Hand instrumentation: exploring your options: part 1.

The most difficult and critical nonsurgical periodontal therapy is root debridement involving scaling and root planing. (1) Achieving optimal gingival health after nonsurgical periodontal instrumentation begins with dental hygienists ensuring that the root surfaces are smooth and free of biofilm and calculus. Dental hygiene treatment has two main areas of focus: initial therapy and maintenance therapy. Modifications or additions to our traditional armamentarium may improve our abilities to identify and remove deposits during both phases of therapy. (2)

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Initial Therapy

Nonsurgical periodontal therapy provided during initial therapy begins with the development of a dental hygiene treatment plan for patients based on information collected during the examination. This includes the medical and dental history, radiographic evaluation and periodontal assessment (probing, mobility, furcation involvement, gingival findings). One of the most important data collection processes is evaluation of the deposits present.

The dental hygienist must take the time to detect and assess the calculus deposits and can do so by using a variety of diagnostic instruments. Deposits cannot be removed if the dental hygienist cannot detect them. The explorer tip used to evaluate root surfaces can be larger than some of the edges of burnished calculus that need to be removed. (3) Therefore, the use of a very fine explorer tip with a shank that provides access to deep pockets is necessary. Periodontal probing should never be underestimated: it not only measures probing depth, but it also determines the topographical map of the pockets that are in need of treatment and is crucial to the clinical evaluation and treatment plan development. (4) An array of probes is available to improve the diagnostic skills of the clinician. Once the diagnosis has been completed and the dental hygiene treatment plan has been determined, deposit removal is initiated.

Effective calculus removal depends on initially accessing the deposits and then using a combination of firm lateral pressure and correct angulation of the blade against the tooth. Burnished calculus will result from inadequate pressure or an incorrect angle. To achieve the correct angle, a variety of instruments and reinforced hand positions should be considered, as well as extraoral or alternative fulcrums. These can provide increased power when using hand instruments. (5) Dental hygienists can occasionally review root morphology to refresh their knowledge of all of the developmental grooves, the heights of contour, developmental depressions, the location of the cementoenamel junction line of contour and the general anatomy of the furcations. A strong foundation in root morphology provides a highly developed understanding of where to find the potential challenges to effective instrumentation. All of these tools are important in helping visualize where the instrument blade is to be adapted and the texture of root surfaces when calculus/deposit free. Modifications to hand instruments have been made to facilitate blade adaptation once the deposits or root surface to be addressed has been determined.

Deposit removal will be neither time efficient nor technically successful no matter what instruments you have chosen, if they do not have a sharp cutting edge. Instruments require sharpening throughout the entire initial phase of treatment. (6), (7) Calculus will inevitably get burnished onto the tooth surface if dull instruments are used, and burnished calculus is more difficult to remove than the initial deposit. Removal of burnished calculus requires a different instrumentation approach than the initial technique used.

Power instrumentation plays a huge role in initial therapy. Because of the thinning and miniaturization of the tips, power instruments have become far more useful and beneficial in removing deposits subgingivally. While it is still possible to gouge roots and burnish calculus with power instruments, they nevertheless greatly reduce the effort required to remove deposits. (8) Ultrasonic instrumentation cannot completely remove subgingival deposits from all the surfaces of the roots and is limited in pockets over 4 mm. Follow-up with hand instruments is always required, especially on interproximal surfaces directly under the contact where the small active portion of a sonic or ultrasonic tip is difficult to adapt. Root coverage is very important, and only a very small portion of the ultrasonic tip is vibrating optimally for deposit removal, This active portion of the tip must touch the entire root surface to ensure thorough deposit removal. A combination of both hand and power instrumentation is the preferred approach.

Degree of root smoothness achieved during initial therapy will be one of the most important factors affecting subsequent maintenance therapy appointments. Root surface smoothness is the criterion for immediate evaluation of scaling and root planing and the most successful evaluation tool to determine complete removal of the calculus and accompanying pathogens. Complete removal of calculus gives the tissue the greatest opportunity to return to a healthy state. Rough root surfaces are very difficult to deplaque and detoxify. If the root surface is smooth, maintenance therapy can be carried out in a much more efficient manner. (9) Subsequent instrumentation and evaluation are straightforward.

Maintenance Therapy

The primary goal of maintenance or supportive periodontal therapy is to remove the bacterial microflora that has re-established since initial therapy. In the time between initial therapy and the first re-evaluation appointment, inflammation in the pocket wall is reduced, and the connective tissue fibres become healthier. As a result, the pocket wall becomes firmer and tighter, and a long junctional epithelium attachment forms. Very little actual bone or cementum is being redeposited, so the epithelial attachment is fragile. The recolonization of the pathogenic biofilm takes approximately three months, and as inflammation recurs, the tissue becomes looser and more flaccid, causing deterioration of the long junctional epithelial attachment. It's a balancing act: the maintenance appointment needs to occur before inflammation at the base of the pocket is re-established because, unless it does, there is a risk of continued loss of alveolar bone and connective tissue attachment. Patients must understand that their pockets haven't disappeared; instead, a nice healthy band of tissue is now hugging the tooth that can become loose again. The preservation of our patients' teeth depends on removing the bacterial microflora from the root surfaces within the pockets on a regular basis. Debridement and the motivation provided by the dental hygienists for their patients at regularly scheduled maintenance therapy appointments are what will make treatment successful.

The bacterial microflora that reforms is lightly adhered to the tooth, so only light instrumentation strokes are required. (9) Mechanical friction disorganizes the bacterial biofilm, and for thorough disorganization, the entire root surface must be contacted. If power instrumentation is selected, fine tips should be used on a very low power setting to prevent unnecessary removal of tooth structure, and the tip must contact the entire tooth surface. The blade of a hand instrument provides more surface area to contact the tooth surface and is therefore more efficient.

Whether power or hand instrumentation is used, thorough root debridement is accomplished using a series of careful, close, overlapping gentle strokes so that the entire root surface is deplaqued and detoxified. Hand instruments can be divided into sets identified for initial and maintenance therapy. A dull blade provides maximum surface area to contact the root surfaces, while sharp new blades are used for shearing off deposits during initial therapy. Older hand instruments demonstrating reduced blade width can be placed in maintenance therapy sets, while the new ones are used for initial therapy.

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Dental hygienists need to have a sufficient armamentarium at their disposal to access all root surfaces and remove deposits. Following are some alternatives available in hand instruments to aid in complete deposit removal and the resulting tissue resolution, as well as some factors to consider when making instrument choices.

Instrument Use as Determined by Pocket Depth

There have been significant advancements in hand instruments and techniques over the years. "Development in instrument design and materials has furthered the dental hygienist's ability to scale tenacious calculus in deep pockets and furcations." (2) We can now provide nonsurgical periodontal therapy to greater depths and with increased predictability than our counterparts were able to in the past.

This review focuses on hand instruments used for the provision of dental hygiene treatment. Hand instruments can be grouped by their area of use for:

1. Supragingival instrumentation

2. Subgingival instrumentation

a. 1mm--4 mm

b. 4 mm to gingival attachment level

Hand instruments have been modified in many ways to provide improved access and adaptation for the different areas requiring instrumentation and to meet the challenges of a variety of potential deposit situations. These modifications include:

* Angulation of the blade to the shank

* Length of the shank

* Length of blade

* Shape of blade

* Location of blade on the shank

* Modifications that allow the practitioner to use various strokes

* Modifications that facilitate furcation instrumentation

There are many modified instruments that the clinician may find useful in practice. There are some assessment questions that can help the clinician evaluate case by case whether an instrument should be included in their armamentarium and what its benefit will be. Of course, intraoral trial and error and the resulting deposit removal are the true tests. The assessment questions that can be used to help focus a personal evaluation of instruments are:

* Access--Can the blade be positioned where it is to be adapted to tooth surfaces?

* Adaptability--Can the blade contact tooth surfaces where instrumentation is required? For example: under contact areas, within furcations or root concavities, etc.

* Activation--Can the blade be activated with the appropriate strokes? Some instruments are designed for heavy powerful stokes, while others are applied with light shaving strokes.

* Comfort--Does the instrument have any qualities that improve comfort for the clinician? For example: a light, large, round handle or grip.

* Modification (if applicable)--Does the instrument feature any modification to improve any qualities for the clinician while in use? For example: a longer terminal shank, shortened blade, etc.?

There have been technological modifications to address specific issues or to improve general comfort in use of the instrument. Examples are variations in handles (stainless steel, resin, etc.) and blades that require little sharpening (EverEdge[TM) and instruments for implants. Table I above and Table II on pages 32 and 33 are lists of some of the available instruments and are grouped by clinical diagnosis of pocket depth.

Table I. Suprgingival Modified Instruments

Name Product code   Blade description  Modification/Details
                    and area of use

Nevi 1 * (SCNEVI1)  Nevi Scalers-      Can be used with a push or pull
                    Disc end Anterior  stroke in all directions Easy
                    use                sharpening with a Bates-style
                                       channel stone

                    Nevi Scalers -     Super-thin anterior curved
                    Sickle end         sickle Ideal for interproximal
                    Anteior use        and curved anterior deposit
                                       removal

Nevi 2 * (SCNEI2)   Posterior use      Super-thin posterior curved
                                       sickle scaler Unique
                                       contra-angle design Great for
                                       interproximal reach and
                                       ergonomic hand positioning

SN135 *             Posterior use      Posterior use scaler Improved
                                       interproximal access for
                                       posterior scaling Rounded back
                                       for less trauma Pointed toe for
                                       hard-to-reach under-contact
                                       areas

Y-ME Curette *      Anterior/Premoler  Contra-angle petite shank
SYME9               use                design coupled with a
                                       70[degrees] offset single
                                       cutting edge provides optimal
                                       tooth-to-blade angulation

                                       Beneficial for line angle
                                       access and pedodontic dentition

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2 Gillette/15       Anterior Use       Disc-shaped end that may be
Younger-Good                           used in a push or pull stroke m
Scaler *                               all directions Super-thin
                                       anterior curved sickle scaler
                                       with a reduced blade length
                                       Ideal for lingual stain and
                                       calculus removal

Montana Jack **     Posterior Use      This scaler is narrower than
Nevi 4 *                               typical scalers with a
                                       contra-angled sweeping blade.
                                       It comes in a Rigid shank
                                       design. **

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SN137 *HS-L5 **     Anterior Use       Replaces two instruments It has
                    Scaler curette     a universal curette on one end
                    combination        and a sickle scaler on the
                                       other It also comes with a mini
                                       curette end and the scaler.
                                       Reduced time searching More
                                       adaptation needed to really
                                       effectively use

* Hu-Friedy
** PDT
*** American Eagle

This column, part 1, includes instruments modified for supragingival and subgingival use in periodontal pockets to 4 mm in depth. A continuation, part 2, will include instruments modified for subgingival use in periodontal pockets over 4 mm in depth to the gingival attachment level and technological modifications of hand instruments to improve comfort or blade integrity.

Subgingival Instruments for Use in Pocket Depths of 1mm - 4mm

Universal and Gracey curettes are the instruments of choice in sulci of normal depth. In shallow sulci, the root surface is broad and generally flat, and a regular blade length is appropriate to adapt to all surfaces. There are concavities and depressions on the root surfaces, but they are generally shallow and can be accessed with the regular dental hygiene armamentarium such as the traditional Gracey and Universal curettes.

Problems can arise when calculus has been previously burnished, whether by hand or ultrasonic instrumentation. Additional instruments will be required to provide a variety of strokes and improve access and adaptability of the blade to provide the force necessary to crush the burnished calculus. Universal curettes are popular instruments of choice in pockets of 1-4 mm. As pocket depths increase when the blade is adapted at the correct angle, the terminal shank compensates and loses the parallel relationship to the surface being instrumented when using universal curettes. The compensation in retaining the parallelism of the terminal shank results in the loss of the ability to access the base of the pocket, and other instrument choices must be made.

Table II. Subgingival Instruments 1-4 mm

Name                Blade          Modification/Details
                    description
                    and area of
                    use

Nabers Furcation    Diagnostic     Modified terminal shank in a curved
Probe                              shape to adapt into furcations with
(Color-coded)                      2 mm markings on the probe
                                   Designed for furcation detection
                                   <1mm Class I
                                   >1mm Class II
                                   Class III furcations connect and
                                   covered with soft tissue
                                   Class IV furcations connect and
                                   clinically exposed

EXD 11/12 Explorer  Diagnostic     Old Dominion University explorer
                                   utilizing the shank design of a
                                   Gracey 11/12; tip is curved like
                                   the 11/12. For subgingival deposit
                                   detection. This is ideal for
                                   posterior calculus detection.
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Columbia 4R/4L      Universal      Blade at 90 degrees to terminal
                    Curette        shank so two cutting surfaces can
                                   be utilized Moderate shank length
                                   for crown clearance and enhanced
                                   access

Columbia 13/14      Universal      Blade at 90 degrees to terminal
                    Curette        shank so two cutting surfaces can
                                   be utilized Moderate shank length
                                   for crown clearance and enhanced
                                   access

McCalls 13/14       Universal       Blade at 90 degrees to terminal
                    Curette        shank so two cutting surfaces can
                                   be utilized Designed with enhanced
                                   rigidity for removal of challenging
                                   deposits

Barnhart 1/2, 5/6   Universal      Blade at 90 degrees to terminal
                    Curette        shank so two cutting surfaces can
                                   be utilized Barnhart 1/2: longer
                                   terminal shank for extended reach,
                                   crown clearance Barnhart 5/6:
                                   shorter terminal shank, longer
                                   blade length

Younger-Good 7/8    Universal      Blade at 90 degrees to terminal
                    Curette        shank so two cutting surfaces can
                                   be utilized Blade shape is narrower
                                   at the heel, pronounced rounded toe
                                   Subtle transition from terminal
                                   shank to working end

15/16 Gracey        Posterior      The terminal shank is modified to
Curette (SGR        sextants       reflect the 13/14 angle of terminal
15/16) Modified     Buccal,        shank with he 11/12 blade angle for
Gracey Curette      lingual and    mesial surfaces. It is used to
                    mesial         improve adaptation to the mesial
                    surfaces of    surfaces of posterior teeth by
                    premolars,     improving fulcrum capabilities. It
                    molars         compares to using the 11/12 Gracey
                                   Curette but has a more dramatic
                                   terminal shank angle. It reaches
                                   intraorally to posterior teeth and
                                   allows for improved blade angle to
                                   the mesial posterior teeth
                                   surfaces.

15/16 Rigid Gracey  Area-specific  Rigid Gracey Curettes reflect a
Curette (SGR        designs        modified terminal shank. The shank
15/16) Modified     Scaling when   is thickened to reduce instrument
Gracey Curette      less flexion   spring when removing tenacious
                    is preferred   calculus deposits. They have the
                                   identical blade size as standard
                                   Graceys

15/16 Extra Rigid                  Extra-Rigid Gracey Curettes reflect
Gracey Curette                     a modified terminal shank. The
(SGR 15/16)                        shank is extra thickened to further
Modified Gracey                    reduce instrument spring when
Curette                            removing tenacious calculus
                                   deposits and also has the identical
                                   blade size as standard Graceys.

17/18 Gracey        Posterior      The 17/18 has a modified terminal
Curette (SGR        Sextants       shank and blade. The terminal shank
17/18)              Distal         is modified to reflect a more
                    surfaces of    dramatic angle to improve
                    premolars,     adaptation to the distal surfaces
                    molars         of posterior teeth. It also has a
                                   thickened shank to reduce
                                   instrument spring when removing
                                   tenacious calculus deposits. It has
                                   a reduced blade length. The 17/18
                                   compares to the 13/14 Gracey
                                   curette.

17/18 Gracey        Area-specific  Rigid Gracey Curettes See 15/16
Curette (SR 17/18)  designs        Rigid
                    Scaling when
                    less flexion
                    is preferred

17/18 Gracey                       Extra-Rigid Gracey Curettes See
Curette (SR 17/18)                 15/16 Extra-Rigid

Langer Curettes     Area-specific  They have a universal blade with
                    designs        Gracey shank design. They have two
                                   blades on each end. A set of the
                                   instruments is required. The SL 3/4
                                   completes the scaling of the
                                   maxillary posteriors, the SL 1/2
                                   instrument the mandibular
                                   posteriors and the SL 5/6 is used
                                   to instrument the mandibular and
                                   maxillary anteriors.

Millennium          Area-specific  Less tissue distension Handles
Curettes 3D - SRP   designs        color-coded to area of use The
Trisha O'Hehir                     unique 3D design presents a blade
                                   with a cutting area of
                                   approximately 310 degrees and can
                                   be utilized in either a push or
                                   pull motion, vertically, laterally
                                   or diagonally.

Debridement         Area-specific  Small disc-shaped blades Entire
Curettes 1/2        designs        edge of the blade is a cutting edge
Buccal - Lingual                   enabling a push or pull stroke in
(Posterior) 3/4                    all directions Extended shank for
Mesial - Distal                    access
(Posterior)
5/6--Anterior 7/8
Extended--Anterior

Turgeon Curettes    Area-specific  Modified blade is triangular in
                    designs        cross-section Back of blade is
                                   thinned to provide a sharper blade
                                   that is easier to sharpen Numbers
                                   are the same as traditional Gracey
                                   curette

Quetin Curette      Area-specific  Quetin Curette - SQBL, SQMD
                    designs        Modified blade is on the tip of the
                                   instrument Needs to be sharpened
                                   right around the tip Available in
                                   blade widths of 1.3 mm and 0.9 mm

DeMarco Curettes    Area-specific  Modified blade is disc-shaped to
                    designs        adapt to root concavities and
                                   furcations Adapt to labial and
                                   lingual surfaces SDM1 Large disc
                                   blade SDM2 Smaller disc blade

Hirschfeld/Orban    Area-specific  Crush burnished calculus
Files               designs        Emargination--excess amalgam
                                   removal Files are difficult to
                                   sharpen.

References

(1.) Cobb CM. Clinical significance of nonsurgical periodontal therapy: an evidence-based perspective of seating and root planning. J Clin Perio. 2002; 29(suppl 2): 6-16.

(2.) Pattison AM. Advancements in hand instrumentation. Dimensions of Dental Hygiene. May 2006, 4(5): 26-7.

(3.) Sherman PR, Hutchens LH, Jewson LG, et al. The effectiveness of subgingival scaling and root planing I. clinical detection of residual calculus. J Periodontol. 1990; 61(1): 9-16.

(4.) Matusda SA. The power of the probe. Dimensions of Dental Hygiene. April 2007; 5(4): 26-9.

(5.) Pattison AM. Trends in instrumentation. Dimensions of Dental Hygiene. July 2005; 3(7): 26-7.

(6.) Tal H, Pannot JM, Vaidyanathan TK. Scanning electron microscope evaluation of wear of dental curettes during standardized root planing. J Periodontol. 1985; 56(9): 532-6.

(7.) Zappa UE. Factors determining the outcome of scaling and root planing. Can Dent Hyg/Probe. 1992; 26.

(8.) Stach D. Back to basics. Dimensions of Dental Hygiene. April 2007; 5(4): 26-9.

(9.) Pattison AM. The use of hand instruments in supportive periodontal treatment. Periodontol 2000. 1996; 12: 71-89.

(10.) Hodges K. The challenges of furcations. Dimensions of Dental Hygiene. February 2008; 6(2): 34-36, 38.

(11.) Rosling B, Serino G, Hellstrom MK et al, Longitudinal periodontal tissue alterations during supportive therapy. J Clin Periodontol. 2001; 28(3): 241-9.

(12.) Darby I, Non-surgical management of periodontal disease. Australian Dent J. 2009; 54(Suppl 1): S86-S95.

This column was made possible by an educational grant sponsored by Hu-Friedy Mfg. Co.,Inc.

Barbara Long, SDT, RDH, CACE, BGS, is currently a lecturer and clinical instructor at the College of Dentistry, University of Saskatchewan and provides professional development programs for dental hygienists. Designer of dental instruments, she holds the patent for the "Vision Curvettes." Registrar-executive eirector of the Saskatchewan Dental Hygienists' Association, she has made significant contributions to the dental hygiene profession through research, clinical experience and active membership in professional associations.

By Barbara Long, SDT, RDH, CACE, BGS