin through esthetic crown lengthening before the final impression for the crown. Additionally, moving the contact point apically to within 5mmof the crest of the bone, as described by Tarnow et al.6 and Grunder,7 would have allowed the gingival embrasure to be filled completely by the gingival papilla.



To date, all restorative dentists have chosen to use abutments and cemented crowns as the final restoration rather than screw-retained crowns. It is important to remind the restorative dentists that the abutments need to be prepared or fabricated with a margin that follows the scalloping of the gingival margin to avoid proximal crown margins and cement lines that are deep subgingivally. It seems intuitive that the deeper the margin, the less likely it will be to clear all excess cement. Given the excellentmarginal stability of these cases, having the cement line (margin) placed a single millimeter subgingivally has proved to be adequate for optimal esthetics while maximizing the chances for maintenance of ideal tissue health.



In Figure 2G, the articulating marks on the cingulum area of the adjacent left central incisor, and the extent of the relief on the lingual of the provisional that was necessary to avoid occlusal contacts. In centric occlusion, this patient had 7 mm vertical overlap in the incisor segment. It is the author’s experience that cases with this sort of close vertical overlap can be extraordinarily challenging to gain an acceptable fit for a temporary removable partial while leaving sufficient acrylic to avoid fracture. The concerns about thin acrylic are exacerbated by placement of a healing cuff, whether immediately as a single-stage implant surgery or some weeks and months postoperatively when undertaken in a traditional two-stage approach to implant surgery. Because the composite retaining the tooth on the provisional abutment extends subgingivally, the technique described in this article offers the additional benefits of a precisely adjusted occlusal relationship and increased strength while offering support of the healing soft tissues and excellent esthetics.



CONCLUSIONS

This article describes, to the author’s knowledge, a novel approach to immediate provisionalization of immediate implants, including modification of the patient’s clinical crown for use as the screw-retained provisional, in the anterior segment. Using the existing crowns as the provisionals allows patients to leave on the day of surgery with essentially the same esthetic condition in which they arrived. Patients find it reassuring to know that they will be able to wear their own tooth (or a close match in cases where the patient’s porcelain crown has fractured in the process of fabricating the provisional) as a fixed provisional crown. This seems particularly important in terms of minimizing the sense of loss invariably experienced by patients as they go through the process of replacing a tooth in the esthetic zone.


ACKNOWLEDGMENTS
On three occasions the author has presented (receiving honoraria) portions of the material in this paper at continuing education courses sponsored by Astra Tech USA, Waltham, MA. The author does not own any Astra Tech stock and did not receive any financial support during the clinical treatment of cases described herein, including having paid full price for all implants and prosthetic components used. All patients paid full fees for the treatments rendered. This was a true ‘‘private practice’’ endeavor. Dr. Doug McMaster of Tucson, Arizona, took the photograph used in Figure 1K and placed the crown for case 1.


REFERENCES
1. Stanford CM, Wagner W, Baena RRY, et al. Multicenter clinical evaluation (FOCUS) of a fluoride modified dental implant (abstract 1488). IADR 85th General Session. Available at: http://iadr.confex.com/iadr/ 2007orleans/techprogram/abstract_88356.htm.Accessed June 25, 2006. 2. Asplund P, Ceder F. The FOCUS project. Insight 2006; 8:16-17. 3. Zeren KJ. Minimally invasive extraction and immediate implant placement: The preservation of esthetics. Int J Periodontics Restorative Dent 2006;26:171-181. 4. Steigmann M, Wang H-L. Esthetic buccal flap for correction of buccal fenestration defects during flapless immediate implant surgery. J Periodontol 2006; 77:517-522. 5. Del Fabbro M, Testori T, Francwtti L, Taschieri S, Weinstein R. Systematic review of survival rates for immediately loaded implants. Int J Periodontics Restorative Dent 2006;26:249-263. 6. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol 1992;63:995-996. 7. Grunder U. Stability of the mucosa; topography around single-tooth implants and adjacent teeth: 1-year results. Int J Periodontics Restorative Dent 2000;20:11-17. Correspondence: Dr. Brien V. Harvey, 899 N. Wilmot, E-2, Tucson, AZ 85711. E-mail: brien@drbrienharvey.com. Accepted for publication October 12, 2006.

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Management and Prevention of Dental Caries In Children

There has been remarkable progress in the reduction of tooth decay in the U.S. over the past 30 years. Nevertheless, dental caries continues to be a significant problem for many children. Dental caries continues to be the most common infectious disease of childhood.

During the past few decades, changes have been observed in the prevalence and distribution of dental caries in the population. This disease is endemic in specific sectors of the population, especially the economically disadvantaged. Some children seem to have a mouthful of cavities, while other children have beautiful teeth. Eighty percent of the dental caries is found in only 25 percent of the children. More than half of all children in the U.S. have dental caries by the second grade of school. By the age of 17, approximately 80% of young people have had a dental cavity.

WHAT IS DENTAL CARIES?
Dental caries is an infectious, communicable disease, which causes destruction of teeth by acid-forming bacteria found in dental plaque. The most important concept to remember is that caries is a dynamic disease process, and not a static problem. Secondly, before a cavity is formed in the tooth, the caries infection can actually be reversed!

Caries progression or reversal is determined by the balance between protective and pathological factors in the mouth. The development of dental caries is a dynamic process: Demineralization of the hard dental tissue by the acidic products of bacterial metabolism – alternating with periods of remineralization.

The development of the carious lesion is episodic, with periods of demineralization alternating with periods of remineralization The lactic acid produced by the cariogenic bacterial dissolve the calcium phosphate mineral of the tooth enamel in a process call demineralization. Baby teeth have thinner enamel than permanent teeth, making them very susceptible to caries.

Dental caries in children is typically first observed clinically as a “white spot lesion.” If the tooth surface remains intact and non-cavitated, then remineralization of the enamel is possible. If the subsurface demineralization of enamel is extensive, it eventually causes the collapse of the overlying tooth surface, resulting in a “cavity.”

Saliva has a critical role in the prevention of dental caries. Saliva provides calcium, phosphate, proteins, lipids, antibacterial substances, and buffers. Saliva buffering can reverse the low pH in plaque, and with a higher pH, calcium and phosphate can be driven back into the tooth enamel. One factor that lowers the risk of cavity formation is normal salivary flow. Anything less than 0.7 ml/minute increases the risk for cavity development.



WHAT IS EARLY CHILDHOD CARIES?
Early childhood caries is a “virulent” form of dental caries that can destroy the teeth of preschool children and toddlers. Early childhood caries can also be defined as the occurrence of any sign of dental caries on any tooth surface during the first 3 years of a child’s life. Economically disadvantaged children are the most vulnerable to ECC.

Early childhood caries is an infectious disease, and the Streptococcus mutans bacteria is the main causative agent. Not only does S. mutans produce acid, it also thrives in acid. High sugar levels in the mouth increase the acid levels on the teeth. In children with ECC, oral Streptococcus mutans levels routinely exceed 30% of the cultivable dental plaque flora.

The clinical pattern of ECC is rampant and characteristic: First affecting the primary upper anterior teeth, followed by the upper primary molar teeth. The initial appearance of early childhood caries is white areas of demineralization on the surface of the enamel along the gum line of the upper incisor teeth. These white spot lesions progress such that they later become cavities that have been discolored. The mandibular incisors are protected by saliva and the position of the tongue during feeding. The ECC process may be so rapid that the teeth appear to have cavities “from the moment they erupt.”

The first event in the natural history of ECC is primary infection with S. mutans. The second event is the accumulation of S. mutans to pathologic levels, due to prolonged exposure to sugars. The third event is demineralization of enamel, which leads to cavity formation in teeth.

Early infection with S. mutans is a significant risk factor for future development of dental caries. Colonization of an infant’s mouth with this bacteria is usually the result of transmission from the child’s mother. S. mutans can apparently colonize the mouths of infants even before their teeth erupt. Children at high risk for early childhood caries may develop carious lesions on their upper front teeth soon after they erupt into the mouth. As the disease progresses, decay appears on the biting surfaces of the primary upper first molars.

New strategies for combating the infectious component using topical antimicrobial therapy appear promising.


THE CAUSES OF DENTAL CARIES - PATHOBIOLOGY
The caries process must be thought of as a dynamic alteration between demineralization and remineralization phases. This represents a competition between the pathologic factors (such as bacteria and carbohydrates) and the protective factors (such as saliva, calcium, phosphate and fluoride). They Keyes diagram (above) shows that cavities are the result of the interaction between a susceptible tooth, a dietary substrate (sugar), a chronic bacterial infection, and time.

Streptococcus mutans is the major cariogenic bacterium. S. mutans forms glucan and levan polymers that are adhesive. The bacteria, along with the polymers, work together to form a biofilm – called dental plaque. The bacteria use a substrate (sugar) to produce acids that dissolve dental enamel. Repeated demineralization by these acids leads to dental cavities.

S. mutans has been highly associated with dental caries. The proportion of S. mutans in plaque associated with ECC can be 30% to 50% of the total viable bacterial counts in dental plaque. In contrast, S. mutans usually constitutes less than 1% of the plaque flora in non-caries active children. Lactobacilli are highly acidogenic microorganisms, associated more with deep cavities in dentin than with the initiation of the disease. Lactobacilli counts alone are not considered reliable enough in predicting dental caries activity, however.



RISK FACTORS FOR DENTAL CARIES
The causes of caries are multifactorial, and the individual risk factors associated with ECC are therefore not necessarily causative.
Frequent intake of carbohydrate-rich or sugary foods enables the cariogenic bacteria to maintain a low pH on the surfaces of the teeth.
Night- time bottle feeding, or prolonged use of a sippy cup, can lead to early childhood caries. The flow of saliva is decreased during sleep, so clearance of the sugary liquid from the oral cavity is slowed down.
The earlier that a child’s mouth is infected with Mutans streptococci, the greater the risk for future caries development.
Children who already have one or more dental cavities are considered high risk for developing more.
A low fluoride level on the surface of the teeth reduces the remineralization process and increases the risk for caries.
When the saliva flow is below 0.7 ml/minute, the saliva cannot wash carbohydrates off the dental surface. In addition, low salivary buffering capacity, low salivary IgA, low salivary calcium, and low salivary phosphate reduce the potential for neutralization of acids in the dental plaque.
Finally, a low socioeconomic status can reduce interest in oral hygiene and a healthy diet.



CARIES RISK ASSESSMENT
Effective dental care requires early identification of children at high risk for dental caries, so that they may receive early and intensive intervention. Caries risk assessment is one of the most important goals of a child’s first oral examination. The goal of caries risk assessment is to deliver patient-specific diagnostic, preventive, and restorative services – based on the needs of each individual child. Caries risk describes the status of the whole patient. It can be defined as the likelihood of a child getting a new cavity.

Universal preventive strategies for all children are no longer appropriate. Since dental caries is no longer pandemic, but rather confined to a specific subset of children and tooth morphology types – a new risk assessment strategy is required. The nonexclusive contributory disease model of caries has three components: “Environment,” “genetic,” and “infectious agent.” In this model, any component may contribute to formation of a cavity – but does not necessarily cause it. Environmental factors include: Sugar consumption, fluoride exposure, oral hygiene practices, and socioeconomic status.

Inherited disorders that affect dental development or salivary flow may increase the risk of dental caries.

Streptococcus mutans levels above 500,000 colony-forming units per milliliter of saliva are associated with higher levels of smooth surface caries in the child. The higher the mother’s own level of S. mutans, the greater the likelihood of transmitting the bacteria to the infant. The best predictor of future caries activity is actually the child’s past caries experience.

Completing a clinical investigation for dental caries is another important goal during a child’s first oral examination.
During the dental examination, the presence of open cavities and fillings represents the prevalence of the disease - which is the most important indicator of the balance between resistance factors and caries inducing agents.
The incidence of the disease must also be evaluated. Caries incidence may be determined by observing the speed at which existing lesions enlarge, or by observing the development of new carious lesions between two clinical examinations. The placement of new restorations within a short period of time indicates a high caries risk in the past.

During the initial dental examination, the number of teeth and restorations should be noted. The number of cavities, and their active or inactive status should be noted: Dark hard tissues indicate inactive dental lesions. The presence of lesions on smooth dental surfaces indicates a high caries risk situation. Furthermore, the development of carious lesions with minimal plaque deposits indicates a very high risk for caries!

Decalcifications should be carefully examined, charted in the record, and demonstrated to parents as evidence of pre-cavitation caries activity. Decalcifications usually appear as discrete white spots. These lesions are amenable to home hygiene and fluoride varnish treatment.



THE ROLE OF DIET IN DENTAL CARIES
The role of diet in ECC disease is critical. Consumption of sucrose is one of the most important factors leading to caries development. Children with early childhood caries often experience frequent or prolonged consumption of sugary liquids.

Sucrose, glucose, and fructose contained in fruit juices are easily metabolized by S. mutans bacteria to form acids which slowly dissolve teeth. Bottles and sippy cups containing juice greatly increase the risk of developing ECC.


BIOCHEMICAL AND MICROBIOLOGIC TESTS FOR DENTAL CARIES
Determination of oral MS bacterial levels can be done using a laboratory facility, or a chairside kit.

When using a laboratory facility, the stimulated saliva is collected after chewing on paraffin for 5 minutes. It is then transported in a special medium to the laboratory. After incubation on selective medium agar plates, the MS colonies on the plates are counted. The results are expressed as colony forming units (CFU) per ml of saliva.

When using a chairside kit for determining MS levels, the choices include an agar kit or a Strip Mutans test. One example of the agar kit is “Cariescreen.” An example of the Strip Mutans test is the “Dentocult Strip Mutans.” All of these kits need to be incubated for 48 hours before they can be read. Caries risk threshold is usually set for values ≥ 100,000 CFU/ml of saliva.

Salivary flow and composition can also affect the health of oral soft and hard tissues. The clearance of acid metabolites by saliva is an important defense mechanism against hard tissue demineralization. To measure the flow of saliva, the child is asked to chew a paraffin tablet for 1 to 2 minutes, and to swallow the saliva. The timer then starts. The child is then asked to chew the paraffin for 5 minutes, frequently spitting saliva into a graduated test tube. When the time is up, the amount of secretion is recorded in milliliters, and the flow rate is calculated in ml/min. Normal stimulated salivary flow in adults is greater than 1.0 ml/min.

The salivary buffer systems act as regulator of oral pH and thereby act to control the remineralization-demineralization process. This capacity is based on the phosphate system, as well as the carbonic acid and bicarbonate systems. Inorganic phosphate is the most concentrated buffer of non-stimulated saliva, while carbonic acid and bicarbonate are the most important in stimulated saliva.



THE MEDICAL MODEL FOR MANAGEMENT OF DENTAL CARIES
In the past the treatment for dental caries was to “drill and fill.” Restorative dentistry unfortunately has little long-term impact on oral S. mutans levels. Diet counseling and educating parents about undesirable feeding practices has also had minimal success in decreasing ECC in high-risk groups of children. Optimal long-term results can only be achieved by treatment of the underlying caries process.

The modern approach to caries management is the “medical model.” The medical model treats the underlying caries process, and has 4 steps:
1) Gaining control of the bacterial infection.
2) Reduction of risk levels.
3) Remineralization of teeth.
4) Long term follow-up.

1) Gaining control of the bacterial infection:
The control of S. mutans is accomplished in two phases: Caries control, followed by chemotheraputic medication. We will start with caries control – treating the cavitated lesions with glass ionomer cements.

1a) Caries control:
The goal of caries control is to reduce the bacterial burden in the mouth of the child. Minimally invasive caries control, also called Atraumatic Restorative Treatment, reduces both the current and future treatment expenses. This mechanical measure will enable the subsequent chemotherapy to be more effective. At caries control visits, the teeth are excavated with spoon excavators and glass ionomer cement is used to seal the teeth. The dentist can be confident that the caries control process has been successfully managed when caries excavation is complete and parents are engaged in managing their child’s disease.

1b) Chemotheraputic medication:
The second phase of gaining control of the oral bacteria involves chemotheraputic antibacterial therapy. A combination of fluoride varnish and chlorhexidine application is used to lower the Mutans streptococci count.

Fluoride varnish can be used alone, or in combination with other antimicrobial agents. The varnishes contain 5% sodium fluoride (NaF) at 22,600 ppm of fluoride. There is a mean caries reduction of 38% when fluoride varnish is used in caries prevention. In an aggressive preventive program, varnish can be applied 3 times within a 10 day period. This is followed by another varnish application every 3 months for the first year. The NIH consensus statement on caries notes that only fluorides and chlorhexidine gluconate are proven antimicrobial treatments for dental caries.

Another successful antibacterial therapy against cariogenic bacteria is treatment with a chlorhexidine gluconate rinse or gel. The 0.12% chlorhexidine gluconate can be applied to toddlers’ teeth twice a day for 14 days. It is applied at least 30 minutes after the use of toothpaste because the sodium lauryl sulfate contained in most toothpastes will neutralize chlohexidine gluconate. It has a long history of safety. If the bacterial challenge is extremely high, only chlorhexidine can successfully deal with the infection.

2) Reduction of risk levels:
Step two in the medical model is reduction of the risk levels for patients. First, sugar intake must be reduced. A dietary assessment can identify when sugar consumption needs to decreased . Increasing fluoride use at home will also reduce the risk of dental caries.

3) Remineralization of teeth:
Step three in the medical model of caries management is the reversal of active caries site by remineralization. There are four parts to this step:
a)Fluoride varnish is applied 3 times in a 10 day period.
b)Fluoride is applied at home. A fluoridated dentifrice is used twice daily. Application of 1.1% NaF gel by toothbrush is recommended for very high risk children with dentin caries.
c)Xylitol gum is recommended.
d)A source of calcium, such as cheese, is also recommended.

4) Long term follow-up:
The last step in the medical model is long term follow-up at home and in the dental office. The office recall frequency should be every 3 months for high risk patients and every six months for low risk cases. Caries activity and risk are re-evaluated at the dental recall visits.



STRATEGIES FOR PREVENTING DENTAL CARIES
1) First, the most important component in the treatment of the caries disease is prevention. Understanding the balance between pathological factors and protective factors is the key to successful prevention of caries.
2) Second, any preventive program for ECC must involve the participation of the parent or caregiver.
3) Third, preventive activities must art at an early age.

There are three principal ways to prevent ECC:
Community-based programs
Home-care methods
Professional dental measures

Professional dental measures are conducted mostly at a dental office. The goal of primary prevention is to decrease or postpone the transmission of Mutans streptococci from mother to child. Preventive therapy should be based on the risk factors for a particular child.

Chemotheraputic treatment of caries is based on the use of two well-known agents (fluoride and chlorhexidine) to achieve selective antimicrobial control of carious microflora. Fluoride and chlorhexidine have an antimicrobial action against MS that is significantly higher than that which they have against other noncariogenic bacterial species.

The systemic and topical use of fluoride is the most effective measure to prevent dental caries. Fluoride, the key agent in battling caries, works primarily by topical action: inhibition of demineralization and enhancement of remineralization. Twice daily exposure to topical fluoride via fluoridated toothpaste is a major component of caries prevention therapy. Fluoride varnish may be applied with a soft brush, and reapplication is recommended every 3 to 6 months.

The anticaries action of fluoride results from two different mechanisms.
First, the fluoride ion is incorporated into the hard tissues of the tooth, strengthening its crystalline structure.
Second, the fluoride ion is able to interfere with the metabolism of cariogenic microorganisms, reducing both their number and pathogenicity. Fluoride inhibits enolase, an enzyme which bacteria need to metabolize carbohydrates.

The differential sensitivity of MS to chlorhexidine makes selective chemotheraputic treatment of caries possible. When chlorhexidine is used in high risk subjects, significant reduction (50%) in children of new lesion development can be obtained. Chlorhexidine varnish seems promising, because the concentration of chlorhexidine, and the frequency of chemotheraputic treatment are the most important factors to prolong MS suppression. EC40 and Chlorzoin are two European chlorhexidine varnishes used for the prevention of dental caries.

There is one other chemotheraputic agent for caries which is currently being researched: providine-iodine. Ten percent provodine-iodine solution may be applied to the teeth of infants at high risk for ECC. Iodine may be appropriate as long as the infant is not allergic to it. Iodine kills all of the bad dental bacteria for three to four months.



THE FOCUS ON FLUORIDE VARNISH
It is now realized that the most important action mechanism of fluoride takes place on the enamel surface of the tooth. Fluoride inhibits the loss of minerals and promotes the remineralization process. Apart from water fluoridation, fluoride varnish seems to be the most suitable and documented fluoride regimen for the infant.

Fluoride varnish contains 2.26% fluoride ion. The actual amount of fluoride used per treatment is 5-11 mg. The volume of fluoride varnish per treatment (0.2 – 0.5 ml) is significantly less than the probable toxic value for a 10 kg child (2.0 ml). The plasma fluoride concentration after varnish application is barely measurable. Therefore, fluoride varnish is very safe for use on infants’ teeth!

Fluoride varnish is available under the trade names Durafluor and Duraphat. Fluoride varnish is recommended for use in preschool age children because of its ease of application, and it equivalency to APF gel systems. The varnish is applied with a small soft brush, and reapplication is recommended every 3 to 6 months. Data show an overall reduction of caries incidence after fluoride varnish applications, ranging from 18% to 70%, compared with untreated control subjects.



DIETARY FLUORIDE SUPPLEMENT
Fluoride incorporated during tooth development is insufficient to play significant role in caries protection. Fluoride is needed regularly throughout life to protect teeth against caries. Fluoride in solution, from topical sources, enhances remineralization by speeding up the growth of a new surface in the partially demineralized subsurface crystals in the carious dental lesion.

Recommendations for fluoride supplementation can be made based on the fluoride content of the water, the child’s age, and the child’s caries risk. The risk of dental fluorosis is highest during the period of enamel maturation, from 1 to 3 years of age.



THE FIRST DENTAL VISIT
The most important ask for today’s dentist is to identify the high caries-risk child before the clinical manifestations of the disease become apparent, and then to provide individualized protection to that child. The preventive process must begin early in infancy to ensure a child’s oral health.

The purpose of the first dental visit is to assess individual risk, and to educate the parent or caregiver about reducing such risk. A clinical examination is an essential part of a child’s first dental visit, and as an important part of risk assessment. A correct and efficient diagnostic investigation must include the identification and evaluation of risk factors.

An initial oral evaluation should occur within 6 months of the eruption of the first primary tooth, and no later than 12 months of age. The best way to accomplish a dental examination on an infant is the “knee-to-knee” method. The dentist and caregiver should sit knee-to-knee facing each other. The child’s legs should be placed around the parent’s waist, and the child’s head is placed in the cradle formed by the dentist’s lap. The dentist should look for early signs of dental caries. White spot lesions represent the early clinical manifestations of the caries process. These chalky lesions represent decalcified enamel, and this finding places the child at high risk for developing cavities.

Anticipatory guidance is another important element that must be incorporated into the child’s first dental visit. Anticipatory guidance refers to sharing with parents or caregivers information about the child’s current oral health status, as well as future needs. When preventive information is provided to parents, it must be easily understood and easily used. The information must as a clear as possible. Diet counseling is an integral part of anticipatory guidance. Bottle-fed infants should not be put to sleep with the bottle. Nocturnal breast-feeding should be discouraged after the first upper incisor erupts. Only 6 ounces of fruit juice should be consumed by infants each day.


During the first dental visit, a variety of information needs to be gathered which will be used in the “non-exclusive contributory disease model” of dental caries. The required information falls into three categories: environmental factors, infectious agent and genetic factors.

1) Environmental factors are noted:
Existing dental caries, estimated sugar intake, estimated fluoride exposure, socioeconomic status, oral hygiene practices, and dietary habits are recorded.

2) Infectious agents can be assessed using microbial sampling, such as the Dentocult SM Strip for assaying MS levels in the mouth.

3) Genetic factors can be evaluated, including:
Salivary flow, salivary buffering capacity, and tooth morphology disorders.



XYLITOL GUM
Xylitol is a naturally occurring, low-calorie sugar substitute with anticariogenic properties. It is a sugar alcohol, derived mainly from birch and other hardwood trees. Xylitol contains 40% fewer calories than sucrose. Data from recent studies indicate that xylitol can reduce the occurrence of dental caries in young children.



TIPS FOR PARENTS
The American Academy of Pediatric Dentistry, the American Dental Association, and the Academy of General Dentistry recommend that children visit a dentist within six months of the eruption of the first tooth, and no later than 12 months of age.
Infants should not be put to sleep with a bottle. Breast-feeding at night should be avoided after 12 months of age.
Infants should be weaned from the bottle at 12-14 months of age.
Consumption of juice from a bottle or sippy cup should be avoided. Juice should be offered to a child only in a cup. Infants and toddlers should drink no more than 6 ounces of juice per day.
Cleansing of the baby teeth should be started by the time of eruption of the first primary tooth. A small piece of clean gauze or a small toothbrush can be used.

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