I. Multi-Dimensional Classification of Diamond Burs

In the field of oral healthcare, diamond burs are extremely important tools for dentists. Their diverse classifications can meet a variety of complex clinical needs. Diamond burs have detailed and practical classification methods based on abrasive grain size, functional design, and head shape.

(I) Classification by Abrasive Grain Size: Layered Control from Coarse to Fine

Coarse-grain burs (125 - 150μm): Their shanks are usually marked with black or green rings, and they function like "bulldozers" in dentistry. When faced with large-area tooth cutting tasks—such as quickly removing a large amount of decayed tissue in cases of severe dental caries, or preparing a large space for denture placement—they can rapidly cut through tooth structure with their large abrasive grains, completing the task efficiently.

Standard-grain burs (106 - 125μm): Marked with blue rings, they are known as the "all-rounders" among burs. They perform excellently in routine tooth preparation work, such as treating common dental caries (removing carious tissue and preparing appropriate cavity shapes) and conducting initial trimming of teeth during full crown preparation. They strike a good balance between treatment efficiency and precision.

Fine-grain burs (53 - 63μm): Identified by red or colorless rings, they are like "meticulous craftsmen". After the initial treatment of a tooth, when fine grinding of the tooth surface is required to achieve a smoother surface and lay a good foundation for subsequent polishing procedures, these burs can play a precise role in removing tiny irregularities.

Extra-fine-grain burs (20 - 30μm): The yellow or white rings on their shanks indicate their identity as "polishing masters". In the final treatment stage of dental restorations, when a mirror-like gloss effect is desired, they perform extremely fine processing on the tooth surface with their ultra-fine abrasives. This ensures that the restored tooth not only regains its function but also achieves an aesthetic appearance close to that of natural teeth.

(II) Classification by Functional Design: Precise Adaptation to Clinical Scenarios

Initial grinding burs: Equipped with coarse abrasive grains larger than 150μm, they act as "pioneers in land reclamation" in oral treatment. When a large amount of tooth tissue needs to be cut—for example, removing old crown restorations or conducting initial trimming of severely worn or deformed teeth—they can complete the task quickly with their efficient cutting ability, significantly shortening treatment time.

Fine grinding burs: Using ultra-fine abrasive grains smaller than 40μm, they are well-deserved "detail adjusters". After the initial preparation of the tooth, they perform fine trimming on the tiny rough residues left on the tooth surface. This avoids problems such as bacterial growth caused by rough surfaces and poor adaptation of restorations, ensuring the tooth surface reaches the ideal level of flatness and smoothness.

Burs with special shank lengths: These burs fully consider individual differences among patients and different clinical situations.

Short-shank burs: Designed specifically for patients with limited mouth opening. Such patients have a small oral opening range, making it difficult to operate with regular burs. Short-shank burs can be flexibly used in the limited space to complete tooth preparation and other operations.Long-shank burs: Used to solve the problem of blind operation areas when the clinical crown is too long. Their extended shanks allow dentists to easily reach the deep part of the crown, achieving comprehensive treatment without blind spots.

Shoulder burs: Uniquely designed with abrasive grains only on the top of the tip, they are "customized experts" for precise trimming of the cervical shoulder of teeth. During crown restoration, the precise trimming of the tooth’s cervical shoulder is crucial, as it directly affects the adaptation and aesthetics of the restoration. Shoulder burs can only cut the shoulder area without damaging other parts of the prepared tooth, providing strong support for the stable placement and long-term use of the restoration.

(III) Classification by Head Shape: Versatile Designs for Complex Teeth

Round burs: Their working ends are spherical, acting like "pulp-opening drills" in oral treatment. When a patient needs pulp opening and drainage due to problems such as pulpitis, the spherical working end of the round bur can easily penetrate the hard enamel, quickly open the pulp chamber channel, release the pressure inside the pulp chamber, and relieve the patient’s pain. When removing deep decayed tissue, the spherical design can also better adapt to the irregular shape of the carious cavity, completely eliminating the decayed tissue.

Fissure burs: With a conical-cylindrical cutting edge, they are like "pioneers in hole expansion". During root canal treatment, they are mainly used to expand the root canal orifice, allowing subsequent root canal cleaning, disinfection, and filling instruments to enter smoothly. When preparing a cavity, they can also be used to deepen the cavity, providing sufficient space for filling materials and enhancing the filling effect.

Inverted cone burs: Featuring a unique inverted cone design, they are known as "undercut architects". During cavity preparation, to enhance the retention force between the filling material and the tooth, it is necessary to prepare a retention undercut at the bottom of the cavity. Inverted cone burs can accurately cut an inverted cone-shaped groove at the bottom of the cavity according to requirements, allowing the filling material to be better embedded in it. This effectively prevents the filling from falling off and extends the service life of the tooth restoration.

Flame-shaped burs (Series F): With a pointed tip shape, they are like "tooth surface carving knives". In anterior tooth restoration, they can flexibly shape the curve of the labial surface of anterior teeth, creating a natural and aesthetic tooth shape to meet the patient’s aesthetic needs. In posterior tooth treatment, for trimming the fine structures of the occlusal surface (such as cusps and fissures), flame-shaped burs can also exert their advantages by accurately adjusting the occlusal relationship to ensure the normal masticatory function of the teeth.

II. Clinical Applications: Precise Selection for Different Scenarios

In clinical oral treatment, diamond burs, with their excellent performance, play an irreplaceable role in various treatment scenarios. They have become a powerful assistant for dentists to achieve precise treatment and ensure patients’ oral health.

(I) Restorative Treatment: The Ideal Partner for Full Crown Preparation

Series T burs: In full crown restoration treatment, Series T burs are known as "customized tools". When performing full crown restoration for a patient, Series T burs with different tip shapes can accurately meet various needs. For example, flat-tipped Series T burs can provide a stable and flat cutting surface when cutting the axial surface of the crown, ensuring the precise placement of the restoration and laying a solid foundation for subsequent restoration work. Round-tipped Series T burs are more suitable for operations in areas that require smooth transitions—such as during the preparation of the shoulder for all-ceramic crowns, where they can gently trim the edge to make the shoulder shape natural and smooth, perfectly matching the aesthetic requirements of all-ceramic crowns.

Shoulder-specific burs: These are the "first choice" for trimming the cervical shoulder. During the restoration of porcelain-fused-to-metal crowns or all-ceramic crowns, the trimming of the cervical shoulder is crucial, as it directly relates to the adaptation and aesthetics of the restoration. Only the tip abrasive grains of shoulder-specific burs come into contact with the tooth, enabling precise trimming of the shoulder while minimizing damage to the surrounding healthy tissue. This provides an ideal edge shape for porcelain-fused-to-metal crowns/all-ceramic crowns, ensuring the restored tooth achieves the best performance in both function and appearance.

(II) Caries Treatment: Dual Protection for Decay Removal and Pulp Opening

In the treatment of dental caries, diamond burs undertake the key tasks of decay removal and pulp opening, serving as important tools to ensure treatment effectiveness.

Coarse-grain burs: Excel in removing carious tissue. With their large abrasive grains, they can quickly and effectively cut through the decayed parts, preventing the further spread of lesions and gaining time for subsequent treatment. After most of the carious tissue is removed, fine-grain burs come into play. They perform fine trimming on the inner wall of the cavity, removing residual tiny decayed tissue and irregularities, reducing the risk of microleakage. This ensures the filling material can closely adhere to the cavity wall, improving the filling effect and extending the service life of the restored tooth.

Pulp opening process: Round burs combined with fissure burs can complete the task efficiently and safely. Round burs take the lead—their spherical working ends can easily penetrate the hard enamel, accurately open the pulp chamber channel, release the pressure inside the pulp chamber, and quickly relieve the patient’s pain symptoms. Subsequently, fissure burs follow to expand the pulp chamber orifice, creating conditions for the smooth entry of subsequent root canal cleaning, disinfection, and filling instruments. The entire operation process is efficient and safe, laying a foundation for the success of root canal treatment.

(III) Aesthetic Adjustment: Fine Shaping of Tooth Morphology

In the field of aesthetic restoration, diamond burs are "art masters" that realize the fine shaping of tooth morphology.

Extra-fine-grain burs: Demonstrate unparalleled advantages in tooth surface polishing. After veneer restoration or resin restoration of teeth, there may be tiny defects on the surface—such as uneven edges and small scratches—which can affect the aesthetics of the teeth. Extra-fine-grain burs can perform extremely fine processing on the tooth surface with their ultra-fine abrasives, removing these tiny defects. This makes the surface of the restored tooth show a natural luster and blend with the surrounding teeth.

Flame-shaped burs: Play an important role in reshaping the proximal contact points of teeth. In daily life, abnormal proximal contact points of teeth may lead to food impaction, which not only affects oral hygiene but also may cause oral diseases such as dental caries. The pointed tip shape of flame-shaped burs allows them to flexibly process the proximal surface of teeth and accurately adjust the position and shape of proximal contact points, effectively improving the problem of food impaction. At the same time, during the adjustment of proximal contact points, flame-shaped burs can also take into account the aesthetics of the teeth, making the tooth shape more natural and harmonious, and truly achieving the perfect combination of function and aesthetics.

III. Usage Tips: Enhancing Both Safety and Efficiency

(I) Operation Standards: Mastering Three Key Elements

When using diamond burs, strictly following operation standards is crucial to ensuring the safety and efficiency of treatment. Among these standards, speed control, uniform pressure, and precise angle are the three key elements that require focused attention.

Speed control: Has a direct impact on treatment results. Due to their large abrasive grains, coarse-grain burs generate more heat during cutting. Therefore, it is recommended to use medium to low speeds, controlling the rotation speed between 100,000 and 200,000 revolutions per minute (rpm). This speed range not only ensures efficient cutting but also avoids excessive heat generation from high-speed friction, which could damage the dental pulp tissue and cause patient pain or pulp lesions. Fine-grain burs, on the other hand, are mainly used for fine surface processing—they have relatively lower requirements for cutting efficiency but higher requirements for surface flatness. Thus, the rotation speed can be appropriately increased to 200,000 - 300,000 rpm. At this speed, the burs can cut the tooth surface more smoothly, achieving the desired smooth cutting effect.

Uniform pressure: Is equally important. During operation, a constant pressure of 30 - 60 grams should be applied. If excessive force is exerted, the burs may get stuck, resulting in uneven cutting. In severe cases, this may even cause tooth fracture, affecting the treatment process and subsequent tooth restoration. It is crucial to use a water mist cooling system simultaneously—this system can promptly dissipate the heat generated by friction between the burs and the tooth, reducing thermal stimulation to the pulp and ensuring treatment is carried out in a safe temperature environment.

Precise angle: Is an important factor in ensuring the quality of restorations. Burs should cut along the long axis of the tooth—this ensures that the cutting direction is compatible with the physiological structure of the tooth, avoiding over-cutting or insufficient cutting. When preparing the shoulder, maintaining a 90° vertical angle is particularly critical. A precise vertical angle can ensure the prepared shoulder has a regular shape, providing good support and adaptation conditions for the restoration. This ensures the edge of the restoration closely adheres to the tooth, reducing the risk of microleakage and extending the service life of the restoration.

(II) Maintenance: Extending Service Life

Proper maintenance of diamond burs not only ensures their stable performance but also effectively extends their service life, reduces medical costs, and guarantees the smooth progress of treatment.

Strict disinfection process after use: After using the burs, ultrasonic cleaning should be performed immediately. High-frequency vibrations of ultrasonic waves are used to thoroughly remove residual tooth debris, bacteria, and other impurities from the surface of the burs. After cleaning, high-pressure sterilization at 135°C for 10 minutes is required. This high-temperature and high-pressure sterilization method can kill most bacteria and viruses, ensuring the burs reach a sterile state and preventing cross-infection. It is particularly important to note that soaking the burs in chlorine-containing disinfectants is prohibited—chlorine-containing disinfectants are corrosive and can react with the metal shanks of the burs, causing rusting of the metal shanks and affecting the strength and service life of the burs.

Appropriate storage environment: Is essential for maintaining the performance of the burs. Burs should be stored in a dry and well-ventilated place to avoid rusting caused by a humid environment. At the same time, collision between burs should be prevented—collision between burs may cause the abrasive grains to fall off, reducing the cutting efficiency and precision of the burs. Regular inspection of the wear condition of the bur tips is a necessary maintenance step. Once severe wear of the tips is found and the cutting efficiency is significantly reduced, the burs should be replaced in a timely manner to ensure treatment effects and the patient’s treatment experience.