NOTE 8 — CONVERTIBLE REDEEMABLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT)

BIOLASE's board of directors (the "Board"), without further stockholder authorization, may authorize the issuance from time to time of up to 1,000,000 shares of the Company’s preferred stock. Of the 1,000,000 shares of preferred stock, as of December 31, 2023, 370,000 shares were designated as Series H, par value $0.001 per share, 160,000 shares were designated as Series J, par value $0.001 per share, and 125,000 shares were designated as Series I, par value $0.001 per share.

Preferred Stock

Series J Preferred Stock

On September 13, 2023, the Company consummated the sale of 75,000 Units (the "Units") with each Unit consisting of (A) one share of BIOLASE Series J Convertible Redeemable Preferred Stock, par value $0.001 per share and a stated value equal to $100.00 (the “Series J Convertible Preferred Stock”), and (B) one warrant (the “Series J Warrants”) to purchase one-half of one (0.50) share of Series J Convertible Preferred Stock, at a price to the public of $60.00 per Unit, less underwriting discounts and commissions. The public offering price of $60.00 per Unit reflects the issuance of the Series J Convertible Preferred Stock with an original issue discount of 40%. The Company filed a registration statement on Form S-1 in September 2023, which registered the Units, the Series J Convertible Preferred Stock, the Series J Warrants and the shares of Series J Convertible Preferred Stock and common stock underlying such securities and additional shares of Series J Convertible Preferred Stock that will be issued, if and when the Board declares such dividends, as paid in-kind dividends (“PIK dividends”) at a rate of 20% per annum and the shares of Common Stock issuable upon conversion of the Series J Convertible Preferred Stock issued as PIK dividends. The registration statement was declared effective on September 13, 2023 and the offering closed on September 18, 2023. Each Warrant has an exercise price of $30.00 per share, is exercisable for one-half of one (0.5) share of Series J Convertible Preferred Stock, is immediately exercisable and will expire one (1) year from the date of issuance.

Each share of Series J Convertible Preferred Stock is convertible at the option of the holder at any time into the number of shares of BIOLASE common stock determined by dividing the $100.00 stated value per share by a conversion price of $3.26. Each outstanding share of Series J Convertible Preferred Stock is mandatorily redeemable by the Company in cash on September 13, 2024 (the "Series J Maturity Date").

Upon any liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary, prior and in preference to the common stock, holders of the Series J Convertible Preferred Stock shall be entitled to receive out of the assets available for distribution to stockholders an amount equal in cash to 100% of the aggregate Stated Value of $100.00 per share of all shares of Series J Convertible Preferred Stock held by such holder, and if the assets of the Company shall be insufficient to pay in full such amounts, then the entire assets to be distributed to the holders shall be ratably distributed among the holders in accordance with the respective amounts that would be payable on such shares if all amounts payable thereon were paid in full.

Gross proceeds from the offering were $4.5 million before broker fees and related expenses of approximately $1.0 million. In accordance with applicable accounting standards, the $4.5 million gross proceeds were allocated to the Series J Convertible Preferred Stock and the Series J Warrants in the amount of $3.5 million and $1.0 million, respectively. The allocation was based on the fair value of the Series J Warrants of $1.0 million as of the commitment date, with the residual proceeds of $3.5 million allocated to the Series J Convertible Preferred Stock. Net proceeds allocated to the Series J Convertible Preferred Stock and Series J warrants was $2.7 million and $0.8 million respectively.

The Series J Convertible Preferred stock was classified as mezzanine equity on the consolidated balance sheet as they are contingently redeemable prior to the Series J Maturity Date and the conversion from preferred shares to shares of BIOLASE common stock is at the option of the holder at any time before the Series J Maturity Date. The Series J warrants were classified as accrued liabilities on the consolidated balance sheet as the warrants are convertible into preferred shares, which are mandatorily redeemable in cash upon the Series J Maturity Date if they are not converted to shares of BIOLASE common stock before such date.

The Series J Convertible Preferred Stock was issued at a discount with the total redemption value of the Series J Convertible Preferred Shares and PIK Dividends of $10.3 million. The redemption value in excess of the net proceeds received allocated to the Series J Convertible Preferred Shares was $7.6 million and was recognized as a decrease in additional paid-in-capital at the commitment date. Upon conversion of Series J warrants to Series J Convertible Preferred shares, the value of the Series J Convertible Preferred shares issued is the stated value per share plus the PIK dividend. The redemption value in excess of the net proceeds received from the exercise of warrants and the fair value of such warrants is recognized as a decrease in additional paid-in-capital at the conversion date.

During the twelve months ended December 31, 2023, 5,960 of the Series J warrants were exercised to 2,980 Series J Convertible Preferred shares, 3,091 Series J Convertible Preferred shares were issued as part of a PIK dividend, and 66,465 Series J Convertible Preferred shares were converted to approximately 2.0 million shares of BIOLASE common stock.

The mezzanine classified Series J Convertible Preferred Stock are presented at their maximum redemption value that includes accretion related to the PIK dividends.

Series I Preferred Stock

On June 5, 2023, the Board declared a dividend of one one-thousandth of a share of Series I Preferred Stock, par value $0.001 per share ("Series I Preferred Stock"), for each share of BIOLASE common stock outstanding as of June 16, 2023 (as calculated on a pre 2023 Reverse Stock Split basis). The certificate of designation for the Series I Preferred Stock provided that all shares of Series I Preferred Stock not present in person or by proxy at any meeting of stockholders held to vote on the 2023 Reverse Stock Split immediately prior to the opening of the polls at such meeting would be automatically redeemed (the “Series I Initial Redemption”) and that any outstanding shares of Series I Preferred Stock that have not been redeemed pursuant to the Series I Initial Redemption would be redeemed in whole, but not in part, (i) if and when ordered by the Board or (ii) automatically upon the effectiveness of the amendment to the Certificate of Incorporation effecting the 2023 Reverse Stock Split that was subject to the vote (the "Series I Subsequent Redemption"). On July 20, 2023, the Series I Initial Redemption occurred, and on July 27, 2023, the Series I Subsequent Redemption occurred. As a result, no shares of Series I Preferred Stock remain outstanding as of July 27, 2023.

Series H Preferred Stock

On May 24, 2023, the Company consummated the sale of 175,000 Units (the "Units") with each Unit consisting of (A) one share of BIOLASE Series H Convertible Redeemable Preferred Stock, par value $0.001 per share and a stated value equal to $50.00 (the “Series H Convertible Preferred Stock”), and (B) one warrant (the “Series H Warrants”) to purchase one-half of one (0.50) share of Series H Convertible Preferred Stock, at a price to the public of $26.00 per Unit, less underwriting discounts and commissions. The public offering price of $26.00 per Unit reflects the issuance of the Series H Convertible Preferred Stock with an original issue discount of 48%. The Company filed a registration statement on Form S-1 in May 2023, which registered the Units, the Series H Convertible Preferred Stock, the Series H Warrants and the shares of Series H Convertible Preferred Stock and common stock underlying such securities and additional shares of Series H Convertible Preferred Stock that will be issued, if and when the Board declares such dividends, as paid in-kind dividends (“PIK dividends”) at a rate of 20% and the shares of Common Stock issuable upon conversion of the Series H Convertible Preferred Stock issued as PIK dividends. The registration statement was declared effective on May 24, 2023 and the offering closed on May 26, 2023. Each Warrant has an exercise price of $13.00 per share, is exercisable for one-half of one (0.5) share of Series H Convertible Preferred Stock, is immediately exercisable and will expire two (2) years from the date of issuance.

Each share of Series H Convertible Preferred Stock is convertible at the option of the holder at any time into the number of shares of BIOLASE common stock determined by dividing the $50.00 stated value per share by a conversion price of $13.98 (as adjusted for the 2023 Reverse Stock Split). Each outstanding share of Series H Convertible Preferred Stock is mandatorily redeemable by the Company in cash on May 24, 2025 (the "Series H Maturity Date").

Upon any liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary, prior and in preference to the common stock, holders of the Series H Convertible Preferred Stock shall be entitled to receive out of the assets available for distribution to stockholders an amount equal in cash to 100% of the aggregate Stated Value of $50.00 per share of all shares of Series H Convertible Preferred Stock held by such holder, and if the assets of the Company shall be insufficient to pay in full such amounts, then the entire assets to be distributed to the holders shall be ratably distributed among the holders in accordance with the respective amounts that would be payable on such shares if all amounts payable thereon were paid in full.

Gross proceeds from the offering were $4.6 million before broker fees and related expenses of approximately $0.9 million. In accordance with applicable accounting standards, the $4.6 million gross proceeds were allocated to the Series H Convertible Preferred Stock and the Series H Warrants in the amount of $3.4 million and $1.2 million, respectively. The allocation was based on the fair value of the Series H Warrants of $1.2 million as of the commitment date, with the residual proceeds of $3.4 million allocated to the Series H Convertible Preferred Stock. Net proceeds allocated to the Series H Convertible Preferred Stock and Series H warrants was $2.7 million and $1.0 million respectively.

The Series H Convertible Preferred stock was classified as mezzanine equity on the consolidated balance sheet as they are contingently redeemable prior to the Series H Maturity Date and the conversion from preferred shares to shares of BIOLASE common stock is at the option of the holder at any time before the Series H Maturity Date. The Series H warrants were classified as accrued

liabilities on the consolidated balance sheet as the warrants are convertible into preferred shares, which are mandatorily redeemable in cash upon the Series H Maturity Date if they are not converted to shares of BIOLASE common stock before such date.

The Series H Convertible Preferred Stock was issued at a discount with the total redemption value of the Series H Convertible Preferred Shares and PIK Dividends of $10.5 million. The redemption value in excess of the net proceeds received allocated to the Series H Convertible Preferred Shares was $7.8 million and was recognized as a decrease in additional paid-in-capital at the commitment date. Upon conversion of Series H warrants to Series H Convertible Preferred shares, the value of the Series H Convertible Preferred shares issued is the stated value per share plus the PIK dividend. The redemption value in excess of the net proceeds received from the exercise of warrants and the fair value of such warrants is recognized as a decrease in additional paid-in-capital at the conversion date.

During the twelve months ended December 31, 2023, 40,000 of the Series H warrants were exercised to 20,000 Series H Convertible Preferred shares and 190,000 Series H Convertible Preferred shares were converted to approximately 0.7 million shares of BIOLASE common stock.

The mezzanine classified Series H Convertible Preferred Stock are presented at their maximum redemption value that includes accretion related to the PIK dividends.

Series G Preferred Stock

On March 1, 2022, the Board declared a dividend of one one-thousandth of a share of Series G Preferred Stock, par value $0.001 per share ("Series G Preferred Stock"), of BIOLASE common stock outstanding as of March 25, 2022 (as calculated on a pre-Reverse Stock Split basis). The certificate of designation for the Series G Preferred Stock provided that all shares of Series G Preferred Stock not present in person or by proxy at the 2022 Annual Meeting immediately prior to the opening of the polls at the 2022 Annual Meeting would be automatically redeemed (the “Initial Redemption”) and that any outstanding shares of Series G Preferred Stock that have not been redeemed pursuant to the Initial Redemption would be redeemed in whole, but not in part, (i) if and when ordered by the Board or (ii) automatically upon the effectiveness of the amendment to the Certificate of Incorporation effecting the Reverse Stock Split that was subject to the vote at the 2022 Annual Meeting (the “Subsequent Redemption”). On April 28, 2022, both the Initial Redemption and the Subsequent Redemption occurred. As a result, no shares of Series G Preferred Stock remain outstanding. On June 6, 2022, the Series G Preferred Stock was eliminated.

Series F Convertible Preferred Stock

On July 23, 2020, the Company consummated the sale of an aggregate of 18,000 shares of Series F Preferred Stock, par value $0.001 per share ("Series F Preferred Stock"), and 45,000,000 warrants (the “July 2020 Warrants”), exercisable to 18,000 shares of BIOLASE common stock, through a registered rights offering the Company completed on July 22, 2020 (the “Rights Offering”). Each share of Series F Preferred Stock was convertible at the Company’s option at any time on or after July 22, 2021 or at the option of the holder at any time, into the number of shares of BIOLASE common stock determined by dividing the $1,000 stated value per share of the Series F Preferred Stock by a conversion price of $1,000 per share. Each share of Series F Preferred Stock was convertible into one share of common stock, and each 2,500 of these July 2020 Warrant entitles the holder thereof to purchase one share of BIOLASE common stock at a conversion price of $1,000 per share.

The gross proceeds from the sale of Series F Preferred Stock and July 2020 Warrants were $18.0 million, before broker fees and related expenses of approximately $1.9 million.

In accordance with applicable accounting standards, the $18.0 million gross proceeds from the Rights Offering were allocated to the Series F Preferred Stock and the July 2020 Warrants in the amount of $2.7 million and $15.3 million, respectively. The allocation was based on the fair value of the July 2020 Warrants of $15.3 million as of the commitment date, with the residual proceeds of $2.7 million allocated to the Series F Preferred Stock.

The Series F Preferred Stock contained a beneficial conversion feature which resulted in a deemed dividend to preferred stockholders of approximately $2.7 million, upon immediate accretion. Additionally, the July 2020 Warrants were recognized as a discount to the Series F Preferred Stock, and upon conversion of approximately 1,000 Series F Preferred Stock to common stock for the year ended December 31, 2021. Upon conversion, this discount was accreted and also recognized as a deemed dividend to preferred stockholders in the amount of $0.2 million, and $0.5 million for the years ended December 31, 2022 and 2021, respectively.

The remaining shares of Series F Preferred Stock were converted into shares of BIOLASE common stock during 2022. Approximately 251 Series F Preferred Stock remained outstanding as of December 31, 2021. On March 3, 2022, the Series F Preferred Stock was eliminated.

Common Stock

At the Company's 2020 annual meeting of stockholders, the Company’s stockholders approved a proposal to amend the Company’s Restated Certificate of Incorporation to increase the number of authorized shares of BIOLASE common stock from 40,000,000 shares to 180,000,000 shares. On May 28, 2020, the Company filed the amendment with the Secretary of State of the State of Delaware to effect such increase.

As of December 31, 2023, 3,415,948 shares of BIOLASE common stock were issued and 3,415,930 were outstanding.

2022 Direct Offering and Private Placement

On June 27, 2022, BIOLASE entered into a Securities Purchase Agreement with certain accredited institutional investors, pursuant to which BIOLASE agreed to issue, (i) in a registered direct offering, 6,787 shares of BIOLASE common stock, par value $0.001 per share, and pre-funded warrants to purchase 7,266 shares of BIOLASE common stock with an exercise price of $0.1 per share, and (ii) in a concurrent private placement, warrants to purchase 14,054 shares of BIOLASE common stock. The combined purchase price for one share of common stock and one Common Warrant was determined to be $462.5, and the combined purchase price for one Pre-Funded Warrant and one Common Warrant was determined to be $462.4. BIOLASE received aggregate gross proceeds from the transactions of approximately $6.5 million, before deducting fees to the placement agent and other transaction expenses payable by BIOLASE. The shares of BIOLASE's common stock, the Pre-Funded Warrants and the shares of BIOLASE common stock issuable upon exercise of the Pre-Funded Warrants were offered by BIOLASE pursuant to a shelf registration statement on Form S-3, which was declared effective on August 23, 2019.

2021 Equity Offering

On February 10, 2021, BIOLASE issued and sold in an underwritten offering an aggregate of 5,600 shares of common stock at a price of $2,575 per share less underwriting discounts and commissions. The Company received gross proceeds of approximately $14.4 million before deducting underwriting discounts and commissions and estimated offering expenses of $1.1 million.

Dividends

There were no cash dividends paid or declared in 2023, 2022 or 2021.

Warrants

The Company issues warrants for the sale of its common stock as approved by the Board.

January 2023 Offering

On January 9, 2023, the Company completed a public offering and issued an aggregate of 171,678 shares of BIOLASE common stock at a price of $35.00 per share and pre-funded warrants to purchase 114,035 shares of BIOLASE common stock with an exercise price of $1.00 per share at a price of $34.00 per share. The Company received gross proceeds of approximately $9.9 million, before deducting underwriting discounts and commissions and estimated offering expenses.

May 2023 Offering

On May 26, 2023, the Company completed a public offering and issued, 175,000 units, with each Unit consisting of (A) one share of the Company’s Series H Convertible Redeemable Preferred Stock, par value $0.001 per share, and (B) one warrant to purchase one-half of one (0.50) share of Series H Convertible Preferred Stock, at a price to the public of $26.00 per Unit, less underwriting discounts and commissions. Each Warrant has an exercise price of $13.00 per share, is exercisable for one-half of one (0.5) share of Series H Convertible Preferred Stock, is immediately exercisable and will expire two (2) years from the date of issuance. The Company received gross proceeds of approximately $4.6 million, before deducting underwriting discounts and commissions, estimated offering expenses, and before the exercise of warrants.

September 2023 Offering

On September 18, 2023, the Company completed a public offering and issued, 75,000 units, with each Unit consisting of (A) one share of the Company’s Series J Convertible Redeemable Preferred Stock, par value $0.001 per share, and (B) one warrant to purchase one-half of one (0.50) share of Series J Convertible Preferred Stock, at a price to the public of $60.00 per Unit, less underwriting discounts and commissions. Each Warrant has an exercise price of $30.00 per share, is exercisable for one-half of one (0.5) share of Series J Convertible Preferred Stock, is immediately exercisable and will expire one (1) year from the date of issuance. The Company received gross proceeds of approximately $4.5 million, before deducting underwriting discounts and commissions, estimated offering expenses, and before the exercise of warrants.

December 2023 Registered Direct Offering

On December 6, 2023, the Company entered into a Securities Purchase Agreement Purchase Agreement with a single institutional investor Purchaser, pursuant to which the Company issued in a registered direct offering, 331,000 shares of the Company’s common stock Shares), par value $0.001 per share Common Stock, and pre-funded warrants to purchase 779,940 shares of Common Stock with an exercise price of $0.001 per share, and in a concurrent private placement, warrants to purchase an aggregate of 2,221,880 shares of Common Stock Common Warrants with an exercise price of $1.23. The combined purchase price for one Share and two Common Warrants was $1.23, and the combined purchase price for one Pre-Funded Warrant and two Common Warrants was $1.229.The Company received gross proceeds of approximately $1.2 million, before deducting underwriting discounts and commissions, estimated offering expenses, and before the exercise of warrants.

June 2022 Direct Offering and Private Placement

On June 27, 2022, the Company entered into a Securities Purchase Agreement with certain accredited institutional investors, pursuant to which the Company agreed to issue to the Purchasers (as defined therein), (i) in a registered direct offering, 6,787 shares of BIOLASE common stock, and pre-funded warrants to purchase 7,266 shares of BIOLASE common stock (the “June 2022 Pre-Funded Warrants”) with an exercise price of $0.1 per share, and (ii) in a concurrent private placement, warrants to purchase 14,054 shares of BIOLASE common stock (each a "Common Warrant" and together with the June 2022 Pre-Funded Warrants, the “June 2022 Warrants”). The combined purchase price for one share of BIOLASE common stock and one Common Warrant was $462.5, and the combined purchase price for one June 2022 Pre-Funded Warrant and one Common Warrant was $462.4. In the offering and concurrent private placement, the Company received aggregate gross proceeds of approximately $6.5 million before deducting fees to the placement agent and other transaction expenses.

Based on the terms and conditions of the June 2022 Warrants, the Company determined that equity classification was appropriate and recognized the net proceeds in excess of par of $5.6 million in Additional Paid-In Capital.

July 2020 Rights Offering

On July 23, 2020, the Company consummated the Rights Offering issuing (i) 18,000 shares of Series F Preferred Stock and (ii) 45,000,000 July 2020 Warrants, exercisable to 18,000 shares of BIOLASE Common Stock, with an exercise price of $1,000 per share of BIOLASE common stock. The initial fair value of the July 2020 Warrants was estimated to be at $850 per share of BIOLASE common stock using the Black-Scholes pricing model with an expected term of 5 years, market price of $1,100 per share, which was the last closing price of BIOLASE common stock prior to the transaction date, volatility of 109.8%, a risk free rate of 0.27% and an expected dividend yield of 0. Based on the terms and conditions of the July 2020 Warrants, the Company initially determined that liability classification was appropriate and recognized the fair value of the July 2020 Warrants as a liability. Based on the fair value of the July 2020 Warrants, the Company allocated approximately $2.7 million to the Series F Preferred Stock and $15.3 million to the July 2020 Warrants before issuance costs. Issuance costs of $1.6 million relating to the July 2020 Warrants were recognized as an expense and were recorded in Other income, net in the consolidated statement of operations for the year ended December 31, 2020.

On September 28, 2020, the warrant agreement with respect to the July 2020 Warrants was amended. The amended terms of the July 2020 Warrants meet the requirements for the July 2020 Warrants’ classification as equity. The fair value upon the amendment was estimated to be $525 per share of BIOLASE common stock using the Black-Scholes pricing model with an expected term of 5 years, a market price of $700 per share of BIOLASE common stock, which was the last closing price of BIOLASE common stock prior to the amendment date, volatility of 109.5%, a risk free rate of 0.26% and an expected dividend yield of 0. On the effective date of the amendment to the warrant agreement, the Company remeasured the fair value of the July 2020 Warrants as described above, reclassified the value of $9.5 million to equity, and recognized the change in fair value as a gain of approximately $5.8 million in the consolidated statement of operations in Other income, net for the year ended December 31, 2020.

None of the July 2020 warrants were exercised during the years ended December 31, 2023 and December 31, 2022. During the year ended December 31, 2021, 28.1 million of the July 2020 warrants were exercised, which converted to approximately 11,225 shares of BIOLASE Common Stock. 2,500 of these warrants are exercisable for one share of BIOLASE common stock

2020 Registered Direct Offering and Concurrent Private Placement

On June 8, 2020, the Company entered into a Securities Purchase Agreement with certain accredited institutional investors, pursuant to which the Company agreed to issue to the Purchasers in a registered direct offering and concurrent private placement, 4,320 shares of BIOLASE common stock, and 10,800,000 Warrants (the “June 2020 Warrants”), exercisable to 4,320 shares of BIOLASE common stock, with an exercise price of $1,288 per share. The June 2020 Warrants are exercisable commencing on the date of their issuance and will expire on June 10, 2025. The combined purchase price for one share of common stock and one June 2020 Warrant in the offering was $1,600 per share. The Company received aggregate gross proceeds of approximately $6.9 million in the concurrent offerings, before deducting fees to the placement agents and other offering expenses of approximately $0.7 million.

Based on the terms and conditions of the June 2020 Warrants, the Company determined that equity classification was appropriate and recognized the values of the common stock and June 2020 Warrants in excess of par in Additional Paid-In Capital. The Company allocated the net proceeds of $6.2 million to the common stock and June 2020 Warrants based on their relative fair values. The fair value of the June 2020 Warrants was estimated to be at $1,050 per share using the Black-Scholes pricing model with an expected term of 5 years, market price of $1,350 which is the last closing price of our common stock prior to the transaction date, volatility of 109.8% and a risk free rate of 0.45% and an expected dividend yield of 0. Based on the relative fair value of the common stock and the June 2020 Warrants, the Company allocated approximately $3.9 million to the common stock and $3.0 million to the June 2020 Warrants before issuance costs.

During the year ended December 31, 2021, 7.5 million of the June 2020 warrants were exercised, which converted to approximately 2,980 shares to BIOLASE common stock. No warrants were exercised in 2023 and 2022. 2,500 of these warrants are exercisable for one share of BIOLASE common stock.

Western Alliance Warrants

On March 6, 2018, in connection with the execution of a business financing agreement with Western Alliance Bank ("Western Alliance"), the Company issued to Western Alliance warrants (the “Original Western Alliance Warrants”) to purchase up to the number of shares of BIOLASE common stock equal to $120,000 divided by the applicable exercise price at the time such warrants are exercised. The Original Western Alliance Warrants are fully vested and exercisable. The Original Western Alliance Warrants may be exercised with a cash payment from Western Alliance, or, in lieu of a cash payment, Western Alliance may convert the warrants into a number of shares, in whole or in part. The initial exercise price of the warrants was $5,875 per share. On September 27, 2018, the Company entered into the Second Modification Agreement to amend the Original Business Financing Agreement. In connection with the Second Modification Agreement, the Original Western Alliance Warrants were terminated, and the Company issued new warrants (the “Western Alliance Warrants”) to purchase up to the number of shares of BIOLASE common stock equal to $120,000 divided by the exercise price of $5,325, which was the closing price of BIOLASE common stock on September 27, 2018 (as adjusted for the Reverse Stock Split). The Western Alliance Warrants were immediately exercisable and expire on September 27, 2028. These warrants contain down-round features that require the Company to adjust the exercise price proportionately should the Company issue shares at a price per share less than the exercise price. The sale of common stock in the second quarter of 2020 triggered an adjustment to the exercise price to approximately $1,500.00 per share. The impact of the adjustment to the exercise price was not material. These warrants are recognized in equity in the consolidated balance sheets as of December 31, 2023 and 2022. 2,500 of these warrants are exercisable for one share of BIOLASE common stock

SWK Warrants

On November 9, 2018, in connection with the Credit Agreement, BIOLASE issued to SWK, LLC or its assignees (collectively with SWK, the “Holder”) 372,023 warrants to purchase shares of common stock (the "SWK Warrants"), exercisable to approximately 148 shares of BIOLASE common stock. The initial exercise price of the SWK Warrants was $3,350 per share, which was the average closing price of common stock for the ten trading days immediately preceding November 9, 2018. The SWK Warrants were immediately exercisable, expire on November 9, 2026 and contain a “cashless exercise feature.” Subject to certain limitations, the Holder has certain piggyback registration rights with respect to the shares that are issued upon exercise of the SWK Warrants. These warrants contain down-round features that require the Company to adjust the exercise price proportionately should the Company issue shares at a price per share less than the exercise price. The fair value of the SWK Warrants was estimated using the Black-Scholes option-pricing model with the following assumptions: expected term of 8 years; volatility of 81.79%; annual dividend per share of $0.00; and risk-free interest rate of 3.13%; and resulted in an estimated fair value of $0.4 million. These warrants are recognized in equity in the consolidated balance sheets as of December 31, 2023 and 2022.

In November 2019, the SWK Warrants were consolidated, and the exercise price was adjusted to $2,500 as part of the Fourth Amendment to the Credit Agreement; and in March 2020, the exercise price was adjusted a second time to $1,225. The impact of both reprice events was de minimis to the consolidated financial statements. In connection with the Fifth Amendment, the Company entered into a Third Amendment to the SWK Warrant Agreement. Under this amendment, the Company granted to SWK 63,779 additional common stock warrants, exercisable to 25 shares of BIOLASE common stock, at an exercise price of approximately $975. All other terms and conditions to the additional warrants were the same as those previously granted. The Company also revised the exercise price of the 487,198 common stock warrants held by SWK, which are exercisable to approximately 194 shares of BIOLASE common stock, to $975. The Company measured the fair value of the 63,779 warrants granted using the Black-Scholes option-pricing model. The fair value of the additional warrants and the aggregate impact of the exercise price adjustments in previous amendments to the Warrant Agreement were less than $0.1 million and not material to the consolidated financial statements. Due to the repricing that occurred in the second quarter of 2020, the down round features of these warrants was not triggered by the Company’s June 2020 sale of common stock. 2,500 of these warrants are exercisable for one share of BIOLASE common stock

DPG Warrants

On November 14, 2018, in connection with the SWK Loan, the Company paid a finder's fee to DPG of $0.4 million cash and issued DPG 279,851 warrants, exercisable to approximately 111 shares of BIOLASE common stock. The DPG Warrants were exercisable immediately and expire on November 9, 2026. The initial exercise price of the DPG Warrants was $3,350 per share, which was the average closing price of common stock for the ten trading days immediately preceding November 9, 2018. The DPG Warrants were immediately exercisable, expire on November 9, 2026 and contain a “cashless exercise feature.” Subject to certain limitations, the Holder has certain piggyback registration rights with respect to the shares that are issued upon exercise of the DPG Warrants. These warrants contain down-round features that require the Company to adjust the exercise price proportionately should the Company issue shares at a price per share less than the exercise price. The fair value of the DPG Warrants of $0.3 million was estimated using the Black-Scholes option pricing model with the following assumptions: expected term of 8 years; volatility of 81.79%; annual dividend per share of $0.00; and risk-free interest rate of 3.13%. In 2019 the Company issued 149,727 warrants to purchase common, exercisable to 59 shares of BIOLASE common stock at a weighted average exercise price of $5,425 to SWK and DPG. These warrants are recognized in equity in the consolidated balance sheet as of December 31, 2023 and 2022.

In November 2019, the exercise price of the DPG Warrants issued on November 14, 2018 was adjusted from $3,350 per share to $2,200 per share and the exercise price of the DPG Warrants issued on May 7, 2019 was adjusted from $5,425 per share to $3,550 per share. The June 2020 sale of common stock triggered the down round features of these warrants, and in August 2020, the Company adjusted the exercise price of these warrants to $1,550 and $950 per share respectively.2,500 of these warrants are exercisable for one share of BIOLASE common stock

The repricing did not have a material impact on the Company’s consolidated financial statements for the years ended December 31, 2023, 2022 and 2021.

Stock-Based Compensation

Stock Options

2002 Stock Incentive Plan

The 2002 Stock Incentive Plan (as amended effective as of May 26, 2004, November 15, 2005, May 16, 2007, May 5, 2011, June 6, 2013, October 30, 2014, April 27, 2015, and May 6, 2017, the “2002 Plan”) was replaced by the 2018 Plan (as defined below) with respect to future equity awards. Persons eligible to receive awards under the 2002 Plan included officers, employees, and directors of the Company, as well as consultants. As of December 31, 2023, a total of 1,244 shares have been authorized for issuance under the 2002 Plan, of which approximately 908 shares of common stock have been issued pursuant to options that were exercised and restricted stock units ("RSUs") that were vested, approximately 140 shares of common stock have been reserved for options that are outstanding, and no shares of common stock remain available for future grants.

2018 Stock Incentive Plan

At the 2018 annual meeting of stockholders, the Company’s stockholders approved the 2018 Long-Term Incentive Plan (as amended effective as of September 21, 2018, May 15, 2019, May 13, 2020, June 11, 2021, and April 27, 2023, the “2018 Plan”). The purposes of the 2018 Plan are (i) to align the interests of the Company’s stockholders and recipients of awards under the 2018 Plan by increasing the proprietary interest of such recipients in the Company’s growth and success; (ii) to advance the interests of the Company by attracting and retaining non-employee directors, officers, other employees, consultants, independent contractors and agents; and (iii) to motivate such persons to act in the long-term best interests of the Company and its stockholders.

Under the terms of the 2018 Plan, 49,372 shares of BIOLASE common stock are available for issuance as of December 31, 2023. As of December 31, 2023, a total of 112,268 shares of common stock have been authorized for issuance under the 2018 Plan, of which approximately 55,081 shares of the Company’s common stock have been reserved for issuance upon the exercise of outstanding options or stock appreciation rights ("SARs"), and/or settlement of unvested RSUs or phantom awards under the 2018 Plan.

Stock options may be granted as incentive or non-qualified options; however, no incentive stock options have been granted to date. The exercise price of options is at least equal to the market price of the stock as of the date of grant. Options may vest over various periods but typically vest on a quarterly basis over four years. Options expire after five years, ten years, or within a specified time from termination of employment, if earlier. The Company issues new shares of common stock upon the exercise of stock options. The following table summarizes option activity under the 2002 Plan and the 2018 Plan (in thousands, except per share data):

Stock Option Activity

There were no option grants in 2023 and 2022, and approximately 30 option grants in 2021.

Restricted Stock Units

2023 Restricted Stock Units Activity

2022 Restricted Stock Units Activity

2021 Restricted Stock Units Activity

Phantom Awards and Stock Appreciation Rights

As of December 31, 2023, there are approximately 1,119 outstanding phantom RSUs granted in lieu of stock-settled RSUs historically granted for leadership bonuses and non-employee director service. The phantom RSUs have either time-based or performance-based vesting conditions and will be settled in cash in 2024 with the Company's option to settle the award in BIOLASE common stock at the sole discretion of the Board. At inception, these phantom RSUs were included as a component of long-term liability on the consolidated balance sheet and were not considered stock-based compensation due to the cash-settlement feature of the award and the then current limitation on the number of remaining shares authorized for issuance. In 2022, as a result of the Reverse Stock Split, the phantom awards were reclassed to equity and included as a component of additional paid-in-capital in the amount of $0.1 million, with a portion remaining as a component of long-term liability on the consolidated balance sheet due to certain guaranteed minimums, and the expense subsequent to the remeasurement date considered stock-based compensation. The expense recognized during the years ended December 31, 2023 and December 31, 2022 was $0.3 million and $0.2 million respectively. As of December 31, 2023 $0.5 million was included in accrued liabilities and $0.2 million was included in additional paid-in-capital on the consolidated balance sheet. The balance included in long-term liabilities and additional paid-in-capital as of December 31, 2022, was $0.3 million, and $0.1 million, respectively.

As of December 31, 2023, there are approximately 236 outstanding SARs granted in 2021 in lieu of stock-settled RSUs historically granted for non-employee director service. Upon exercise, the SARs could be settled in cash with the Company's option to settle in BIOLASE common stock at the sole discretion of the Board. In 2021, these SARS were included in accrued liabilities on the consolidated balance sheet and not considered stock-based compensation due to the cash-settlement feature of the award and limitation on the number of remaining shares authorized for issuance. In 2022, as a result of the Reverse Stock Split, the SARs were reclassed to equity and included as a component of additional paid-in-capital on the consolidated balance sheet in the amount of $0.5 million. These SARs were fully vested in 2022. No expense was recognized during the year ended December 31, 2023 and the expense recognized during the year ended December 31, 2022 was $0.3 million and was included in additional paid-in-capital on the consolidated balance sheet as of December 31, 2022.

Deferred Compensation Plan

In July 2019, the Company introduced a Deferred Compensation Plan pursuant to the IRC Section 409A. The purpose of the plan is to provide income deferral opportunities to certain eligible employees. As of December 31, 2023, the Company had seven individuals enrolled. For individuals enrolled for the year ended December 31, 2023, all of the RSUs that granted in 2023 were eligible for this program. As of December 31, 2023, there were approximately 7,000 vested and releasable RSUs and approximately 18,000 unvested and outstanding RSUs.